Risk factor changes after cessation of intervention in the Multiple Risk Factor Intervention Trial. The MRFIT Research Group

The long-term effect of a population-based life-style intervention on smoking and alcohol consumption. The Inter99 Study--a randomized controlled trial

AIMS

To examine whether improvements in smoking and alcohol consumption throughout the 5-year course of a population-based multi-factorial life-style intervention were sustained 5 years after its discontinuation.

DESIGN

Population-based randomized controlled trial.

SETTING

Suburbs of Copenhagen, Denmark.

PARTICIPANTS

A total of 9415 people aged 30-60 years were randomized to an intervention group (n = 6091) and an assessment-only control group (n = 3324).

INTERVENTION

All participants in the intervention group received screening, risk assessment and individual life-style counselling; participants at high risk of ischaemic heart disease-according to pre-specified criteria-were also offered group-based counselling.

MEASUREMENTS

Self-reported point abstinence from smoking as well as changes in the average alcohol consumption per week and binge drinking in the past week from baseline to 10-year follow-up were investigated using random-effects modelling.

FINDINGS

At 10-year follow up, people in the intervention group reported a higher smoking abstinence rate [odds ratio (OR) = 1.84, 95% confidence interval (CI) = 1.02-3.33, P = 0.043] and a greater reduction in binge drinking (net change = -0.08 days with binge drinking in the last week, 95% CI = -0.16 to -0.01, P = 0.028) than in the control group. There were no detectable long-term intervention effects on the average alcohol consumption per week.

CONCLUSIONS

A population-based multi-factorial life-style intervention of 5 years' duration in Denmark had sustained beneficial effects on smoking abstinence and binge drinking 5 years after its discontinuation.

The long-term effect of screening and lifestyle counseling on changes in physical activity and diet: the Inter99 Study - a randomized controlled trial

BACKGROUND

Multi-factorial intervention studies have been found to be successful in the initiation of lifestyle changes. However, little is known about the longer-term maintenance of health behavior improvements. The purpose of this study was to investigate whether improvements in physical activity and dietary habits achieved in a population-based multi-factorial lifestyle intervention of five years duration were maintained five years after intervention activities have ended.

METHODS

The study was a population-based randomized controlled trial, Inter99 (1999-2006), Copenhagen, Denmark. Over five years, all participants in the intervention group (n = 6,091) received individual lifestyle counseling; participants at high risk of ischemic heart disease - according to pre-specified criteria - were also offered group-based counseling. The control group (n = 3,324) was followed by questionnaires. Both groups were followed one, three, five, and ten years after baseline. Changes in physical activity and dietary habits (intake of vegetables, fruit, fish, and saturated fat) during and after the intervention were investigated using random-coefficient models.

RESULTS

Five years after the intervention, women in the intervention group reported greater improvements in the intake of fruit (M Δ = 90.2 g/week, p = 0.041) and less intake of saturated fat (OR = 0.30, 95% CI: 0.17-0.54) than the control group. Men in the intervention group reported greater improvements in physical activity (M Δ = 19.6 min/week, p = 0.003) and less intake of saturated fat (OR = 0.31, 95% CI: 0.17-0.56) than the control group. Improvements in the intake of vegetables and fish achieved during the intervention were not maintained in the longer-term.

CONCLUSIONS

Screening and lifestyle counseling had sustained effects on physical activity and dietary habits five years after its discontinuation. The patterns of long-term changes in lifestyle differed across behaviors and between men and women.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT00289237 ).

Mortality and morbidity during and after the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

