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.     

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)     

The relationship of body fat distribution to blood pressure in normotensive men: the normative aging study

Body fat distribution may be a more specific marker than obesity for risk of cardiovascular disease and diabetes. The relationship between body fat distribution and sitting systolic and diastolic blood pressure was examined in a cross-sectional analysis of 1936 normotensive men aged 21 to 80 years. In this analysis body fat distribution was represented by the ratio of abdomen circumference to hip breadth (denoted as WHbR). Pearson product-moment correlations adjusted for age revealed a positive correlation between WHbR and both systolic and diastolic blood pressure (r = 0.13 and r = 0.14, respectively). In a multiple linear regression model controlling for age, smoking status and body mass index (BMI), WHbR was associated with systolic blood pressure [regression coefficient (standard error) = 3.58 (1.8), P = 0.048)], but had much less of an association with diastolic blood pressure [regression coefficient (standard error) = 1.90 (1.3), P = 0.141]. Further adjustment for alcohol intake decreased the association between WHbR and systolic blood pressure [regression coefficient (standard error) = 2.90 (1.81), P = 0.110]. Body fat distribution, as represented by WHbR was associated with level of systolic blood pressure independently of overall level of obesity (BMI) in normotensive men; adjustment for alcohol intake attenuated the relationship. These data suggest that dietary factors, notably alcohol intake, may influence the effect of body fat distribution on blood pressure.     

Body weight and weight change in relation to blood pressure in normotensive men

We examined blood pressure (BP) in association with weight change since age 20, body mass index (BMI) at different ages and fat distribution in normotensive individuals using baseline survey data collected in the Shanghai Men's Health Study, an ongoing population-based prospective cohort study of Chinese men aged 40-74 years. All anthropometric and BP measurements were performed by medical professionals. Included in this analysis were 25 619 men who had no prior history of hypertension, diabetes or cardiovascular disease, never took any antihypertensive medication and had both normal systolic BP (SBP) and diastolic BP (DBP) (<140/90 mm Hg). Both SBP and DBP increased linearly across the whole range of weight gain since age 20. The adjusted mean differences between the highest and the lowest quintiles of weight gain were 6.0 mm Hg (95% confidence interval (CI): 5.6, 6.5) for SBP and 3.9 (95% CI: 3.6, 4.2) for DBP. When accounting for BMI at age 20, the multivariate-adjusted odds ratio of prehypertension (SBP, 120-139 and/or DBP, 80-89 mm Hg) was 4.1 (95% CI: 3.7, 4.5; P for trend <0.0001) comparing the extreme quintiles of weight gain. Similar positive associations were also observed for BMI at age 40, current BMI, circumferences of the waist and hips and waist-to-hip ratio. In conclusion, these data suggest that weight gain since age 20 and elevated adiposity may contribute significantly to the rise in BP in normotensive individuals, emphasizing the importance of weight control throughout adulthood in preventing high BP.     

Apolipoprotein E polymorphism in middle-aged Belgian men: phenotype distribution and relation to serum lipids and lipoproteins

Apo E phenotype was determined in 760 Belgian men, aged 35 to 59 years. Serum lipids and lipoproteins were related to the apo E polymorphism in 734 participants. By comparison with the most frequent apo E3/3 phenotype, the presence of the 2 allele was associated with a lower serum total and non-HDL cholesterol, and with a lower apo B and a higher HDL cholesterol, independently of age, lifestyle factors and apo E concentration. In contrast, the presence of the 4 allele was associated with a higher serum total and non-HDL cholesterol, and with a lower HDL cholesterol and a lower apo AI. The apo E phenotype explained 17.4% of the variance in apo E concentration; the proportion of the variance in total cholesterol, HDL cholesterol, apo AI and apo B levels explained by the apo E polymorphism was low but statistically significant. Among the lifestyle factors, waist to hip ratio was the only variable significantly associated with apo E concentration. The data suggest that besides the well-documented increasing effect on non-HDL cholesterol, the 4 allele could further predispose to coronary heart disease through a decreasing effect on HDL while the 2 allele could exert a protective influence through both a decreasing effect on non-HDL cholesterol and an increasing effect on HDL cholesterol.     

