Effect of lifestyle modifications on blood pressure by race, sex, hypertension status, and age

Recommendations for control of high blood pressure (BP) emphasize lifestyle modification, including weight loss, reduced sodium intake, increased physical activity, and limited alcohol consumption. The Dietary Approaches to Stop Hypertension (DASH) dietary pattern also lowers BP. The PREMIER randomized trial tested multicomponent lifestyle interventions on BP in demographic and clinical subgroups. Participants with above-optimal BP through stage 1 hypertension were randomized to an Advice Only group or one of two behavioural interventions that implement established recommendations (Est) or established recommendations plus DASH diet (Est plus DASH). The primary outcome was change in systolic BP at 6 months. The study population was 810 individuals with an average age of 50 years, 62% women, 34% African American (AA), 95% overweight/obese, and 38% hypertensive. Participants in all the three groups made lifestyle changes. Mean net reductions in systolic (S) BP in the Est intervention were 1.2 mmHg in AA women, 6.0 in AA men, 4.5 in non-AA women, and 4.2 in non-AA men. The mean effects of the Est Plus DASH intervention were 2.1, 4.6, 4.2, and 5.7 mmHg in the four race-sex subgroups, respectively. BP changes were consistently greater in hypertensives than in nonhypertensives, although interaction tests were nonsignificant. The Est intervention caused statistically significant BP reductions in individuals over and under age 50. The Est Plus DASH intervention lowered BP in both age groups, and significantly more so in older individuals. In conclusion, diverse groups of people can adopt multiple lifestyle changes that can lead to improved BP control and reduced CVD risk.

Effects of weight gain on medical care costs

OBJECTIVE

To examine in middle-aged adults the effect of medical care costs of large, rapid weight gain compared to weight maintenance.

DESIGN

: Retrospective cohort study for a 3-y time period.

SETTING AND PARTICIPANTS

Population-based sample (N=15174) of men and women members of a large managed care organization, aged 35-65 y, with a body mass index (BMI) >25 kg/m(2) at baseline. Health-care utilization and costs were measured at baseline and over the 3-y follow-up period.

RESULTS

Mean age at baseline was 49.7 y and mean BMI was 31.5 kg/m(2). During the 3-y follow-up period, 40.8% were classified as weight maintainers (+/-4 pounds), 45.3% gained 5-19 pounds, and 13.9% gained >/=20 pounds. A weight gain of >/=20 pounds was significantly associated with increased total medical care costs in all subgroups evaluated. Among all subjects, for those who gained >/=20 pounds compared to those who maintained weight, the adjusted 3-y increase in costs was 561 dollars. Among the subgroup with baseline comorbidities, the adjusted 3-y change in total medical care costs was 711 dollars. Multivariate analyses showed no significant differences between those who gained 5-19 pounds and those who maintained weight. Baseline BMI and comorbidities were also significant predictors of change in medical care costs, independent of weight gain.

CONCLUSION

A large 3-y weight gain (>/=20 lb) in middle-aged overweight and obese adults is associated with a correspondingly larger increase in total medical care costs compared to weight maintainers. The prevention of large weight gains holds promise for significantly reducing future medical care costs. Future studies should examine the causes of rapid weight gain and evaluate approaches to prevent and reverse such weight gain.

Body mass index and future healthcare costs: a retrospective cohort study

OBJECTIVE

To assess the relationship between body mass index (BMI) and future healthcare costs.

RESEARCH METHODS AND PROCEDURES

We undertook a retrospective cohort study of the relationship between obesity and future healthcare costs at Kaiser Permanente Northwest Division, a large health maintenance organization in Portland, Oregon. Study subjects (n = 1286) consisted of persons who responded to a 1990 health survey that was mailed to a random sample of adult Kaiser Permanente Northwest Division members who were 35 to 64 years of age; had a BMI > or = 20 kg/m(2) (based on self-reported height and weight); did not smoke cigarettes; and did not have a history of coronary heart disease, stroke, human immunodeficiency virus, or cancer. Subjects were stratified according to their BMI in 1990 (20 to 24.9, 25 to 29.9, and > or = 30 kg/m(2); n = 545, 474, and 367, respectively). We then tallied their costs (in 1998 US dollars) for all inpatient care, outpatient services, and prescription drugs over a 9-year period (1990 through 1998).

RESULTS

For persons with BMIs of 20 to 24.9 kg/m(2), mean (+/-SE) annual costs of prescription drugs, outpatient services, inpatient care, and all medical care averaged $261 (+/-18), $848 (+/-59), $532 (+/-85), and $1631 (+/-120), respectively, over the study period. Cost ratios (95% confidence intervals) for persons with BMIs of 25 to 29.9 kg/m(2) and > or = 30 kg/m(2), respectively, were 1.37 (1.12 to 1.66) and 2.05 (1.62 to 2.55) for prescription drugs, 0.96 (0.83 to 1.13) and 1.14 (0.97 to 1.37) for outpatient services, 1.20 (0.81 to 1.86) and 1.38 (0.91 to 2.14) for inpatient care, and 1.10 (0.91 to 1.35) and 1.36 (1.11 to 1.68) for all medical care.

DISCUSSION

Future healthcare costs are higher for persons who are overweight, especially those with BMIs > or = 30 kg/m(2).