A randomized, double-blind, active-controlled, multicenter trial assigned 32,804 participants aged 55 years and older with hypertension and ≥ 1 other coronary heart disease risk factors to receive chlorthalidone (n=15,002), amlodipine (n=8898), or lisinopril (n=8904) for 4 to 8 years, when double-blinded therapy was discontinued. Passive surveillance continued for a total follow-up of 8 to 13 years using national administrative databases to ascertain deaths and hospitalizations. During the post-trial period, fatal outcomes and nonfatal outcomes were available for 98% and 65% of participants, respectively, due to lack of access to administrative databases for the remainder. This paper assesses whether mortality and morbidity differences persisted or new differences developed during the extended follow-up. Primary outcome was cardiovascular mortality and secondary outcomes were mortality, stroke, coronary heart disease, heart failure, cardiovascular disease, and end-stage renal disease. For the post-trial period, data are not available on medications or blood pressure levels. No significant differences (P<.05) appeared in cardiovascular mortality for amlodipine (hazard ratio [HR], 1.00; 95% confidence interval [CI], 0.93-1.06) or lisinopril (HR, 0.97; CI, 0.90-1.03), each compared with chlorthalidone. The only significant differences in secondary outcomes were for heart failure, which was higher with amlodipine (HR, 1.12; CI, 1.02-1.22), and stroke mortality, which was higher with lisinopril (HR, 1.20; CI, 1.01-1.41), each compared with chlorthalidone. Similar to the previously reported in-trial result, there was a significant treatment-by-race interaction for cardiovascular disease for lisinopril vs chlorthalidone. Black participants had higher risk than non-black participants taking lisinopril compared with chlorthalidone. After accounting for multiple comparisons, none of these results were significant. These findings suggest that neither calcium channel blockers nor angiotensin-converting enzyme inhibitors are superior to diuretics for the long-term prevention of major cardiovascular complications of hypertension.

Cardiovascular prevention in the Hartslag Limburg project: effects of a high-risk approach on behavioral risk factors in a general practice population

BACKGROUND

This study describes a general-practice-based high-risk cardiovascular prevention approach in Maastricht, The Netherlands (1999-2003). The intervention consisted of a complete registration of risk factors, optimization of medical treatment and health counseling on high fat consumption, smoking and physical inactivity.

METHODS

Behavioral effects were assessed in a trial, randomization by practice and usual care as control. Validated questionnaires were completed by 1300 patients at baseline, 1174 after 4 months (90.3%) and 1046 (80.5%) after 18 months.

RESULTS

After 4 months, intention-to-treat analyses revealed a decrease in saturated fat intake of 1.3 points (scale ranging from 7 to 30 points, p=0.000). This was partly sustained after 18 months (-0.5 points, p=0.014). After 18 months, obese intervention patients were more likely to be sufficiently physically active than their control counterparts (OR=1.90, p=0.023). No intervention effects were found for smoking.

CONCLUSION

Given the multiple factor and multiple component high-risk approach, the intervention had modest effects on only some of the behavioral risk factors addressed. Process data showed that the registration of risk factors and the optimization of medical treatment were only partly implemented, that the health counseling component could be further improved and that the intervention could benefit from additional health promoting strategies.

Follow-up of diet and cardiovascular risk factors 20 years after cessation of intervention in the Oslo Diet and Antismoking Study

OBJECTIVE

The Oslo Diet and Antismoking study was a 5-year randomised trial initiated in 1972-1973, which studied the effect of dietary change and smoking cessation for the prevention of coronary heart disease among high-risk middle-aged men. To test the long-term maintenance of lifestyle change, we examined diet and cardiovascular risk factors in subjects initially randomised to the control and intervention groups 20 years after cessation of the intervention.

SUBJECTS AND DESIGN

Of the original cohort that included 1232 participants, 910 survivors were identified in 1997 and cardiovascular risk factors were measured in 563 (62%) in 1997-1999. Of these, 558 (99%) also completed questionnaires about their food intake and attitudes to health and diet.

RESULTS

Cigarette smoking was nearly halved between baseline and 20-year follow-up in each of the intervention and control groups (P<0.001 within groups), but did not differ between the intervention group (39%) versus the control group (34%); P=0.07. Body mass index increased by 1.4+/-2.6 and 1.6+/-2.6 kg/m(2) between baseline and 20-year follow-up in the intervention and control groups, respectively (P<0.001 within groups; NS between groups). Serum total cholesterol and triglyceride concentrations decreased substantially in subjects treated or untreated with statins (P<0.001 within the intervention and control groups) but did not differ between the groups (total cholesterol change of -1.4+/-1.3 and -1.3+/-1.2 mmol/l, respectively, and triglyceride change of -0.5+/-1.0 mmol/l in both groups). Men in the intervention group reported a less atherogenic fat quality score and lower intakes of fat, saturated fat and cholesterol, higher intakes of long chain polyunsaturated fatty acids, protein and beta-carotene and greater attention to lifestyle and change of diet than the control group (all P<0.05). The fatty acid concentrations did not differ, however, between the intervention and control groups (P>0.05).

