Trial of Nonpharmacologic Intervention in the Elderly (TONE). Design and rationale of a blood pressure control trial

Effects of Antihypertensive Deprescribing Strategies on Blood Pressure, Adverse Events, and Orthostatic Symptoms in Older Adults: Results From TONE

BACKGROUND

The Trial of Nonpharmacologic Interventions in the Elderly (TONE) demonstrated the efficacy of weight loss and sodium reduction to reduce hypertension medication use in older adults. However, the longer-term effects of drug withdrawal (DW) on blood pressure (BP), adverse events, and orthostatic symptoms were not reported.

METHODS

TONE enrolled adults, ages 60-80 years, receiving treatment with a single antihypertensive and systolic BP (SBP)/diastolic BP <145/<85 mm Hg. Participants were randomized to weight loss, sodium reduction, both, or neither (usual care) and followed up to 36 months; ~3 months postrandomization, the antihypertensive was withdrawn and only restored if needed for uncontrolled hypertension. BP and orthostatic symptoms (lightheadedness, feeling faint, imbalance) were assessed at randomization and throughout the study. Two physicians independently adjudicated adverse events, masked to intervention, classifying symptomatic (lightheadedness, dizziness, vertigo), or clinical events (fall, fracture, syncope).

RESULTS

Among the 975 participants (mean age 66 years, 48% women, 24% black), mean (±SD) BP was 128 ± 9/71 ± 7 mm Hg. Independent of assignment, DW increased SBP by 4.59 mm Hg (95% confidence interval [CI]: 3.89, 5.28) compared with baseline. There were 113 adverse events (84 symptomatic, 29 clinical), primarily during DW. Compared with usual care, combined weight loss and sodium reduction mitigated the effects of DW on BP (β = -4.33 mm Hg; 95% CI: -6.48, -2.17) and reduced orthostatic symptoms long term (odds ratio = 0.62; 95% CI: 0.41, 0.92), without affecting adverse events (hazard ratio = 1.81; 95% CI: 0.90, 3.65). In contrast, sodium reduction alone increased risk of adverse events (hazard ratio = 1.75; 95% CI: 1.04, 2.95), mainly during DW.

CONCLUSIONS

In older adults, antihypertensive DW may increase risk of symptomatic adverse events, highlighting the need for caution in withdrawing their antihypertensive medications.

CLINICAL TRIALS REGISTRATION

Trial Number NCT00000535.

Mecor: An R package for measurement error correction in linear regression models with a continuous outcome

Measurement error in a covariate or the outcome of regression models is common, but is often ignored, even though measurement error can lead to substantial bias in the estimated covariate-outcome association. While several texts on measurement error correction methods are available, these methods remain seldomly applied. To improve the use of measurement error correction methodology, we developed mecor, an R package that implements measurement error correction methods for regression models with a continuous outcome. Measurement error correction requires information about the measurement error model and its parameters. This information can be obtained from four types of studies, used to estimate the parameters of the measurement error model: an internal validation study, a replicates study, a calibration study and an external validation study. In the package mecor, regression calibration methods and a maximum likelihood method are implemented to correct for measurement error in a continuous covariate in regression analyses. Additionally, methods of moments methods are implemented to correct for measurement error in the continuous outcome in regression analyses. Variance estimation of the corrected estimators is provided in closed form and using the bootstrap.

Efficient study design to estimate population means with multiple measurement instruments

Outcomes from studies assessing exposure often use multiple measurements. In previous work, using a model first proposed by Buonoccorsi (1991), we showed that combining direct (eg, biomarkers) and indirect (eg, self-report) measurements provides a more accurate picture of true exposure than estimates obtained when using a single type of measurement. In this article, we propose a tool for efficient design of studies that include both direct and indirect measurements of a relevant outcome. Based on data from a pilot or preliminary study, the tool, which is available online as a shiny app at https://michalbitan.shinyapps.io/shinyApp/, can be used to compute: (1) the sample size required for a statistical power analysis, while optimizing the percent of participants who should provide direct measures of exposure (biomarkers) in addition to the indirect (self-report) measures provided by all participants; (2) the ideal number of replicates; and (3) the allocation of resources to intervention and control arms. In addition we show how to examine the sensitivity of results to underlying assumptions. We illustrate our analysis using studies of tobacco smoke exposure and nutrition. In these examples, a near-optimal allocation of the resources can be found even if the assumptions are not precise.

Long-term effects of weight-reducing diets in people with hypertension

BACKGROUND

All major guidelines for antihypertensive therapy recommend weight loss. Dietary interventions that aim to reduce body weight might therefore be a useful intervention to reduce blood pressure and adverse cardiovascular events associated with hypertension.

OBJECTIVES

Primary objectives To assess the long-term effects of weight-reducing diets in people with hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events). Secondary objectives To assess the long-term effects of weight-reducing diets in people with hypertension on change from baseline in systolic blood pressure, change from baseline in diastolic blood pressure, and body weight reduction.

SEARCH METHODS

For this updated review, the Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to April 2020: the Cochrane Hypertension Specialised Register, CENTRAL (2020, Issue 3), Ovid MEDLINE, Ovid Embase, and ClinicalTrials.gov. We also contacted authors of relevant papers about further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least 24 weeks' duration that compared weight-reducing dietary interventions to no dietary intervention in adults with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risks of bias and extracted data. Where appropriate and in the absence of significant heterogeneity between studies (P > 0.1), we pooled studies using a fixed-effect meta-analysis. In case of moderate or larger heterogeneity as measured by Higgins I², we used a random-effects model.

MAIN RESULTS

This second review update did not reveal any new trials, so the number of included trials remains the same: eight RCTs involving a total of 2100 participants with high blood pressure and a mean age of 45 to 66 years. Mean treatment duration was 6 to 36 months. We judged the risks of bias as unclear or high for all but two trials. No study included mortality as a predefined outcome. One RCT evaluated the effects of dietary weight loss on a combined endpoint consisting of the necessity of reinstating antihypertensive therapy and severe cardiovascular complications. In this RCT, weight-reducing diet lowered the endpoint compared to no diet: hazard ratio 0.70 (95% confidence interval (CI) 0.57 to 0.87). None of the trials evaluated adverse events as designated in our protocol. The certainty of the evidence was low for a blood pressure reduction in participants assigned to weight-loss diets as compared to controls: systolic blood pressure: mean difference (MD) -4.5 mm Hg (95% CI -7.2 to -1.8 mm Hg) (3 studies, 731 participants), and diastolic blood pressure: MD -3.2 mm Hg (95% CI -4.8 to -1.5 mm Hg) (3 studies, 731 participants). We judged the certainty of the evidence to be high for weight reduction in dietary weight loss groups as compared to controls: MD -4.0 kg (95% CI -4.8 to -3.2) (5 trials, 880 participants). Two trials used withdrawal of antihypertensive medication as their primary outcome. Even though we did not consider this a relevant outcome for our review, the results of these RCTs strengthen the finding of a reduction of blood pressure by dietary weight-loss interventions.

AUTHORS' CONCLUSIONS

In this second update, the conclusions remain unchanged, as we found no new trials. In people with primary hypertension, weight-loss diets reduced body weight and blood pressure, but the magnitude of the effects are uncertain due to the small number of participants and studies included in the analyses. Whether weight loss reduces mortality and morbidity is unknown. No useful information on adverse effects was reported in the relevant trials.

Behavioral Counseling to Promote a Healthy Diet and Physical Activity for Cardiovascular Disease Prevention in Adults With Cardiovascular Risk Factors: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Cardiovascular disease is the leading cause of death in the US, and poor diet and lack of physical activity are major factors contributing to cardiovascular morbidity and mortality.

OBJECTIVE

To review the benefits and harms of behavioral counseling interventions to improve diet and physical activity in adults with cardiovascular risk factors.

DATA SOURCES

MEDLINE, PubMed, PsycINFO, and the Cochrane Central Register of Controlled Trials through September 2019; literature surveillance through July 24, 2020.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of behavioral counseling interventions to help people with elevated blood pressure or lipid levels improve their diet and increase physical activity.

DATA EXTRACTION AND SYNTHESIS

Data were extracted from studies by one reviewer and checked by a second. Random-effects meta-analysis and qualitative synthesis were used.

MAIN OUTCOMES AND MEASURES

Cardiovascular events, mortality, subjective well-being, cardiovascular risk factors, diet and physical activity measures (eg, minutes of physical activity, meeting physical activity recommendations), and harms. Interventions were categorized according to estimated contact time as low (≤30 minutes), medium (31-360 minutes), and high (>360 minutes).

RESULTS

Ninety-four RCTs were included (N = 52 174). Behavioral counseling interventions involved a median of 6 contact hours and 12 sessions over the course of 12 months and varied in format and dietary recommendations; only 5% addressed physical activity alone. Interventions were associated with a lower risk of cardiovascular events (pooled relative risk, 0.80 [95% CI, 0.73-0.87]; 9 RCTs [n = 12 551]; I2 = 0%). Event rates were variable; in the largest trial (Prevención con Dieta Mediterránea [PREDIMED]), 3.6% in the intervention groups experienced a cardiovascular event, compared with 4.4% in the control group. Behavioral counseling interventions were associated with small, statistically significant reductions in continuous measures of blood pressure, low-density lipoprotein cholesterol levels, fasting glucose levels, and adiposity at 12 to 24 months' follow-up. Measurement of diet and physical activity was heterogeneous, and evidence suggested small improvements in diet consistent with the intervention recommendation targets but mixed findings and a more limited evidence base for physical activity. Adverse events were rare, with generally no group differences in serious adverse events, any adverse events, hospitalizations, musculoskeletal injuries, or withdrawals due to adverse events.

CONCLUSIONS AND RELEVANCE

Medium- and high-contact multisession behavioral counseling interventions to improve diet and increase physical activity for people with elevated blood pressure and lipid levels were effective in reducing cardiovascular events, blood pressure, low-density lipoproteins, and adiposity-related outcomes, with little to no risk of serious harm.

