Dieting to reduce body weight for controlling hypertension in adults

The relationship between tooth loss and hypertension: a systematic review and meta-analysis

As tooth loss is the high end of periodontal problems and edentulous individuals are at higher risk of nutritional problems like obesity, understanding the association between tooth loss and hypertension is important for improving cardiovascular health. We searched for publications from the last two decades using three electronic databases (PubMed, Web of Science and Scopus) and conducted a systematic review and meta-analysis on the association between tooth loss and hypertension according to PRISMA-P guidelines. Quality assessments were performed using the Newcastle–Ottawa Scale and the GRADE approach. Twenty-four studies (20 cross-sectional, and 4 cohort) met the inclusion criteria for this review. Most cross-sectional studies showed that subjects with more tooth loss exhibited a greater proportion of hypertension and higher systolic blood pressure than those with less tooth loss. Meta-analyses revealed a statistically significant association between tooth loss and hypertension. The pooled odds ratios of hypertension for having tooth loss with no tooth loss and for edentulous with dentate were 2.22 (95% CI 2.00–2.45) and 4.94 (95% CI 4.04–6.05), respectively. In cohort studies, subjects with more tooth loss had a greater incidence of hypertension than those with less tooth loss during the follow-up period. The present systematic review and meta-analysis suggests that tooth loss is associated with an increased risk of hypertension and higher systolic blood pressure.

Role of Nutrition and Exercise Programs in Reducing Blood Pressure: A Systematic Review

The combined effect of diet and strength training (ST) on blood pressure (BP) seems to be very important for the treatment of prehypertension and hypertension (HT). Therefore, the aim of this study was to determine whether ST alone or combined with nutrition or supplementation has an impact on the arterial pressure reduction in normotensive and hypertensive populations. A systematic computerized literature search was performed according to the PRISMA guidelines using PubMed, Scopus and Google Scholar; only English language studies published from 1999 until 2018 were included. This systematic search identified the results of 303 individuals from nine studies. The ST program alone had a similar effectiveness as the nutrition program (NP) alone; however, their combination did not result in increased effectiveness in terms of a high BP reduction. The consumption of L-citrulline had a similar effect as ST on lowering BP; on the other hand, caffeine led to an increase in BP during the ST session. Our data suggest that a combination of ST 2-3 times a week at moderate intensity and a NP seems to be equally effective in terms of lowering BP (systolic and diastolic) as ST and NP alone.

Does hormone therapy affect blood pressure changes in the Diabetes Prevention Program?

OBJECTIVE

This study aims to examine whether blood pressure reductions differ by estrogen use among overweight glucose-intolerant women.

METHODS

We conducted a secondary analysis of Diabetes Prevention Program postmenopausal participants who used oral estrogen with or without progestogen at baseline and 1-year follow-up (n = 324) versus those who did not use oral estrogen with or without progestogen at either time point (n = 382). Changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) were examined by randomization arm (intensive lifestyle change [ILS], metformin 850 mg twice daily, or placebo). Associations between changes in blood pressure and changes in sex hormone-binding globulin, estradiol, testosterone, and dehydroepiandrosterone were also examined.

RESULTS

Estrogen users and nonusers had similar prevalences of baseline hypertension (33% vs 34%, P = 0.82) and use of blood pressure medications at baseline (P = 0.25) and on follow-up (P = 0.10). Estrogen users and nonusers randomized to ILS had similar decreases in SBP (-3.3 vs -4.7 mm Hg, P = 0.45) and DBP (-3.1 vs -4.7 mm Hg, P = 0.16). Among estrogen users, women randomized to ILS had significant declines in SBP (P = 0.016) and DBP (P = 0.009) versus placebo. Among nonusers, women randomized to ILS had significant declines in DBP (P = 0.001) versus placebo, but declines in SBP were not significant (P = 0.11). Metformin was not associated with blood pressure reductions versus placebo regardless of estrogen therapy. Blood pressure changes were not associated with changes in sex hormones regardless of estrogen therapy.