CONCLUSIONS

No long-term differences in smoking rates or lipid concentrations between the intervention and control groups were observed in the surviving attendees two decades after the end of the trial. Lifestyle intervention still influenced the dietary intake, though modestly.

The Impact of Cardiovascular Risk Factor Case Management on the Metabolic Syndrome in a Primary Prevention Population: Results From a Randomized Controlled Trial

No study has examined the effect of case management on the development of the metabolic syndrome. The authors randomized 450 consenting, asymptomatic men and women to a 6-month cardiovascular case management program or usual care. Participants were reassessed at 1 year for change in a composite measure of five factors that define the metabolic syndrome. Of the cohort (mean age 42 years; 79% male), 46% had at least one metabolic syndrome factor and 4.3% had the metabolic syndrome. At 1 year, there was greater improvement in motivation to change in the case management group (+0.58 vs. +0.06, 10-point scale; p = 0.001), lower incidence of the metabolic syndrome (1.5% vs. 4.5%; p = 0.12), and lower prevalence (decrease of 0.8% vs. increase of 2.6%; p = 0.04). A 6-month case management program focused on cardiovascular risk factors had a modest effect on the prevalence of the metabolic syndrome in this primary prevention screening population after 1 year. Further study is needed to clarify the overall health impact of preventing the metabolic syndrome.

Effect of diet intervention on long-term mortality in healthy middle-aged men with combined hyperlipidaemia

OBJECTIVES

The aim was to study the effect of a 5-year diet intervention on 24-year mortality in middle aged men with combined hyperlipidaemia.

SETTING

We studied 104 initially healthy men (in 1972) aged 40-49 years with baseline values of total serum cholesterol >6.45 mmol L-1 and fasting triglycerides >2.55 mmol L-1, within the randomized diet and smoking cessation trial of the Oslo study (n = 1232).

METHODS

The participants were randomized to a 5-year diet intervention or a control group. The diet consisted of a traditional lipid-lowering diet with emphasis on reduction of saturated fat, total caloric intake and body weight. The groups were initially well balanced with regard to traditional risk factors for mortality.

RESULTS

Thirty-three subjects died during the 24-year observation period [17 of cardiovascular disease (CVD) and 12 of cancer]. In the diet intervention group, mortality was 51% lower (RR = 0.49, 95% CI 0.22-0.91, P = 0.022) as compared with the control group. This difference remained significant in a Cox regression analysis after adjusting for age and smoking status (RR = 0.47, 95% CI 0.23-0.96, P = 0.038).

CONCLUSION

This study indicates that the investigated 5-year diet intervention significantly reduces late mortality in healthy middle-aged men with combined hyperlipidaemia.

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT): clinical center recruitment experience

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is a randomized clinical outcome trial of antihypertensive and lipid-lowering therapy in a diverse population (including substantial numbers of women and minorities) of 42,419 high-risk hypertensives aged > or = 55 years with a planned mean follow-up of 6 years. In this paper, we describe our experience in the identification, recruitment, and selection of clinical centers for this large simple trial capable of meeting the recruitment goals outlined for ALLHAT, and we highlight factors associated with clinical center performance. Over 135,000 recruitment brochures were mailed to physicians. Requests for information and application packets were received from 9351 (6.8%) interested investigators. A total of 1053 completed applications were received and 909 sites (86%) were eventually approved to join the trial. Of the approved sites, 278 either later declined participation or were never activated, and 8 were closed within a year for lack of enrollment. The final 623 randomizing centers exceeded the trial's recruitment goal to enroll at least 40,000 participants into the trial, although the recruitment period was extended 1.5 years longer than planned. Fewer than a quarter of the sites (22.6%) were recruited from academic medical centers or Department of Veterans Affairs Medical Centers. More than half of the sites (54.7%) were private solo or group practices, which contributed 53% of randomized participants. Community health centers comprised about 8% of the ALLHAT sites and 2.9% were part of health maintenance organizations. More than 22% of the principal investigators reported that they had no previous clinical research experience. In summary, ALLHAT was successful in recruiting a diverse group of clinical centers to achieve its patient recruitment goals.