Increasing vegetable and fruit intake: randomized intervention and monitoring in an at-risk population

High vegetable and fruit (V&F) consumption has been associated with a lower risk of several cancers. However, little is known about the ability of individuals to increase their intakes markedly. In this 1-year randomized, controlled diet intervention study of men and women with a recent history of adenomas, the intervention group (n = 100) was asked to increase V&F intake to at least eight servings per day; the control group (n = 101) continued eating their usual diet. End-point measures included V&F intake assessed by 3-day diet records, plasma carotenoids, serum lipids, urinary sodium and potassium, and body weight. The intervention group increased their daily V&F intake an average of 5.5 servings over 1 year; the control group had an average decrease of 0.5 servings per day (P < 0.001). Plasma total carotenoids, alpha-carotene, beta-carotene, beta-cryptoxanthin, and lutein/zeaxanthin were each statistically significantly elevated over baseline (11-54%) in the intervention group compared with the control group over the duration of follow-up (P < 0.001). Urinary potassium excretion was elevated 14% over baseline in the intervention group compared with no change in the control group (P < 0.001). Modest decreases in the intervention but not the control group were observed for total and low-density lipoprotein cholesterol. Plasma lycopene, triglycerides, high-density lipoprotein cholesterol, body weight, and urinary sodium were not affected by the intervention. V&F intake was significantly increased in this motivated population at higher risk of colon cancer and maintained for at least 12 months, as assessed using diet records and an ensemble of biomarkers.

Patterns in child and adolescent consumption of fruit and vegetables: effects of gender and ethnicity across four sites

OBJECTIVES

Few studies have examined the association of gender and ethnicity with fruit and vegetable consumption. We examined these associations using baseline data from four school-based sites funded under the National Cancer Institute's 5 A Day for Better Health Program.

METHODS

Diet was measured using 24-hour recalls at three sites and seven-day food records at one site. Demographics were obtained via self-report or school records. Regression analyses for clustered data were employed with fruit and vegetables combined and fruit and vegetables separately.

RESULTS

Girls ate more fruit, more vegetables and more fruit and vegetables combined than boys at the Georgia site. Ethnicity was significant in two sites: In Georgia, African-Americans ate more fruit and more fruit and vegetables combined than European-Americans; in Minnesota, Asian-American/Pacific Islanders and African-Americans ate more fruit than European-Americans, and European-Americans and African-Americans ate more vegetables than Asian-Americans. No significant effects were found at the Alabama or Louisiana sites.

CONCLUSIONS

Ethnicity was related to fruit and vegetable consumption in Georgia and Minnesota. Consistent with prior studies, gender was related to fruit and vegetable consumption, with girls consuming more servings than boys; however, this was observed at one site only, Georgia. Consumption levels were similar to national estimates for children and varied by region. Further studies are needed using a single methodology to facilitate regional comparisons.

Urinary sodium and potassium profile of blacks and whites in relation to education in two different geographic urban areas. TOMHS Research Group. Treatment of Mild Hypertension Study

The high Na/low K environment of modern society is related to the genesis of hypertension and stroke. There is prior evidence of racial, geographical, and social class differences in Na and K intake and blood pressure. Baseline data from the Treatment of Mild Hypertension Study (TOMHS) was used to assess urinary Na and K excretion profiles by race, clinic geographic area, and education. Participants were adult black and white hypertensive patients from the Birmingham, Alabama, and Chicago, Illinois, area. Level of education was categorized as: less than college graduate and college graduate or more. Two overnight urine samples were collected and analyzed for Na and K at entry from 154 blacks and 281 whites. The urinary Na:K ratio was significantly higher in both blacks (5.1 v 3.8, P < .001) and whites (4.1 v 3.4, P < .005) in Birmingham compared with Chicago. This was primarily due to the lower excretion of urinary K in blacks (12.8 v 16.9 mmol/8 h, P < .01) and whites (14.0 v 16.5 mmol/8 h, P < .01). The highest urinary Na:K ratio was observed in blacks in Birmingham with lower education level; urinary Na excretion was high in blacks with a lower education level in both cities. No such differences were seen in whites. Although TOMHS was not population-based, these findings suggest the possibility that potassium intake among persons with stage 1 hypertension is related to geographic area in both blacks and whites, and sodium intake is inversely related to education level in blacks.

Comparison of food frequency questionnaires: the reduced Block and Willett questionnaires differ in ranking on nutrient intakes

Food frequency questionnaires, major tools in epidemiologic studies, are often criticized for biased and imprecise intake estimates. The aim of this study was to compare the performance of two widely used food frequency questionnaires, a reduced 60-item Block questionnaire and a 153-item Willett food frequency questionnaire, relative to three 24-hour recalls administered by telephone. The dietary data were collected in 1991 from a group of healthy women age 25-49 years (n=101) during the baseline period of a weight-loss intervention study in Minneapolis, Minnesota. Total energy and macro- and micronutrient intakes were compared across methods by using four analytic approaches: comparison of means and correlation coefficients, regression analysis, and estimation of percent agreement between each questionnaire and recalls. The Block instrument showed an overall underestimation bias, but was more successful in categorizing individuals on percent energy from fat and carbohydrate intakes than was the Willett instrument. The Willett instrument showed no overall underestimation bias and was more successful in classifying individuals on vitamin A and calcium intakes. Diverging performance characteristics of diet assessment methods have an implication for the design of studies, interpretation of results, and comparison of findings across studies.