Estimating the intervention effect in calibration substudies

Exposure assessment is often subject to measurement errors. We consider here the analysis of studies aimed at reducing exposure to potential health hazards, in which exposure is the outcome variable. In these studies, the intervention effect may be estimated using either biomarkers or self-report data, but it is not common to combine these measures of exposure. Bias in the self-reported measures of exposure is a well-known fact; however, only few studies attempt to correct it. Recently, Keogh et al addressed this problem, presenting a model for measurement error in this setting and investigating how self-report and biomarker data can be combined. Keogh et al find the maximum likelihood estimate for the intervention effect in their model via direct numerical maximization of the likelihood. Here, we exploit an alternative presentation of the model that leads us to a closed formula for the MLE and also for its variance, when the number of biomarker replicates is the same for all subjects in the substudy. The variance formula enables efficient design of such intervention studies. When the number of biomarker replicates is not constant, our approach can be used along with the EM-algorithm to quickly compute the MLE. We compare the MLE to Buonaccorsi's method (Buonaccorsi, 1996) and find that they have similar efficiency when most subjects have biomarker data, but that the MLE has clear advantages when only a small fraction of subjects has biomarker data. This conclusion extends the findings of Keogh et al (2016) and has practical importance for efficiently designing studies.

Effect of a salt-reduction strategy on blood pressure and acceptability among customers of a food concessionaire in Lima, Peru

AIM

Limited information exists regarding the implementation of salt reduction strategies on collective food services, such as restaurants and food concessionaires. The present study aimed to assess the effect of a salt reduction strategy on blood pressure levels and food acceptability among customers of a food concessionaire.

METHODS

A quasi-experimental study with two phases was conducted. In the pre-intervention phase, the amount of salt used in food preparation was determined. In the intervention phase, a reduction of 20% in salt added to food preparations was implemented. Four hedonic tests and two blood pressure measurements were performed before and after the intervention implementation using standardised techniques. In addition, an evaluation of uneaten food was conducted daily on all customers' plates. Mixed linear regression models were generated to assess the effect of the intervention on blood pressure and acceptability.

RESULTS

A total of 71 workers were evaluated, mean age of 37.5 years, 57.8% females, who consumed the food of the concessionaire, on average, 4.4 (SD: 0.7) days per week. Systolic and diastolic blood pressure were reduced by 3.1 (P < 0.001) and 2.9 (P < 0.001) mmHg at the end of the study, respectively. The results of the hedonic tests and the uneaten food before and after the intervention did not vary significantly.

CONCLUSIONS

The reduction of 20% of salt added to food from a concessionaire had a positive impact on the reduction of customers' blood pressure without reducing food acceptability. This strategy could be implemented in other contexts.

Considerations to facilitate a US study that replicates PREDIMED

The PREDIMED clinical trial provided strong evidence that a Mediterranean dietary pattern (MedDiet) could help prevent cardiovascular disease (CVD) events in high risk middle-aged/older people. This report considers the feasibility of replicating PREDIMED in the U.S., including recommendations for dietary and behavioral principles. A 14-point Mediterranean diet Adherence Score (MEDAS) guided the PREDIMED MedDiet recommendations. At baseline MEDAS points were ~8.5. During intervention this score increased to nearly 11 in MedDiet vs. 9 in control. In the MedDiet groups, only about 0.5 points of the net 2 point MEDAS increase was attributable to the gratis supplements of olive oil or nuts. An issue in a U.S. replication is the large difference in typical U.S. versus Spanish diet and lifestyle. A typical U.S. diet would achieve a MEDAS of 1-2. A replication is scientifically feasible with an assumption such as that the MedDiet reflects a continuum of specific food choices and meal patterns. As such, a 2 point change in MEDAS at any point on the continuum would be hypothesized to reduce incident CVD. A conservative approach would aim for a randomized 4 point MEDAS difference, e.g. 5-6 points vs. an average U.S. diet group that achieved only 1-2 points.

Antihypertensive withdrawal for the prevention of cognitive decline

BACKGROUND

Clinical trials and observational data have variously shown a protective, harmful or neutral effect of antihypertensives on cognitive function. In theory, withdrawal of antihypertensives could improve cerebral perfusion and reduce or delay cognitive decline. However, it is also plausible that withdrawal of antihypertensives may have a detrimental effect on cognition through increased incidence of stroke or other vascular events.

OBJECTIVES

To assess the effects of complete withdrawal of at least one antihypertensive medication on incidence of dementia, cognitive function, blood pressure and other safety outcomes in cognitively intact and cognitive impaired adults.

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group, with additional searches conducted in MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov and the World Health Organization Portal/ICTRP on 12 December 2015. There were no language or date restrictions applied to the electronic searches, and no methodological filters were used to restrict the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) provided they compared withdrawal of antihypertensive medications with continuation of the medications and included an outcome measure assessing cognitive function or a clinical diagnosis of dementia. We included studies with healthy participants, but we also included studies with participants with all grades of severity of existing dementia or cognitive impairment.

DATA COLLECTION AND ANALYSIS

Two review authors examined titles and abstracts of citations identified by the search for eligibility, retrieving full texts where needed to identify studies for inclusion, with any disagreement resolved by involvement of a third author. Data were extracted independently on primary and secondary outcomes. We used standard methodological procedures expected by Cochrane.The primary outcome measures of interest were changes in global and specific cognitive function and incidence of dementia; secondary outcomes included change in systolic and diastolic blood pressure, mortality, adverse events (including cardiovascular events, hospitalisation and falls) and adherence to withdrawal. The quality of the evidence was evaluated using the GRADE approach.

MAIN RESULTS

We included two RCTs investigating withdrawal of antihypertensives in 2490 participants. There was substantial clinical heterogeneity between the included studies, therefore we did not combine data for our primary outcome. Overall, the quality of included studies was high and the risk of bias was low. Neither study investigated incident dementia.One study assessed withholding previously prescribed antihypertensive drugs for seven days following acute stroke. Cognition was assessed using telephone Mini-Mental State Examination (t-MMSE) and Telephone Interview for Cognitive Status (TICS-M) at 90 days as a secondary outcome. The t-MMSE score was a mean of 1.0 point higher in participants who withdrew antihypertensive medications compared to participants who continued them (95% confidence interval (CI) 0.35 to 1.65; 1784 participants) and the TICS-M was a mean of 2.10 points higher (95% CI 0.69 to 3.51; 1784 participants). However, in both cases the evidence was of very low quality downgraded due to risk of bias, indirectness and evidence from a single study. The other study was community based and included participants with mild cognitive impairment. Drug withdrawal was for 16 weeks. Cognitive performance was assessed using a composite of at least five out of six cognitive tests. There was no evidence of a difference comparing participants who withdrew antihypertensive medications and participants who continued (mean difference 0.02 points, 95% CI -0.19 to 0.21; 351 participants). This evidence was of low quality and was downgraded due to risk of bias and evidence from single study.In one study, the systolic blood pressure after seven days of withdrawal was 9.5 mmHg higher in the intervention compared to the control group (95% CI 7.43 to 11.57; 2095 participants) and diastolic blood pressure was 5.1 mmHg higher (95% CI 3.86 to 6.34; 2095 participants). This evidence was low quality, downgraded due to indirectness, because the data must be interpreted in the context of the wider study looking at glyceryl trinitrate administration or not, and evidence from a single study. In the other study, systolic blood pressure increased by 7.4 mmHg in the withdrawal group compared to the control group (95% CI 7.08 to 7.72; 356 participants) and diastolic blood pressure increased by 2.6 mmHg (95% CI 2.42 to 2.78; 356 participants). This was moderate quality evidence, downgraded as evidence was from a single study. We combined data for mortality and cardiovascular events. There was no clear evidence that antihypertensive medication withdrawal affected adverse events, although there was a possible trend to increased cardiovascular events in the large post-stroke study (pooled mortality risk ratio 0.88, 95% CI 0.72 to 1.08; 2485 participants; and cardiovascular events risk ratio 1.29, 95% CI 0.96 to 1.72). Certain prespecified outcomes of interest (falls, hospitalisation) were not reported.

AUTHORS' CONCLUSIONS

The effects of withdrawing antihypertensive medications on cognition or prevention of dementia are uncertain. There was a signal of a positive effect in one study looking at withdrawal after acute stroke but these results are unlikely to be generalisable to non-stroke settings and were not a primary outcome of the study. Withdrawing antihypertensive drugs was associated with increased blood pressure. It is unlikely to increase mortality at three to four months' follow-up, although there was a signal from one large study looking at withdrawal after stroke that withdrawal was associated an increase in cardiovascular events.

Statistical issues related to dietary intake as the response variable in intervention trials

The focus of this paper is dietary intervention trials. We explore the statistical issues involved when the response variable, intake of a food or nutrient, is based on self‐report data that are subject to inherent measurement error. There has been little work on handling error in this context. A particular feature of self‐reported dietary intake data is that the error may be differential by intervention group. Measurement error methods require information on the nature of the errors in the self‐report data. We assume that there is a calibration sub‐study in which unbiased biomarker data are available. We outline methods for handling measurement error in this setting and use theory and simulations to investigate how self‐report and biomarker data may be combined to estimate the intervention effect. Methods are illustrated using data from the Trial of Nonpharmacologic Intervention in the Elderly, in which the intervention was a sodium‐lowering diet and the response was sodium intake. Simulations are used to investigate the methods under differential error, differing reliability of self‐reports relative to biomarkers and different proportions of individuals in the calibration sub‐study. When the reliability of self‐report measurements is comparable with that of the biomarker, it is advantageous to use the self‐report data in addition to the biomarker to estimate the intervention effect. If, however, the reliability of the self‐report data is low compared with that in the biomarker, then, there is little to be gained by using the self‐report data. Our findings have important implications for the design of dietary intervention trials. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

Lower Sodium Intake and Risk of Headaches: Results From the Trial of Nonpharmacologic Interventions in the Elderly

OBJECTIVES

To determine the effect of sodium (Na) reduction on occurrence of headaches.

METHODS

In the Trial of Nonpharmacologic Interventions in the Elderly, 975 men and woman (aged 60-80 years) with hypertension were randomized to a Na-reduction intervention or control group and were followed for up to 36 months. The study was conducted between 1992 and 1995 at 4 clinical centers (Johns Hopkins University, Wake Forest University School of Medicine, Robert Wood Johnson Medical School, and the University of Tennessee).

RESULTS

Mean difference in Na excretion between the Na-reduction intervention and control group was significant at each follow-up visit (P < .001) with an average difference of 38.8 millimoles per 24 hours. The occurrence of headaches was significantly lower in the Na-reduction intervention group (10.5%) compared with control (14.3%) with a hazard ratio of 0.59 (95% confidence interval = 0.40, 0.88; P = .009). The risk of headaches was significantly associated with average level of Na excretion during follow-up, independent of most recent blood pressure. The relationship appeared to be nonlinear with a spline relationship and a knot at 150 millimoles per 24 hours.

