Relationship of sex hormone binding globulin to overall adiposity and body fat distribution in a biethnic population

Previous data have indicated that decreased sex hormone binding globulin (SHBG) is associated with increased overall and upper body adiposity and higher levels of glucose, insulin and triglyceride (TG) and decreased levels of high-density lipoprotein (HDL) cholesterol. Since Mexican Americans have greater overall and upper body adiposity, higher rates of non-insulin-dependent diabetes mellitus, higher TG and lower HDL levels than non-Hispanic whites, we postulated that they would also have lower levels of SHBG. We measured total testosterone and total estradiol using a commercial radioimmunoassy and SHBG using a dextran-coated charcoal technique in premenopausal women (61 Mexican American and 39 non-Hispanic white) as part of the San Antonio Heart Study, a population-based study of diabetes and cardiovascular risk factors. There were no significant ethnic differences in total testosterone or total estradiol. SHBG, however, was lower in Mexican American (0.285 micrograms/dl) than in non-Hispanic white women (0.429 micrograms/dl) (P = 0.009). After adjustment for body mass index (BMI), ratio of waist-to-hip circumference (WHR) and ratio of subscapular-to-triceps skinfolds (centrality index), SHBG remained lower in Mexican Americans (0.307 micrograms/dl) than in non-Hispanic whites (0.396 micrograms/dl), although this difference was no longer statistically significant (P = 0.083). BMI, WHR and centrality index were all negatively associated with SHBG (P less than 0.01). The lower levels of SHBG in premenopausal Mexican American women compared to non-Hispanic white women may reflect greater in-vivo androgenicity and may be related to a variety of metabolic abnormalities seen in this ethnic group.     

Body fat and its distribution in relation to casual and ambulatory blood pressure

This study was undertaken to evaluate the associations of body fat and its distribution with casual and ambulatory blood pressure in nonobese men. One hundred and thirty-five normotensive or mildly hypertensive (but untreated) men employed at three work sites were studied. Casual blood pressure was measured at the work site at initial screening and on a second occasion by a nurse. Ambulatory blood pressure was measured noninvasively for 24 hours on a workday and analyzed as work, home, and sleep blood pressure measurements. Anthropometric measurements included height, weight, and waist and hip circumferences. Blood pressure was highest while at work; home blood pressure was higher than screening blood pressure or nurse blood pressure, and sleep blood pressure was lowest. Weight and both waist and hip circumferences (but not their ratio) were all significantly correlated with screening, nurse, and sleep blood pressures but not with work or home blood pressures. Stepwise regression analysis showed that waist circumference was the best overall predictor of blood pressure. We suggest that in situations where blood pressure is the dependent variable, correlations with other variables may be closest for "basal" measures of blood pressure and may be obscured by the effects of daily activities on blood pressure.     

Body fat distribution in relation to serum lipids and blood pressure in 38-year-old European men: the European fat distribution study

A study on 512 38-year-old European men selected from 6 different towns was conducted. There were significant differences between the centers in averages of anthropometric variables (except for thigh circumference), serum lipids (except for LDL-cholesterol), and blood pressure. In the pooled material, body mass index (BMI) as well as waist circumference, waist/hip ratio and waist/thigh ratio and subscapular skinfold were positively correlated to serum triglycerides, total cholesterol, LDL-cholesterol, and blood pressure and negatively with HDL-cholesterol. After adjustment for BMI, waist, waist/hip, and waist/thigh were all still significantly correlated with serum triglycerides (P less than 0.001). In addition, waist/hip and waist/thigh ratio showed significant partial correlations with total cholesterol (r = 0.16, P less than 0.001, r = 0.10, P less than 0.05 respectively), and diastolic blood pressure (r = 0.10, P less than 0.05, r = 0.09, P less than 0.05 respectively). In addition, waist/hip was, independently of BMI, correlated to LDL-cholesterol (r = 0.12, P less than 0.01), and waist/thigh ratio with HDL-cholesterol (r = -0.12, P less than 0.01). The partial association between waist/thigh with HDL cholesterol became insignificant after adjustment for smoking habits and physical activity. Adjustment for differences in anthropometric measurements did not explain the differences in serum lipids and blood pressure between the centers. The authors conclude that indicators of body fat distribution are associated with unfavorable risk profiles for cardiovascular disease in European men covering a large geographical and cultural variety and a wide range of body measurements and cardiovascular risk factors.     