Effects of reducing dietary saturated fatty acids on plasma lipids and lipoproteins in healthy subjects: the DELTA Study, protocol 1

Few well-controlled diet studies have investigated the effects of reducing dietary saturated fatty acid (SFA) intake in premenopausal and postmenopausal women or in blacks. We conducted a multicenter, randomized, crossover-design trial of the effects of reducing dietary SFA on plasma lipids and lipoproteins in 103 healthy adults 22 to 67 years old. There were 46 men and 57 women, of whom 26 were black, 18 were postmenopausal women, and 16 were men > or =40 years old. All meals and snacks, except Saturday dinner, were prepared and served by the research centers. The study was designed to compare three diets: an average American diet (AAD), a Step 1 diet, and a low-SFA (Low-Sat) diet. Dietary cholesterol was constant. Diet composition was validated and monitored by a central laboratory. Each diet was consumed for 8 weeks, and blood samples were obtained during weeks 5 through 8. The compositions of the three diets were as follows: AAD, 34.3% kcal fat and 15.0% kcal SFA; Step 1, 28.6% kcal fat and 9.0% kcal SFA; and Low-Sat, 25.3% kcal fat and 6.1% kcal SFA. Each diet provided approximately 275 mg cholesterol/d. Compared with AAD, plasma total cholesterol in the whole group fell 5% on Step 1 and 9% on Low-Sat. LDL cholesterol was 7% lower on Step 1 and 11% lower on Low-Sat than on the AAD (both P<.01). Similar responses were seen in each subgroup. HDL cholesterol fell 7% on Step 1 and 11% on Low-Sat (both P<.01). Reductions in HDL cholesterol were seen in all subgroups except blacks and older men. Plasma triglyceride levels increased approximately 9% between AAD and Step 1 but did not increase further from Step 1 to Low-Sat. Changes in triglyceride levels were not significant in most subgroups. Surprisingly, plasma Lp(a) concentrations increased in a stepwise fashion as SFA was reduced. In a well-controlled feeding study, stepwise reductions in SFA resulted in parallel reductions in plasma total and LDL cholesterol levels. Diet effects were remarkably similar in several subgroups of men and women and in blacks. The reductions in total and LDL cholesterol achieved in these different subgroups indicate that diet can have a significant impact on risk for atherosclerotic cardiovascular disease in the total population.

ApoE genotype does not predict lipid response to changes in dietary saturated fatty acids in a heterogeneous normolipidemic population. The DELTA Research Group. Dietary Effects on Lipoproteins and Thrombogenic Activity

Recent studies have suggested that variations in apoE genotypes may influence the magnitude of plasma lipid changes in response to dietary interventions. We examined the ability of apoE genotype to predict plasma lipid response to reductions in percent of calories from total fat (TF) and saturated fat (SF) in a normolipidemic study population (n = 103) heterogeneous with respect to age, gender, race, and menopausal status. Three diets, an average American diet (34.3% TF, 15.0% SF), an AHA Step 1 diet (28.6% TF, 9.0% SF), and a low saturated fat (Low-Sat) diet (25.3% TF, 6.1% SF) were each fed for a period of 8 weeks in a three-way crossover design. Cholesterol was kept constant at 275 mg/d; monounsaturated and polyunsaturated fat were kept constant at approximately 13% and 6.5% of calories, respectively. Fasting lipid levels were measured during each of the final 4 weeks of each diet period. Participants were grouped by apoE genotype: E2 (E2/2, E2/3, E2/4); E3 (E3/3); E4 (E3/4, E4/4). Relative to the average American diet, both the Step 1 and Low-Sat diets significantly reduced total cholesterol, LDL cholesterol, and HDL cholesterol in all three apoE genotype groups. No evidence of a significant diet by genotype interaction, however, could be identified for any of the measured lipid and lipoprotein end points. Additional analysis of the data within individual population subgroup (men and women, blacks and whites) likewise provided no evidence of a significant diet by genotype interaction. Thus, in a heterogeneous, normolipidemic study population, apoE genotype does not predict the magnitude of lipid response to reductions in dietary saturated fat.

Higher education and income are related to a better Na:K ratio in blacks: baseline results of the Treatment of Mild Hypertension Study (TOMHS) data

In the United States, blacks have higher rates of hypertension than whites. A possible contributing factor to this higher rate of hypertension could be dietary differences between blacks and whites relating to sodium and potassium intake, which in turn could be related to socioeconomic differences between blacks and whites. Baseline data from the Treatment of Mild Hypertension Study (TOMHS) was used to assess differences in the urinary excretion of sodium and potassium, and the Na:K ratio between black and white participants, and also to explore the relationship of socioeconomic status (SES) and urinary electrolyte excretion within each ethnic group. Participants were men and women ages 45 to 69 with stage I diastolic hypertension (DBP < or = 99 mm Hg). Level of education and annual household income were used as indicators of SES. Two overnight urine samples were collected and analyzed for Na and K at entry on 172 black and 710 white participants. Blacks had a significantly higher mean Na:K ratio than whites, 4.3 v 3.6 (P < .001). This was primarily due to higher urinary Na excretion in blacks than whites, 57.8 v 52.7 mmol/8 h (P = .05). Analysis by education and income level showed that higher levels of urinary Na and Na:K in blacks than whites was restricted to those with lower education and income levels. For higher education and income levels, blacks had slightly lower levels of urinary Na and Na:K than whites. Correspondingly, education and income levels were related to urinary Na and Na:K in blacks but not in whites. This suggests that lower SES blacks could benefit from interventions to reduce dietary Na and increase dietary K, which would decrease their urinary Na:K ratio and may make them less prone to developing hypertension.