CONCLUSIONS

Reduced sodium intake, currently recommended for blood pressure control, may also reduce the occurrence of headaches in older persons with hypertension.

Long-term effects of weight-reducing diets in people with hypertension

BACKGROUND

All major guidelines for antihypertensive therapy recommend weight loss. Thus dietary interventions that aim to reduce body weight might be a useful intervention to reduce blood pressure and adverse cardiovascular events associated with hypertension.

OBJECTIVES

Primary objectivesTo assess the long-term effects of weight-reducing diets in people with hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events). Secondary objectivesTo assess the long-term effects of weight-reducing diets in people with hypertension on change from baseline in systolic blood pressure, change from baseline in diastolic blood pressure, and body weight reduction.

SEARCH METHODS

We obtained studies from computerised searches of the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Hypertension Specialised Register, Ovid MEDLINE, and Ovid EMBASE, and from searches in reference lists, systematic reviews, and the clinical trials registry ClinicalTrials.gov (status as of 2 February 2015).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least 24 weeks' duration that compared weight-reducing dietary interventions to no dietary intervention in adults with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias and extracted data. We pooled studies using fixed-effect meta-analysis. In case of moderate or larger heterogeneity as measured by Higgins I(2), we used a random-effects model.

MAIN RESULTS

This review update did not reveal any new studies, so the number of included studies remained the same: 8 studies involving a total of 2100 participants with high blood pressure and a mean age of 45 to 66 years. Mean treatment duration was 6 to 36 months. We judged the risk of bias as unclear or high for all but two trials. No study included mortality as a predefined outcome. One RCT evaluated the effects of dietary weight loss on a combined endpoint consisting of the necessity of reinstating antihypertensive therapy and severe cardiovascular complications. In this RCT, weight-reducing diet lowered the endpoint compared to no diet: hazard ratio 0.70 (95% confidence interval (CI), 0.57 to 0.87). None of the studies evaluated adverse events as designated in our protocol. There was low-quality evidence for a blood pressure reduction in participants assigned to weight loss diets as compared to controls: systolic blood pressure: mean difference (MD) -4.5 mm Hg (95% CI -7.2 to -1.8 mm Hg) (3 of 8 studies included in analysis), and diastolic blood pressure: MD -3.2 mm Hg (95% CI -4.8 to -1.5 mm Hg) (3 of  8  studies included in analysis). There was moderate-quality evidence for weight reduction in dietary weight loss groups as compared to controls: MD -4.0 kg (95% CI -4.8 to -3.2) (5 of 8 studies included in analysis). Two studies used withdrawal of antihypertensive medication as their primary outcome. Even though we did not consider this a relevant outcome for our review, the results of these studies strengthen the finding of reduction of blood pressure by dietary weight loss interventions.

AUTHORS' CONCLUSIONS

In this update, the conclusions remain the same, as we found no new trials. In people with primary hypertension, weight loss diets reduced body weight and blood pressure, however the magnitude of the effects are uncertain due to the small number of participants and studies included in the analyses. Whether weight loss reduces mortality and morbidity is unknown. No useful information on adverse effects was reported in the relevant trials.

Reduced dietary salt for the prevention of cardiovascular disease

BACKGROUND

This is an update of a Cochrane review that was first published in 2011 of the effects of reducing dietary salt intake, through advice to reduce salt intake or low-sodium salt substitution, on mortality and cardiovascular events.

OBJECTIVES

1. To assess the long-term effects of advice and salt substitution, aimed at reducing dietary salt, on mortality and cardiovascular morbidity.2. To investigate whether a reduction in blood pressure is an explanatory factor in the effect of such dietary interventions on mortality and cardiovascular outcomes.

SEARCH METHODS

We updated the searches of CENTRAL (2013, Issue 4), MEDLINE (OVID, 1946 to April week 3 2013), EMBASE (OVID, 1947 to 30 April 2013) and CINAHL (EBSCO, inception to 1 April 2013) and last ran these on 1 May 2013. We also checked the references of included studies and reviews. We applied no language restrictions.

SELECTION CRITERIA

Trials fulfilled the following criteria: (1) randomised, with follow-up of at least six months, (2) the intervention was reduced dietary salt (through advice to reduce salt intake or low-sodium salt substitution), (3) participants were adults and (4) mortality or cardiovascular morbidity data were available. Two review authors independently assessed whether studies met these criteria.

DATA COLLECTION AND ANALYSIS

A single author extracted data and assessed study validity, and a second author checked this. We contacted trial authors where possible to obtain missing information. We extracted events and calculated risk ratios (RRs) and 95% confidence intervals (CIs).

MAIN RESULTS

Eight studies met the inclusion criteria: three in normotensives (n = 3518) and five in hypertensives or mixed populations of normo- and hypertensives (n = 3766). End of trial follow-up ranged from six to 36 months and the longest observational follow-up (after trial end) was 12.7 years.The risk ratios (RR) for all-cause mortality in normotensives were imprecise and showed no evidence of reduction (end of trial RR 0.67, 95% confidence interval (CI) 0.40 to 1.12, 60 deaths; longest follow-up RR 0.90, 95% CI 0.58 to 1.40, 79 deaths n=3518) or in hypertensives (end of trial RR 1.00, 95% CI 0.86 to 1.15, 565 deaths; longest follow-up RR 0.99, 95% CI 0.87 to 1.14, 674 deaths n=3085). There was weak evidence of benefit for cardiovascular mortality (hypertensives: end of trial RR 0.67, 95% CI 0.45 to 1.01, 106 events n=2656) and for cardiovascular events (hypertensives: end of trial RR 0.76, 95% CI 0.57 to 1.01, 194 events, four studies, n = 3397; normotensives: at longest follow-up RR 0.71, 95% CI 0.42 to 1.20, 200 events; hypertensives: RR 0.77, 95% CI 0.57 to 1.02, 192 events; pooled analysis of six trials RR 0.77, 95% CI 0.63 to 0.95, n = 5912). These findings were driven by one trial among retirement home residents that reduced salt intake in the kitchens of the homes, thereby not requiring individual behaviour change.Advice to reduce salt showed small reductions in systolic blood pressure (mean difference (MD) -1.15 mmHg, 95% CI -2.32 to 0.02 n=2079) and diastolic blood pressure (MD -0.80 mmHg, 95% CI -1.37 to -0.23 n=2079) in normotensives and greater reductions in systolic blood pressure in hypertensives (MD -4.14 mmHg, 95% CI -5.84 to -2.43 n=675), but no difference in diastolic blood pressure (MD -3.74 mmHg, 95% CI -8.41 to 0.93 n=675).Overall many of the trials failed to report sufficient detail to assess their potential risk of bias. Health-related quality of life was assessed in one trial in normotensives, which reported significant improvements in well-being but no data were presented.

AUTHORS' CONCLUSIONS

Despite collating more event data than previous systematic reviews of randomised controlled trials, there is insufficient power to confirm clinically important effects of dietary advice and salt substitution on cardiovascular mortality in normotensive or hypertensive populations. Our estimates of the clinical benefits from advice to reduce dietary salt are imprecise, but are larger than would be predicted from the small blood pressure reductions achieved. Further well-powered studies would be needed to obtain more precise estimates. Our findings do not support individual dietary advice as a means of restricting salt intake. It is possible that alternative strategies that do not require individual behaviour change may be effective and merit further trials.

Differences in weight loss and health outcomes among African Americans and whites in multicentre trials

The efficacy of behavioural lifestyle interventions (BLI) for weight loss and prevention and treatment of diabetes and hypertension is well established but may vary among racial/ethnic subgroups. This report reviews literature from 1990 to 2012 to determine if outcomes were similar among African Americans (AA) and whites participating in multicentre BLIs funded by the National Institutes of Health. We identified seven relevant trials that reported subgroup analyses for AA. On average, AA lost less weight at 6 months (AA: -1.6 to -7.5 kg; whites: -3.8 to -8.2 kg), but also had less or similar weight regain compared with whites. There were no reported differences between races in diabetes incidence. Three analyses reported no differences in blood pressure; however, a fourth reported that AA women were the only group that did not experience a significant change in blood pressure. Despite increased attention to cultural relevance, race-specific differences in weight loss persist in trials spanning 20 years; however, risk factor modification was similar across race/ethnic groups. Additional research is needed to understand the mechanisms of risk factor modification, and potential for weight change to promote even greater risk factor modification for AA than has been observed to date.

Psychometric Validation of the Self-Efficacy for Restricting Dietary Salt in Hemodialysis Scale

The development and progression of left ventricular hypertrophy is a consequence of multiple comorbid conditions associated with end-stage renal disease and large variations in interdialytic weight gains. The literature suggests that dietary sodium restriction alone significantly reduces interdialytic weight gains. A total of 124 hemodialysis participants in an ongoing randomized control trial participated in the validation in which psychometric properties of a self-efficacy survey were a secondary analysis. We evaluated the internal consistency, construct validity, and convergent validity of the instrument. The overall Cronbach α was 0.93. Three factors extracted explain 67.8% of the variance of the white and African American participants. The Self-Efficacy Survey has adequate internal consistency and construct and convergent validity. Future research is needed to evaluate the stability and discriminant validity of the instrument.

Weight loss maintenance in African American women: a systematic review of the behavioral lifestyle intervention literature

We performed a systematic review of the behavioral lifestyle intervention trials conducted in the United States published between 1990 and 2011 that included a maintenance phase of at least six months, to identify intervention features that promote weight loss maintenance in African American women. Seventeen studies met the inclusion criteria. Generally, African American women lost less weight during the intensive weight loss phase and maintained a lower % of their weight loss compared to Caucasian women. The majority of studies failed to describe the specific strategies used in the delivery of the maintenance intervention, adherence to those strategies, and did not incorporate a maintenance phase process evaluation making it difficult to identify intervention characteristics associated with better weight loss maintenance. However, the inclusion of cultural adaptations, particularly in studies with a mixed ethnicity/race sample, resulted in less % weight regain for African American women. Studies with a formal maintenance intervention and weight management as the primary intervention focus reported more positive weight maintenance outcomes for African American women. Nonetheless, our results present both the difficulty in weight loss and maintenance experienced by African American women in behavioral lifestyle interventions.