Psychological status and the role of coping style after coronary artery bypass graft surgery. Results of a prospective study

The results of a prospective study in patients who underwent a first coronary artery bypass graft operation are presented. The goals of this project consisted in assessing the psychological changes during the first year after surgery. For that purpose, 330 consecutive patients were recruited. They were assessed by means of several psychological scales before and on three occasions after surgery. These scales were: the Heart Patients' Psychological Questionnaire (HPPQ), the State-Trait Anxiety Scale (STAI), the Symptom Check List (SCL-90), the Maastricht Questionnaire (MQ) and the Marlowe Crowne Desirability Scale. Furthermore, the study focused on the differential influence of three coping styles. The data demonstrate a clear overall improvement in psychological status over the first year, more specifically during the first 6 months after CABG. Patients were less anxious, less depressed, less exhausted and experienced more subjective well-being. However, almost 30% of all patients did not experience that average favourable evolution. The final psychological end-state was predicted by psychological variables, measured pre-operatively (somatic complaints, hostility and dysphoria) and short-term post-operatively (anxiety). No single medical variable could predict patients' psychological end-state. Finally, the most favourable change was made by patients who display the sensitising coping style, resulting in lower anxiety and depression. Health care providers, physicians as well as nursing staff and psychologists, should therefore use psychodiagnostic tools in order to identify patients at risk for negative psychological outcome. Appropriate therapeutic interventions may consequently be developed and evaluated in future research.

Knowledge of cardiovascular disease prevention: an analysis from two New England communities

BACKGROUND

Cardiovascular disease (CVD) mortality has been decreasing in the United States, possibly due in part to educational programs about CVD prevention. This study investigates CVD risk-reduction knowledge among demographic subgroups in two New England cities and how the level of knowledge changed in these subgroups over time.

METHODS

Six independent cross-sectional surveys including a series of open-ended recall CVD knowledge questions were conducted biennially from 1981 to 1993 as part of the outcome evaluation for the Pawtucket Heart Health Program. We constructed a raw CVD knowledge score and then created an analysis of variance model with knowledge score as the dependent variable and explanatory variables including demographics, survey, and city.

RESULTS

CVD prevention knowledge improved significantly over time in both cities and in every demographic subgroup, increasing rapidly from 1981 to about 1988 and then plateauing between 1988 and 1993. Adjusted knowledge scores were higher for people born in the United States, women, more educated individuals, and those who spoke English at home. The increase in knowledge over time came mainly from an increase in the identification of physical inactivity, and blood cholesterol/high fat diet as CVD risk factors, while there was a decrease in the identification of overweight and blood pressure.

CONCLUSIONS

In order to assure that reductions in CVD morbidity and mortality will be sustained, national educational efforts which stress behavior change skills as well as knowledge must continue. These programs should focus particularly on higher risk subgroups, and risk factors such as weight reduction and blood pressure control should be special priorities.

Adherence to non-pharmacologic therapy for hypertension: problems and solutions

The efficacy of a number of non-pharmacologic interventions in the therapy of primary hypertension has been firmly established. Most prominently, weight reduction, sodium restriction, and alcohol restriction have significant effects on lowering blood pressure. Increased physical activity contributes to management of hypertensive patients in a variety of ways: apart from having a direct impact on blood pressure level, it is an important supportive factor in a weight-reducing regime. The success in applying these non-pharmacologic measures in standard patient population is rather limited. A salient example is the lack of success in weight reduction. Reduction of sodium in the diet is somewhat more successful, however, the problem is that most of the salt intake is non-discretionary. Adherence to physical activity regimes is in the range of what has been observed in pharmacologic therapy. Research and experience in the past few years are providing a better understanding of the factors determining compliance with prescribed therapeutical regimes. Further research is needed to develop innovative strategies for providing efficacious non-pharmacologic measures to hypertensive patients.