Body fat distribution in healthy young and older men

Central and/or intraabdominal (IA) fat is an independent predictor of obesity-related metabolic abnormalities in young and middle-aged subjects. The elderly are "fatter" at any given relative weight and often have similar metabolic abnormalities. In this study we compare body composition, circumferences, and specific fat depots areas in a population of healthy young and older men. Although the two groups were similar in body mass index and percent body fat, their distribution of adiposity was different. The young subjects had 16% and 10% larger thigh (p = .0001) and arm (p less than .01) circumferences respectively, while the ratio of waist-to-hip circumference was greater in the older subjects (0.93 +/- 0.04 vs 0.97 +/- 0.04, p = less than .01). The most striking differences between the groups were noted on computed tomography, with a twofold greater IA fat area (72.6 +/- 38.2 vs 143.6 +/- 56.2 cm2, p less than .0001), and a twofold lesser thigh subcutaneous fat area (156.3 +/- 69.3 vs 82.4 +/- 29.7 cm2, p less than .001) in the older subjects. We conclude there is an age-related central and intraabdominal redistribution of adipose mass, even in healthy older subjects. Since these changes occur in the absence of clinical disease, the associations between metabolic abnormalities and a central and or IA distribution of adiposity in the elderly must be investigated further.     

Body fat, fat distribution and serum lipids, lipoproteins and apolipoproteins in African-American and Caucasian-American prepubertal children.

OBJECTIVE: The purpose of the present study was to determine the impact of body fat mass and fat distribution on serum lipids, lipoproteins and apolipoproteins in African-American and Caucasian-American prepubertal children. SUBJECTS: Study participants included 62 African-American children (age 8.3+/-1.4 y; body mass 37.3+/-13.6 kg; height 133+/-11 cm) and 39 Caucasian children (age 8.6+/-1.2 y; body mass 34.1+/-11.0 kg; height 131+/-9 cm). METHODS: Venous blood samples were obtained after a 12 h overnight fast and serum was analyzed for total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), triacylglycerol (TAG), apolipoprotein A-I (ApoA-I), apolipoprotein B (ApoB) and lipoprotein (a) (Lp(a)) concentrations. Body composition and body fat distribution were measured by dual-energy X-ray absorptiometry and computed tomography, respectively. RESULTS: African-American children had lower TAG (46+/-20 vs 61+/-32 mg/dl, P=0.015) and higher Lp(a) (34+/-25 vs 17+/-28 mg/dl, P=0.001) and HDL-C (44+/-11 vs 39+/-8 mg/dl, P=0.041). There were no ethnic differences in TC, ApoA-I and ApoB (P=0.535, P=0.218, P=0.418, respectively). The ethnic difference in TAG and Lp(a) was not explained by total fat or abdominal fat. The ethnic difference in HDL-C was explained by visceral fat and TAG. CONCLUSION: In prepubertal children, neither body fat nor fat distribution explain the ethnic difference in TAG or Lp(a), but visceral fat and TAG may contribute to differences in HDL-C.     

Visceral fat accumulation measured by magnetic resonance imaging in relation to serum lipids in obese men and women.

In 91 apparently healthy obese subjects (45 premenopausal women and 46 men) the associations between specific fat depots and serum lipids were studied. Magnetic resonance imaging was used to quantify fat depots at abdominal and hip level. In women, an accumulation of visceral fat was associated with a less favourable lipid profile, even after adjustment for age and body fat percentage: higher triglycerides levels (P less than 0.001), lower levels of HDL-cholesterol (P less than 0.01) and a diminished HDL-cholesterol/LDL-cholesterol ratio (P less than 0.01). In men, however, the significant inverse relationship between an abundance of visceral fat and the HDL-cholesterol/LDL-cholesterol ratio and the significant positive correlations with total-, LDL-cholesterol and triglycerides disappeared after adjustment for age and fat percentage. Within each sex, subcutaneous fat neither at abdominal level nor at hip level was significantly related to serum lipids. It is concluded that there are gender differences in the associations between visceral fat accumulation and serum lipids.     