Long-term effects of weight-reducing diets in hypertensive patients

BACKGROUND

All major guidelines for antihypertensive therapy recommend weight loss. Thus dietary interventions that aim to reduce body weight might be a useful intervention to reduce blood pressure and adverse cardiovascular events associated with hypertension.

OBJECTIVES

Primary objectivesTo assess the long-term effects of weight-reducing diets in hypertensive patients on-   all cause mortality -   cardiovascular morbidity -   adverse events (including total serious adverse events, withdrawal due to adverse events and total non-serious adverse events)Secondary objectivesTo assess the long-term effects of weight-reducing diets in hypertensive patients on-   change from baseline in systolic blood pressure -   change from baseline in diastolic blood pressure -   body weight reduction

SEARCH STRATEGY

Studies were obtained from computerised searches of Ovid MEDLINE, EMBASE, CENTRAL and from searches in reference lists and systematic reviews.

SELECTION CRITERIA

Randomised controlled trials (RCT) in adult hypertensive patients were included if they had a study duration of at least 24 weeks and compared weight reducing dietary interventions to no dietary intervention in adult patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. Studies were pooled using fixed-effect meta-analysis. In case of moderate or larger heterogeneity as measured by Higgins I(2), a random effects model was used.

MAIN RESULTS

Eight studies involving a total of 2100 participants with high blood pressure and a mean age of 45 to 66 years met our inclusion criteria. Mean treatment duration was 6 to 36 months. No study included mortality as a pre-defined outcome. One RCT evaluated the effects of dietary weight loss on a combined endpoint, consisting of the necessity of reinstating antihypertensive therapy and severe cardiovascular complications. In this RCT weight reducing diet lowered the endpoint, hazard ratio 0.70 (95% confidence interval [CI], 0.57 to 0.87) compared to no diet. None of the studies evaluated adverse events as designated in our protocol. Blood pressure was reduced in patients assigned to weight loss diets as compared to controls: systolic blood pressure (SBP): weighted mean difference (WMD): -4.5 mm Hg; 95% CI, -7.2 to -1.8 mm Hg (3 of  8  studies included in analysis), and diastolic blood pressure (DBP): WMD -3.2 mm Hg; 95% CI, -4.8 to -1.5 mm Hg (3 of  8  studies included in analysis). Patients' body weight was also reduced in dietary weight loss groups as compared to controls, WMD of -4.0 kg (95% CI: -4.8 to -3.2) (5 of  8  studies included in analysis). Two studies used withdrawal of antihypertensive medication as their primary outcome. Even though this was not considered a relevant outcome for this review, the results of these studies strengthen the finding of reduction of blood pressure by dietary weight loss interventions.

AUTHORS' CONCLUSIONS

In patients with primary hypertension, weight loss diets reduced body weight and blood pressure, however the magnitude of the effects are uncertain as a result of the small number of patients and studies that could be included in the analyses. It is not known whether weight loss reduces mortality and morbidity. No useful information on adverse effects was reported in the relevant trials.

The effect of intentional weight loss on all-cause mortality in older adults: results of a randomized controlled weight-loss trial

BACKGROUND

Despite the reported benefits, weight loss is not always advised for older adults because some observational studies have associated weight loss with increased mortality. However, the distinction between intentional and unintentional weight loss is difficult to make in an observational context, so the effect of intentional weight loss on mortality may be clarified in the setting of a randomized controlled trial.

OBJECTIVE

The objective was to determine the effect of intentional weight loss on all-cause mortality by using follow-up data from a randomized trial completed in 1995 that included a weight-loss arm.

DESIGN

The Trial of Nonpharmacologic Intervention in the Elderly (TONE) used a 2 × 2 factorial design to determine the effect of dietary weight loss, sodium restriction, or both on blood pressure control in 585 overweight or obese older adults being treated for hypertension (mean ± SD age: 66 ± 4 y; 53% female). All-cause mortality was ascertained by using the Social Security Index and National Death Index through 2006.

RESULTS

The mortality rate of those who were randomly assigned to the weight-loss intervention (n = 291; mean weight loss: 4.4 kg) did not differ significantly from that of those who were not randomly assigned to this group (n = 294; mean weight loss: 0.8 kg). The adjusted HR was 0.82 (95% CI: 0.55, 1.22).

CONCLUSIONS

Intentional dietary weight loss was not significantly associated with increased all-cause mortality over 12 y of follow-up in older overweight or obese adults. Additional studies are needed to confirm and extend our findings to older age groups. This trial is registered at clinicaltrials.gov as NCT00000535.

Impact of restrictive diets on the risk of undernutrition in a free-living elderly population

BACKGROUND & AIMS

Elderly subjects are at risk for undernutrition. Restrictive diets may increase this risk. The aim was to evaluate the impact of restrictive diets on undernutrition and its risk in free-living elderly.

METHODS

Ambulatory patients over age 75 and under a restrictive diet (low salt, low cholesterol, diabetic) were included prospectively, along with age- and gender-matched controls. Weight and height were measured, and the short-form of the Mini Nutritional Assessment was scored. Groups were compared to determine variables associated with a low MNA-SF(®).

RESULTS

95 patients in the diet group (62 F, 33 M, 80 ± 4 y) and 95 controls (57 F, 38 M, 82 ± 5 y) were included. Restrictive diets (low salt n = 33, diabetic n = 19, low cholesterol n = 15, combination n = 27) had been followed since 11.0 ± 5.9 years. Using the cut-off of 12 for MNA-SF(®), 44 patients in the diet group were at risk vs. 22 among controls (P < 0.001). In multivariate analysis, a restrictive diet increased the probability of having an MNA-SF(®) < 12 (OR = 3.6, (95%)CI = 1.8-7.2, P < .001).

CONCLUSIONS

Restrictive diets in patients over 75 increase the risk of undernutrition. On an individual level, these diets may need reassessment. Society guidelines should promote specific recommendations for the elderly.

Reduced dietary salt for the prevention of cardiovascular disease: a meta-analysis of randomized controlled trials (Cochrane review)

BACKGROUND

Although meta-analyses of randomized controlled trials (RCTs) of salt reduction report a reduction in the level of blood pressure (BP), the effect of reduced dietary salt on cardiovascular disease (CVD) events remains unclear.

METHODS

We searched for RCTs with follow-up of at least 6 months that compared dietary salt reduction (restricted salt dietary intervention or advice to reduce salt intake) to control/no intervention in adults, and reported mortality or CVD morbidity data. Outcomes were pooled at end of trial or longest follow-up point.

RESULTS

Seven studies were identified: three in normotensives, two in hypertensives, one in a mixed population of normo- and hypertensives and one in heart failure. Salt reduction was associated with reductions in urinary salt excretion of between 27 and 39 mmol/24 h and reductions in systolic BP between 1 and 4 mm Hg. Relative risks (RRs) for all-cause mortality in normotensives (longest follow-up-RR: 0.90, 95% confidence interval (CI): 0.58-1.40, 79 deaths) and hypertensives (longest follow-up RR 0.96, 0.83-1.11, 565 deaths) showed no strong evidence of any effect of salt reduction CVD morbidity in people with normal BP (longest follow-up: RR 0.71, 0.42-1.20, 200 events) and raised BP at baseline (end of trial: RR 0.84, 0.57-1.23, 93 events) also showed no strong evidence of benefit. Salt restriction increased the risk of all-cause mortality in those with heart failure (end of trial RR 2.59, 1.04-6.44, 21 deaths).We found no information on participant's health-related quality of life.

CONCLUSIONS

Despite collating more event data than previous systematic reviews of RCTs (665 deaths in some 6,250 participants) there is still insufficient power to exclude clinically important effects of reduced dietary salt on mortality or CVD morbidity. Our estimates of benefits from dietary salt restriction are consistent with the predicted small effects on clinical events attributable to the small BP reduction achieved.

Reduced dietary salt for the prevention of cardiovascular disease

BACKGROUND

An earlier Cochrane review of dietary advice identified insufficient evidence to assess effects of reduced salt intake on mortality or cardiovascular events.

OBJECTIVES

1. To assess the long term effects of interventions aimed at reducing dietary salt on mortality and cardiovascular morbidity.2. To investigate whether blood pressure reduction is an explanatory factor in any effect of such dietary interventions on mortality and cardiovascular outcomes.

SEARCH STRATEGY

The Cochrane Library (CENTRAL, Health Technology Assessment (HTA) and Database of Abstracts of Reviews of Effect (DARE)), MEDLINE, EMBASE, CINAHL and PsycInfo were searched through to October 2008. References of included studies and reviews were also checked. No language restrictions were applied.

SELECTION CRITERIA

Trials fulfilled the following criteria: (1) randomised with follow up of at least six-months, (2) intervention was reduced dietary salt (restricted salt dietary intervention or advice to reduce salt intake), (3) adults, (4) mortality or cardiovascular morbidity data was available. Two reviewers independently assessed whether studies met these criteria.

DATA COLLECTION AND ANALYSIS

Data extraction and study validity were compiled by a single reviewer, and checked by a second. Authors were contacted where possible to obtain missing information. Events were extracted and relative risks (RRs) and 95% CIs calculated.

MAIN RESULTS

Seven studies (including 6,489 participants) met the inclusion criteria - three in normotensives (n=3518), two in hypertensives (n=758), one in a mixed population of normo- and hypertensives (n=1981) and one in heart failure (n=232) with end of trial follow-up of seven to 36 months and longest observational follow up (after trial end) to 12.7 yrs. Relative risks for all cause mortality in normotensives (end of trial RR 0.67, 95% CI: 0.40 to 1.12, 60 deaths; longest follow up RR 0.90, 95% CI: 0.58 to 1.40, 79 deaths) and hypertensives (end of trial RR 0.97, 95% CI: 0.83 to 1.13, 513 deaths; longest follow up RR 0.96, 95% CI; 0.83 to 1.11, 565 deaths) showed no strong evidence of any effect of salt reduction. Cardiovascular morbidity in people with normal blood pressure (longest follow-up RR 0.71, 95% CI: 0.42 to 1.20, 200 events) or raised blood pressure at baseline (end of trial RR 0.84, 95% CI: 0.57 to 1.23, 93 events) also showed no strong evidence of benefit. Salt restriction increased the risk of all-cause death in those with congestive heart failure (end of trial relative risk: 2.59, 95% 1.04 to 6.44, 21 deaths). We found no information on participants health-related quality of life.

