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.

The DASH diet for high blood pressure: from clinical trial to dinner table.

Three recent studies show that a diet rich in fruits, vegetables, whole grains, and lowfat dairy products and low in fat, refined carbohydrates, and sodium can lower blood pressure either alone or in combination with other lifestyle changes. These studies have greatly expanded our knowledge of nonpharmacologic interventions to prevent and manage hypertension. They also underscore the need for diet and lifestyle counseling in the primary care setting.

The impact of angiotensin II receptor blockade and the DASH diet on markers of endogenous fibrinolysis.

Hypertension is associated with impaired fibrinolysis. Both angiotensin receptor blockers (ARB) and the DASH (Dietary Approaches to Stop Hypertension) diet effectively lower blood pressure in hypertensive patients. Some evidence suggests that treatment with ARBs could increase fibrinolysis, however, data is conflicting. The impact of the DASH diet on fibrinolytic parameters is not known. Fifty-five hypertensive participants (35 African-American, 20 white) were randomly assigned to receive 8 weeks of either a control diet or the DASH diet. The diets did not differ in sodium content (approximately 3 g/day). Within each diet, individuals were randomly assigned to receive losartan or placebo for 4 weeks in double-blind, cross-over fashion. Tissue plasminogen activator (t-PA) antigen, t-PA activity, plasminogen activator inhibitor-1 (PAI-1) activity and plasma renin activity (PRA) were measured at the end of a 2-week run-in period on the control diet and after each treatment period. The DASH diet did not affect markers of fibrinolysis. Losartan significantly lowered t-PA antigen levels (-1.8 ng/mL, P = 0.045), but had no effect on t-PA or PAI-1 activities. This effect was more pronounced in whites (-4.1 ng/mL (P = 0.003)) compared with African-Americans (-0.3 ng/mL (P = 0.7), P-interaction = 0.03). Results were not materially affected by adjustment for basline values or changes in blood pressure. This study demonstrates that losartan reduces t-PA antigen levels in white, but not African-American hypertensive individuals. In contrast, the DASH diet had no significant effect on markers of fibrinolysis in whites or African-Americans.

Effects of diet and sodium intake on blood pressure: subgroup analysis of the DASH-sodium trial.

BACKGROUND: Initial findings from the Dietary Approaches to Stop Hypertension (DASH)-Sodium Trial demonstrated that reduction of sodium intake in two different diets decreased blood pressure in participants with and without hypertension. OBJECTIVE: To determine effects on blood pressure of reduced sodium intake and the DASH diet in additional subgroups. DESIGN: Randomized feeding study. SETTING: Four clinical centers and a coordinating center. PARTICIPANTS: 412 adults with untreated systolic blood pressure of 120 to 160 mm Hg and diastolic blood pressure of 80 to 95 mm Hg. INTERVENTION: Participants followed the DASH diet or a control (typical U.S.) diet for three consecutive 30-day feeding periods, during which sodium intake (50, 100, and 150 mmol/d at 2100 kcal) varied according to a randomly assigned sequence. Body weight was maintained. MEASUREMENTS: Systolic and diastolic blood pressure. RESULTS: In all subgroups, the DASH diet and reduced sodium intake were each associated with significant decreases in blood pressure; these two factors combined produced the greatest reductions. Among nonhypertensive participants who received the control diet, lower (vs. higher) sodium intake decreased blood pressure by 7.0/3.8 mm Hg in those older than 45 years of age (P < 0.001) and by 3.7/1.5 mm Hg in those 45 years of age or younger (P < 0.05). CONCLUSION: The DASH diet plus reduced sodium intake is recommended to control blood pressure in diverse subgroups.

Postchallenge hyperglycemia in a national sample of U.S. adults with type 2 diabetes.