Metabolic disorders and adiposity in a rural population

The aim of this cross-sectional study was to verify the prevalence of overweight and central adiposity (CA) in a sample of 287 adult subjects that lived in a rural community of Minas Gerais State. Means lipids, lipoproteins, glucose and blood pressure levels were compared according adiposity categories using One-way ANOVA and Tukey tests. Prevalence of overweight was 24.8% (37.4% for female; 11.5% for male). CA was verified in 28.1% of the individuals (50.3% for female; 4.3% for male). The associations between CA and overweight with the metabolic disorders: arterial hypertension (AH), dyslipidemia and hyperglycemia were estimated. Subjects with CA presented higher mean values of blood pressure, total cholesterol, LDL, triglycerides, fasting glucose, and lower mean values of HDL. CA was associated with AH, dyslipidemia and hyperglycemia. Associations between overweight and AH, dyslipidemia and hyperglycemia were also verified. These results confirm the potential effect of body composition shifting, especially at the abdominal level, on lipids, glucose metabolism and on blood pressure levels in rural populations.     

Tobacco smoking in relation to body fat mass and distribution in a general population sample

OBJECTIVE: To investigate the effects of variable amounts of tobacco smoking on body mass index and waist-to-hip ratio among current smokers. DESIGN: Population-based cohort study. SUBJECTS: A total of 22 059 apparently healthy men and women, who enrolled in the Greek EPIC cohort, aged 25-84 years, who had never smoked (14 751) or were current cigarette smokers (7308). MEASUREMENTS: Body mass index and waist-to-hip ratio (by anthropomentry), amount of tobacco smoking and energy expenditure (by an interviewer-administered, lifestyle questionnaire), energy intake and ethanol intake (by an interviewer-administered, validated, semiquantitative, food frequency questionnaire), at enrollment. RESULTS: In comparison to nonsmokers, smokers of the average number of cigarettes have lower body mass index. Among smokers, however, increased amount of smoking tends to be positively associated with body mass index, particularly among men. Waist-to-hip ratio is positively associated with amount of cigarettes smoked per day, among both men and women. CONCLUSION: Among smokers, tobacco smoking is positively associated with body mass index and waist-to-hip ratio. Our data suggest that the lower body mass index of smokers compared to nonsmokers reflects personality characteristics of those who choose to smoke and that the tendency to gain weight after smoking cessation may have behavioral rather than tobacco-related pharmacological roots.     

Leptin plasma concentrations are dependent on body fat distribution in obese patients

AIM: To evaluate whether fat distribution plays a role in determining serum leptin concentrations. PATIENTS AND METHODS: One-hundred and forty-seven obese patients, 77 males and 70 females, aged 45.1 +/- 13.2 y (mean +/- s.d.; range 21-73 y), with body mass index (BMI) ranging from 30 to 55 kg/m2 (mean 42.3 +/- 5.9). Ultrasound assessment of the thickness of subcutaneous and preperitoneal fat was carried out and calculation of their ratio as abdominal fat index (AFI), waist-hip ratio (WHR), body composition by bioelectrical impedance to evaluate the percentage of fat mass (FM%) and total amount of fat (FMKg) were also determined. Plasma leptin was measured by radio immuno assay (RIA). RESULTS: In the whole group of patients, serum leptin concentrations were 37.2 +/- 18.4 ng/ml (range 6-101.3 ng/ml); in spite of BMI values not being significantly different, women had leptin values significantly higher (47.4 +/- 17.4 ng/ml) (P < 0.01) than males (28.1 +/- 15.1 ng/ml), also after correction for fat mass. The mean thickness of abdominal subcutaneous fat was 33.7 +/- 12.9 mm and it was significantly (P < 0.001) higher in female (40.9 +/- 10.6 mm) than in male (27.1 +/- 11.2 mm) patients; preperitoneal thickness was 22.9 +/- 7.1 mm, with significantly (P < 0.05) higher values in males (24.2 +/- 6.8 mm) than in females (21.7 +/- 7.3 mm). Accordingly, AFI (in all patients 0.84 +/- 0.6) was significantly higher in males (1.09 +/- 0.6) than in females (0.56 +/- 0.2). In the overall population, leptin concentrations were directly and significantly related to subcutaneous but not preperitoneal fat; they showed a strong inverse relationship with AFI and WHR. When the results were evaluated dividing the patients according to gender, subcutaneous fat thickness showed a stronger association with leptin levels in males than in females, whereas no association was found with preperitoneal fat thickness. Leptin and AFI values were significantly related only in men. WHR values were not correlated with leptin concentrations in either sex. When fat mass was added to the model, subcutaneous fat thickness, AFI and WHR remained independently associated with leptin concentrations. Age and diabetes did not influence these measures. CONCLUSIONS: Fat distribution contributes to the variability in serum leptin in obese patients. In particular, subcutaneous abdominal fat is a determinant of leptin concentration, also independently of the amount of fat mass, whereas the contribution of preperitoneal visceral fat is not significant.     