Health counseling in adolescent preventive visits: effectiveness, current practices, and quality measurement

Most morbidity and mortality among adolescents results from their participation in health-compromising behaviors. Recent guidelines for clinical adolescent preventive services recommend that primary care clinicians routinely screen for and counsel adolescents about these behaviors, identify and address related social, psychological, and biologic factors. Office-based counseling can influence adult health behaviors, but little is known about the effectiveness of office-based counseling for adolescents. In this review we: (a) evaluate available information about the effectiveness of office-based health counseling to improve outcomes; (b) report what is known about the health counseling adolescents receive from primary care clinicians; and (c) critically review different approaches that have been, or might be, used to measure the content and quality of health counseling provided during adolescent medical visits. With the emphasis on accountability in the current health care environment, evidence supporting the effectiveness of counseling is needed to justify investment in this aspect of clinical adolescent preventive services. Challenges to studying the effectiveness of health counseling include the lack of well-defined theory-based models for adolescent office-based counseling, the complexity of measuring counseling quality, and the many factors that influence adolescent outcomes. Reliable and valid measures of counseling quality are needed both to study and to ensure the quality of counseling received by adolescents. No single measure can be expected to fully capture counseling quality, although patient self-report deserves further development.

Compliance with cardiovascular disease prevention strategies: a review of the research

The efficacy of cardiovascular risk-reduction programs has been established. However, the extent to which risk-reduction interventions are effective may depend on adherence. Non-compliance, or non-adherence, may occur with any of the recommended or prescribed regimens and may vary across the treatment course. Compliance problems, whether occurring early or late in the treatment course, are clinically significant, as adherence is one mediator of the clinical outcome. This article, which is based on a review of the empirical literature of the past 20 years, addresses compliance across four regimens of cardiovascular risk reduction: pharmacological therapy, exercise, nutrition, and smoking cessation. The criteria for inclusion of a study in this review were: (a) focus on cardiovascular disease risk reduction; (b) report of a quantitative measure of compliance behavior; and (c) use of a randomized controlled design. Forty-six studies meeting these criteria were identified. A variety of self-report, objective, and electronic measurement methods were used across these studies. The interventions employed diverse combinations of cognitive, educational, and behavioral strategies to improve compliance in an array of settings. The strategies demonstrated to be successful in improving compliance included behavioral skill training, self-monitoring, telephone/mail contact, self-efficacy enhancement, and external cognitive aids. A series of tables summarize the intervention strategies, compliance measures, and findings, as well as the interventions demonstrated to be successful. This review reflects the progress made over two decades in compliance measurement and research and, further, advances made in the application of behavioral strategies to the promotion of cardiovascular risk reduction.

Stroke risk management: changes in mainstream practice

BACKGROUND

Research shows that identification and control of risk factors reduces ischemic stroke. The impact of this evidence and health initiatives on mainstream practice remains unknown.

METHODS

The purpose of this observational study was to investigate prior management of risk factors (hypertension, atrial fibrillation, previous stroke/transient ischemic attacks) in patients with acute cerebral infarction. Data were collected on the frequency of known risk factors before the incident stroke and their management compared with predefined criteria for appropriateness. The proportion of patients receiving treatment for risk factors before the acute episode was studied over 3 years.

RESULTS

One thousand seventy-four patients (median age, 76 years; 60% women) were included in the study over 3 years. The proportion of patients with known hypertension (41% to 46%), diabetes (12% to 13%), previous stroke or transient ischemic attack (TIA) (21% to 31%), and atrial fibrillation (16% to 21%) remained stable. Overall, approximately 45% patients with atrial fibrillation, 60% patients with hypertension, and 70% with cerebrovascular disease were being actively managed. Time trends analysis showed a significant increase in the proportion of patients being treated for risk due to known cerebrovascular disease (59% to 85%), atrial fibrillation (18% to 59%), ischemic heart disease (35% to 72%), and carotid disease (13% to 85%) between the first and third year. The proportion of patients receiving treatment for hypertension remained unchanged. Patients with preexisting symptomatic vascular disease were more likely to receive appropriate risk management compared with asymptomatic patients (72% versus 46%, P<.001).

