Sagittal abdominal diameter compared with other anthropometric measurements in relation to cardiovascular risk

BACKGROUND: Abdominal adiposity has been described as an independent risk factor for coronary heart disease. Sagittal abdominal diameter has been found to be closely related to the amount of visceral adipose tissue. AIM: To compare the sagittal abdominal diameter with other anthropometric measures regarding their relationships to risk factors for coronary heart disease (CHD). DESIGN: A study of 885 men and women participating in a health survey. MEASUREMENTS: Sagittal abdominal diameter, body mass index (BMI), waist and hip circumferences, waist-to-hip ratio, serum concentrations of risk factors for CHD, blood pressure. RESULTS: In men the sagittal abdominal diameter showed stronger correlations to the CHD risk factors serum cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, glucose, insulin, apolipoprotein B (apoB), plasminogen activator inhibitor tissue-type plasminogen activator (t-PA) and lipid-corrected alpha tocopherol, and to systolic and diastolic blood pressures than the other anthropometric measurements. In women, compared with the other anthropometric measurements the sagittal abdominal diameter was more strongly correlated to serum cholesterol, LDL cholesterol, LDL/HDL (high-density lipoprotein), apo B and t-PA, and to systolic and diastolic blood pressure. The sagittal abdominal diameter showed a stronger correlation to 'total risk' for cardiovascular disease (+ 0.66 for men, 0.62 for women), than waist circumference (+ 0.63 for men, + 0.57 for women) and waist-to-hip ratio (+ 0.61 for men and +0.48 for women; P <0.0001 for all correlations). This diameter was also more strongly correlated to 'metabolic risk' (+ 0.64 for men, + 0.59 for women) than waist circumference (+ 0.60 for men, + 0.59 for women) and waist-to-hip ratio (+ 0.58 for men, + 0.52 for women)(P < 0.0001 for all correlations). In a regression analysis including the anthropometric measurements and the risk values, the sagittal diameter was the strongest measure of cardiovascular risk in both men and women. CONCLUSIONS: Among both men and women in this study the sagittal abdominal diameter showed stronger correlations to cardiovascular risk and to other risk factors in the metabolic syndrome than other anthropometric variables such as waist circumference, waist-to hip ratio and BMI.     

Serum leptin in NASH correlates with hepatic steatosis but not fibrosis: a manifestation of lipotoxicity?

Nonalcoholic steatohepatitis (NASH) is a disorder characterized by hepatic steatosis, inflammation, and fibrosis. Leptin is an adipocyte-derived antiobesity hormone that in rodents prevents "lipotoxicity" by limiting triglyceride accumulation and also regulates matrix deposition (fibrosis) during wound healing. We therefore determined serum leptin levels in patients with NASH to determine whether relationships existed between leptin levels and severity of hepatic steatosis or fibrosis. We used a radioimmunoassay to determine serum [total] leptin concentrations in 27 men and 20 women with NASH and 47 controls matched for gender and body mass index (BMI; and partly for age). Serum leptin values were correlated with hepatic steatosis, fibrosis, and inflammation (each categorized semiquantitatively on liver histology), and with anthropometric indices, serum lipids, glucose, insulin, c-peptide, and alanine aminotransferase (ALT) levels. Compared with the controls, mean serum leptin levels were raised in both men and women with NASH (men 14 +/- 11 ng/mL vs. 7.2 +/- 4.1 ng/mL, P =.003; women 35 +/- 16 ng/mL vs. 15 +/- 8.2 ng/mL, P <.001). Leptin values correlated with serum c-peptide levels but not with BMI. In a multivariate analysis, serum leptin (P =.027), serum c-peptide (P =.001), and age (P =.027) were selected as independent predictors of the severity of hepatic steatosis. However, serum leptin was not an independent predictor of hepatic inflammation or fibrotic severity. In conclusion, hyperleptinemia occurs in NASH and is not explained simply by gender, obesity, or the presence of type 2 diabetes. Furthermore, leptin levels correlate directly with the severity of hepatic steatosis but not with inflammation or fibrosis. We propose that the relationship between leptin and steatosis reflects a pathogenic role of leptin in hepatic insulin resistance and/or a failure of the antisteatotic actions of leptin ("peripheral leptin resistance").     