Reliability and comparability of three dietary assessment methods for estimating fruit and vegetable intakes

Although fruits and vegetables have been evaluated in numerous epidemiologic studies, few validation studies have examined fruits and vegetables. We examined the reproducibility and comparability of fruit and vegetable intakes estimated by diet records, food frequency questionnaires, and modules (brief food frequency questionnaires) in 101 control participants of a 1-year diet intervention trial. For each method, mean intakes at baseline and 3 months were generally within 0.3 serving per day for juice, fruits, vegetables, and total fruits and vegetables. In addition, Pearson correlations for the two time periods generally exceeded 0.55 for these four groups for each method. We evaluated comparability of intakes for 15 days of diet records, 1-year food frequency questionnaires, and modules, respectively. Mean total fruit and vegetable intakes were 6.3, 6.5, and 3.8 servings per day for diet records, food frequency questionnaires, and modules. For each pair-wise combination of methods, Pearson correlations exceeded 0.45 for juice, fruits, and total fruits and vegetables; correlations were lower for vegetables. Exact agreement in quintile assignment was less than 45%, however. These results indicate that estimates of fruit and vegetable intakes and disease associations may differ depending on the method used to assess fruit and vegetable intake.

Long-term effects on sexual function of five antihypertensive drugs and nutritional hygienic treatment in hypertensive men and women. Treatment of Mild Hypertension Study (TOMHS)

Problems with sexual function have been a long-standing concern in the treatment of hypertension and may influence the choice of treatment regimens and decisions to discontinue drugs. The Treatment of Mild Hypertension Study (TOMHS) provides an excellent opportunity for examination of sexual function and effects of treatment on sexual function in men and women with stage I diastolic hypertension because of the number of drug classes studied, the double-blind study design, and the long-term follow-up. TOMHS was a double-blind, randomized controlled trial of 902 hypertensive individuals (557 men, 345 women), aged 45 to 69 years, treated with placebo or one of five active drugs (acebutolol, amlodipine maleate, chlorthalidone, doxazosin maleate, or enalapril maleate). All participants received intensive lifestyle counseling regarding weight loss, dietary sodium reduction, alcohol reduction (for current drinkers), and increased physical activity. Sexual function was ascertained by physician interviews at baseline and annually during follow-up. At baseline, 14.4% of men and 4.9% of women reported a problems with sexual function. In men, 12.2% had problems obtaining and/or maintaining an erection; 2.0% of women reported a problem having an orgasm. Erection problems in men at baseline were positively related to age, systolic pressure, and previous antihypertensive drug use. The incidences of erection dysfunction during follow-up in men were 9.5% and 14.7% through 24 and 48 months, respectively, and were related to type of antihypertensive therapy. Participants randomized to chlorthalidone reported a significantly higher incidence of erection problems through 24 months than participants randomized to placebo (17.1% versus 8.1%, P = .025). Incidence rates through 48 months were more similar among treatment groups than at 24 months, with nonsignificant differences between the chlorthalidone and placebo groups. Incidence was lowest in the doxazosin group but was not significantly different from the placebo group. Incidence for acebutolol, amlodipine, and enalapril groups was similar to that in the placebo group. In many cases, erection dysfunction did not require withdrawal of medication. Disappearance of erection problems among men with problems at baseline was common in all groups but greatest in the doxazosin group. Incidence of reported sexual problems in women was low in all treatment groups. In conclusion, long-term incidence of erection problems in treated hypertensive men is relatively low but is higher with chlorthalidone treatment. Effects of erection dysfunction with chlorthalidone appear relatively early and are often tolerable, and new occurrences after 2 years are unlikely. The rate of reported sexual problems in hypertensive women is low and does not appear to differ by type of drug. Similar incidence rates of erection dysfunction in placebo and most active drug groups caution against routine attribution of erection problems to antihypertensive medication.

Long-term effects on plasma lipids of diet and drugs to treat hypertension. Treatment of Mild Hypertension Study (TOMHS) Research Group

OBJECTIVE

- To compare long-term plasma lipid changes among 6 antihypertensive treatment interventions for stage I (mild) hypertension.

DESIGN

- Multicenter, randomized, double-blind, parallel-group clinical trial.

SETTING

- Four academic clinical research units in the United States.

PARTICIPANTS

- A total of 902 men and women, aged 45 to 69 years, with stage I diastolic hypertension (diastolic blood pressure <100 mm Hg), recruited from 11914 persons screened in their communities.

INTERVENTIONS

- Participants were randomized to 1 of 6 treatment groups: (1) placebo, (2) beta-blocker (acebutolol), (3) calcium antagonist (amlodipine), (4) diuretic (chlorthalidone), (5) alpha1-antagonist (doxazosin), and (6) angiotensin-converting enzyme inhibitor (enalapril). All groups received intensive lifestyle counseling to achieve weight loss, dietary sodium and alcohol reduction, and increased physical activity.

MAIN OUTCOME MEASURES

- Changes in plasma total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides from baseline to annual visits through 4 years.

RESULTS

- Mean changes in all plasma lipids were favorable in all groups. The degree of weight loss with fat-modified diet and exercise was significantly related to favorable lipid changes. Significant differences (P<.01) among groups for average changes during follow-up in each lipid were observed. Decreases in plasma total cholesterol and LDL cholesterol were greater with doxazosin and acebutolol (for plasma total cholesterol, 0.36 and 0.30 mmol/L [13.8 and 11.7 mg/dL], respectively), less with chlorthalidone and placebo (0.12 and 0.13 mmol/L [4.5 and 5.1 mg/dL], respectively). Decreases in triglycerides were greater with doxazosin and enalapril, least with acebutolol. Increases in HDL cholesterol were greater with enalapril and doxazosin, least with acebutolol. Significant relative increases in plasma total cholesterol with chlorthalidone compared with placebo at 12 months were no longer present at 24 months and beyond, when mean plasma total cholesterol for the chlorthalidone group fell below baseline. Analyses of participants continuing to receive chlorthalidone throughout the 4 years of follow-up indicated this was not due solely to an increasing percentage of participants changing or discontinuing use of medication during follow-up.

