Cardiovascular disease risk factors in 2 distinct ethnic groups: Indian and Pakistani compared with American premenopausal women.
(57/19326)
BACKGROUND: Although people from the Indian subcontinent have high rates of cardiovascular disease (CVD), studies of such in Indian and Pakistani women living in the United States are lacking. OBJECTIVE: This study accounted for variability in serum lipid (total cholesterol and triacylglycerol) and lipoprotein [LDL cholesterol, lipoprotein(a), and HDL cholesterol] concentrations in Indian and Pakistani compared with American premenopausal women in the United States. Body composition, regional fat distribution, dietary intake, and energy expenditure were compared between groups. DESIGN: The 2 groups were 47 Indian and Pakistani and 47 American women. Health was assessed via medical history, physical activity, body composition (via anthropometry and dual-energy X-ray absorptiometry), dietary intake (via 7-d food records), and serum lipids. RESULTS: Serum total cholesterol, triacylglycerol, LDL cholesterol, lipoprotein(a), the ratio of total to HDL cholesterol, and the ratio of LDL to HDL cholesterol were greater (P <0.03), whereas HDL-cholesterol values were lower (P = 0.011) in Indians and Pakistanis than in Americans. Multiple regression analysis indicated that approximately 18% of the variance in total cholesterol (P = 0.0010) and LDL cholesterol (P = 0.0009) was accounted for by ethnicity, energy expenditure, and the ratio of the sum of central to the sum of peripheral skinfold thicknesses. Ethnicity, sum of central skinfold thicknesses, ratio of polyunsaturated to saturated fat, and monounsaturated fat intake accounted for approximately 43% of the variance in triacylglycerol concentration (P < 0.0001). Monounsaturated fat, percentage body fat, and alcohol intake accounted for approximately 26% of variance in HDL cholesterol. Ethnicity contributed approximately 22% of the 25% overall variance in lipoprotein(a). CONCLUSIONS: Results suggest that these Indian and Pakistani women are at higher CVD risk than their American counterparts, but that increasing their physical activity is likely to decrease overall and regional adiposity, thereby improving their serum lipid profiles. (+info)
Correlates of individual differences in body-composition changes resulting from physical training in obese children.
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BACKGROUND: No studies have been reported in children that assess correlates of body-composition changes in response to a physical training intervention. OBJECTIVE: The hypothesis studied was that variation in diet and physical activity would explain a significant portion of the interindividual variation in the response of body composition to physical training. DESIGN: The participants were 71 obese children aged 7-11 y (22 boys, 49 girls; 31 whites, 40 blacks). Body composition was measured by dual-energy X-ray absorptiometry, physical activity by a 7-d recall interview, and diet by two, 2-d recalls. The children underwent 4 mo of physical training. RESULTS: The mean attendance was 4 d/wk, the mean (+/-SD) heart rate for the 40-min sessions was 157 +/- 7 beats/min, and the mean energy expenditure was 946 +/- 201 kJ/session. On average, the percentage body fat decreased significantly in the total group, and total mass, fat-free soft tissue, bone mineral content, and bone mineral density increased, but there was a good deal of individual variability. Multiple regression models indicated that in general, more frequent attendance, being a boy, lower energy intake, and more vigorous activity were associated with healthier body-composition changes with physical training. Ethnicity was not retained as a correlate of the change of any component of body composition. CONCLUSIONS: In obese children, age, vigorous activity, diet, and baseline percentage body fat together accounted for 25% of the variance in the change in percentage body fat with physical training. (+info)
Socioeconomic differences in weight gain and determinants and consequences of coronary risk factors.