Fasting serum leptin level correlates with mid-arm fat area in peritoneal dialysis patients

Leptin correlates with body fat content and plays a pivotal role in inflammatory response. This study aimed to investigate the relationships of fasting serum leptin levels and the anthropometric fat components among peritoneal dialysis (PD) patients. Fasting blood samples were obtained from 40 PD patients. Leptin levels were measured using a commercial enzyme-linked immunosorbent assay kit. Body weight (r=0.424; P=0.006), waist circumference (r=0.352; P=0.026), body mass index (BMI; r=0.483; P=0.002), body fat mass (r=0.352; P=0.026), high sensitivity C-reactive protein (hs-CRP; r=0.494; P=0.001), triceps skinfold thickness (TSF; r=0.505; P=0.001), mid-arm circumference (MAC; r=0.471; P=0.002), and mid-arm fat area (MAFA; r=0.564; P<0.001) were positively correlated, while high density lipoprotein (HDL)-cholesterol (r=-0.345; P=0.028) was negatively correlated with fasting serum leptin levels among the PD patients. Multivariate forward stepwise linear regression analysis showed that MAFA (R(2)=0.318, P=0.011) was the independent predictor of fasting serum leptin levels among the PD patients. In conclusion, fasting leptin level was positively associated with body fat composition (body weight, waist circumference, BMI, body fat mass, TSF, MAC, and MAFA) and hs-CRP among PD patients, and MAFA was the independent predictor of fasting serum leptin levels among the PD patients.     

Increased occurrence of diabetes in people with ischemic cardiovascular disease and general and abdominal obesity

BACKGROUND: Diabetes worsens the prognosis of patients with ischemic cardiovascular disease (ICVD). Increased body weight and abdominal obesity have been shown to increase the risk of diabetes in people without ICVD. Such a relationship has not been assessed in patients with ICVD who may have a different occurrence due to their disease and medications. OBJECTIVE: To examine the risk of developing diabetes among patients with ICVD according to body mass index (BMI), waist-to-hip ratio and waist circumference METHODS: Anthropometric measurements were done in 4699 men and 1187 women with ICVD (mean age 66 years) and without known diabetes at entry to the Heart Outcomes Prevention Evaluation (HOPE) study. During the median 4.5-year follow-up, a diagnosis of diabetes was reported in 261 (4.4%) participants. RESULTS: There was a positive and graded association between increased BMI, waist circumference and waist-to-hip ratio, and the risk of developing diabetes (P for trends <0.0001). After adjusting for all baseline characteristic differences including medications, the relative risk of developing diabetes after the first 40th percentile of each anthropometric measure increased by 12% (95% CI 9% to 15%) for every 1 kg/m2 increase in BMI; the relative risk increased by 5% (95% CI 4% to 6%) for every 1 cm increase in waist circumference and by 38% (95% CI 18% to 61%) for every 0.1 unit increase in waist-to-hip ratio. CONCLUSION: In patients with ICVD, increased BMI, waist-to-hip ratio and particularly waist circumference constitute independent risk factors for development of diabetes.     

Gender differences in the association between anthropometric indices of obesity and blood pressure in Japanese.

To investigate which of four anthropometric variables of obesity has the strongest association with blood pressure (BP), and to investigate whether there are gender differences in these relationships in Asian adults, we evaluated the associations of four anthropometric variables, body mass index (BMI), waist circumference, waist-to-hip ratio and waist-to-height ratio, with BP and the prevalence of hypertension in a cross-sectional study. A total of 4,557 employees of a metal-products factory in Toyama, Japan (2,935 men and 1,622 women, aged 35 to 59 years) were included in the study. Waist circumference in men and BMI in women had the strongest associations with BP. As for the age-adjusted rate ratio (RR) of the prevalence of hypertension for one standard deviation increase in each anthropometric variable, RR was the highest for waist circumference in men (RR, 1.44; 95% confidence interval [CI], 1.31-1.58), and for BMI in women (RR, 1.61; 95% CI, 1.38-1.88). The associations of waist circumference in men and BMI in women remained significant after adjustment for each of the other variables. The associations of waist-to-height ratio with BP and the prevalence of hypertension were a little weaker than those of waist circumference for both men and women. In conclusion, among four anthropometric variables of obesity--i.e., BMI, waist circumference, waist-to-hip ratio, and waist-to-height ratio-waist circumference had the strongest association with BP and the prevalence of hypertension in men and BMI had the strongest association with BP and hypertension in women. Waist circumference in men and BMI in women should be given more importance in the screening of and guidelines on hypertension in Asians.     