CONCLUSIONS

- Weight loss with a fat-modified diet plus increased exercise produces favorable long-term effects on blood pressure and all plasma lipid fractions of adults with stage I hypertension; blood pressure reduction is enhanced to a similar degree by addition of a drug from any one of 5 classes of antihypertensive medication. These drugs differ quantitatively in influencing the degree of long-term favorable effects on blood lipids obtained with nutritional-hygienic treatment.

Efficacy and tolerance of antihypertensive treatment in men and women with stage 1 diastolic hypertension. Results of the Treatment of Mild Hypertension Study

OBJECTIVE

To explore the sex-specific benefits and risks of treatment of stage 1 diastolic hypertension.

METHODS

Participants were African-American and white hypertensive men (n = 557) and women (n = 345) (age range, 45 to 69 years) with a diastolic blood pressure less than 100 mm Hg. Participants were randomized to treatment with placebo, chlorthalidone (15 mg/d), acebutolol hydrochloride (400 mg/d), doxazosin mesylate (2 mg/d), amlodipine besylate (5 mg/d), or enalapril maleate (5 mg/d); all were given nutritional-hygienic intervention.

RESULTS

After 4 years, women who were randomized to lifestyle intervention only were less likely to be receiving step 1 therapy alone (placebo) than men who were randomized to placebo therapy (46% vs 66%, respectively, P < .01). There were significantly greater decreases in the mean systolic blood pressure in both men and women who were assigned to treatment with active drugs compared with those participants who were receiving placebo therapy; differences among treatments with active drugs were similar between men and women. Men experienced larger falls in their total and low-density lipoprotein cholesterol and triglyceride levels regardless of the treatment assignment than did women; however, there were no significant sex-by-treatment interactions. Quality-of-life indexes were generally improved with active drug treatment compared with placebo therapy in both sexes; there was a sex-by-treatment interaction for the general health index. The relative risk (RR) for combined clinical events was similar in women (RR, 0.64; 95% confidence interval [CI], (0.36 to 1.16) and in men (RR, 0.67; 95% CI, 0.40 to 1.14) who were assigned to treatment with all active drugs combined, compared with those who were receiving placebo therapy.

CONCLUSION

In these exploratory analyses, men and women who were assigned to treatment with active drugs experienced greater and generally similar benefits from treatment than those participants who were assigned to lifestyle intervention only.

Lifestyle intervention: results of the Treatment of Mild Hypertension Study (TOMHS)

BACKGROUND

Questions regarding the efficacy of nonpharmacologic approaches for the treatment of stage 1 hypertension were addressed as part of the Treatment of Mild Hypertension Study (TOMHS), a 4-year, randomized clinical trial (N = 902). This report describes the lifestyle intervention program used in TOMHS, presents data on the lifestyle changes observed, and focuses on the effect of weight loss on blood pressure and blood lipid levels.

METHODS

Participants were randomly assigned to receive either placebo or one of five different antihypertensive medications. All took part in a lifestyle intervention program to reduce weight and sodium and alcohol intake and to increase physical activity.

RESULTS

Substantial changes from baseline levels were achieved for all lifestyle intervention variables. Mean weight change was -10.5 lb (-5.6%) at 1 year, -8.5 lb (-4.5%) at 2 years, -7.4 lb (-4.0%) at 3 years, and -5.7 lb (-3.0%) at 4 years. At 4 years, 70% of participants remained below baseline weight and 34% maintained a weight loss of 10 lb or greater. Mean change in urinary sodium excretion was -12.5 mmol/8 hr (-23%) at 1 year, -10.7 mmol/8 hr (-20%) at 2 years, -8.4 mmol/8 hr (-16%) at 3 years, and -4.6 mmol/8 hr (-9%) at 4 years. Alcohol intake declined by 1.6 drinks/week among drinkers at 4 years. Reported leisure physical activity increased by 86% at 1 year and remained 50% above baseline at 4 years. Beneficial changes in blood pressure and serum lipids were associated with these changes.

CONCLUSIONS

These results support a role for lifestyle interventions as the initial treatment for stage 1 hypertension and demonstrate that such interventions can be successfully implemented in the clinical setting.

The University of Minnesota Cancer Prevention Research Unit vegetable and fruit classification scheme (United States)

High vegetable and fruit (V&F) intake has been associated with a lower risk of many cancers. However, the specific V&F, the active compounds present in V&F, and the dose at which they confer protection are unknown. Standard methods for assessing, classifying, and quantifying V&F exposures in epidemiologic studies have not been established. Differences among studies occur due to inherent differences among V&F, and across dietary assessment methods, study populations, etiologic hypotheses, and analytic methods. The V&F classification scheme presented here characterizes and quantifies V&F consumption for elucidating risk relationships, identifying chemopreventive compounds present in V&F, and facilitating identification of potential biomarkers of V&F intake. Broad criteria define which plant foods count as V&F. Formation of food groups is based on proposed biological mechanisms of action. Five main groups are included: Total V&F; Total Vegetables; Total Fruits; and two groups orthogonal to these -- the Botanical and Phytochemical groups. Subgroups are specified within each main group. V&F exposure is quantified as the absolute amount consumed (weight) or as the number of household servings. This classification scheme has public health applications and may be used to examine associations with chronic diseases other than cancer.

