Effects Of Central Adiposity Research Articles

Effect of central adiposity on lung function tests in adolescents

Objectives: The objectives of the study were to study the relation of total body adiposity and abdominal adiposity markers with forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) in adolescents in Bengaluru. Methods: 125 healthy children from a school and 70 asthmatics from Ramaiah hospital between 10 and 15 years were included in the study. Anthropometry including weight, body mass index (BMI), waist and hip circumference, and abdominal height was done in all study adolescents. The subjects were categorized according to BMI. Pulmonary function tests (PFTs) were done by Knudson methodand FEV1, FVC, and peak expiratory flow (PEF) were measured. The patients were classified by their asthma severity according to GINA guidelines. Results: BMI, weight, waist and hip circumference correlated with abdominal height in male asthmatics and controls where they revealed significant correlations with FEV1/FVC% ratio. In females, abdominal height correlated with BMI, weight, waist and hip circumference in both the groups. PEF correlated with BMI, weight, waist circumference, and abdominal height in healthy females. FEV1/FVC correlated with BMI, abdominal height in female asthmatics, with weight in healthy females.Independent predictors of FEV1/FVC% ratio were hip circumference in males and abdominal height, and waist circumference in females. Conclusion: Increase in obesity is associated with reduced lung volumes and flows. The abdominal adiposity markers (waist and hip circumference, and abdominal height) are significant and effective predictors of obesity and the variations of PFT’s than total adiposity markers (BMI and weight).

Central adiposity and other anthropometric factors in relation to risk of macrosomia in an african american population

Previous studies have consistently identified maternal obesity and gestational weight gain as risk factors for macrosomia, but little is known about the effects of central adiposity and body fat distribution. Using self-reported data from the Black Women's Health Study (BWHS), a large follow-up study of U.S. black women, we examined the risk of macrosomia in relation to prepregnancy waist circumference, prepregnancy waist-to-hip ratio, prepregnancy body mass index (BMI), and gestational weight gain. During 1995–2003, BWHS participants ages 21 to 44 years delivered 6,687 full-term singleton births (gestational age >37 weeks). We compared mothers of 691 infants weighing ≥4000g with mothers of 5,996 infants weighing <4000g. Generalized estimating equation models that accounted for more than one birth per mother were used to estimate multivariable odds ratios (OR) and 95% confidence intervals (CI). Independent of prepregnancy BMI, prepregnancy waist circumference was positively associated with risk of macrosomia (OR=1.58, 95% CI 1.07–2.32, for ≥35.0 vs. <27.0 inches (≥88.9 vs. <68.6 cm); P-trend= 0.04). As expected, prepregnancy BMI was also positively associated with macrosomia (OR=1.74, 95% CI 1.25–2.41 for BMI ≥35.0 vs. 18.5–24.9 kg/m2). Gestational weight gain above the amount recommended by the 2009 Institute of Medicine report was associated with an increased risk of macrosomia and the association was present in each category of prepregnancy BMI (18.5–24.9, 25.0–29.9, and ≥30.0 kg/m2; P-trend<0.001). Our data suggest that overall obesity, high gestational weight gain, and high waist circumference are independent risk factors for macrosomia among U.S. black women.

Body fat distribution and breast cancer risk: findings from the Nigerian breast cancer study

The relationship between overall obesity and breast cancer risk has been well recognized, but the role of central obesity in breast cancer development is uncertain. Between 1998 and 2009, 1,233 invasive breast cancer cases and 1,101 community controls were recruited into the Nigerian Breast Cancer Study at Ibadan, Nigeria. Logistic regressions were used to calculate multivariate odds ratio (OR) and 95% confidence intervals (CI), adjusting for age, body mass index (BMI), and other known risk factors for breast cancer. The OR for the highest quartile group of waist circumference relative to the lowest was 2.39 (95% CI, 1.59-3.60; P-trend < 0.001). Comparing women with waist/hip ratio (WHR) in the lowest quartile group, the OR for women in the highest quartile category was 2.15 (95% CI, 1.61-2.85; P-trend < 0.001). An inverse association was observed between hip circumference and breast cancer, with an OR of 0.36 for the highest quartile (95% CI, 0.24-0.55; P-trend < 0.001). The effects of these three measures existed in both pre- and postmenopausal women. Of note, we found a significant interaction between WHR and BMI (P-interaction = 0.016): the OR comparing the highest to the lowest WHR quartile was 2.81 (95% CI, 1.90-4.16) for women with BMI < 25 kg/m2 and 1.70 (95% CI, 1.11-2.61) for women with BMI ≥ 25 kg/m2. These results suggest that central adiposity, measured by waist circumference and waist/hip ratio, was an important risk factor for breast cancer in Nigerian women, and the effect of central adiposity was strong in normal-weight women.