Anthropometric measures and absolute cardiovascular risk estimates in the Australian Diabetes, Obesity and Lifestyle (AusDiab) Study.

BACKGROUND: Framingham risk functions are widely used for prediction of future cardiovascular disease events. They do not, however, include anthropometric measures of overweight or obesity, now considered a major cardiovascular disease risk factor. We aimed to establish the most appropriate anthropometric index and its optimal cutoff point for use as an ancillary measure in clinical practice when identifying people with increased absolute cardiovascular risk estimates. DESIGN: Analysis of a population-based, cross-sectional survey was carried out. METHODS: The 1991 Framingham prediction equations were used to compute 5 and 10-year risks of cardiovascular or coronary heart disease in 7191 participants from the Australian Diabetes, Obesity and Lifestyle Study (1999-2000). Receiver operating characteristic curve analysis was used to compare measures of body mass index (BMI), waist circumference, and waist-to-hip ratio in identifying participants estimated to be at 'high', or at 'intermediate or high' absolute risk. RESULTS: After adjustment for BMI and age, waist-to-hip ratio showed stronger correlation with absolute risk estimates than waist circumference. The areas under the receiver operating characteristic curve for waist-to-hip ratio (0.67-0.70 in men, 0.64-0.74 in women) were greater than those for waist circumference (0.60-0.65, 0.59-0.71) or BMI (0.52-0.59, 0.53-0.66). The optimal cutoff points of BMI, waist circumference and waist-to-hip ratio to predict people at 'high', or at 'intermediate or high' absolute risk estimates were 26 kg/m2, 95 cm and 0.90 in men, and 25-26 kg/m2, 80-85 cm and 0.80 in women, respectively. CONCLUSIONS: Measurement of waist-to-hip ratio is more useful than BMI or waist circumference in the identification of individuals estimated to be at increased risk for future primary cardiovascular events.     

Reduced leptin concentrations in subjects with type 2 diabetes mellitus in Sudan

Differences have been observed in the relationship between leptin and metabolic perturbations in glucose homeostasis. Because no information is available from indigenous African populations with diabetes, the purpose of this study was to investigate the possible associations between leptin and different clinical and biochemical characteristics of a large group of subjects with type 2 diabetes mellitus in Sudan. A total of 104 (45 men and 59 women) consecutive type 2 diabetes patients and 75 control subjects (34 men and 41 women) were studied. The body mass index (BMI), blood glucose, serum insulin, and proinsulin were measured and related to serum leptin concentrations. Leptin was higher in females than in males and correlated significantly to BMI. The main novel finding was that serum leptin was significantly lower in diabetic subjects compared with controls in both females (P =.0001) and males (P =.019), although BMI did not differ between diabetic and nondiabetic subjects. Diabetic subjects treated with sulphonylurea (n = 81) had lower BMI than those treated with diet alone or other hypoglycemic drugs (n = 23) (P =.0017), but there was no difference in leptin levels between the 2 groups after adjustment for BMI (P =.87). In diabetic subjects, serum leptin correlated positively with the homeostatic assessment (HOMA) of both beta-cell function (P =.018) and insulin resistance (P =.038), whereas in control subjects, leptin correlated with insulin resistance (P =.0016), but not with beta-cell function. Diabetic subjects had higher proinsulin levels (P =.0031) and higher proinsulin to insulin ratio (P =.0003) than nondiabetic subjects. In univariate analysis, proinsulin showed a weak correlation to leptin (P =.049). In conclusion, we show in a large cohort of Sudanese subjects with type 2 diabetes that circulating leptin levels are lower in diabetic subjects than in controls of similar age and BMI. The lower serum leptin in diabetic subjects may be a consequence of differences in fat distribution.     