OBJECTIVE: Postchallenge hyperglycemia (PCH) is known to contribute to suboptimal glycemic control in adults with non-insulin-requiring type 2 diabetes. The objective of this study was to estimate the prevalence of PCH among individuals with diabetes. RESEARCH DESIGN AND METHODS: We conducted a cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey (1988-1994) in adults aged 40-74 years with diabetes who were not using insulin (i.e., they used oral hypoglycemics or received no pharmacological therapy). Each respondent underwent a standard 75-g oral glucose tolerance test. PCH was defined as a 2-h glucose level >or=200 mg/dl. RESULTS: Overall, PCH was present in 74% of those with diagnosed diabetes. Although it was present in virtually all (99%) of the diabetic adults under suboptimal glycemic control (HbA(1c) >or=7.0%), PCH was also common (39%) among those under optimal control (HbA(1c) <7.0%). Likewise, among sulfonylurea users, PCH was present in 99% of those under suboptimal control and in 63% of those under good control. Similar patterns were observed in those with undiagnosed diabetes. Isolated PCH (2-h glucose >or=200 mg/dl and fasting glucose <126 mg/dl) was present in 9.8% of the adults with diagnosed diabetes. CONCLUSIONS: These data suggest that PCH is common among diabetic adults in the U.S., even in the setting of "optimal" glycemic control and sulfonylurea use. Interventions designed to lower postprandial glucose excursions may help improve overall glycemic control in the general population of U.S. adults with diabetes.

Relationship between systemic markers of inflammation and serum beta-carotene levels.

BACKGROUND: Low serum levels of beta-carotene have been associated with increased risk of cancer and cardiovascular disease. However, in clinical trials, supplementation of the diet with beta-carotene either had no benefit or caused harm. This pattern of findings raises the possibility that confounding by other factors might explain the association between serum beta-carotene level and disease risk. METHODS: We used data from 14 470 current smokers, ex-smokers, and never smokers aged 18 years or older who participated in the Third National Health and Nutrition Examination Survey to assess the relationship between serum beta-carotene and markers of inflammation (C-reactive protein and white blood cell count). RESULTS: After adjustment for beta-carotene intake and other factors, geometric mean levels of serum beta-carotene for individuals with undetectable (< 0.22 mg/dL), mildly elevated (0.22-0.99 mg/dL), and clinically elevated (> or =1.0 mg/dL) C-reactive protein levels were 18.0, 16.1, and 13.6 microg/dL, respectively, in never smokers; 18.1, 15.7, and 13.9 microg/dL in ex-smokers; and 11.3, 10.2, and 9.4 microg/dL in current smokers (P< .001 for all). In corresponding analyses, white blood cell count was also inversely related to serum beta-carotene concentration (P< .05 for all). CONCLUSIONS: The strong and inverse association of serum beta-carotene level with C-reactive protein level and white blood cell count suggests that the relationship between serum beta-carotene concentration and disease risk might be confounded by inflammation. More broadly, for beta-carotene and likely other nutrients, it seems unwise to interpret biomarker data as prima facie evidence of dietary intake without a more complete understanding of the physiologic processes that affect nutrient levels.

Nutrition-related cardiovascular risk factors in older people: results from the Third National Health and Nutrition Examination Survey.

SETTING: In view of the recognized potential benefits of nutritional therapy in older persons, Congress is evaluating the coverage of nutritional services for Medicare beneficiaries. OBJECTIVE: To estimate the number of older persons in the US who have one or more cardiovascular risk factors (hypertension, increased low density lipoprotein (LDL) cholesterol, and diabetes mellitus), for which nutritional therapy is recommended. DESIGN: Cross-sectional analysis of adults, aged > or = 65, participating in the Third National Health and Nutrition Examination Survey (NHANES III). MAIN OUTCOMES: The authors estimated the proportion of adults, aged > or = 65, with diabetes mellitus, increased LDL cholesterol, and/or hypertension. Efforts were made to assess whether obesity status, gender, race, and/or socioeconomic factors were associated with the prevalence of any or all three conditions. RESULTS: Approximately 86% (20 million persons) in the US, aged > or = 65, have at least one of the index conditions. Whereas a higher body mass index (BMI) increased the likelihood of having any or all three conditions, 81% of persons of average body weight (BMI <25 kg/m2) had at least one condition. After adjusting for age, gender, BMI, marital status, and poverty index, blacks were more likely than whites to have any one condition (odds ratio (OR) = 3.0, P < .01) or all three conditions (OR = 2.3, P = .05). CONCLUSIONS: Almost 90% of Americans aged > or = 65 have one or more nutrition-related cardiovascular risk factors. Improved nutritional interventions may be valuable especially for blacks, who have a higher prevalence of conditions requiring nutritional therapy.