CONCLUSIONS

Among overweight women with dysglycemia, the magnitude of blood pressure reductions after ILS is unrelated to postmenopausal estrogen use.

Hypertensive Disorders of Pregnancy - A Life-Long Risk?!

Background: Arterial hypertension is one of the most important causes of cardiovascular diseases, and the latter are responsible for almost half of the deaths in the industrialised nations. Hypertensive disorders of pregnancy constitute one of the most frequent causes of feto-maternal morbidity and mortality; on the other hand the occurrence of a hypertensive disorder of pregnancy represents a risk for the later development of hypertension and the cardiovascular risks resulting therefrom. The aim of this article is to demonstrate the association of hypertensive disorders of pregnancy with consecutive cardiovascular diseases. Materials and Methods: Specific selective literature research. Results: After the occurrence of a hypertensive disorder of pregnancy the relative risks for hypertension are 3.7 (2.70-5.05), for ischaemic heart disease 2.2 (1.86-2.52), for cerebral insult 1.8 (1.45-2.27) and for mortality resulting from cardiovascular causes 1.5 (1.05-2.14) and are thus significant. According to a recent study 56 % of internal specialists and 23 % of gynecologists do not know about the association of preeclampsia with ischemic heart disease, 48 % and 38 % respectively are not aware of the link with stroke and 79 % and 77 % respectively are not aware of the association with a reduced life expectancy after preeclampsia. The presence of hypertension is not known by many of the patients, merely 28-38 % receive an appropriate therapy. Conclusion: Adequate follow-up after hypertensive disorders of pregnancy and the early recognition of and therapy for hypertension represent the cornerstones in the prevention of late cardiovascular sequelae. General practitioners, specialist for internal medicine and gynaecologists have a special responsibility with regard to the reduction of later complications.

A systematic review of recent clinical practice guidelines on the diagnosis, assessment and management of hypertension

BACKGROUND

Despite the availability of clinical practice guidelines (CPGs), optimal hypertension control is not achieved in many parts of the world; one of the challenges is the volume of guidelines on this topic and their variable quality. To systematically review the quality, methodology, and consistency of recommendations of recently-developed national CPGs on the diagnosis, assessment and the management of hypertension.

METHODOLOGY/PRINCIPAL FINDINGS

MEDLINE, EMBASE, guidelines' websites and Google were searched for CPGs written in English on the general management of hypertension in any clinical setting published between January 2006 and September 2011. Four raters independently appraised each CPG using the AGREE-II instrument and 2 reviewers independently extracted the data. Conflicts were resolved by discussion or the involvement of an additional reviewer. Eleven CPGs were identified. The overall quality ranged from 2.5 to 6 out of 7 on the AGREE-II tool. The highest scores were for "clarity of presentation" (44.4%-88.9%) and the lowest were for "rigour of development" (8.3%-30% for 9 CGPs). None of them clearly reported being newly developed or adapted. Only one reported having a patient representative in its development team. Systematic reviews were not consistently used and only 2 up-to-date Cochrane reviews were cited. Two CPGs graded some recommendations and related that to levels (but not quality) of evidence. The CPGs' recommendations on assessment and non-pharmacological management were fairly consistent. Guidelines varied in the selection of first-line treatment, adjustment of therapy and drug combinations. Important specific aspects of care (e.g. resistant hypertension) were ignored by 6/11 CPGs. The CPGs varied in methodological quality, suggesting that their implementation might not result in less variation of care or in better health-related outcomes.

CONCLUSIONS/SIGNIFICANCE

More efforts are needed to promote the realistic approach of localization or local adaptation of existing high-quality CPGs to the national context.