Relation between leptin and the metabolic syndrome in elderly women

BACKGROUND: Leptin has been shown to be linked to adiposity and insulin resistance in middle-aged participants. However, the association between leptin and metabolic syndrome independently of body fat and body fat distribution has not been evaluated in healthy elderly people. METHODS: We studied the independent relation between leptin and the components of the metabolic syndrome in 107 women aged 67-78 years with body mass index (BMI) ranging from 18.19 to 36.16 kg/m2. In all participants, we evaluated BMI, waist and hip circumferences, body composition by dual energy X-ray absorptiometry, fasting, and 2-hour glucose, lipids, insulin, homeostasis model assessment of insulin resistance (HOMA), systolic (SBP), diastolic blood pressure (DBP), and leptin. RESULTS: Significant correlation was found between leptin, BMI, waist circumference, fat mass, DBP, SBP, cholesterol, triglycerides, insulin, and HOMA. After adjusting for age and waist circumference, as well for age and fat mass, leptin was significantly related to insulin levels, HOMA, and cholesterol. In a stepwise multiple regression analysis using insulin levels or HOMA as dependent variables and age, waist circumference, fat mass, leptin, SBP, DBP, cholesterol, and triglycerides as independent variables, leptin entered the regression first, waist circumference second, and age third. CONCLUSION: Our study shows that leptin is significantly related to indices of adiposity in elderly women, and leptin is significantly associated with insulin levels, HOMA, and cholesterol independent of age, body fat, and fat distribution. Leptin, waist circumference, and age together explained 31% and 33% of insulin levels and HOMA variance, respectively, in healthy elderly women.     

The relationship between simple anthropometric indices and C-reactive protein: ethnic and gender differences

C-reactive protein (CRP) is an independent risk factor for cardiovascular disease (CVD) that is strongly associated with indicators of body fat, yet the effect of potential confounders, such as ethnic background and gender has not been characterized. Our purpose was to determine the effect ethnicity and gender has on the relationship between CRP, body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) in men and women of Chinese and European descent. BMI, WC, WHR, and CRP were measured in European (n = 91) and Chinese (n = 91) men and women recruited from local hospital staff. Pearson correlation coefficients were determined between CRP, age, and anthropometric measures for the entire cohort and stratified by ethnicity and gender. Multiple regression analyses were performed using interactions between BMI, WC, and WHR for each ethnicity and gender with CRP as the outcome. CRP levels were significantly lower in Chinese compared with Europeans, but this difference disappeared after correction for either BMI or WC. In women, BMI (r =.55, P <.01) and WC (r =.59, P <.01) correlated with CRP. Gender significantly interacted with WC to predict CRP after adjusting for age, smoking status, alcohol, and BMI (P <.05). There was a nonsignificant interaction between gender and BMI as a predictor of CRP. Differences in CRP remained significant after adjusting for WHR. The relationship between CRP levels and BMI or WC was similar between men and women of Chinese and European descent. Gender significantly modified the relationship between CRP and WC. At a WC beyond 70 cm, CRP levels increased at a greater rate in women than men.     

Serum ascorbic acid and gallbladder disease prevalence among US adults: the Third National Health and Nutrition Examination Survey (NHANES III)

BACKGROUND: Ascorbic acid-deficient guinea pigs frequently develop gallstones, and ascorbic acid status may also affect the risk of gallbladder disease in humans. To examine the relationship of ascorbic acid, an antioxidant nutrient involved in cholesterol catabolism, to gallbladder disease, we analyzed data collected from a probability sample of US adults. METHODS: Analyses of data from 7042 women and 6088 men enrolled in the Third National Health and Nutrition Examination Survey, 1988-1994, were performed. Multiple logistic regression models stratified by sex were examined, controlling for the effects of age, race, diet, body mass index, and other potential confounders. RESULTS: A total of 761 women (11%) and 235 men (4%) reported a history of clinical gallbladder disease (symptomatic gallstones or cholecystectomy). Of the 9650 participants without a history of clinical gallbladder disease or abdominal pain consistent with gallbladder disease, and with valid abdominal ultrasonography, 408 (8%) of 4863 women and 274 (6%) of 4787 men had asymptomatic gallstones. Serum ascorbic acid level was inversely related to prevalence of clinical and asymptomatic gallbladder disease among women, but not among men. Among women, each SD (27 micromol/L) increase in serum ascorbic acid level was independently associated with a 13% lower prevalence of clinical gallbladder disease (P = .006) and asymptomatic gallstones (P = .048). CONCLUSION: Ascorbic acid, which affects the catabolism of cholesterol to bile acids and, in turn, the development of gallbladder disease in experimental animals, may affect the risk of gallbladder disease among women.     