AUTHORS' CONCLUSIONS

Despite collating more event data than previous systematic reviews of randomised controlled trials (665 deaths in some 6,250 participants), there is still insufficient power to exclude clinically important effects of reduced dietary salt on mortality or cardiovascular morbidity in normotensive or hypertensive populations. Further RCT evidence is needed to confirm whether restriction of sodium is harmful for people with heart failure. Our estimates of benefits from dietary salt restriction are consistent with the predicted small effects on clinical events attributable to the small blood pressure reduction achieved.

Evaluation of a standardized wellness protocol to improve anthropometric and physiologic function and to reduce health risk factors: a retrospective analysis of outcome

OBJECTIVES

The objective of this study was to determine whether a standardized, commercial wellness protocol (Creating Wellness) that focuses on diet, exercise, vitamin supplementation, and one-on-one coaching improves anthropometric and physiologic function and reduces health risk factors.

METHODS

Using a retrospective analysis of subject data collected through a central data repository, several measures of anthropometric and physiologic function were analyzed for changes in outcome.

RESULTS

There were 197 private chiropractic clinics in the United States utilizing the Creating Wellness protocol in 2007. A total of 178 subjects completed an 18-week protocol and had initial and final assessments. All anthropometric and physiologic measures showed improvement following the intervention; therefore, this standardized wellness protocol was shown to improve weight, heart rate, blood pressure, strength, body-mass index, and forced vital capacity. Paired sample t tests and significance testing for the entire sample, and for both genders separately, determined that these changes were statistically significant.

CONCLUSIONS

The Creating Wellness protocol leads to improved health risk factor outcomes based on improvement in anthropometric and physiologic measures in this study population. The results of these tests are generally accepted measures of risk for cardiovascular events, diabetes, metabolic syndrome, and cancer. There are little evaluative data on health outcomes related to programs designed to reduce risk of lifestyle-related diseases. For those clients utilizing the program evaluated in this study, there appears to be evidence suggesting improved health risk factor outcomes from participation in this specific protocol. The results of this study have implications related to a broad number of public health issues related to management of chronic lifestyle diseases.

WITHDRAWN: Dieting to reduce body weight for controlling hypertension in adults

BACKGROUND

As early as the 1920's, researchers noted a relationship between caloric restriction, weight loss and a decreased incidence of hypertension (Terry 1922, Preble 1923, Bauman 1928, Master 1929). In 1988 a meta-analysis of aggregate data from 12 prospective studies, including 5 randomized controlled trials (RCTs), found that on average each 1 kilogram decrease in body weight in obese hypertensive patients was associated with a 2.4 mm Hg systolic and 1.5 mm Hg diastolic decrease in blood pressure (Staessen 1988). Blood pressure reductions were not dependent upon degree of baseline obesity.This review aims to: 1) update the work of Staessen (Staessen 1988) looking specifically at randomized controlled trials, and 2) assess whether any of the trials assess effects of weight-reducing diets on clinical outcomes such as quality of life, morbidity or mortality.

OBJECTIVES

Evaluate whether weight-loss diets are more effective than regular diets or other antihypertensive therapies in controlling blood pressure and preventing morbidity and mortality in hypertensive adults.

SEARCH STRATEGY

MEDLINE and The Cochrane Library were searched through November 1997. Trials known to experts in the field were included through June 1998.

SELECTION CRITERIA

For inclusion in the review, trials were required to meet each of the following criteria: 1) randomized controlled trials with one group assigned to a weight-loss diet and the other group assigned to either normal diet or antihypertensive therapy; 2) ambulatory adults with a mean blood pressure of at least 140 mm Hg systolic and/or 90 mm Hg diastolic; 3) active intervention consisting of a calorie-restricted diet intended to produce weight loss (excluded studies simultaneously implementing multiple lifestyle interventions where the effects of weight loss could not be disaggregated); and 4) outcome measures included weight loss and blood pressure.

DATA COLLECTION AND ANALYSIS

Studies were dual abstracted by two independent reviewers using a standardized form designed specifically for this review. The primary mode of analysis was qualitative; graphs of effect sizes for individual studies were also used.

MAIN RESULTS

Eighteen trials were found. Only one small study of inadequate power reported morbidity and mortality outcomes. None addressed quality of life or general well being issues. In general, participants assigned to weight-reduction groups lost weight compared to control groups.Six trials involving 361 participants assessed a weight-reducing diet versus a normal diet. The data suggested weight loss in the range of 4% to 8% of body weight was associated with a decrease in blood pressure in the range of 3 mm Hg systolic and diastolic. Three trials involving 363 participants assessed a weight-reducing diet versus treatment with antihypertensive medications. These suggested that a stepped-care approach with antihypertensive medications produced greater decreases in blood pressure (in the range of 6/5 mm Hg systolic/diastolic) than did a weight-loss diet. Trials that allowed adjustment of participants' antihypertensive regimens suggested that patients required less intensive antihypertensive drug therapy if they followed a weight-reducing diet. Data was insufficient to determine the relative efficacy of weight-reduction versus changes in sodium or potassium intake or exercise.

AUTHORS' CONCLUSIONS

Weight-reducing diets in overweight hypertensive persons can affect modest weight loss in the range of 3-9% of body weight and are probably associated with modest blood pressure decreases of roughly 3 mm Hg systolic and diastolic. Weight-reducing diets may decrease dosage requirements of persons taking antihypertensive medications.

Moderators and mediators of behaviour change in a lifestyle program for treated hypertensives: a randomized controlled trial (ADAPT)

We aimed to examine moderators and mediators of behaviour change in a cognitive lifestyle program for drug-treated overweight hypertensives in Perth, Australia. We collected data at baseline, 4 months (post-intervention) and 1-year follow-up in a randomized controlled trial of a program that focused on weight loss, diet, and exercise. Mediation analysis used regression models that estimate indirect effects with bootstrapped confidence limits. Outcomes examined were saturated fat intake (% energy) and physical activity (hours per week). In total, 90/118 individuals randomized to usual care and 102/123 to the program-completed follow-up. Sex was a moderator of response post-intervention for diet and physical activity, with a greater response among women with usual care and among men with the program. Change in self-efficacy was a mediator of dietary change post-intervention [effect size (ES) -0.055, 95% confidence interval (CI) -0.125, -0.005] and at follow-up (ES 0.054, 95% CI -0.127, -0.005), and in physical activity post-intervention (ES 0.059, 95% CI 0.003, 0.147). These findings highlight different responses of men and women to the program, and the importance of self-efficacy as a mediator. Mediators for physical activity in the longer term should be investigated in other models, with appropriate cognitive measurements, in future trials.

Trial design: blood pressure control and weight gain prevention in prehypertensive and hypertensive smokers: the treatment and prevention study

BACKGROUND

Cigarette smokers with elevated blood pressure (BP) are at substantially higher risk for cardiovascular events compared to normotensive smokers. Although smoking cessation should be a primary treatment goal for these patients, increases in body weight accompanying smoking abstinence may further increase BP. Intervention strategies that facilitate smoking cessation and modify adverse changes in body weight and BP are needed.

METHODS

We describe an ongoing multi-site, two-phase, five-year randomized clinical trial. Participants are cigarette smokers with Prehypertension or Stage I Hypertension. In the first phase, participants receive a smoking cessation intervention combining behavioral counseling and nicotine replacement in an open-label fashion. In the second phase, participants who successfully quit smoking are randomly assigned to one of three lifestyle interventions: 1) weight gain prevention, 2) blood pressure control, or 3) usual lifestyle. Participants are followed for one year to assess changes in blood pressure, body weight, dietary intake, and physical activity.

CONCLUSIONS

Results from the proposed study will provide important insights into the efficacy of various approaches to lifestyle modification in smokers at increased risk for cardiovascular events.

The Future of Antihypertensive Treatment

Despite progress in recent years in the prevention, detection, and treatment of high blood pressure (BP), hypertension remains an important public health challenge. Hypertension affects approximately 1 billion individuals worldwide. High BP is associated with an increased risk of mortality and morbidity from stroke, coronary heart disease, congestive heart failure, and end-stage renal disease; it also has a negative impact on the quality of life. Hypertension cannot be eliminated because there are no vaccines to prevent the development of hypertension, but, its incidence can be decreased by reducing the risk factors for its development, which include obesity, high dietary intake of fat and sodium and low intake of potassium, physical inactivity, smoking, and excessive alcohol intake. For established hypertension, efforts are to be directed to control BP by lifestyle modification (LSM). However, if BP cannot be adequately controlled with LSM, then pharmacotherapy can be instituted along with LSM. Normalization of BP reduces cardiovascular risk (for cardiovascular death, myocardial infarction, and cardiac arrest), provides renoprotection (prevention of the onset or slowing of proteinuria and progression of renal dysfunction to end-stage renal disease in patients with hypertension, diabetes mellitus types 1 and 2, and chronic renal disease), and decreases the risk of cerebrovascular events (stroke and cognition impairment), as has been amply demonstrated by a large number of randomized clinical trials. In spite of the availability of more than 75 antihypertensive agents in 9 classes, BP control in the general population is at best inadequate. Therefore, antihypertensive therapy in the future or near future should be directed toward improving BP control in treated hypertensive patients with the available drugs by using the right combinations at optimum doses, individually tailored gene-polymorphism directed therapy, or development of new modalities such as gene therapy and vaccines. Several studies have shown that BP can be reduced by lifestyle/behavior modification. Although, the reductions appear to be trivial, even small reductions in systolic BP (for example, 3-5 mm Hg) produce dramatic reduction in adverse cardiac events and stroke. On the basis of the results of clinical and clinical/observational studies, it has been recommended that more emphasis be placed on lifestyle/behavior modification (obesity, high dietary intake of fat and sodium, physical inactivity, smoking, excessive alcohol intake, low dietary potassium intake) to control BP and also to improve the efficacy of pharmacologic treatment of high BP. New classes of antihypertensive drugs and new compounds in the established drug classes are likely to widen the armamentarium available to combat hypertension. These include the aldosterone receptor blockers, vasodilator beta-blockers, renin inhibitors, endothelin receptor antagonists, and dual endopeptidase inhibitors. The use of fixed-dose combination drug therapy is likely to increase. There is a conceptual possibility that gene therapy may yield long-lasting antihypertensive effects by influencing the genes associated with hypertension. But, the treatment of human essential hypertension requires sustained over-expression of genes. Some of the challenging tasks for successful gene therapy that need to be mastered include identification of target genes, ideal gene transfer vector, precise delivery of genes into the required site (target), efficient transfer of genes into the cells of the target, and prompt assessment of gene expression over time. Targeting the RAS by antisense gene therapy appears to be a viable strategy for the long-term control of hypertension. Several problems that are encountered in the delivery of gene therapy include 1) low efficiency for gene transfer into vascular cells; 2) a lack of selectivity; 3) problem in determining how to prolong and control transgene expression or antisense inhibition; and 4) difficulty in minimizing the adverse effects of viral or nonviral vectors. In spite of the hurdles that face gene therapy administration in humans, studies in animals indicate that gene therapy may be feasible in treating human hypertension, albeit not in the near future. DNA testing for genetic polymorphism and determining the genotype of a patient may predict response to a certain class of antihypertensive agent and thus optimize therapy in individual patients. In this regard, there are some studies that report the effectiveness of antihypertensive therapy based upon the genotype of selected patients. Treatment of human hypertension with vaccines is feasible but is not likely to be available in the near future.