Hypertension in sub-Saharan Africa: cross-sectional surveys in four rural and urban communities

Background

Cardiovascular disease (CVD) is the leading cause of adult mortality in low-income countries but data on the prevalence of cardiovascular risk factors such as hypertension are scarce, especially in sub-Saharan Africa (SSA). This study aims to assess the prevalence of hypertension and determinants of blood pressure in four SSA populations in rural Nigeria and Kenya, and urban Namibia and Tanzania.

Methods and Findings

We performed four cross-sectional household surveys in Kwara State, Nigeria; Nandi district, Kenya; Dar es Salaam, Tanzania and Greater Windhoek, Namibia, between 2009–2011. Representative population-based samples were drawn in Nigeria and Namibia. The Kenya and Tanzania study populations consisted of specific target groups. Within a final sample size of 5,500 households, 9,857 non-pregnant adults were eligible for analysis on hypertension. Of those, 7,568 respondents ≥18 years were included. The primary outcome measure was the prevalence of hypertension in each of the populations under study.

The age-standardized prevalence of hypertension was 19.3% (95%CI:17.3–21.3) in rural Nigeria, 21.4% (19.8–23.0) in rural Kenya, 23.7% (21.3–26.2) in urban Tanzania, and 38.0% (35.9–40.1) in urban Namibia. In individuals with hypertension, the proportion of grade 2 (≥160/100 mmHg) or grade 3 hypertension (≥180/110 mmHg) ranged from 29.2% (Namibia) to 43.3% (Nigeria). Control of hypertension ranged from 2.6% in Kenya to 17.8% in Namibia. Obesity prevalence (BMI ≥30) ranged from 6.1% (Nigeria) to 17.4% (Tanzania) and together with age and gender, BMI independently predicted blood pressure level in all study populations. Diabetes prevalence ranged from 2.1% (Namibia) to 3.7% (Tanzania).

Conclusion

Hypertension was the most frequently observed risk factor for CVD in both urban and rural communities in SSA and will contribute to the growing burden of CVD in SSA. Low levels of control of hypertension are alarming. Strengthening of health care systems in SSA to contain the emerging epidemic of CVD is urgently needed.

Health practitioners' state of knowledge and challenges to effective management of hypertension at primary level

Background

Patient- and physician-related factors impact on the management and control of hypertension.

Objectives

To systematically examine: (1) South African primary care doctors’ state of knowledge on the management of hypertension; (2) primary health practitioners’ knowledge on the South African hypertension guidelines; (3) current approaches to management of hypertensive patients; and (4) challenges to effective management of hypertension at primary level.

Methods

A cross-sectional, observational study using a semi-structured questionnaire was carried out in two large community health centres (CHCs) in the Cape Town metropole. All 16 doctors employed at both CHCs were voluntarily enrolled, seven (43.7%) of whom were female, with 14 (87.5%) younger than 40 years of age. The majority (81.2%) of the doctors surveyed had been practicing for less than 10 years.

Results

Ten (62.5%) of the doctors surveyed aimed to treat hypertension to target, and recommendations on lifestyle modifications were reportedly poorly done. While 11 (68.8%) of the doctors were aware of the South African hypertension guidelines, were (81.8%) of them were not conversant with the contents thereof. Doctors estimated that only 35% of their patients are treated to target. Poor patient adherence to prescribed treatment, language difficulty, heavy patient load, medical staff shortages, and patient loss to follow up were identified by the doctors as significant impediments to the effective management of hypertension at the primary level of care.

Conclusion

Primary healthcare practitioners’ knowledge regarding hypertension and the South African hypertension guidelines is poor. Management of hypertension by these doctors is sub-optimal. There are significant challenges to effective management of hypertension at this level of care.

Dietary counseling on long-term weight loss in overweight hypertensive patients

OBJECTIVE

This study aimed to evaluate long-term weight loss in overweight hypertensive patients receiving dietary counseling.