CONCLUSIONS

Although a significant number of ischemic events remain potentially preventable, there appears to be a positive trend in improved control of stroke risk.

Can dietary interventions change diet and cardiovascular risk factors? A meta-analysis of randomized controlled trials

OBJECTIVES

This study evaluated the effectiveness of dietary advice in primary prevention of chronic disease.

METHODS

A meta-analysis was conducted of 17 randomized controlled trials of dietary behavior interventions of at least 3 months' duration. Results were analyzed as changes in reported dietary fat intakes and biomedical measures (serum cholesterol, urinary sodium, systolic and diastolic blood pressure) in the intervention group minus changes in the control group at 3 to 6 months and 9 to 18 months of follow-up.

RESULTS

After 3 to 6 months, mean net changes in each of the five outcomes favored intervention. For dietary fat as a percentage of food energy, the change was -2.5% (95% confidence interval [CI] = -3.9%, -1.1%). Mean net changes over 9 to 18 months were as follows: serum cholesterol, -0.22 (95% CI = -0.39, -0.05) mmol/L; urinary sodium, -45.0 (95% CI = -57.1, -32.8) mmol/24 hours; systolic blood pressure, -1.9 (95% CI = -3.0, 0.8) mm Hg; and diastolic blood pressure, -1.2 (95% CI = -2.6, 0.2) mm Hg.

CONCLUSIONS

Individual dietary interventions in primary prevention can achieve modest improvements in diet and cardiovascular disease risk status that are maintained for 9 to 18 months.

Lung cancer mortality after 16 years in MRFIT participants in intervention and usual-care groups. Multiple Risk Factor Intervention Trial

PURPOSE

The Multiple Risk Factor Intervention Trial (MRFIT), a randomized clinical trial for the primary prevention of coronary heart disease, enrolled 12,866 men (including 8194 cigarette smokers) aged 35-57 years at 22 clinical centers across the United States. Participants were randomized either to special intervention (SI), which included an intensive smoking cessation program, or to usual care (UC). After 16 years of follow-up, lung cancer mortality rates were higher in the SI than in the UC group. Since rates of smoking cessation in SI were higher than those for UC for the 6 years of the trial, and since risk of lung cancer mortality is known to decline with smoking cessation, these results were unexpected. The purpose of the present study was to investigate hypotheses that could explain the higher observed lung cancer mortality rates in the SI as compared with the UC group.

METHODS

Analytic methods were employed to determine whether SI and UC participants differed either in baseline characteristics or in characteristics that changed during the trial and to determine whether these differences could explain the higher rates of lung cancer mortality among SI as compared to UC participants. Rates of mortality from coronary heart (CHD) were examined to explore the possibility that prevention of CHD death may have contributed to greater mortality due to lung cancer in the SI group.

RESULTS

From randomization through December 1990, 135 SI and 117 UC participants died from lung cancer. The relative difference between the SI and U groups adjusted for age and number of cigarettes smoked per day, was 1.17 (95% CI:0.92-1.51). The greatest difference between the SI and UC groups in lung cancer mortality rates occurred among the heaviest smokers at baseline who did not achieve sustained smoking cessation by year 2. In this group the rates of death from CHD were approximately the same among the SI and UC subjects. No differences in baseline characteristics were found between SI and UC smokers who did not achieve sustained cessation by year 2, and there were no differences in follow-up characteristics between the two study groups that could explain the difference in lung cancer mortality.

CONCLUSIONS

None of the hypotheses proposed to explain the unexpected higher rates of lung cancer mortality among SI as compared with UC subjects were sustained by the data. Thus we conclude that the difference observed is due to chance, and that a longer period of sustained smoking cessation plus follow-up is necessary to detect a reduction in lung cancer mortality as a result of smoking cessation intervention in a randomized clinical trial.