A lifestyle program for treated hypertensives improved health-related behaviors and cardiovascular risk factors, a randomized controlled trial

OBJECTIVE

To assess effects of a cognitively based program on health-related behaviors and cardiovascular risk factors in overweight drug-treated hypertensives.

STUDY DESIGN AND SETTING

In a clinical trials center, volunteers, recruited by advertisement, were randomized to usual care (N=118) or to a 4-month program (N=123) incorporating weight loss; a low-sodium diet, high in fruit, vegetables, and fish; and increased physical activity. Diet, physical activity, weight, blood lipids, glucose, and insulin were measured at 4 and 16 months.

RESULTS

Ninety-eight usual care and 106 program participants completed the 4-month assessment; 90 and 102, respectively, completed follow-up. Using intention-to-treat analysis, relative to usual care, net changes with the program at 4 months were as follows: dietary fat (-2.6% energy; P<0.001); sodium (-290mg/d; P=0.004); energy (-313mJ/d; P=0.005); fish (+2.1 serves/wk; P<0.001); vegetables (+3.0 serves/wk; P<0.001); physical activity (+37min/wk; P=0.004); weight (-2.8kg; P<0.001); waist girth (-3.1cm; P<0.001); total cholesterol (-0.2mmol/L; P=0.017); and triacylglycerols (-0.12mmol/L; P=0.002). One year later, net changes included dietary fat (-2.2% energy; P<0.001); sodium (-150mg/d; P=0.029); fish (+2.0 serves/wk; P<0.001); vegetables (+4.3 serves/wk; P<0.001); weight (-2.5kg; P=0.001); waist girth (-3.1cm; P<0.001); high-density lipoprotein cholesterol (+0.03mmol/L; P=0.031).

CONCLUSION

Improvements in behaviors and risk factors, several maintained long term, suggest the potential for long-term benefits in hypertensives.

Obesity in older adults: a systematic review of the evidence for diagnosis and treatment

OBJECTIVE

Although obesity is increasing in older U.S. adults, treatment is controversial in this age group. We sought to examine evidence concerning obesity's health-related risks, diagnostic methods, and treatment outcomes in older individuals.

RESEARCH METHODS AND PROCEDURES

We searched MEDLINE and Cochrane Library databases, consulted with experts, and examined bibliographies for English language studies discussing obesity in older adults (mean age > or = 60), published between January 1980 and November 2005. Inclusion criteria were met by 32 longitudinal analyses, seven diagnostic studies, and 17 randomized controlled trial articles. At least two authors independently reviewed and abstracted study design, population, results, and quality information.

RESULTS

Correlations between body fat and three anthropometric measures (BMI, waist circumference, waist-to-hip ratio) decrease with age but remain clinically significant. Obesity contributes to risk for several cardiovascular endpoints, some cancers, and impaired mobility but protects against hip fracture. The association between obesity and mortality declines as age increases. Intensive counseling strategies incorporating behavioral, dietary, and exercise components promote a weight loss of 3 to 4 kg over 1 to 3.3 years. The loss is linked with improved glucose tolerance, improved physical functioning, reduced incidence of diabetes and a combined hypertension and cardiovascular endpoint, and reduced bone density.

DISCUSSION

In older adults, obesity can be diagnosed with standard clinical measures. Intensive counseling can promote modest sustained weight loss, but data are insufficient to evaluate surgical or pharmacological options. Obesity treatment is most likely to benefit individuals with high cardiovascular risk. Limited data suggest possible functional improvement. Treatment should incorporate measures to avoid bone loss.

Hypertension: trends in prevalence, incidence, and control

Hypertension is the leading cause of cardiovascular disease worldwide. Prior to 1990, population data suggest that hypertension prevalence was decreasing; however, recent data suggest that it is again on the rise. In 1999-2002, 28.6% of the U.S. population had hypertension. Hypertension prevalence has also been increasing in other countries, and an estimated 972 million people in the world are suffering from this problem. Incidence rates of hypertension range between 3% and 18%, depending on the age, gender, ethnicity, and body size of the population studied. Despite advances in hypertension treatment, control rates continue to be suboptimal. Only about one third of all hypertensives are controlled in the United States. Programs that improve hypertension control rates and prevent hypertension are urgently needed.

Outpatient weight management in African-Americans: the Healthy Eating and Lifestyle Program (HELP) study

BACKGROUND

Effective clinical weight management approaches are needed to reach African-Americans.

METHODS

African-Americans recruited through outpatient practices for a culturally-adapted Healthy Eating and Lifestyle Program were offered 10 weekly weight loss classes (Phase 1) with the option of continuing for another 8-18 months (Phase 2) in a randomized comparison of further group counseling or staff-facilitated self-help vs. follow-up clinic visits only.

RESULTS

Of 237 enrollees (91% women; mean age 43.5 years; mean body mass index 38.0 kg/m(2)), 70 [corrected] attended no classes or only the first Phase 1 class, 134 provided Phase 1 follow-up data, 128 were randomized in Phase 2, and 87 provided final follow-up data ("completers"). Mean weight changes for completers were: -1.5 (P < 0.001), +0.3 (P = 0.47), and -1.2 (P = 0.04) kg, respectively, for Phase 1, Phase 2, and overall (baseline to final visit; average 18 months total duration), with no Phase 2 treatment effect (P = 0.55). Final study weight was > or =5% below baseline for 25% of completers and was strongly predicted by Phase 1 weight loss.

CONCLUSIONS

Weight loss achieved in Phase 1 was maintained even with relatively minimal follow-up contact. Increasing the percent who achieve clinically significant weight loss initially would improve long-term results.

Advice to reduce dietary salt for prevention of cardiovascular disease

BACKGROUND

Restricting sodium intake in elevated blood pressure over short periods of time reduces blood pressure. Long term effects (on mortality, morbidity or blood pressure) of advice to reduce salt in patients with elevated or normal blood pressure are unclear.

OBJECTIVES

To assess in adults the long term effects (mortality, cardiovascular events, blood pressure, quality of life, weight, urinary sodium excretion, other nutrients and use of anti-hypertensive medications) of advice to restrict dietary sodium using all relevant randomised controlled trials.

SEARCH STRATEGY

The Cochrane Library, MEDLINE, EMBASE, bibliographies of included studies and related systematic reviews were searched for unconfounded randomised trials in healthy adults aiming to reduce sodium intake over at least 6 months. Attempts were made to trace unpublished or missed studies and authors of all included trials were contacted. There were no language restrictions.

SELECTION CRITERIA

Inclusion decisions were independently duplicated and based on the following criteria: 1) randomisation was adequate; 2) there was a usual or control diet group; 3) the intervention aimed to reduce sodium intake; 4) the intervention was not multifactorial; 5) the participants were not children, acutely ill, pregnant or institutionalised; 6) follow-up was at least 26 weeks; 7) data on any of the outcomes of interest were available.

DATA COLLECTION AND ANALYSIS

Decisions on validity and data extraction were made independently by two reviewers, disagreements were resolved by discussion or if necessary by a third reviewer. Random effects meta-analysis, sub-grouping, sensitivity analysis and meta-regression were performed.

MAIN RESULTS

Three trials in normotensives (n=2326), five in untreated hypertensives (n=387) and three in treated hypertensives (n=801) were included, with follow up from six months to seven years. The large, high quality (and therefore most informative) studies used intensive behavioural interventions. Deaths and cardiovascular events were inconsistently defined and reported; only 17 deaths equally distributed between intervention and control groups occurred. Systolic and diastolic blood pressures were reduced at 13 to 60 months in those given low sodium advice as compared with controls (systolic by 1.1 mm Hg, 95% CI 1.8 to 0.4, diastolic by 0.6 mm hg, 95% CI 1.5 to -0.3), as was urinary 24 hour sodium excretion (by 35.5 mmol/ 24 hours, 95% CI 47.2 to 23.9). Degree of reduction in sodium intake and change in blood pressure were not related. People on anti-hypertensive medications were able to stop their medication more often on a reduced sodium diet as compared with controls, while maintaining similar blood pressure control.

REVIEWER'S CONCLUSIONS

Intensive interventions, unsuited to primary care or population prevention programmes, provide only minimal reductions in blood pressure during long-term trials. Further evaluations to assess effects on morbidity and mortality outcomes are needed for populations as a whole and for patients with elevated blood pressure. Evidence from a large and small trial showed that a low sodium diet helps in maintenance of lower blood pressure following withdrawal of antihypertensives. If this is confirmed, with no increase in cardiovascular events, then targeting of comprehensive dietary and behavioural programmes in patients with elevated blood pressure requiring drug treatment would be justified.

Aggressive blood pressure management

More than one third of all Americans have high or high-normal blood pressure and are at risk for stroke, cardiovascular disease, kidney disease, and heart failure. Many of these are not diagnosed or are inadequately treated. The large number of untreated individuals at risk for the complications of hypertension, or who have not achieved goal pressures on therapy, require a concerted effort by health care professionals to screen and treat this condition. Aggressive identification and treatment of even high-normal hypertension can reduce adverse outcomes. The importance of aggressive management is outlined in this article.

Reduced dietary salt for prevention of cardiovascular disease

BACKGROUND

Restricting sodium intake in elevated blood pressure over short periods of time reduces blood pressure. Long term effects (on mortality, morbidity or blood pressure) of advice to reduce salt in patients with elevated or normal blood pressure are unclear.