Putting medical practice guidelines into practice: the cholesterol model

As more and more medical practice guidelines are developed in the United States, commensurate evaluation efforts should assess their impact on professional practice and patient outcomes. We describe an ongoing research program designed to develop and test practice models for applying the 1988 Adult Treatment Panel Guidelines for the clinical management of high blood cholesterol. Four studies are evaluating different models to assist nonacademic community practices in the detection, evaluation, and treatment of high blood cholesterol. We have designed randomized controlled trials set in solo and small-group primary care practices of family or general practitioners and internists situated in rural, suburban, and urban settings. Patients include adult men and women who represent diverse socioeconomic and ethnic backgrounds. We are measuring rates of cholesterol screening; dietary and drug treatment and follow-up; changes in dietary intake and compliance with drug therapy; changes in quality of life and cost of intervention; and reduction in cholesterol level. Scheduled for completion in 1994, this program will provide insights into practical and effective methods of lipid management. It serves as a model for studying the application of health guidelines in the context of nonacademic primary care practices serving diverse patient populations.

Treatment of Mild Hypertension Study. Final results. Treatment of Mild Hypertension Study Research Group

OBJECTIVE

To compare six antihypertensive interventions for the treatment of mild hypertension.

DESIGN

Randomized, double-blind, placebo-controlled clinical trial.

SETTING

Four hypertension screening and treatment centers in the United States.

PARTICIPANTS

Hypertensive men and women, aged 45 to 69 years, with diastolic blood pressure less than 100 mm Hg.

INTERVENTION

Sustained nutritional-hygienic advice to all participants to reduce weight, dietary sodium intake, and alcohol intake, and increase physical activity. Participants were randomly allocated to take (1) placebo (n = 234); (2) chlorthalidone (n = 136); (3) acebutolol (n = 132); (4) doxazosin mesylate (n = 134); (5) amlodipine maleate (n = 131); or (6) enalapril maleate (n = 135).

MAIN OUTCOME MEASURES

Blood pressure, quality of life, side effects, blood lipid levels and analysis of other serum components, echocardiographic and electrocardiographic changes, and incidence of cardiovascular events over an average of 4.4 years of follow-up.

RESULTS

Blood pressure reductions were sizable in all six groups, and were significantly greater for participants assigned to drug treatment than placebo (-15.9 vs -9.1 mm Hg for systolic blood pressure and -12.3 vs -8.6 mm Hg for diastolic blood pressure; P < .0001). After 4 years, 59% of participants assigned to placebo and 72% of participants given drug treatment continued on their initial medication as monotherapy. A smaller percentage of participants assigned to the drug-treatment groups died or experienced a major nonfatal cardiovascular event than those assigned to the placebo group (5.1% vs 7.3%; P = .21). After including other clinical events, the percentage of participants affected was 11.1% for those in the drug-treatment groups and 16.2% for those in the placebo group (P = .03). Incidence rates of most resting electrocardiographic abnormalities were lower and quality of life was improved more for those assigned to drug-treatment groups rather than the placebo group. Differences among the five drug treatments did not consistently favor one group in terms of regression of left ventricular mass, blood lipid levels, and other outcome measures.

CONCLUSIONS

As an initial regimen, drug treatment in combination with nutritional-hygienic intervention was more effective in preventing cardiovascular and other clinical events than was nutritional-hygienic treatment alone. Drug-treatment group differences were minimal. Pending results from large-scale clinical trials to evaluate drug treatments for their effect on cardiovascular clinical events, these findings support the recommendations of the new fifth Joint National Committee report regarding treatment choices for people with stage 1 ("mild") hypertension.

Alcohol consumption and blood pressure in black adults: the Pitt County Study

While there is a clear consensus in the epidemiologic literature on the direct association between alcohol consumption and blood pressure, the shape of this relation and its strength in blacks are uncertain. Therefore, the association between alcohol and blood pressure was examined in a community-based random sample of 1,784 black adults aged 25 to 50 years living in eastern North Carolina. These individuals were interviewed in 1988 for a study of psychosocial and dietary risk factors for elevated blood pressure. Alcohol consumption was estimated from responses to a food frequency questionnaire and was divided into four categories, which ranged from abstention (52% of the sample) to greater than or equal to seven drinks/week (12%). After adjustment for age and body mass, the systolic blood pressure of adults reporting greater than or equal to seven drinks/week exceeded that of nondrinkers by 6.8 mmHg for men and women (p less than 0.001). There was no evidence of a threshold effect, and similar patterns were observed for diastolic blood pressure. Being in the highest category of alcohol consumption was related to low socioeconomic status, lower social integration, and higher levels of socioeconomic stressors. These data are consistent with a graded association between alcohol and blood pressure in black adults and suggest the importance of social factors underlying this association.

Racial and ethnic modifiers of the salt-blood pressure response

The relation between sodium and blood pressure is a centuries-old question. A substantial body of epidemiological and experimental data has accumulated that strongly implicates NaCl as having a causal role in the genesis of arterial hypertension. Prospective studies that have been performed in diverse populations that have manipulated NaCl exposure by diet or infusion have repeatedly documented an NaCl pressor effect. Further, similar studies in biracial populations have also demonstrated a greater prevalence of "salt sensitivity" in blacks compared with whites. The reasons for this observation are not entirely clear; however, intrinsic or hypertension-induced renal abnormalities that limit natriuretic capacity, reduced Na+,K(+)-ATPase pump activity, other membrane ion transport disturbances, differential exposure to psychological stressors, greater insulin resistance, and dietary factors (reduced Ca+ and K+ intake) have all been suggested as possibly playing a role. Salt sensitivity appears to be a widespread phenomenon. However, it is critically important to determine what factors account for racial differences in salt sensitivity. Moreover, the prevalence of salt sensitivity in the general population is unknown. Current definitions of salt sensitivity are varied and unidirectional. In comparison with bidirectional criteria (blood pressure increase with salt loading and blood pressure decrease with salt restriction), they are probably inadequate to identify salt-sensitive individuals who manifest less extreme blood pressure change after dietary sodium or plasma volume manipulations. More sensitive criteria for diagnosing salt sensitivity will facilitate a better understanding of racial and ethnic differences in the prevalence of salt sensitivity.