Tolerability, safety, and quality of life and hypertensive therapy: the case for low-dose diuretics

The safety and tolerability of antihypertensive therapies are an important clinical concern, because the demonstrated benefits of successful blood pressure-lowering depend on long-term compliance with pharmacologic treatments. Thiazide diuretics and beta blockers have been specifically recommended as preferred initial drug therapy by the Fifth Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC-V), unless their use is contraindicated by concomitant disease, there is intolerance to these agents, or there is a specific indication for another drug class. These recommendations are a result of the lengthy clinical experience with these drugs and the results of long-term clinical trials that have demonstrated significant reductions in cardiovascular morbidity and mortality. However, data from these same clinical studies have also shown that diuretics (and beta blockers) can cause abnormalities in carbohydrate, electrolyte, and lipid metabolism and also may influence quality of life. The safety of diuretics was evaluated with regard to effects on carbohydrate, electrolyte, and lipid metabolism by seeking references from a MEDLINE search of documents published from 1966 to 1994 based on the search terms "hypertension," "human," and "hydrochlorothiazide" (HCTZ) dosed in a range of 12.5-25 mg daily. Two long-term clinical trials using low-dose (12.5-15 mg/day) chlorthalidone-the Systolic Hypertension in the Elderly Program (SHEP) and the Treatment of Mild Hypertension Study (TOMHS)-were also included. During the course of treatment with HCTZ in these studies, serum potassium was reduced and uric acid was increased in a dose-dependent manner. Although low doses of HCTZ elevated serum glucose, cholesterol, and triglycerides, the magnitude of effect was small in most cases and was probably of no clinical significance. Other laboratory parameters were not adversely affected, and subjective reporting of clinical adverse events was generally lower with low-dose HCTZ than with placebo or standard HCTZ dosing. The literature on the effects of low-dose diuretic therapy on quality of life is not large, although the results from the SHEP and TOMHS studies support the concept that diuretics either do not interfere with, or may actually improve, quality of life in hypertensive patients. Low-dose thiazide treatment is a well-tolerated, excellent first-line choice for hypertensive patients, especially older patients. However, diuretics should probably be avoided, whenever possible, in patients with preexisting diabetes, gout, and in men with erectile dysfunction.

Mortality after 16 years for participants randomized to the Multiple Risk Factor Intervention Trial

BACKGROUND

A mortality follow-up of 12,866 men was conducted 16 years after randomization to special intervention (SI) or usual care (UC) groups of the Multiple Risk Factor Intervention Trial to assess the long-term effect of cardiovascular risk factor intervention on coronary heart disease (CHD), cardiovascular death (CVD), and total mortality.

METHODS AND RESULTS

During the 7-year active-intervention phase of the trial, 6428 of the men were given dietary recommendations to lower blood cholesterol, antihypertensive drugs to lower blood pressure, and counseling for cigarette smoking cessation. The remaining 6438 men were referred to their usual source of medical care. After 16 years, 370 SI and 417 UC men had died from CHD, which represents an 11.4% lower mortality rate for SI versus UC men (95% CI, -23% to 1.9%). Results for total mortality followed a similar pattern; 991 SI and 1050 UC men had died by the end of follow-up (relative difference, -5.7%; 95% CI, -13% to 2.8%). For acute myocardial infarction, a subcategory of CHD, the relative difference was -20.4% (95% CI, -34.4% to -3.4%). Differences between SI and UC men in mortality rates from acute myocardial infarction, CHD, and all causes were greater during the posttrial follow-up period than during the trial.

CONCLUSIONS

Results of a 7-year multifactor intervention program aimed at lowering blood pressure and serum cholesterol and at cigarette smoking cessation among high-risk men give additional evidence of a long-term, continuing mortality benefit from the program.

Diet and exercise profiles of 30- to 60-year-old male smokers: implications for community heart health programs