Body fat distribution and flow-mediated endothelium-dependent vasodilation in older men

OBJECTIVE: Recent studies indicate that abdominal fat accumulation, in particular intra-abdominal fat, is related to impaired endothelial function in young healthy volunteers. The aim of this study was to examine whether the distribution of body fat depots is related to impaired endothelial function in older men. METHODS: Cross-sectional sample of 38 older (68+/-1 y) sedentary (VO(2max)=2.4+/-0.1 l/min) men. Flow-mediated endothelial dependent vasodilation (EDD) was assessed in the brachial artery in response to reactive hyperemia using high-resolution ultrasound. Abdominal subcutaneous and visceral fat depots were assessed by computed tomography scan (CT-scan) at the L(4)-L(5) region in the supine position. Percentage body fat was assessed via dual-energy X-ray absorptiometry (DEXA). RESULTS: Flow-mediated percentage change in brachial artery was 7.6+/-0.7%, suggesting an impaired flow-mediated EDD. Using simple linear regression analysis, there were no statistically significant relationship observed between flow-mediated EDD and the indices of total and abdominal adiposity (percentage body fat=29.3+/-0.9%, r=-0.11; total abdominal fat area=465+/-23 cm(2), r=-0.1; intra-abdominal fat area=200+/-14 cm(2), r=-0.14; subcutaneous fat area=265+/-13 cm(2), r=-0.05; BMI=29.3+/-0.9 kg/m(2), r=-0.07; and waist to hip ratio=0.98+/-0.01, r=-0.20). CONCLUSION: These findings suggest that in older sedentary men there is no clear correlation between adiposity and body fat distribution and impairment of flow-mediated endothelium dependent vasodilation.     

Relationships between weight change and changes in blood pressure and serum lipids in men and women

An examination was made of the relationships between weight change and changes in blood pressure and serum lipids over a five-year period in apparently healthy men and women not engaging in a systematic regime of diet and/or weight control. Weight change was positively correlated with systolic and diastolic blood pressure, cholesterol, and triglycerides, though the correlation coefficients were small (0.11 to 0.28) and not statistically significant for systolic blood pressure and cholesterol for men, and triglycerides for women. After controlling for the effects of differences in age, weight, physical work capacity and initial values in risk factors, and for changes in physical work capacity, weight change in women was found to account independently for a proportion of the variance of changes in systolic blood pressure (3 per cent), diastolic blood pressure (6 per cent), and cholesterol (2 per cent); in men weight change was independently related only to change in diastolic blood pressure (4 per cent). Subjects with elevated blood pressure (diastolic greater than or equal to 95 mmHg) were apparently more sensitive to weight change than those with 'normal' blood pressure. It was concluded that in free-living populations the relationships between weight change and changes in blood pressure and lipids are not strong, and that the general value of weight control in this context may have been exaggerated.     

Fat distribution and gender differences in serum lipids in men and women from four European communities.

We studied male/female differences in serum lipids in randomly selected 38-year-old men (n = 337) and women (n = 342) from various cities in The Netherlands, Sweden, Italy, and Poland. Overall, men had higher triglycerides and total cholesterol levels and lower HDL-levels compared to women (P less than 0.001). Adjustment for smoking habits, city, and body mass index did not remove the gender difference. Further adjustments for waist circumference alone and waist/hip and waist/thigh circumference ratio removed the gender differences in serum triglycerides and total cholesterol. Only adjustment for waist/thigh ratio removed the gender difference in HDL-cholesterol but linear relationships were different in men and women. The average male/female difference in serum lipids, particularly for total and LDL-cholesterol varied considerably among centers. In analyses of the data from the separate centers we found that sex differences in serum triglycerides and HDL-cholesterol in all 4 centers disappeared when adjusted for waist circumference alone and for waist/hip and waist/thigh ratio. For total and LDL-cholesterol, however, adjustment for circumference ratios tended to increase the male/female difference in 2 of the 4 centers. It is concluded that, in European men and women, fat distribution may be responsible for male/female differences in serum triglycerides but that such conclusions are less clear for HDL-, total- and LDL-cholesterol.     