Dietary sodium reduction for hypertension prevention and treatment

Nutritional-nonpharmacological approaches for the treatment and prevention of hypertension are of great interest. Sodium reduction is one of the primary methods recommended for these purposes. The general public is interested in the reduction of dietary sodium intake and has responded with a decrease in table salt use, the purchase of lowered sodium food products, and the use of food labels to help guide food purchases. Countervailing trends in the use of convenience foods and dining out increase the difficulty for individuals to lower sodium intake. Clinical trials that have used sodium reduction alone or in combination with other lifestyle therapies have demonstrated the feasibility of reducing dietary sodium intake from 30% to 50% for up to 4 years, in a variety of populations. Trials that used lifestyle and weight loss interventions have also achieved significant reductions in body weight and alcohol consumption and increases in physical activity. A variety of studies indicate that long-term sodium reduction is feasible and that it is acceptable to patients. No negative consequences of these interventions have been observed, and in some cases improvement in the intake of other nutrients has occurred. Nonpharmacological interventions have resulted in hypertension control in significant proportions of the trial populations. These studies demonstrate that the foregoing types of interventions can significantly contribute to hypertension treatment and prevention.

Characteristics of participants at baseline in the Treatment of Mild Hypertension Study (TOMHS)

The Treatment of Mild Hypertension Study (TOMHS) is a randomized, double-blind clinical trial currently being conducted to compare the effects of nonpharmacologic therapy alone with those of 1 of 5 active drug regimens combined with nonpharmacologic therapy, for long-term management of patients with mild hypertension. Six classes of drugs were studied: (1) acebutolol (beta blocker), (2) amlodipine (calcium antagonist), (3) chlorthalidone (diuretic), (4) doxazosin (alpha 1 antagonist), (5) enalapril (angiotensin-converting enzyme inhibitor) and (6) placebo. All participants received nutritional-hygienic advice to reduce weight and sodium and alcohol intakes and to increase physical activity. End points include blood pressure change, side effects and quality-of-life indices; incidence of electrocardiographic and echocardiographic abnormalities; and incidence of cardiovascular clinical events, including death, among participants receiving drugs as first-step treatment as well as nonpharmacologic treatment compared with incidence among those participants randomized to nonpharmacologic treatment only as the initial step.

The influence of oral potassium chloride on blood pressure in hypertensive men on a low-sodium diet

Clinical and epidemiologic studies suggest that the intake of potassium chloride lowers blood pressure. To investigate whether supplemental potassium chloride (96 mmol of microcrystalline potassium chloride a day) reduced the need for antihypertensive medication in hypertensive men on a restricted-sodium diet, we conducted a randomized, placebo-controlled, double-blind clinical trial. A total of 287 men 45 to 68 years of age, 142 given potassium chloride and 145 given placebo, were followed for an average of 2.2 years after the withdrawal of their antihypertensive medication. Men in both groups received instructions on following a low-sodium diet. Overnight urinary sodium excretion fell from 63 mmol per eight hours at base line to an average of 45 mmol per eight hours during follow-up. Participants given supplemental potassium chloride had significantly higher (P less than 0.001) serum potassium levels and urinary potassium excretion (averaging 4.5 mmol per liter and 42.5 mmol per eight hours, respectively) during follow-up than participants given placebo (4.2 mmol per liter and 20.0 mmol per eight hours). Seventy-nine participants in each group required reinstitution of antihypertensive medication according to strict indications defined by the protocol. No significant differences in systolic or diastolic blood pressure were observed between the two groups. During follow-up, systolic and diastolic blood pressure averaged 130.6 and 82.5 mm Hg, respectively, for participants given supplemental potassium, and 132.5 and 83.1 mm Hg for participants given placebo. We conclude that supplemental potassium chloride does not reduce the need for antihypertensive medication in hypertensive men on a restricted-sodium diet.

Effect of potassium supplementation combined with dietary sodium reduction on blood pressure in men taking antihypertensive medication

It has long been suspected that sodium and potassium intake influence blood pressure. Since both these electrolytes can be modified by diet, attention has focused on decreasing sodium intake and increasing potassium intake as a potential way of treating and preventing hypertension. Several short-term controlled clinical trials have examined the effect of supplemental potassium intake on blood pressure, but with inconsistent results. The Minnesota Mount Sinai Hypertension Trial (MSHT) is a double-blind study comparing placebo with potassium supplementation for controlling blood pressure in hypertensive men on a sodium-restricted diet over a 2-3 year follow-up period. At the time of randomization to placebo or supplemental potassium and through 12 weeks of follow-up, the patients were taking antihypertensive medication. This preliminary report compares blood pressure changes between the placebo and supplemental potassium groups over the first 12 weeks of the trial.

Nutrient intake in a metropolitan area, 1973-74 vs 1980-82: the Minnesota Heart Survey

Trends in dietary intake in the Twin Cities metropolitan area were measured by comparing data from two independent surveys conducted in 1973-74 and 1980-82. Dietary information was collected by 24-h recall and coded by a single coding center. For men reported caloric intake declined significantly and fat, protein, and carbohydrate each declined approximately 6%; changes in reported dietary intake for women were smaller and mostly nonsignificant. Few trends were observed for either sex in nutrient intake relative to energy intake. Changes in mean serum total-cholesterol levels and body mass indices between 1973-74 and 1980-82 were not consistent with the direction of dietary trends. The proportion of subjects whose 24-h intake met five selected US dietary goals was calculated. In 1980-82, less than 15% of persons reached the goals for carbohydrate and fat intake on the day surveyed; the cholesterol-intake goal (less than or equal to 300 mg/d) was met by 39% of men and 64% of women during the 24-h period surveyed.