Usefulness of anthropometrics and dual-energy x-ray absorptiometry for estimating abdominal obesity measured by magnetic resonance imaging in older men and women

PURPOSE: Increasing evidence suggests that abdominal obesity may be a better predictor of disease risk than total fatness. This study sought to determine how obesity and fat distribution measured by readily available anthropometric and dual-energy x-ray absorptiometry (DXA) methods is related to abdominal obesity assessed by magnetic resonance imaging (MRI). METHODS: Men (n = 43) and women (n = 47), ages 55 to 75 years, were assessed for body mass index, waist-to-hip ratio, waist circumference, and skin folds by anthropometric methods; for percentage of body fat by DXA; and for abdominal total, subcutaneous, and visceral fat by MRI. RESULTS: In stepwise regression models, the waist-to-hip ratio explained 50% of the variance in abdominal visceral fat among men (P <.01), and body mass index explained an additional 6% of the variance (P <.01). Among women, waist circumference was the only independent correlate of abdominal visceral fat, accounting for 52% of the variance (P <.01). Among men, the percentage of body fat was the only independent correlate of abdominal subcutaneous fat, explaining 65% of the variance (P <.01). Among women, the percentage of body fat explained 77% of the variance in abdominal subcutaneous fat and body mass index explained an additional 3% (P <.01). CONCLUSIONS: Obesity and body composition obtained by readily available anthropometric methods and DXA provide informative estimates of abdominal obesity assessed by MRI imaging.     

Impact of sex-specific body composition on cardiovascular risk factors: the Hong Kong Cardiovascular Risk Factor Study

The aim of the study was to analyze the effects of sex-specific distribution of adiposity, particularly emphasizing the independent contribution of waist and hip circumferences relative to body mass index (BMI), on cardiovascular risk factors in a Chinese population. Blood pressure and anthropometric and biochemical parameters were measured in 2510 population-based Chinese subjects. The relative contributions of waist and hip circumferences to the presence of cardiovascular risk factors were determined. The Chinese men were significantly larger than women, with greater BMI and central adiposity. Waist and hip circumferences were both positively associated with the presence of hypertension, dyslipidemia, and diabetes. However, after adjustment for BMI and age, hip circumference exhibited a significant dose-dependent inverse relationship with dyslipidemia and diabetes in women, but not men. Sex-specific differences exist. After adjustment for age and BMI, hip circumferences independently and inversely contribute to cardiovascular risk in women, but not in men. Increasing adjusted waist circumference was associated with increased risk of hypertension and diabetes in Chinese and dyslipidemia in women only.     

Dual energy X-ray absorptiometry body composition and aging in a population-based older cohort

OBJECTIVE: The aims of this cross-sectional study were (1) to examine the effect of age on body composition in older adults using dual-energy X-ray absorptiometry (DXA) and (2) to evaluate the agreement of DXA with standard indirect anthropometric measures (body mass index (BMI), waist circumference and waist-to-hip ratio (WHR)). RESEARCH METHODS AND PROCEDURES: A population-based sample of 731 adults aged between 50 and 79 years underwent measurement of BMI, waist circumference, WHR, DXA total body fat mass, DXA % total body fat, DXA % trunk fat and DXA lean body mass. Linear regression was used to test for trend in measures of body composition between age categories in men and women. Partial correlations and Bland-Altman analysis were used to examine the agreement of DXA measures with indirect measures. RESULTS: DXA lean body mass decreased significantly with increasing age in both sexes (P<0.05). In males, BMI (P=0.01) and body weight (P<0.01) decreased with age, and in females, WHR (P=0.05), DXA % total fat (P=0.02) and DXA % trunk fat (P=0.05) increased with age. There was good agreement between DXA measures of fatness and indirect anthropometric measures, except for WHR, which showed greater variability in its comparisons with DXA. CONCLUSION: Using the highly sensitive and direct DXA method of measuring body composition, a decline in lean body mass and an increase in adiposity was observed with aging. Except for WHR, indirect anthropometric measures generally showed high levels of agreement with DXA fat measures in this older cohort.     