METHODS

Longitudinal study included overweight hypertensive patients who had an initial individual consultation with a nutritionist between January 2002 and December 2005 and were followed for four years in a hypertension clinic. Patients who had at least four consultations during the follow-up period were included in the dietary counseling group. Those who scheduled their first consultation but missed that appointment or had fewer than four consultations during the follow-up period were allocated to the control group. Target Energy intake was calculated at 20-25 kcal/kg actual body weight/day.

RESULTS

The study included 102 patients aged 55 ± 1 years old (58 in the dietary counseling group). As compared with the control group, patients in the dietary counseling group showed a significantly greater reduction in body weight (-3.6 ± 0.8 vs. 0.8 ± 0.7 kg), which remained significant after controlling for age, gender, baseline body mass index, and the use of different antihypertensive and antidiabetic drugs. Weight loss between 5.0% and 9.9% was observed in a significantly higher percentage of patients in the dietary counseling group (28% vs. 11%). A weight loss of at least 10% was only observed in dietary counseling group patients, who had a significantly lower odds ratio for increasing the number and/or dosage of antihypertensive agents, even after controlling for age, gender, and baseline body mass index.

CONCLUSIONS

Dietary counseling may be associated with long-term weight loss in overweight hypertensive patients.

Do we need more than just powerful blood pressure reductions? New paradigms in end-organ protection

Antihypertensive therapy can lower the risk of cardiovascular morbidity and mortality. Yet, partly because of inadequate dosing, wrong pharmacological choices, and poor patient adherence, hypertension control remains suboptimal in the majority of hypertensive patients. Achieving greater blood pressure control requires a multifaceted approach that raises awareness of hypertension, uses effective therapies, and improves adherence. Particular classes of antihypertensive therapy have beneficial actions beyond blood pressure and studies have evaluated differences in cardiovascular protection among classes. The LIFE and HOPE studies showed between-class differences that may be due to effects other than blood pressure-lowering. In the ONTARGET study, telmisartan and ramipril provided similar cardiovascular protection but adherence was higher with telmisartan, which was better tolerated. This difference in compliance is likely to be important for long-term therapy. The selection of an agent for cardiovascular protection should depend on an appreciation of its composite properties, including any beneficial effects on tolerability and increased patient adherence, as these are likely to be advantageous for the long-term management of hypertension. This review examines the evidence that the effects beyond blood pressure provided by some antihypertensive agents can also lower the risk of cardiovascular, cerebrovascular, and renal events in patients with hypertension.

Relaxation therapies for the management of primary hypertension in adults

BACKGROUND

Lifestyle interventions are often recommended as initial treatment for mild hypertension, but the efficacy of relaxation therapies is unclear.

OBJECTIVES

To evaluate the effects of relaxation therapies on cardiovascular outcomes and blood pressure in people with elevated blood pressure.

SEARCH STRATEGY

We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review.

INCLUSION CRITERIA

RCTs of a parallel design comparing relaxation therapies with no active treatment, or sham therapy; follow-up >/=8 weeks; participants over 18 years, with raised systolic blood pressure (SBP) >/=140 mmHg or diastolic blood pressure (DBP) >/=85 mmHg); SBP and DBP reported at end of follow-up.

EXCLUSION CRITERIA

participants were pregnant; participants received antihypertensive medication which changed during the trial.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted.

MAIN RESULTS

29 RCTs, with eight weeks to five years follow-up, met our inclusion criteria; four were excluded from the primary meta-analysis because of inadequate outcome data. The remaining 25 trials assessed 1,198 participants, but adequate randomisation was confirmed in only seven trials and concealment of allocation in only one. Only one trial reported deaths, heart attacks and strokes (one of each). Meta-analysis indicated that relaxation resulted in small, statistically significant reductions in SBP (mean difference: -5.5 mmHg, 95% CI: -8.2 to -2.8, I2 =72%) and DBP (mean difference: -3.5 mmHg, 95% CI: -5.3 to -1.6, I2 =75%) compared to control. The substantial heterogeneity between trials was not explained by duration of follow-up, type of control, type of relaxation therapy or baseline blood pressure. The nine trials that reported blinding of outcome assessors found a non-significant net reduction in blood pressure (SBP mean difference: -3.2 mmHg, 95% CI: -7.7 to 1.4, I(2) =69%) associated with relaxation. The 15 trials comparing relaxation with sham therapy likewise found a non-significant reduction in blood pressure (SBP mean difference: -3.5 mmHg, 95% CI: -7.1 to 0.2, I(2) =63%).