The aim of this study was to estimate the prevalence of diet and exercise behaviors in middle-aged male smokers and identify their determinants of behaviors, with the ultimate goal of designing more effective interventions in a community heart health program. Self-administered, postal questionnaires produced a sample of n = 671 male smokers, 30 to 60 years of age residing in Laval, Quebec's second most populous city. Variables for the study were derived from the theory of planned behavior. Correspondence analysis explained 65% of the variance, classifying smokers into five groups based on diet and exercise behavior. Group 1, smokers with diet and exercise behaviors deemed inadequate for heart health, comprised 43% of the total. Groups 2 and 3, smokers with a diet deemed inadequate or needing improvement respectively, and Group 4, smokers with inadequate exercise, comprised 42% of the total. Group 5, smokers with neither of the other high-risk behaviors, comprised 15% of the total. Four significant variables contrasted Groups 1 to 4 with group 5: age, number of cigarettes smoked daily, and perceived behavioral control (PBC) in both diet and exercise. However, coefficients for age and smoking were weak for all groups. Coefficients for PBC in diet were high and negative only for smokers with an inadequate one. For PBC in exercise, they were high and negative only for smokers who exercised inadequately. Intervention groups based on specific deficiencies in diet and exercise behaviors were then identified. Therefore, the results suggest that smoking cessation programs may be made more effective by targeting specific sub-groups and by providing resources and opportunities to counteract the lack of perceived behavioral control in middle-aged male smokers vis-a-vis diet and exercise.

Glucose and cholesterol elevations during thiazide therapy: intention-to-treat versus actual on-therapy experience

PURPOSE

This nonrandomized, parallel-group, prospective clinical series in consecutive patients was conducted to determine if the method of analysis of biochemical data collected in long-term treatment trials can explain the controversy regarding the effects of thiazides on plasma glucose or cholesterol.

PATIENTS AND METHODS

Fasting serum glucose, potassium, and cholesterol levels were determined before therapy, and yearly thereafter (4.0 +/- 0.1 years) in 634 consecutive patients treated for more than 1 year with antihypertensive monotherapy.

RESULTS

When the data were analyzed by the intention-to-treat paradigm (ignoring changes in therapy), glucose and cholesterol levels in the thiazide group were significantly higher (compared to baseline or to the other therapy group) only at year 1. When the data were analyzed by actual on-therapy experience (censoring patients when therapy is altered)--a more traditional way to examine side effects--these differences were significant for all 5 years studied. Even if as few as 8% of patients who changed therapies were included in an intention-to-treat analysis, these differences became nonsignificant.

CONCLUSION

These comparisons not only indicate why a dichotomy might exist between clinical practice (analyzed by actual on-therapy experience) and randomized trials (analyzed by intention-to-treat methods), regarding biochemical changes in glucose and cholesterol during thiazide therapy, but also that, for secondary hypotheses, analyzing data by both methods of assignment is important.

Behavioral diagnosis of 30 to 60 year-old men in the Fabreville Heart Health Program

To develop effective interventions in the Fabreville Heart Health Program, a behavioral diagnosis was conducted on a sample of 1,600 men 30 to 60 years of age residing in the Fabreville district of Laval, Quebec's second most populous city. The response rate of the self-administered postal questionnaire was 73.5%. The results indicate that dietary fat consumption, smoking and a sedentary lifestyle were more prevalent among the younger respondents, particularly those less-educated. The results underline the importance of segmenting the target population so that heart health interventions can respond to the specific needs of each sub-population. Furthermore, the data seem to suggest the need to adapt educational messages to the target lifestyle habits. The results showed that in terms of diet, consumption of meat and dairy products contributed the most to fat intake. Of the 30% who were smokers, a large proportion would be reluctant to stop the habit; 20% smoked 26 cigarettes or more a day, and more than half had already tried once or more to stop. Although 60% of respondents indicated they engaged in physical activity, only 37.0% did it regularly. These results demonstrate the need to clearly target specific behaviours and subgroups in our promotion messages for a healthy heart.

Light-harvesting chlorophyll c-like pigment in Prochloron

A chlorophyll c-like pigment, similar to magnesium-3,8-divinyl pheoporphyrin a5 monomethyl ester, has been isolated from Prochloron sp. obtained from five species of didemnid ascidians from the Great Barrier Reef, Australia, and from Palau, Micronesia. The pigment represents 4-15% of the total chlorophyll content and is shown to function in a light-harvesting pigment protein complex of Prochloron. The observation that all of the major chlorophylls (a+b+c) function in a light-harvesting role in Prochloron and possibly in other prochlorophytes is discussed in terms of the phylogeny of the prochlorophytes.