(59/19326)
BACKGROUND: The increasing prevalence of overweight and obesity is a major public health concern in many developed countries. OBJECTIVE: We aimed to describe socioeconomic differences in change in body mass index (BMI; in kg/m2) from age 25 y, assess possible factors behind these differences, and study whether socioeconomic differences in a variety of coronary risk factors can be accounted for by change in BMI. DESIGN: The data come from a cohort study of London-based civil servants (Whitehall II), who participated in the first (1985-1988) and third (1991-1993) phases of the study and were 35-55-y old at phase 1: altogether there were 5507 men and 2466 women. Both study phases included a questionnaire and a screening examination. RESULTS: In men and women, employment grade--the measure of socioeconomic status used in this cohort--was strongly related to BMI gain from age 25 y to phase 3 (25 y apart on average). The lower the grade the larger the gain in BMI. Adjustment for health behaviors reduced the grade differences in BMI gain by approximately 20%. A substantial part of the grade differences in diastolic and systolic blood pressure and plasma triacylglycerol concentrations could be accounted for by BMI change from age 25 y. CONCLUSIONS: Grade differences in BMI change are evident, but many of the determinants of these differences remain unknown. If lower-status persons continue to gain weight more rapidly than higher-status persons, overweight is likely to be of growing importance as a pathway to social inequalities in ill health. (+info)
Sympathovagal balance is major determinant of short-term blood pressure variability in healthy subjects.
(60/19326)
Short-term blood pressure variability (BPV) has been suggested to provide important information about cardiovascular regulation. However, the background of BPV, its determinants, and physiological correlates have remained obscure. The aim of this study was to characterize physiological correlates of BPV and to investigate associations between BPV and neural and hormonal regulatory systems at rest in healthy subjects. We studied 117 healthy, normal-weight, nonsmoking male and female subjects aged 23-77 yr. Spectral analysis of BPV and heart rate variability (HRV) was performed from 5-min blood pressure (Finapres) and electrocardiogram recordings during controlled breathing. Baroreflex sensitivity (BRS) was measured using the phenylephrine method. In addition, plasma concentrations of norepinephrine, epinephrine, and arginine vasopressin and plasma renin activity were measured. We found that the ratio between the low- and high-frequency components of HRV, an index of cardiac sympathovagal balance, correlated positively with total power and very low- and low-frequency components of systolic and diastolic BPV and inversely with high-frequency components of systolic and diastolic BPV. BRS, predominantly a measure of cardiac vagal regulation, correlated inversely with BPV. Furthermore, age, gender, body mass index, and systolic blood pressure contributed to BPV. Vasoactive hormones were not significant correlates of BPV. We conclude that sympathovagal balance of cardiovascular regulation is the major determinant of BPV. Other factors associated with BPV are age, gender, body mass index, blood pressure, and BRS. (+info)
Physiological doses of estradiol decrease nocturnal blood pressure in normotensive postmenopausal women.
(61/19326)
The effect of a 2-mo treatment with transdermal estradiol (50 microgram/day) versus placebo on 24 h of blood pressure rhythm was investigated in 18 normotensive healthy postmenopausal women. Whereas daytime blood pressure was not modified, nighttime blood pressure was reduced by estradiol. Estradiol magnified the nocturnal decrement of systolic (14.3 +/- 7.2 vs. 9.8 +/- 6.7 mmHg, P = 0. 0033), diastolic (11.6 +/- 5.0 vs. 7.5 +/- 7.3 mmHg, P = 0.028), and mean (10.8 +/- 5.6 vs. 7.2 +/- 4.5 mmHg, P = 0.011) blood pressure. As a consequence, the 24-h rhythm of mean blood pressure was restored in 50% of the subjects (P = 0.045) in whom it was absent and was amplified in the remaining 50% of the subjects. Body mass index was an independent determinant of blood pressure values being directly related to the amplitude of the 24-h mean blood pressure rhythm (r2 = 0.38; P = 0.0067). In normotensive postmenopausal women, physiological doses of estradiol amplify the nocturnal decline of blood pressure. (+info)
Linkage analysis of glucocorticoid and beta2-adrenergic receptor genes with blood pressure and body mass index.