OBJECTIVES

To assess in adults the long term effects (mortality, cardiovascular events, blood pressure, quality of life, weight, urinary sodium excretion, other nutrients and use of anti-hypertensive medications) of advice to restrict dietary sodium using all relevant randomised controlled trials.

SEARCH STRATEGY

The Cochrane Library, MEDLINE, EMBASE, bibliographies of included studies and related systematic reviews were searched for unconfounded randomised trials in healthy adults aiming to reduce sodium intake over at least 6 months. Attempts were made to trace unpublished or missed studies and authors of all included trials were contacted. There were no language restrictions.

SELECTION CRITERIA

Inclusion decisions were independently duplicated and based on the following criteria: 1) randomisation was adequate; 2) there was a usual or control diet group; 3) the intervention aimed to reduce sodium intake; 4) the intervention was not multifactorial; 5) the participants were not children, acutely ill, pregnant or institutionalised; 6) follow-up was at least 26 weeks; 7) data on any of the outcomes of interest were available.

DATA COLLECTION AND ANALYSIS

Decisions on validity and data extraction were made independently by two reviewers, disagreements were resolved by discussion or if necessary by a third reviewer. Random effects meta-analysis, sub-grouping, sensitivity analysis and meta-regression were performed.

MAIN RESULTS

Three trials in normotensives (n=2326), five in untreated hypertensives (n=387) and three in treated hypertensives (n=801) were included, with follow up from six months to seven years. The large, high quality (and therefore most informative) studies used intensive behavioural interventions. Deaths and cardiovascular events were inconsistently defined and reported; only 17 deaths equally distributed between intervention and control groups occurred. Systolic and diastolic blood pressures were reduced at 13 to 60 months in those given low sodium advice as compared with controls (systolic by 1.1 mm Hg, 95% CI 1.8 to 0.4, diastolic by 0.6 mm hg, 95% CI 1.5 to -0.3), as was urinary 24 hour sodium excretion (by 35.5 mmol/ 24 hours, 95% CI 47.2 to 23.9). Degree of reduction in sodium intake and change in blood pressure were not related. People on anti-hypertensive medications were able to stop their medication more often on a reduced sodium diet as compared with controls, while maintaining similar blood pressure control.

REVIEWER'S CONCLUSIONS

Intensive interventions, unsuited to primary care or population prevention programmes, provide only minimal reductions in blood pressure during long-term trials. Further evaluations to assess effects on morbidity and mortality outcomes are needed for populations as a whole and for patients with elevated blood pressure. Evidence from a large and small trial showed that a low sodium diet helps in maintenance of lower blood pressure following withdrawal of antihypertensives. If this is confirmed, with no increase in cardiovascular events, then targeting of comprehensive dietary and behavioural programmes in patients with elevated blood pressure requiring drug treatment would be justified.

Dietary electrolytes and hypertension in the elderly

The effect of age on older hypertensive patient's blood pressure response to increased sodium intake is well known. Salt sensitivity which does increase with age and the decrease in renal function limiting the ability of aged kidney to excrete sodium load are major factors, responsible for rise in blood pressure during Na consumption in the elderly. Clinical studies encourage salt reduction with and without weight loss. Although potassium consumption is highly recommended, one should be aware of potassium overload in the elderly.

Association of angiotensin-converting enzyme DD genotype with blood pressure sensitivity to weight loss

BACKGROUND

Weight loss and sodium reduction are useful nonpharmacologic interventions in the management of hypertension. Salt sensitivity--the degree of blood pressure change in response to a change in sodium load--has been extensively explored. However, the determinants of the extent of blood pressure change after weight reduction have not been evaluated.

METHODS

We studied the relationship of the angiotensin-converting enzyme insertion-deletion (ACE I/D) polymorphism to blood pressure change after weight loss in the Trial Of Nonpharmacologic interventions in the Elderly (TONE). We focused on the 86 overweight white hypertensive TONE participants who were randomized to weight loss only.

RESULTS

A similar weight reduction was observed across all ACE genotypes, whereas a significantly greater decrease in blood pressure after weight loss was seen among participants with the DD genotype. In addition, DD participants had a higher probability of remaining normotensive for the duration of the trial.

CONCLUSIONS

The DD genotype may be associated with higher "weight sensitivity" in overweight white hypertensive persons, potentially through reduced activity of the renin-angiotensin and sympathetic systems after weight loss.

Ethnic comparison of weight loss in the Trial of Nonpharmacologic Interventions in the Elderly

OBJECTIVE

To compare weight loss in blacks and whites in the Trial of Nonpharmacologic Interventions in the Elderly (TONE).

RESEARCH METHODS AND PROCEDURES

TONE enrolled 421 overweight white and 164 overweight black adults, 60 to 79 years old, with blood pressure well-controlled on a single, antihypertensive drug. Drug therapy withdrawal was attempted 3 months after randomization to counseling for weight loss, sodium reduction, both weight loss and sodium reduction, or to usual care, with follow-up for 15 to 36 months after enrollment. Statistical procedures included repeated measures analysis of covariance and logistic and proportional hazards regression.

RESULTS

In the weight-loss condition, net weight change (in kilograms) was -2.7 in blacks and -5.9 in whites (p < 0.001; ethnic difference, p = 0.0002) at 6 months and -2.0 (p < 0.05) in blacks and -4.9 (p < 0.001) in whites at the end of follow-up (ethnic difference, p = 0.007). In weight/sodium, net weight change was -2.1 (p < 0.01) in blacks and -2.8 (p < 0.001) in whites at 6 months, and -1.9 in blacks and -1.7 in whites at the end of follow-up (p < 0.05; ethnic difference, p > 0.5). Exploratory analyses suggested a more favorable pattern of weight change in blacks than in whites from 6 months onward. There was no ethnic difference in blood pressure outcomes.

DISCUSSION

Whites lost more weight than blacks without, but not with, a concurrent focus on sodium reduction.

Quality of life with nonpharmacologic treatment of hypertension

Therapeutic treatment of hypertension has been achieved successfully with both pharmacologic and nonpharmacologic interventions. Clinical trials have shown that various approaches to treatment result in different levels of blood pressure reduction as well as varying effects on quality of life. Standardizing the approach to measuring quality of life would be beneficial to the assessment of treatment outcomes in hypertension trials. This article reviews some of the strengths and weaknesses of both pharmacologic and nonpharmacologic treatments of hypertension, with special emphasis placed on effects of quality of life.

Dietary advice given by a dietitian versus other health professional or self-help resources to reduce blood cholesterol

BACKGROUND

The average level of blood cholesterol is an important determinant of the risk of coronary heart disease. Blood cholesterol can be reduced by dietary means. Although dietitians are trained to provide dietary advice, for practical reasons it is also given by other health professionals and occasionally through the use of self-help resources.

OBJECTIVES

To assess the effects of dietary advice given by a dietitian compared with another health professional, or the use of self-help resources, in reducing blood cholesterol in adults.

SEARCH STRATEGY

We searched The Cochrane Library (to Issue 2 1999), MEDLINE (1966 to January 1999), EMBASE (1980 to December 1998), Cinahl (1982 to December 1998), Human Nutrition (1991 to 1998), Science Citation Index, Social Sciences Citation Index, hand searched conference proceedings on nutrition and heart disease, and contacted experts in the field.

SELECTION CRITERIA

Randomised trials of dietary advice given by a dietitian compared with another health professional or self-help resources. The main outcome was difference in blood cholesterol between dietitian groups compared with other intervention groups.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed study quality.

MAIN RESULTS

Eleven studies with 12 comparisons were included, involving 704 people receiving advice from dietitians, 486 from other health professionals and 551 people using self-help leaflets. Four studies compared dietitian with doctor, seven with self-help resources, and one compared dietitian with nurse. Participants receiving advice from dietitians experienced a greater reduction in blood cholesterol than those receiving advice only from doctors (-0.25 mmol/L (95% CI -0.37, -0.12 mmol/L)). There was no statistically significant difference in change in blood cholesterol between dietitians and self-help resources (-0.10 mmol/L (95% CI -0.22, 0.03 mmol/L)). No statistically significant differences were detected for secondary outcome measures between any of the comparisons with the exception of dietitian versus nurse for HDLc, where the dietitian groups showed a greater reduction (-0.06 mmol/L (95% CI -0.11, -0.01)). No significant heterogeneity between the studies was detected.

REVIEWER'S CONCLUSIONS

Dietitians were better than doctors at lowering blood cholesterol in the short to medium term, but there was no evidence that they were better than self-help resources. The results should be interpreted with caution as the studies were not of good quality and the analysis was based on a limited number of trials. More evidence is required to assess whether change can be maintained in the longer term. There was no evidence that dietitians provided better outcomes than nurses.

Exercise and weight loss in obese older adults with knee osteoarthritis: a preliminary study

OBJECTIVE

The purposes of this pilot study were to determine if a combined dietary and exercise intervention would result in significant weight loss in older obese adults with knee osteoarthritis, and to compare the effects of exercise plus dietary therapy with exercise alone on gait, strength, knee pain, biomarkers of cartilage degradation, and physical function.

DESIGN

Single-blind, two-arm, randomized clinical trial conducted for 24 weeks.

SETTING

A university health and exercise science center.

PARTICIPANTS

Twenty-four community-dwelling obese older adults aged > or = 60 years, body mass index > or = 28, knee pain, radiographic evidence of knee osteoarthritis, and self-reported physical disability.

INTERVENTION

Randomization into two groups: exercise and diet (E&D) and exercise alone (E). Exercise consisted of a combined weight training and walking program for 1 hour three times per week. The dietary intervention included weekly sessions with a nutritionist utilizing cognitive-behavior modification to change dietary habits to reach a group goal of an average weight loss of 15 lb (6.8 kg) over 6 months.

MEASUREMENTS

All measurements were conducted at baseline and 3 and 6 months, except for synovial fluid analysis, which was obtained only at baseline and 6 months. In addition, weight was measured weekly in the E&D group. Physical disability and knee pain were measured by self-report and physical performance was measured using the 6-minute walk and stair climb tasks. Biomechanical testing included kinetic and kinematic analysis of gait and isokinetic strength testing. Synovial fluid was analyzed for levels of total proteoglycan, keratan sulfate, and interleukin-1 beta.