Blood pressure in relation to three candidate genes in a Chinese population

OBJECTIVE: In a prospective analysis of a Caucasian population, we recently found that the genes encoding angiotensin-converting enzyme (ACE, I/D polymorphism), alpha-adducin (Gly460Trp) and aldosterone synthase (-344C/T) jointly influence the incidence of hypertension. We therefore investigated the association between blood pressure and these three genes in a Chinese population. METHODS: We genotyped 479 Han Chinese from 125 nuclear families recruited in northern China via random sampling (approximately 75%) and at specialized hypertension clinics (approximately 25%). We performed population-based and family-based association analyses using generalized estimating equations (GEE) and the quantitative transmission disequilibrium test (QTDT), respectively, while controlling for covariables. RESULTS: The participants included 239 (49.9%) women and 132 (27.6%) hypertensive patients, of whom 77 took antihypertensive drugs. The blood pressure, measured at the subjects' homes, averaged 126/80 mmHg. Mean values of urinary sodium, potassium and Na/K ratio were 226 mmol/day, 37 mmol/day and 6.31, respectively. In adjusted GEE analyses, systolic blood pressure was 9.3 mmHg (95% confidence interval 3.6-15.0 mmHg; P = 0.001) and 14.6 mmHg (95% confidence interval 3.4-25.8 mmHg; P = 0.01) higher in the ACE DD than II subjects among the alpha-adducin TrpTrp (n = 141) and aldosterone synthase CC (n = 33) homozygotes, respectively (P < or =0.05 for interactions of the ACE genotype with the alpha-adducin and aldosterone synthase polymorphisms). Among 40 informative offspring homozygous for the alpha-adducin Trp allele, systolic blood pressure was significantly associated with transmission of the ACE D allele (beta = 5.5 mmHg; P = 0.046). CONCLUSIONS: The ACE I/D, alpha-adducin Gly460Trp and aldosterone synthase -344C/T polymorphisms interact to influence systolic blood pressure in Chinese, suggesting that these genes might indeed predispose to hypertension, especially in an ecogenetic context characterized by a high salt intake.     

Relationship of adiposity to the population distribution of plasma triglyceride concentrations in vigorously active men and women

Although it is known that triglyceride concentrations increase with adiposity, whether the same increase applies for different percentiles of the triglyceride distribution has not been reported. Therefore, physician-supplied triglyceride concentrations from 7288 male and 2326 female runners were divided into strata according to the body mass index (BMI) and circumferences of the waist, hip and chest. The percentiles of the triglyceride distribution within each stratum were used to determine the cross-sectional regression slope between adiposity and triglyceride levels at each triglyceride percentile. Compared to the 5th percentile of the triglyceride distribution, the rise in men's triglycerides at the 95th percentile per unit of adiposity was 14-fold greater for BMI, 7.8-fold greater for waist circumference, 3.6-fold greater for hip circumference, and 4.4-fold greater for chest circumference. The rise in women's triglyceride concentrations at the 95th percentile was 8-fold greater than at the 5th percentile for each kg/m(2) increase in BMI. These results suggest that the metabolic effects of adiposity on plasma triglycerides depend upon whether the concentrations are high or low. This contradicts statistical assumptions upon which prior studies of adiposity have based their analyses. We speculate that the reported greater increases in triglycerides per unit of adiposity in whites than blacks, in men than women, and in low-density lipoprotein (LDL) pattern B than A are all consistent with the relationships we observe. It remains to be verified whether these relationship also apply to less active populations.     