Background and design of the new U.S. trial on diet and drug treatment of "mild" hypertension (TOMHS)

A multicenter, randomized, controlled, double-blind U.S. trial is comparing the combined effects of diet treatment and 1 of 5 active drug regimens with diet treatment alone, for the long-term management of middle-aged adults with "mild" hypertension. Factors stimulating this trial are data documenting the high prevalence of mild hypertension in the adult population; mild hypertension's responsibility for a high proportion of morbidity and mortality attributable to hypertension overall; data from long-term hypertension intervention trials showing reduced morbidity and mortality of people with mild hypertension with use of either diuretics or beta blockers as step-1 therapy, and other trials that failed to demonstrate beneficial impact on morbidity and mortality, possibly due to residual questions concerning aspects of benefit to risk ratios with these medications; recent data from trials showing long-term control of mild hypertension and other risk factors by nutritional means; lack of data from long-term trials on benefit to risk ratios with newer drugs such as selective alpha 1 inhibitors, angiotensin converting enzyme inhibitors and calcium channel blockers; paucity of data from trials on long-term combined effects of diet and drug therapy, and of diet alone, for people with mild hypertension. During the next few years, phase 1 of the trial will study 6 groups of drugs. The step-1 drugs are angiotensin converting enzyme inhibitor (enalapril), alpha 1 inhibitor (doxazosin), beta blocker (acebutolol), calcium channel blocker (amlodipine), diuretic (chlorthalidone) and placebo. All participants are to receive vigorous sustained nutritional counseling to reduce obesity, moderate sodium intake and avoid heavy use of alcohol. Key endpoints for phase 1 of the study are the need for additional medication to control mild hypertension, side effects (i.e., clinical and biochemical) and consequent need to discontinue drug and quality of life. Phase-1 data are to be used to complete the phase-2 design, with the ultimate aim to assess effects on morbidity and mortality.

Comparison of nutrient calculation systems

A set of 54 24-hour dietary recalls collected in 1975-1976 from males aged 35-57 years who were participating in a cardiovascular risk factor intervention program was submitted to three different nutrient calculation systems to investigate how much of a difference exists among systems in calculating nutrient intakes. The three computerized systems were of varying levels of sophistication. Among differences found, one system reported 1.4% more calories derived from polyunsaturated fat than the other two. For studies investigating the effects of dietary fat intake, this difference between systems may be important. Other significant group differences were seen for carbohydrate and alcohol. Although mean differences among the three systems were not great, dramatic differences were encountered when evaluating individual recalls. Nutrient intake data obtained from dietary recalls for individuals and for groups for whatever purpose are subject to the bias of the nutrient calculation system used. These biases should be considered when interpreting results, comparing results with other studies, and when developing treatment plans in the clinical setting. Recommendations for enhanced standardization include: 1) thorough descriptions in research reports of the particular system used; 2) exchange of standard menus between systems; 3) enhanced quality control of the coding process; 4) periodic updating of the nutrient data base to accommodate new food products and changes in composition of foods.

Low-sodium, high-potassium diet: feasibility and acceptability in a normotensive population

Sixty-nine normotensive volunteers participated in an eight-week study to test the feasibility and acceptability of two low-sodium (less than 70 mEq), high-potassium (greater than 100 mEq) diets. The diet groups differed only in the use of KCl salt substitute. Both dietary groups were able to reduce sodium and increase potassium intake compared to the control group. Urine sodium excretion decreased in the diet groups but no change was observed in potassium. Potassium chloride salt substitute was not used as recommended, suggesting its unacceptability.

Weight and sodium reduction for the prevention of hypertension: a comparison of group treatment and individual counseling

Ninety-three overweight adult males with labile blood pressure elevation participated in a 20-week dietary intervention program to achieve a 10 per cent reduction in body weight and a reduction in dietary sodium intake to 70 milliequivalents per day. By random assignment, half were treated with intensive group treatment procedures and half with individual counseling. Written handouts and assignments were identical, as was the schedule of treatment visits. Both techniques produced significant decreases in weight, sodium intake, calorie intake, and blood pressure. Calorie and sodium knowledge also increased significantly with both intervention approaches. The two treatment modalities did not differ in effectiveness.

A dietary survey of 14 Wisconsin nursing homes

The nutrient content of meals planned for and consumed by residents of 14 Wisconsin nursing homes was determined. Menus were low in energy, niacin, magnesium, zinc, vitamin B6, and total folate. Intakes of those nutrients and nine others were also low for a large proportion of the population. Approximately 30 percent of the men and women consumed fewer than 1,200 kcal. It is recommended that nursing homes should; (a) use a food plan which meets the nutrient needs for a broad range of energy intakes and (b) periodically monitor dietary patterns to detect those residents who consume inadequate diets.

Changing sodium intake in children. The Minneapolis Children's Blood Pressure Study

To assess the effects of modifying dietary sodium intake, 80 school children with blood pressures above the 95th percentile for age and sex but below 130/90 mm Hg at school screening were randomized to a family intervention program or a control group. Twenty children aged 6 to 9 years and their families began a program to modify the family diet toward a goal of 70 mEq sodium per person per day. Adherence was assessed by 3-day food records and urine collections in children and adults. The sodium intakes and blood pressures of the intervention and control group were compared 1 year after randomization. Sodium intake was significantly lower in the intervention group only in the active participants as compared to dropouts and controls (87 vs 130 and 133 mmoles/24 hr). There were no significant differences between the groups in height, weight, or blood pressure.