Heritability of leptin levels and the shared genetic effects on body mass index and leptin in adult Finnish twins

OBJECTIVES: Leptin is involved in the regulation of body weight, but the relative role of genetic and environmental influences on inter-individual variation in leptin levels is unknown. DESIGN AND SUBJECTS: To investigate the genetic and environmental contributions to the association of body mass index (BMI) with serum leptin levels, 58 monozygotic (MZ, 27M, 31F), and 74 like-sexed dizygotic (DZ, 32M, 42F) Finnish twin pairs aged 50--76 y were studied. MEASUREMENTS: Serum leptin levels, weight, height, hip and waist measurements. RESULTS: Women had higher mean leptin levels (16.8+/-9.5 ng/ml), and more overall variability in leptin levels than men (6.4+/-3.5 ng/ml; P<0.0001). Leptin levels correlated highly with BMI in men and women. Among women, the MZ and DZ pairwise correlations for leptin were 0.41 (P=0.009) and 0.07 (P=0.32), respectively. Among men the MZ and DZ pairwise correlations for leptin were 0.47 (P=0.006) and 0.23 (P=0.10). Univariate twin analysis indicated that, among women, 34% and, among men, 45% of the variance in leptin can be attributed to additive genetic effects, and the remainder to unique environmental effects. Significant non-additive genetic or shared familial effects could not be demonstrated. A bivariate twin analysis of leptin and BMI indicated that the correlation between additive genetic effects on leptin and BMI was 0.79 (95% CI 0.68--0.86) in women, and 0.68 (0.51--0.80) in men. The correlation between environmental effects on leptin and BMI was 0.77 (95% CI 0.66--0.85) in women, and 0.48 (0.26--0.66) in men. CONCLUSION: Leptin levels are moderately heritable in older adults, and a substantial proportion of genetic effects are in common on leptin levels and obesity in both women and men. International Journal of Obesity (2001) 25, 132-137     

The G1422A variant of the cannabinoid receptor gene (CNR1) is associated with abdominal adiposity in obese men

Since recent data suggest that the endocannabinoid system controls food intake through central, and lipogenesis via peripheral CB1 receptors, we hypothesized that genetic variation at the cannabinoid receptor-1 (CNR1) locus could have an effect on adiposity. We investigated, whether a specific CNR1 G1422A genotype is associated with anthropometric markers of obesity and fat distribution in adult obese individuals. A total of 1,064 obese subjects (BMI > or = 30 kg/m2) without diabetes, impaired glucose tolerance or other endocrine diseases and 251 healthy control persons were genotyped for the G1422A variant (rs1049353) with a TaqMan assay. Anthropometric measures as body weight, BMI, waist and waist-to-hip ratio (WHR) were assessed by classical methods. Fat mass (FM) was measured by bio-impedance. The prevalence of the G1422A variant was not significantly different between cases and controls (OR = 1.056; P = 0.626). In obese women, no meaningful associations between CNR1 genotype and anthropometric parameters were found. In obese men, CNR1 1422 A/A genotype was significantly associated with higher WHR (P = 0.009) and waist circumference (P = 0.008) after adjusting for age and BMI. Fat mass percentage showed an association (P = 0.011) which disappeared after adjusting for age and BMI. A trend for an association was seen for fat mass (unadjusted P = 0.099; adjusted P = 0.033). Our data indicate that the G1422A polymorphism in the CNR1 gene is associated with increased abdominal adiposity in obese men.     

Plasma leptin levels are associated with coronary atherosclerosis in type 2 diabetes

Leptin signaling may promote atherothrombosis and lead to cardiovascular disease. However, whether leptin is associated with human atherosclerosis, distinct from thrombosis, is unknown. We determined the association of plasma leptin levels with coronary artery calcification (CAC), a measure of coronary atherosclerosis, in a cross-sectional study of type 2 diabetes. Leptin levels were associated with CAC after adjusting for established risk factors [odds ratio (95% confidence interval) for 5 ng/ml leptin increase: 1.31 (1.10-1.55); P = 0.002]. Leptin remained associated with CAC after further controlling for body mass index (BMI) [1.29 (1.07-1.55); P = 0.008], waist circumference [1.30 (1.09-1.57); P = 0.003], C-reactive protein (CRP) levels [1.28 (1.07-1.55); P = 0.008], and subclinical vascular disease [1.30 (1.08-1.57); P = 0.006]. Addition of BMI (P = 0.97), waist (P = 0.55), or CRP (P = 0.39) to a model with leptin failed to improve the model's explanatory power, whereas addition of leptin to a model with BMI (P = 0.029), waist (P = 0.006), or CRP (P = 0.005) improved the model significantly. Plasma leptin levels were associated with CAC in type 2 diabetes after controlling adiposity and CRP. Whether leptin signaling promotes atherosclerosis directly or represents a therapeutic target for the prevention of atherosclerotic cardiovascular disease remains to be explored.     