Fasting serum insulin in relation to fat distribution, serum lipid profile, and blood pressure in European women: the European Fat Distribution Study

Samples of 38-year-old women were randomly selected from five European centers: Ede (The Netherlands), Warsaw (Poland), Gothenburg (Sweden), Verona (northern Italy), and Afragola (Naples-southern Italy). In total, 452 healthy women were studied. Anthropometric measurements were taken by one operator in each country after common training of all operators and blood parameters of all women were determined in one laboratory. Body mass index (BMI) was different among centers, mainly due to the higher values in southern Italy. Women from southern Europe had more central fat distribution than women from north European centers. Fasting serum insulin was higher in women from Poland and The Netherlands than in the other three centers. After adjustment for BMI, fasting insulin was significantly related to subscapular skinfold, subscapular to triceps skinfold ratio, waist circumference, and waist to thigh circumference ratio, although the partial correlations varied somewhat between the centers. In the pooled data, waist circumference showed the highest correlations with fasting serum insulin when adjusted for BMI. Fasting serum insulin showed significant partial correlations, adjusted for BMI, with lipid profile and blood pressure only in women from the two Italian centers. In the pooled data, fasting serum insulin was significantly positively correlated with serum triglycerides and total cholesterol and negatively to high-density lipoprotein (HDL) cholesterol and HDL/total cholesterol, independently of BMI and waist circumference. While blood pressure was not related to insulin in the pooled women, when adjusted for BMI and waist circumference; here as well, there were some differences in relationships between the centers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ambulatory blood pressure and blood pressure load responses to low sodium intervention in Han Chinese population

Abstract

We aimed to illustrate ambulatory blood pressure monitoring parameters responses to low sodium intake and their differences between salt-sensitive and non-salt-sensitive individuals. A total of 186 participants were included in this analysis. Twenty-four hour, day-time and night-time blood pressure (BP) and BP load decreased during low sodium intervention, especially in salt-sensitive (SS) group. After multivariable adjustment, 24-h systolic BP, diastolic BP, mean arterial pressure and BP load responses to low sodium intervention of SS individuals were more pronounced than those of non–salt-sensitive individuals. Thus, reducing salt intake is potentially needed for the prevention of hypertension, especially in SS individuals.

Trial registration: ClinicalTrials.gov identifier: NCT00721721.     

Altered relationship of blood pressure to adiposity in hypertension

BACKGROUND: Blood pressure levels and the prevalence of hypertension are related to adiposity. We evaluated the relationship of adiposity to blood pressure in normotensive and untreated hypertensive African Americans-an ethnic group with a high prevalence of hypertension and obesity. METHODS: Outpatient measurements were obtained in 1,858 normotensive and 1,998 hypertensive subjects (44% untreated) residing in Milwaukee. The blood pressure-adiposity relationship was also analyzed in non-Hispanic black (n = 908) and non-Hispanic white (n = 2182) National Health and Nutrition Examination Survey (NHANES) participants. RESULTS: In Milwaukee subjects, body mass index (BMI), waist/hip ratio, waist/height ratio, and percent body fat were higher in hypertensives (P < 0.0001). Combining normotensive and untreated hypertensive subjects, each of the anthropometric indices was correlated with systolic and diastolic blood pressure (P <0.0001). In separate analyses, correlations of the indices with blood pressure were observed in normotensive subjects (P < 0.0001), but generally not in hypertensive subjects. Further, separating all subjects into quartiles based on systolic blood pressure, indices of adiposity correlated with blood pressure only in subjects in the lowest blood pressure quartile (blood pressure <120/78 mm Hg). Similarly, among NHANES participants, blood pressure correlated with anthropometric indices in normotensive (P < 0.0005), but not in untreated hypertensive blacks or whites. CONCLUSIONS: Although indices of adiposity were greater in hypertensive than in normotensive subjects, blood pressures were significantly correlated with measures of adiposity in normotensive, but not in untreated hypertensive subjects. We hypothesize that the blood pressure-adiposity relationship in hypertensives is modulated by a combination of environmental and genetic factors.     