Left ventricular hypertrophy in men with normal blood pressure: relation to exaggerated blood pressure response to exercise

OBJECTIVE: To determine whether normal, nonhypertensive subjects who have unusually large increases of systolic blood pressure with exercise have left ventricular hypertrophy (LVH). DESIGN: Case-comparison using echocardiography as a criterion standard for measurement of left ventricular mass and the diagnosis of LVH. SETTING: Population-based health fitness screening program and referral Veterans Affairs Hospital. SUBJECTS: Thirty-nine men (average age, 44.6 +/- 8.5 years; range, 34 to 71 years) were studied, including 25 participants in a health fitness screening program and an additional 14 normal men with atypical chest pain. Twenty-two subjects with a systolic blood pressure during peak exercise of 210 mm Hg or greater were compared with 17 others with systolic pressure less than 210 mm Hg during exercise. MEASUREMENTS AND MAIN RESULTS: Left ventricular hypertrophy (left ventricular mass index greater than 134 g/m2) was found in 14 of 22 men with a systolic blood pressure of 210 mm Hg or greater (present in 6.3% of normotensive healthy male volunteers in a health screening program) but in only 1 person with a lower exercise blood pressure. Left ventricular mass index was linearly correlated (r = 0.65, n = 39, P less than 0.001) with maximum exercise blood pressure. Whereas LVH was mild in about 50%, substantial LVH was present in the others. The presence of LVH was not related to superior physical conditioning and was accompanied by increased left atrial size suggesting impaired left ventricular filling. CONCLUSIONS: Even in the absence of hypertension, exaggerated blood pressure responses during exercise testing suggest a probability of 0.64 (95% CI, 0.41 to 0.83) of LVH, a finding associated with the cardiac "end-organ" manifestations of hypertension.     

Body fat distribution in relation to smoking and exogenous hormones in British women

Objective Both cigarette smoking and use of exogenous hormones are associated with changes in regional distribution of body fat, but their combined effects are less investigated. We examined the interrelation between smoking, exogenous hormones and fat distribution in premenopausal and postmenopausal women. Method We used data from 20 962 women without known cardiovascular disease (CVD) who were employees of a major department store in Britain. They completed a health questionnaire and attended a clinical examination that included waist and hip circumference measurements. The cross‐sectional analyses were conducted using linear regression models. Results Cigarette smoking, particularly smoking ≥20 cigarettes/day, was associated with larger waist circumference and higher waist/hip ratio (WHR) in pre‐ and postmenopausal women after adjusting for potential confounding factors (all P < 0·001). Premenopausal women using combined oral contraceptive (COC) and postmenopausal women using oestrogen‐only hormone replacement therapy (HRT) had lower WHR than non‐hormone users in both smokers and nonsmokers. However, smokers had higher WHR than nonsmokers in both groups of hormone users and nonusers. There was no significant interaction between smoking and hormone use in premenopausal and postmenopausal women (P > 0·05). Conclusion Although exogenous hormones use was related to a more favourable fat distribution in women, smoking was associated with greater abdominal fat accumulation.     

Body mass, fat distribution and blood pressure in Southern Italian children: results of the ARCA project

OBJECTIVE: To investigate the association between the degree of adiposity, assessed using the international reference values for body mass index (BMI) of the International Obesity Task Force (IOTF), the fat distribution pattern and the blood pressure (BP) profile in children. METHODS: Anthropometric indices and blood pressure were measured in 3923 children aged 6-11 years in southern Italy. RESULTS: The prevalence of overweight and obesity (by IOTF references) and pediatric hypertension was, respectively: 27, 21 and 10% for boys; 25, 21 and 14% for girls. Body mass index and waist z-scores were the strongest determinants of BP by regression analysis. Overweight and obesity were associated with a greater tendency for central fat deposition and higher BP (waist, cm; boys: 59.2+/-6.0, 69.5+/-7.9, 79.0+/-9.7; girls: 58.8+/-6.5, 68.2+/-7.4, 75.3+/-8.9; SBP/DBP, mmHg; boys: 94/60+/-12/9, 99/62+/-13/8, 103/64+/-15/10; girls: 93/59+/-12/9, 99/62+/-14/9, 101/63+/-14/9; normal weight, overweight and obese, respectively; P<0.0001; M+/-SD), and a higher risk of hypertension (overweight: RR=2.33; 95% CI 1.76-3.08; obesity: RR=3.69; 95% CI 2.78-4.90), independent of age, physical activity, birth weight, parental adiposity and education. Among normal weight children, 99% had waist <85th percentile and 93% were normotensive. CONCLUSIONS: Overweight and obese children, identified according to the IOTF growth charts, are characterized by a central fat distribution pattern and higher BP.     