Determinants of the association of overweight with elevated serum alanine aminotransferase activity in the United States

BACKGROUND & AIMS: In the absence of other causes, overweight and obesity increase the risk of liver disease. We examined whether central adiposity and metabolic markers explain the association of body mass index (BMI as kg/m(2)) with abnormal serum alanine aminotransferase (ALT) activity in a national, population-based study. METHODS: Adult participants (5724) in the third U.S. National Health and Nutrition Examination Survey (1988-1994) underwent anthropometric measures and phlebotomy after an overnight fast. Participants with excessive alcohol consumption, hepatitis B, hepatitis C, iron overload, or known diabetes were excluded. RESULTS: Elevated ALT levels were found in 2.8% of the population. In univariate analysis, factors associated with elevated ALT levels (P < 0.05) included younger age, male sex, Mexican-American ethnicity, and higher BMI, waist-to-hip circumference ratio (WHR), and fasting serum leptin, triglyceride, insulin, and glucose concentrations. The proportion of elevated ALT activity due to overweight and obesity (BMI > or =25 kg/m(2)) was 65%. In multivariate logistic regression analysis, control for WHR, demographic factors, and glucose concentration diminished but did not eliminate the association of higher BMI with elevated ALT activity. After adding leptin and insulin concentrations, abnormal ALT activity was most strongly associated with higher WHR (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.12-1.56) and leptin (OR, 1.12; 95% CI, 1.01-1.24) and insulin (OR, 1.27; 95% CI, 1.01-1.60) concentrations, whereas BMI was not independently related. CONCLUSIONS: In this large, national, population-based study, central adiposity, hyperleptinemia, and hyperinsulinemia were the major determinants of the association of overweight with elevated serum ALT activity.     

C-reactive protein in young, apparently healthy men: associations with serum leptin, QTc interval, and high-density lipoprotein-cholesterol

To determine which anthropometric, biochemical, and cardiovascular variables are associated with serum levels of C-reactive protein (CRP) in young, apparently healthy men, a cross-sectional study of 179 male college students aged 18 to 22 years was performed. Multiple regression analysis was used to derive models for serum CRP concentrations in terms of the other variables measured. Although CRP was positively correlated with body mass index (BMI), percent fat mass, and serum leptin, correlations with BMI (r = 0.15, P =.05) and percent body fat (r = 0.16, P =.003) were not as strong as the correlation with leptin (r = 0.28, P =.0002). CRP was also associated with resting heart rate (r = 0.14, P =.05), heart-rate corrected QT (QTc) interval (r = 0.22, P =.003) and several components of the insulin resistance (IR) syndrome. CRP showed a strong and negative association with high-density lipoprotein (HDL)-cholesterol (r = -0.26, P =.0005) and a marginal and positive association with triglyceride (r = 0.14, P =.05). Although CRP was associated with fasting insulin (r = 0.15, P =.04), it was not related to serum adiponectin or IR index estimated using homeostasis model assessment (HOMA). Multiple regression analysis indicated that serum CRP was positively related to serum leptin (P =.003) and QTc interval (P =.01), and negatively correlated with HDL-cholesterol (P =.01, R(2) = 0.15). In young, apparently healthy men, serum leptin but not BMI was independently associated with serum CRP, suggesting that amount of body fat may be the most significant predictor of CRP. Although low-grade inflammation was associated with long QTc interval and low HDL-cholesterol, the mechanism underlying these associations is an important question to be addressed.     