AUTHORS' CONCLUSIONS

In view of the poor quality of included trials and unexplained variation between trials, the evidence in favour of causal association between relaxation and blood pressure reduction is weak. Some of the apparent benefit of relaxation was probably due to aspects of treatment unrelated to relaxation.

Obesity and pre-hypertension in family medicine: implications for quality improvement

Background.

Prevention of pre-hypertension is an important goal for primary care patients. Obesity is a risk factor for hypertension, but has not been addressed for pre-hypertension in primary care populations. The objective of this study was to assess the degree to which obesity independently is associated with risk for pre-hypertension in family medicine patients.

Methods.

This study was a retrospective analysis of information abstracted from medical records of 707 adult patients. Multivariable logistic regression was used to test the relationship between body mass index (BMI) and pre-hypertension, after adjustment for comorbidity and demographic characteristics. Pre-hypertension was defined as systolic pressure between 120 and 139 mm Hg or diastolic pressure between 80 and 89 mm Hg.

Results.

In our sample, 42.9% of patients were pre-hypertensive. Logistic regression analysis revealed that, in comparison to patients with normal body mass, patients with BMI > 35 had higher adjusted odds of being pre-hypertensive (OR = 4.5, CI 2.55–8.11, p < .01). BMI between 30 and 35 also was significant (OR = 2.7, CI 1.61–4.63, p < 0.01) as was overweight (OR = 1.8, CI 1.14–2.92, p = 0.01).

Conclusion.

In our sample of family medicine patients, elevated BMI is a risk factor for pre-hypertension, especially BMI > 35. This relationship appears to be independent of age, gender, marital status and comorbidity. Weight loss intervention for obese patients, including patient education or referral to weight loss programs, might be effective for prevention of pre-hypertension and thus should be considered as a potential quality indicator.

Can electronic search engines optimize screening of search results in systematic reviews: an empirical study

Background

Most electronic search efforts directed at identifying primary studies for inclusion in systematic reviews rely on the optimal Boolean search features of search interfaces such as DIALOG^® and Ovid™. Our objective is to test the ability of an Ultraseek^® search engine to rank MEDLINE^® records of the included studies of Cochrane reviews within the top half of all the records retrieved by the Boolean MEDLINE search used by the reviewers.

Methods

Collections were created using the MEDLINE bibliographic records of included and excluded studies listed in the review and all records retrieved by the MEDLINE search. Records were converted to individual HTML files. Collections of records were indexed and searched through a statistical search engine, Ultraseek, using review-specific search terms. Our data sources, systematic reviews published in the Cochrane library, were included if they reported using at least one phase of the Cochrane Highly Sensitive Search Strategy (HSSS), provided citations for both included and excluded studies and conducted a meta-analysis using a binary outcome measure. Reviews were selected if they yielded between 1000–6000 records when the MEDLINE search strategy was replicated.

Results

Nine Cochrane reviews were included. Included studies within the Cochrane reviews were found within the first 500 retrieved studies more often than would be expected by chance. Across all reviews, recall of included studies into the top 500 was 0.70. There was no statistically significant difference in ranking when comparing included studies with just the subset of excluded studies listed as excluded in the published review.

Conclusion

The relevance ranking provided by the search engine was better than expected by chance and shows promise for the preliminary evaluation of large results from Boolean searches. A statistical search engine does not appear to be able to make fine discriminations concerning the relevance of bibliographic records that have been pre-screened by systematic reviewers.