Relationship of cigarette smoking to blood pressure and serum lipids

The relationship between cigarette smoking and blood pressure and serum lipids was studied in 1775 men aged 20-59 years, in non-drinkers and drinkers separately, controlling for body mass index and physical fitness (VO2max). While systolic blood pressure was not associated with cigarette smoking, diastolic blood pressure decreased with increasing levels of cigarette smoking in non-drinkers but not in drinkers. Total cholesterol was inversely associated with smoking cigarettes in drinkers and was not associated in non-drinkers. High density lipoprotein (HDL)-cholesterol decreased with an increasing degree of cigarette consumption in non-drinkers but not in drinkers. An increase in total cholesterol/HDL-cholesterol ratio and triglyceride levels was positively associated with smoking cigarettes regardless of drinking habit. The present study suggests that cigarette smoking is a cardiovascular risk factor, partly due to its effect of increasing the atherogenic index, but it remains to be consolidated whether chronic smoking has an effect of lowering diastolic blood pressure.     

Body fat distribution and male/female differences in lipids and lipoproteins

The role of body fat distribution, as assessed by the ratio of waist-to-hip circumferences (WHR), in statistically explaining differences in levels of lipoproteins between men and women was studied using data collected in 1985-1986 from employed adults (mean age, 40 years). As compared with the 415 women, the 709 men had higher mean levels of triglycerides (+38 mg/dl) and apolipoprotein B (+11 mg/dl) as well as lower mean levels of high density lipoprotein (HDL) cholesterol (-15 mg/dl) and apolipoprotein A-I (-19 mg/dl). Additionally, men were more overweight, consumed more alcohol, and exercised more frequently than women but were less likely to smoke cigarettes. Controlling for these characteristics, however, did not alter the differences in lipoprotein levels between men and women. In contrast, adjustment for WHR (which was greater among men) reduced the sex differences in levels of apolipoprotein B (by 98%), triglycerides (by 94%), HDL cholesterol (by 33%), and apolipoprotein A-I (by 21%). Similar results were obtained using analysis of covariance, stratification, or matching; at comparable levels of WHR, differences in lipid and lipoprotein levels between men and women were greatly reduced. Although these results are based on cross-sectional analyses of employed adults and need to be replicated in other populations, the findings emphasize the relative importance of body fat distribution. Whereas generalized obesity and body fat distribution are associated with lipid levels, fat distribution (or a characteristic influencing fat patterning) can be an important determinant of sex differences in levels of triglycerides, HDL cholesterol, and apolipoproteins B and A-I.     

Relation of body fat distribution to serum lipids and lipoproteins in elderly women

Fat distribution measured by dual photon absorptiometry, serum lipids and lipoproteins were determined in 95 elderly women with mild osteoporosis. Increasing obesity, determined anthropometrically as body mass index (BMI) = body weight/(height)2, was associated with a more central fat distribution (P less than 0.001) Central fat distribution correlated positively and independently of BMI and body weight to serum cholesterol, low density lipoprotein-cholesterol (LDL-C), triglycerides and the ratio LDL-C/HDL-C (P less than 0.05), whereas the correlation between central fat distribution and high density lipoprotein-cholesterol (HDL-C) was negative (P less than 0.05). We conclude that the increased risk of cardiovascular disease observed in subjects with central fat distribution might be partly mediated through changes in the lipoprotein profile.     

Atrial natriuretic peptide (ANP) in relation to blood pressure: a study in middle-aged men with normal and elevated blood pressure

In order to investigate the potential role of atrial natriuretic peptide (ANP) in mild to moderate essential hypertension, a study was conducted in groups of normotensive and hypertensive middle-aged men born in 1926 and 1927. Venous plasma concentrations of immunoreactive ANP (irANP) were studied in relation to measurements of cardiac structure and function, urinary electrolytes as well as some cardiovascular hormones. Plasma irANP did not differ between normotensive controls (31 +/- 14 pmol l-1) and borderline or untreated hypertensive patients. However, irANP concentrations were slightly but significantly (P less than 0.05) lower in the borderline (26 +/- 8 pmol l-1) compared to the untreated established hypertensives (35 +/- 14 pmol l-1). No relationships were found between irANP and blood pressure, indices of left ventricular structure and function or hormone parameters in subgroups or the whole study group. Our data do not support the view that plasma irANP is increased in uncomplicated essential hypertension, since our groups of borderline or established hypertensive middle-aged men without major cardiac involvement did not differ in irANP concentrations compared to normotensive controls. Thus, during the development or in the early stages of essential hypertension, ANP secretion does not seem to be abnormal.     