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Glucocorticoids and catecholamines exert important effects on cardiovascular physiology and metabolism. Variants of the glucocorticoid receptor gene (GRL) and the beta2-adrenergic receptor gene (ADRB2) have been associated with high blood pressure and obesity. These genes are close on human chromosome 5q31-5q32, and we undertook a linkage analysis of this region in 264 families from the general population in relation to systolic and diastolic blood pressure, body mass index, weight, height, and pulse rate. All family members were genotyped at four microsatellite loci (D5S207, D5S210, D5S519, and D5S119) located on chromosome 5q31-5q33.3. Using quantitative identity-by-descent sibling pair linkage analysis, we found that at no loci was genetic similarity associated with phenotypic similarity for systolic and diastolic blood pressure, body mass index, weight, height, or pulse rate. Although it is not possible to exclude the influence of specific combinations of certain GRL and ADRB2 polymorphisms, the absence of significant linkage in our population argues against a role for GRL or ADRB2 in physiological variation of blood pressure and body mass index. (+info)
Influence of excess weight on mortality and hospital stay in 1346 hemodialysis patients.
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BACKGROUND: Body mass index (BMI) at its extremes contributes to morbidity and mortality in the general population. Its influence on morbidity and mortality in patients on hemodialysis is not clearly defined. METHODS: The BMI in 1346 patients attending limited-care hemodialysis units across the state of Mississippi was determined, and its relation to one-year mortality and hospital stay was assessed using the Cox proportional hazard model. RESULTS: Of these patients, 89% were black, and 11% were white. Thirty-eight percent of patients were overweight (BMI > 27.5), and 13% were underweight (BMI < 20). The highest (27.60 +/- 0.29, mean +/- SE) and the lowest (24.54 +/- 0.48) BMI were noted in black females and white males, respectively. BMI, race, hematocrit (Hct), and biochemical markers of better nutrition positively influenced the survival, whereas age, serum globulin, and diabetes had a negative influence. In a Cox multivariate analysis, BMI, age, diabetes, prealbumin, and creatinine, but not race, serum albumin, Hct, or serum globulin, retained significant influence on survival. Compared with the normal weight (BMI between 20 and 27.5), the one-year survival rate was significantly higher in the overweight patients and lower in the underweight patients. With a one-unit increase in BMI over 27.5, the relative risk for dying was reduced by 30% (P < 0.04), and with a one-unit decrease in BMI below 20, the relative risk was increased by 1.6-fold (P < 0.01). Furthermore, underweight patients had significantly lower levels of biochemical markers of nutrition and higher frequency and longer duration of hospital stay. CONCLUSION: Adequate dialysis with special attention to proper nutrition aimed to achieve the high end of normal BMI may help to reduce the high mortality and morbidity in hemodialysis patients. (+info)
Status of the year 2000 health goals for physical activity and fitness.
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In Healthy People 2000, the national strategy for improving the health of the American people by the year 2000, lifestyle factors such as physical inactivity are major determinants of chronic disease and disability. Despite the documented benefits of exercise in enhancing health and reducing the risk of premature death, only 1 of the 13 physical activity and fitness objectives of Healthy People 2000 has been met or exceeded. Although progress toward 5 objectives for the year 2000 has been made, 3 objectives are actually farther from attainment. Coronary heart disease death rates (Objective 1.1) have declined, and the prevalence of overweight people (Objective 1.2) has increased. Overall physical activity in adults (Objectives 1.3 and 1.4) and strengthening and stretching activities in children (Objective 1.6) have increased, but reduction in the percentage of sedentary persons (Objective 1.5) has showed no change. The proportion of the population adopting sound dietary practices combined with regular physical activity to attain appropriate body weight (Objective 1.7) has declined. Even though participation in daily school physical education (Objective 1.8) has shown a decline during the past several years, students who are enrolled in physical education classes are spending more time performing physical activities (Objective 1.9). The proportion of work sites offering employer-sponsored physical activity and fitness programs (Objective 1.10) has increased substantially, surpassing the year 2000 goal. Data to update progress for increasing physical activity levels of children (Objectives 1.3-1.5), community exercise facilities (Objective 1.11), clinician counseling about physical activity (Objective 1.12), and improvement in personal self-care activities (Objective 1.13) are not yet available. (+info)