Implementation of a pharmacist-led clinic for hypertensive patients in primary care--a pilot study

OBJECTIVES

To implement a pharmacist-led Hypertension Management Clinic in one general medical practice. To evaluate the impact of the clinic on blood pressure (BP) control and prevention of coronary heart disease (CHD).

METHOD

A total of 242 patients attended the pharmacist-led hypertension clinic over a 10-month period. Lifestyle and drug therapy alterations were implemented to achieve British Hypertension Society (BHS) target level BP. A sub-group of 160 patients were used to compare BP control in the clinic setting against that with the general practitioner (GP). Assessment was made of 10-year CHD risk in patients with no artherosclerotic disease. Patients with underlying artherosclerotic disease were prescribed statins, and antiplatelet drugs where indicated.

MAIN OUTCOME MEASURES

Changes in numbers of hypertensive patients meeting the BHS target level BP. Changes in prescribing of antiplatelet agents and statins for primary and secondary prevention of artherosclerosis.

RESULTS

In 206 patients with established hypertension, the number achieving target level BPs increased from 74 (36%) pre-clinic to 174 (85%) post-clinic; P < 0.001 chi-squared test. After attending the clinic, for 5 months 74 patients (80%) achieved target level BP in the clinic compared with 27 (40%) with standard GP care; P < 0.001 chi-squared test. Of 188 patients assessed for primary prevention therapy, 126 (67%) required treatment with aspirin and 37 (20%) with a statin. Post-clinic 101 (80%) received aspirin compared with 17 (13%) pre-clinic and 34 (92%) received a statin in comparison with 4 (11%) pre-clinic; both P < 0.001 chi-squared test.A total of 52 (96%) of 54 patients received an antiplatelet agent for secondary prevention of artherosclerosis compared with 40 patients (74%) pre-clinic. Thirty six of 54 patients required a statin for secondary prevention. Thirty five patients (97%) received a statin compared with 23 (64%) pre-clinic; both P < 0.01 chi-squared test.

CONCLUSION

Implementation of a pharmacist-led clinic improved blood pressure control and appropriate prescribing of antiplatelet agents and statins for primary prevention of CHD and secondary prevention of artherosclerosis.

Randomised controlled factorial trial of dietary advice for patients with a single high blood pressure reading in primary care

OBJECTIVE

To assess the effect of brief interventions during the "watchful waiting" period for hypertension.

DESIGN

Factorial trial.

SETTING

General practice.

METHODS

296 patients with blood pressure > 160/90 mm Hg were randomised to eight groups defined by three factors: an information booklet; low sodium, high potassium salt; prompt sheets for high fruit, vegetable, fibre; and low fat.

MAIN OUTCOME MEASURES

Blood pressure (primary outcome); secondary outcomes of diet, weight, and dietary biomarkers (urinary sodium:potassium (Na:K) ratio; carotenoid concentrations).

RESULTS

Blood pressure was not affected by the booklet (mean difference (diastolic blood pressure) at one month 0.2, 95% confidence interval 1.6 to 2.0), salt (0.13; 1.7 to 2.0), or prompts (0.52; 1.3 to 2.4). The salt decreased Na:K ratio (difference 0.32; 0.08 to 0.56, P = 0.01), and the prompts helped control weight (difference 0.39 (0.85 to 0.05) kg at one month, P = 0.085; 1.2 (0.1 to 2.25) kg at six months, P = 0.03). Among those with lower fruit and vegetable consumption (< 300 g per day), prompts increased fruit and vegetable consumption and also carotenoid concentrations (difference 143 (16 to 269) mmol/l, P < 0.03) but did not decrease blood pressure.

CONCLUSION

During watchful waiting, over and above the effect of brief advice and monitoring, an information booklet, lifestyle prompts, and low sodium salt do not reduce blood pressure. Secondary analysis suggests that brief interventions-particularly lifestyle prompts-can make useful changes in diet and help control weight, which previous research indicates are likely to reduce the long term risk of stroke.

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.