辽宁省阜新农村地区老年高血压人群体重指数与血脂及血压的关系

目的探讨辽宁省阜新农村地区老年高血压人群体重指数(BMI)与血脂及血压的关系。方法采用分层随机整群抽样方法,对辽宁省阜新农村地区≥65岁的1 637例老年高血压患者按不同BMI分为Ⅰ组(1 155例,BMI<24 kg/m2)、Ⅱ组(397例,24 kg/m2≤BMI<28 kg/m2)、Ⅲ组(85例,BMI≥28 kg/m2),进行流行病学调查和血脂及血压检测。结果Ⅱ、Ⅲ组收缩压、舒张压、TC、TG、LDL-C较Ⅰ组显著升高(P<0.05),血脂异常发生率显著升高(P<0.05),HDL-C异常率组间比较无显著差异,随BMI升高,高血压分级逐渐升高。结论积极控制BMI对预防血脂异常、高血压的发生发展,降低心脑血管事件的发病率有重要意义。     

Genetics and blood pressure response to exercise,and its interactions with adiposity

Regular aerobic exercise has the potential to induce several beneficial health effects, including a decrease in blood pressure level, especially in hypertensive patients and in subjects with high-normal blood pressure. However, it is also well documented that some people show more pronounced blood pressure responses to endurance training than others, despite identical training programs and similar initial blood pressure levels. This kind of variation is an example of normal biologic diversity and most likely originates from interactions with genetic factors. Data from genetic epidemiologic studies indicate that there is a genetic component that affects both resting blood pressure and blood pressure responses to acute exercise. Evidence from molecular genetic studies is scarce, but the first reports suggest that DNA sequence variation in the hypertension candidate genes, such as angiotensinogen, also modify blood pressure responses to endurance training. The current knowledge regarding the role of genetic factors in the modification of blood pressure responses to endurance training will be summarized and discussed.     

Central adiposity, regional fat distribution, and the risk of cholecystectomy in women

PURPOSE: Whether central adiposity contributes independently of total adiposity to the risk for gall stones is inconclusive. We examined prospectively indicators of central adiposity in relation to the occurrence of gall stone disease. METHODS: We evaluated the relationship between abdominal circumference and waist to hip ratio and risk of cholecystectomy in a cohort of women who had no history of gall stone disease. As part of the Nurses' Health Study, the women reported on questionnaires their weights, heights, and waist and hip circumferences, and the occurrence of cholecystectomy. A total of 42,312 women, aged 39-66 years in 1986, who were free of prior gall stone disease, provided complete waist and hip circumference measurements in 1986. RESULTS: We documented 3197 cases of cholecystectomy during 514,283 person years of follow up. After adjusting simultaneously for regional (waist circumference or waist to hip ratio) and total adiposity (body mass index) measures as well as for other risk factors of gall stone disease, women with a height adjusted waist circumference of 36 inches or larger had a relative risk (RR) of 1.96 (95% confidence interval (CI) 1.53-2.51; p trend < 0.0001) compared with women with a height adjusted waist circumference of less than 26 inches. Waist to hip ratio was directly associated with the risk, with an RR of 1.39 (95% CI 1.16-1.66; p trend < 0.0001) for women with a waist to hip ratio of 0.86 or higher compared with women with a waist to hip ratio of less than 0.70. CONCLUSION: Abdominal circumference and waist to hip ratio were associated with an increased risk of cholecystectomy, independently of body mass index in women.     

Obesity, body morphology, and blood pressure in urban and rural population groups of Yucatan

OBJECTIVE: To characterize body morphology and blood pressure of adults of the Mexican state of Yucatan. MATERIAL AND METHODS: Rural-urban differences in weight, height, waist, and hip circumferences, and blood pressure were analyzed in 313 urban and 271 rural subjects. RESULTS: No rural-urban differences in prevalence of obesity and overweight were found. Hypertension was marginally higher in urban subjects. Rural abnormal waist circumference was higher in young men and young women. Comparison with two national surveys and a survey in the aboriginal population (rural mixtecos) showed similar prevalence of obesity as ENSA-2000 and higher than mixtecos and ENEC-1993. Abnormal waist circumference was intermediate between ENSANUT-2006 and mixtecos and hypertension was intermediate between ENEC and mixtecos. CONCLUSION: The Maya and mestizo population of Yucatan showed a high prevalence of obesity and abnormal waist circumference not accompanied by a comparable higher hypertension frequency. This finding requires further confirmation.