Effects of alcohol and caloric restrictions on blood pressure and serum lipids in overweight men.

We have examined the independent and combined effects on blood pressure and blood lipids of alcohol restriction and weight loss in overweight male drinkers with a view to assessing overall effects on cardiovascular risk of two widely promoted nonpharmacological approaches for hypertension. Eighty-six men with a mean age of 44.3 years, a mean regular alcohol intake of 440 ml/wk (five or six standard drinks per day), a mean blood pressure of 137.4 mm Hg systolic and 84.8 mm Hg diastolic, and a mean body mass of 92.5 kg entered a controlled two-way factorial study. The subjects were randomly assigned to four groups for an 18-week intervention in which members of two groups drank only low-alcohol beer, thereby reducing their alcohol intake by 374 ml/wk, while those of the other two groups continued their normal alcohol intake. Within the low and normal alcohol intake groups subjects either continued their usual diet or reduced their caloric intake by 4,200-6,300 kJ/day (1,000-1,500 kcal/day) (with protein, fat, and carbohydrate provided as 15%, 30%, and 55% of total calories, respectively). Calorie reduction and alcohol restriction caused weight losses of 7.5 (p less than 0.001) and 2.1 (p less than 0.01) kg, respectively. Calorie reduction and alcohol restriction were associated with decreases in systolic blood pressure of 5.4 (p less than 0.001) and 4.8 (p less than 0.01) mm Hg, respectively, and in diastolic blood pressure of 4.2 (p less than 0.001) and 3.3 (p less than 0.01) mm Hg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Body fat distribution,serum leptin,and cardiovascular risk factors in men with obstructive sleep apnea

STUDY OBJECTIVE:s: To determine whether traditional risk factors for cardiovascular disease (CVD) and regional fat distribution, especially the central obesity type and increased parapharyngeal fat pads, are associated with the degree of obstructive sleep apnea (OSA). To determine whether there are interrelationships between body fat, serum leptin levels, and the degree of OSA. DESIGN AND SETTING: Prospective mono-center cross-sectional study in a university hospital in Germany. PATIENTS: Eighty-five consecutive male patients who were referred for evaluation of suspected OSA. Measurements and results: The major dependent outcome variable was the apnea-hypopnea index (AHI), the average number of apneas and hypopneas per hour of sleep, determined by overnight polysomnography. Independent measures were anthropometric data, body composition analysis (bioelectrical impedance analysis [BIA]), cardiovascular risk factor evaluation (smoking, hypertension, serum lipoproteins, diabetes or impaired glucose tolerance, uric acid, fibrinogen), and leptin. Adipose tissue quantification of the abdominal and neck regions was performed by nuclear MRI (NMR). Significant linear relationships of AHI with fasting blood glucose, uric acid, fibrinogen, body weight, body mass index (BMI), sum of fat skin folds, and percentage of body fat could be established, whereas there was no correlation with age. The presence of OSA was independent of smoking, hypertension, and lipoproteins. NMR scans showed that AHI was significantly correlated with intra-abdominal fat and subcutaneous abdominal fat, whereas subcutaneous fat in the neck region and parapharyngeal fat in the airway vicinity were not correlated. Leptin concentrations correlated with AHI and with biochemical markers of the metabolic syndrome (lipoproteins, glucose) but were not dependent on AHI. Logistic regression analysis found percentage of body fat (BIA) and BMI as good predictors of AHI > 10 with a sensitivity of 95.5% but a low specificity (46.2%). Multiple regression analysis identified the sum of fat skin folds, body weight, and BMI as good predictors for the degree of OSA. CONCLUSIONS: We conclude that OSA is independent from most traditional risk factors for CVD. Regional body fat distribution predicts the presence and degree of OSA, but fat accumulation in the neck and parapharyngeal region are of minor importance. Leptin concentrations when controlled for body fat are not related to the degree of OSA.