RESULTS

Twenty-one of the 24 participants completed the study, with one dropout in the E&D group and two in the E group. The E&D group lost a mean of 18.8 lb (8.5 kg) at 6 months compared with 4.0 lb (1.8 kg) in the E group (P = .01). Significant improvements were noted in both groups in self-reported disability and knee pain intensity and frequency as well as in physical performance measures. However, no statistical differences were found between the two groups at 6 months in knee pain scores or self-reported performance measures of physical function. There was no difference in knee strength between the groups, with both groups showing modest improvements from baseline to 6 months. At 6 months, the E&D group had a significantly greater loading rate (P = .03) and maximum braking force (P = .01) during gait. There were no significant between-group differences in the other biomechanical measures. Synovial fluid samples were obtainable at both baseline and 6 months in eight participants (four per group). The level of keratan sulfate decreased similarly in both groups from an average baseline of 96.8 +/- 37.1 to 71.5 +/- 23 ng/microg total proteoglycan. The level of IL-1 decreased from 25.3 +/- 9.8 at baseline to 8.3 +/- 6.1 pg/mL. The decrease in IL-1 correlated with the change in pain frequency (r = -0.77, P = .043).

CONCLUSIONS

Weight loss can be achieved and sustained over a 6-month period in a cohort of older obese persons with osteoarthritis of the knee through a dietary and exercise intervention. Both exercise and combined weight loss and exercise regimens lead to improvements in pain, disability, and performance. Moreover, the trends in the biomechanical data suggest that exercise combined with diet may have an additional benefit in improved gait compared with exercise alone. A larger study is indicated to determine if weight loss provides additional benefits to exercise alone in this patient population.

Effect of voluntary weight loss on bone mineral density in older overweight women

OBJECTIVES

To examine the effect of diet and exercise-induced weight loss on bone mineral density in overweight postmenopausal women

DESIGN

A 1-year prospective, randomized clinical trial.

SETTING

Two university medical school research centers.

PARTICIPANTS

Sixty-seven overweight postmenopausal women, a subset of the women who participated in the Trial of Nonpharmacological Interventions in the Elderly (TONE) to control hypertension. The participants were assigned randomly to one of four groups: usual care, weight loss only, sodium restriction only, or combined weight loss/sodium restriction.

INTERVENTION

All TONE participants in the treatment groups attended regular dietary intervention sessions to lose weight, reduce sodium intake, or both that they might refrain from using antihypertensive medications for a period of 15 to 36 months (median = 29 months).

MEASUREMENTS

Bone mineral density (BMD) assessed by dual energy X-ray absorptiometry (DXA), serum and urine markers of bone metabolism, and other demographic and clinical data were collected at baseline, 6 months, and 12 months.

RESULTS

Women assigned to the weight loss interventions lost 9.2 +/- 1.2 lbs (mean +/- SE) at 6 months and 7.7 +/- 2.0 lbs at 12 months compared with 1.8 +/- 1.0 lbs at 6 months and 1.9 +/- 1.6 lbs at 12 months for those assigned to no weight loss intervention (P < .0001). Weight loss was correlated with a decrease in total body BMD (P = .004) and an increase in osteocalcin (P = .004) after controlling for baseline bone measures, intervention assignment, and other baseline covariates. Regression analyses indicated that total body BMD decreased by 6.25 +/- 2.06 g/cm2 x 10-4 for each pound of weight loss.

CONCLUSIONS

Voluntary weight loss in overweight postmenopausal women is associated with modest decrease in total body BMD. Clinicians recommending weight loss for older postmenopausal women may need to include recommendations for reducing the risk of bone loss.

Dieting to reduce body weight for controlling hypertension in adults

OBJECTIVES

Evaluate whether weight-loss diets are more effective than regular diets or other antihypertensive therapies in controlling blood pressure and preventing morbidity and mortality in hypertensive adults.

SEARCH STRATEGY

MEDLINE and The Cochrane Library were searched through November 1997. Trials known to experts in the field were included through June 1998.

SELECTION CRITERIA

For inclusion in the review, trials were required to meet each of the following criteria: 1) randomized controlled trials with one group assigned to a weight-loss diet and the other group assigned to either normal diet or antihypertensive therapy; 2) ambulatory adults with a mean blood pressure of at least 140 mm Hg systolic and/or 90 mm Hg diastolic; 3) active intervention consisting of a calorie-restricted diet intended to produce weight loss (excluded studies simultaneously implementing multiple lifestyle interventions where the effects of weight loss could not be disaggregated); and 4) outcome measures included weight loss and blood pressure.

DATA COLLECTION AND ANALYSIS

Studies were dual abstracted by two independent reviewers using a standardized form designed specifically for this review. The primary mode of analysis was qualitative; graphs of effect sizes for individual studies were also used.

MAIN RESULTS

Eighteen trials were found. Only one small study of inadequate power reported morbidity and mortality outcomes. None addressed quality of life or general well being issues. In general, participants assigned to weight-reduction groups lost weight compared to control groups. Six trials involving 361 participants assessed a weight-reducing diet versus a normal diet. The data suggested weight loss in the range of 4% to 8% of body weight was associated with a decrease in blood pressure in the range of 3 mm Hg systolic and diastolic. Three trials involving 363 participants assessed a weight-reducing diet versus treatment with antihypertensive medications. These suggested that a stepped-care approach with antihypertensive medications produced greater decreases in blood pressure (in the range of 6/5 mm Hg systolic/diastolic) than did a weight-loss diet. Trials that allowed adjustment of participants' antihypertensive regimens suggested that patients required less intensive antihypertensive drug therapy if they followed a weight-reducing diet. Data was insufficient to determine the relative efficacy of weight-reduction versus changes in sodium or potassium intake or exercise.

REVIEWER'S CONCLUSIONS

Weight-reducing diets in overweight hypertensive persons can affect modest weight loss in the range of 3-9% of body weight and are probably associated with modest blood pressure decreases of roughly 3 mm Hg systolic and diastolic. Weight-reducing diets may decrease dosage requirements of persons taking antihypertensive medications.

Dietary fish as a major component of a weight-loss diet: effect on serum lipids, glucose, and insulin metabolism in overweight hypertensive subjects

BACKGROUND

Obesity in hypertensive patients is associated with dyslipidemia and insulin resistance, both of which are improved by weight control. n-3 Fatty acids have diverse effects on mechanisms underlying atherosclerosis, including a decrease in serum triacylglycerols and an increase in HDL(2) cholesterol.

OBJECTIVE

The objective was to examine whether dietary fish enhances the effects of weight loss on serum lipids, glucose, and insulin in 69 overweight, treated hypertensive patients.

DESIGN

Overweight patients being treated for hypertension were randomly assigned to either a daily fish meal (3.65 g n-3 fatty acids), a weight-loss regimen, the 2 regimens combined, or a control group for 16 wk.

RESULTS

Sixty-three subjects completed the study. Weight decreased by a mean (+/-SEM) of 5.6 +/- 0.8 kg with energy restriction. Weight loss decreased fasting insulin (P = 0.003) and the area under the curve for insulin (P = 0.003) and glucose (P = 0.047) during an oral-glucose-tolerance test. The greatest decrease occurred in the fish + weight-loss group. There was no independent effect of fish on glucose or insulin. Fish increased HDL(2) cholesterol (P = 0.004) and decreased HDL(3) cholesterol (P = 0.026) without altering total, LDL, or HDL cholesterol. Weight loss had no effect on these variables. Fasting triacylglycerols fell significantly with fish consumption (29%) and weight loss (26%). The fish + weight-loss group showed the greatest improvement in lipids: triacylglycerols decreased by 38% (P < 0.001) and HDL(2) cholesterol increased by 24% (P = 0.04) compared with the control group.

CONCLUSIONS

Incorporating a daily fish meal into a weight-loss regimen was more effective than either measure alone at improving glucose-insulin metabolism and dyslipidemia. Cardiovascular risk is likely to be substantially reduced in overweight hypertensive patients with a weight-loss program incorporating fish meals rich in n-3 fatty acids.

Does withdrawal of antihypertensive medication increase the risk of cardiovascular events? Trial of Nonpharmacologic Interventions in the Elderly (TONE) Cooperative Research Group

The Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure recommends that attempts to discontinue antihypertensive drug therapy be considered after blood pressure (BP) has been controlled for 1 year. However, discontinuation of drug therapy could unmask underlying conditions and precipitate clinical cardiovascular events. The Trial of Nonpharmacologic Interventions in the Elderly (TONE) was a clinical trial of the efficacy of weight loss and/or sodium reduction in controlling BP after withdrawal of drug therapy in patients with a BP< 145/85 mm Hg on 1 antihypertensive medication. Of 975 participants, 886 entered the drug withdrawal phase of the trial and 774 were successfully withdrawn from their medications. Thirty-three events (stroke, transient ischemic attack, myocardial infarction, arrhythmia, congestive heart failure, angina, other) occurred between randomization and the onset of drug withdrawal (median time 3.6 months), 57 events occurred either during or after drug withdrawal (14.0 months), and 36 events occurred after resumption of antihypertensive therapy (15.9 months). Event rates per 100 person-years were 5.5, 5.5, and 6.8 for the 3 time periods (p=0.84) in the nonoverweight group and 7.2, 5.2, and 5.6 (p=0.08) in the overweight group. The study shows that antihypertensive medication can be safely withdrawn in older persons without clinical evidence of cardiovascular disease who do not have diastolic pressure > or = 150/90 mm Hg at withdrawal, providing that good BP control can be maintained with nonpharmacologic therapy.

Pilot study to enhance start-up of a multicenter nutrition intervention trial

Multicenter trials are important for answering questions that require large numbers of subjects. Such trials require standardized implementation of behavioral change programs across diverse populations, regions, and staff. Researchers involved with the Trial of Nonpharmacologic Interventions in the Elderly conducted a 17-week pilot study of their most complex intervention (combined weight and sodium reduction) before actual start-up of the main study. This allowed staff to rehearse implementing the program and to identify and address intervention and standardization issues. Registered dietitians in 4 US communities recruited 28 participants for the pilot study, using eligibility criteria similar to those for the main trial. Participant evaluations reflected high satisfaction with the program materials and overall approach. Minor protocol changes suggested by results of the pilot study were made easily in time for start-up of the main study. Reductions in weight and sodium intake were less than targeted but were sufficient to suggest that the intervention would be effective under optimal conditions. This partial achievement of goals in the pilot study underscored the need to allow for a learning curve, for without it standardization and outcomes of the main study would be compromised.