Serum leptin concentration in moderate and severe obesity: relationship with clinical, anthropometric and metabolic factors

OBJECTIVE: To study clinical, anthropometric and metabolic determinants of serum leptin concentrations in a series of patients with a wide range of obesity. SUBJECTS: 400 patients, 116 males and 284 females, aged 44+/-12.3 years with body mass index (BMI) ranging from 31 to 82 kg/m2 (mean 41.4+/-7.1). MEASUREMENTS: Energy intake by 7-day recall, resting energy expenditure (REE) by indirect calorimetry, body composition determined by bioelectrical impedance; C index, an anthropometric index of abdominal fat distribution, and waist-hip ratio (WHR), blood glucose serum leptin concentrations, total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, uric acid, and insulin concentrations HOMA IRI (homeostastis model assessment of insulin resistance index). RESULTS: Leptin concentrations were higher in obese than in normal subjects and in females than in males without differences between diabetic and non-diabetic patients; leptin concentrations were not related to age and showed a strong negative association with energy intake only in the group of women with BMI less than 40. Leptin concentrations showed a direct correlation with BMI and body fat values (expressed either as percentage of total body mass or absolute fat mass) independent of age and sex. After adjustment for fat mass, leptin values higher than predicted were found in women whereas concentrations lower than predicted were found predominantly in men. Leptin showed an inverse correlation with WHR and C-index, the latter persisting also after correction for gender and fat mass. REE, but not REE/kg fat-free mass (FFM) was inversely related to leptin also after correction for sex and absolute fat mass. Leptin concentrations were directly associated with HOMA IRI, insulin and HDL cholesterol and inversely associated with triglycerides and uric acid. The relationship of leptin with HOMA IRI was still evident after adjusting for sex but was lost when absolute fat mass was added to the model; HDL cholesterol and triglycerides appeared to be variables independent of leptin concentrations even when both sex and fat mass were added to the model. CONCLUSIONS: In a large group of obese patients (half of whom had severe obesity, gender, BMI and fat mass accounted for the largest proportion of serum leptin concentrations variability. We found that in obese subjects there is an effect of fat distribution on leptin concentrations and that, after excluding variability due to absolute fat mass, patients with a greater amount of abdominal fat have relatively low leptin concentrations which in turn relates to a metabolic profile compatible with an increased cardiovascular risk. Women with milder obesity may retain some degree of control of food intake by leptin.     

Effect of a 24-week weight management program on serum leptin level in correlation to anthropometric measures in obese female: A randomized controlled clinical trial

BackgroundObesity is a major contributor to preventable disease and death across the globe. Obesity is complex. Although its risk factors are myriad and compounding, there is an urgent need for a deeper understanding of the way risk factors interact with each other. Leptin is a peptide regulates food intake and body weight. However, the notion of leptin as an anti-obesity hormone was called into question because obesity is typically associated with high leptin levels and not leptin deficiency thus, we aimed to measure leptin levels in obese female in correlation to anthropometric measures and to evaluate the impact of weight loss on its level and metabolic parameters.Subject and methodscase-control study enrolled 40 control groups, 50 obese women. We measured anthropometric measures BMI, Waist/hip ratio (WHR). Fat mass index (FMI%) and free fat mass index (FFMI%) were assessed by dual energy X-Ray absorptiometry (DEXA) The serum levels of leptin were measured by ELISA.ResultsOur results revealed that serum leptin levels were higher in obese women compared to controls. Moreover, it was positively correlated to anthropometric measures, glycemic and lipid profile. Linear regression analysis revealed that BMI was the main independent studied parameters associated with serum leptin level among other clinical and laboratory biomarkers. Interestingly, after 12 weeks of following the Mediterranean diet (MD)–based weight loss program, serum leptin levels were decreased. Logistic regression analysis was performed to detect the main predictors' biomarkers associated with weight loss among obese women. We found that serum leptin and FMI% were an independent predictor of response with odds ratios of 1.69 and 1.64 respectively (P < 0.001), Receiver operating characteristic analyses revealed that the AUC of serum leptin in discriminating obese women from lean ones was 0.893 (95% CI = 0.815–0.917) with sensitivity = 90%, specificity = 96%, and the cutoff values was 36.32 ng/ml.ConclusionSerum leptin could be a valuable diagnostic marker of obesity and its comorbidities. Moreover, significant weight loss leads to decrease serum leptin levels and improvement of glycemic and lipid profiles.