Plasma Epinephrine Predicts Fasting Glucose in Centrally Obese African‐American Women

The high prevalence of diabetes in African-American (AA) women has been widely assumed to be related to the greater prevalence of obesity in this group. Catecholamine release acting on central adipose tissue has been proposed to be a contributing factor. The aim of this article was to examine the interaction of plasma catecholamines and central adiposity on fasting and nonfasting glucose levels in two separate samples. In both studies, the women were healthy, nondiabetic of similar age. In addition, both studies assessed plasma epinephrine (EPI) and norepinephrine (NOREPI) levels collected at three time points. In study 1, catecholamines were measured during a standardized laboratory mental stress task and in study 2, they were measured during the initial phase (10 min) of an intravenous glucose tolerance test (IVGTT). Results from both studies revealed significant effects of EPI on fasting glucose in the obese women. In study 1, mean EPI levels were significantly related to fasting glucose in AA women with high trunk fat (beta = 0.60, P < 0.001). Because high BMI was associated with high trunk fat in women, we used BMI >30 as a proxy for high trunk fat (>32%) in study 2. In study 2, EPI response to the glucose bolus was a strong predictor of fasting glucose in AA women with BMI >30 (beta = 0.75, P < 0.003). We conclude that the effect of central adiposity on fasting glucose may be moderated by plasma EPI. This suggests that adrenal medullary activity could play a role in the pathophysiology of type 2 diabetes.

T1246 The Effect of Central Adiposity On Esophageal Acid Exposure and Symptoms of Gastro-Esophageal Reflux Disease

INTRODUCTION: Epidemiologic evidence suggests a link between gastro-esophageal reflux disease (GERD) and obesity. Studies suggest that this relationship is due to the effects of central adiposity on intragastric pressure with disruption of the gastro-esophageal junction (GEJ) reflux barrier, however the clinical relevance of these findings has not been proven. METHODS: From Aug 2005 to Dec 2006, patients sent to a referral center for physiologic investigation of GERD were studied. Height, weight and waist circumference (WC) were measured. Stationary manometry and 24hr ambulatory pH studies off acid-suppressants were performed and symptom severity was assessed by a validated questionnaire. Linear regression models were used to analyze associations between covariates of interest and Pearson's correlation coefficient (PC) was applied to assess the strength of association. RESULTS: 582/676(86%) consecutive patients (age 48 (range 14-89), 56% female) had complete data for analysis. The prevalence of obesity defined by BMI≥30kg.m-2 in males and females was 16% and 23% (p=ns) respectively. More men hadWC≥99cm (M41%:F28%; p<0.001)). %time pH<4 at 5cm above the lower esophageal sphincter (LES) increased with obesity (PC=0.255 and 0.240 for BMI and WC respectively; both p<0.001) and age (PC= 0.162; p<0.001) and was higher in men than women (p=0.014) Increase in %time pH<4 was associated with a reduction in LES pressure and abdominal LES length (PC=-0.327, -0.344 respectively; p<0.001). There was a weak negative association of BMI with LES pressure (PC=-0.140; p=0.005) but no link with abdominal LES length. In contrast, there was a significant negative association of WC with LES pressure (PC=-0.225; p<0.001) and abdominal LES length (PC=-0.213; p<0.001). Overall symptom severity increased with %time pH<4 (PC=0.209; p<0.001); however there was no change in symptom severity with BMI (PC=0.056, p=0.17) and the effect of WC was weak and of borderline significance (PC=0.083, p=0.05). CONCLUSION: In this large cohort of clinical patients referred for investigation of reflux symptoms, gastro-esophageal reflux increased with obesity and was most prevalent in elderly males with central adiposity. WC but not BMI was associated with both reduced LES pressure and abdominal length. These findings confirm the mechanistic link between increasing WC and the risk of reflux via raised intragastric pressure and disruption of the GEJ. In contrast, there was little change in symptom severity despite increased acid exposure in this group. The relative insensitivity to acid reflux may explain the increased prevalence of severe and complicated reflux in obese patients.

T1247 Effects of Chenodeoxycholic Acid On Gastrointestinal and Colonic Transit and Bowel Function in Healthy Volunteers

INTRODUCTION: Epidemiologic evidence suggests a link between gastro-esophageal reflux disease (GERD) and obesity. Studies suggest that this relationship is due to the effects of central adiposity on intragastric pressure with disruption of the gastro-esophageal junction (GEJ) reflux barrier, however the clinical relevance of these findings has not been proven. METHODS: From Aug 2005 to Dec 2006, patients sent to a referral center for physiologic investigation of GERD were studied. Height, weight and waist circumference (WC) were measured. Stationary manometry and 24hr ambulatory pH studies off acid-suppressants were performed and symptom severity was assessed by a validated questionnaire. Linear regression models were used to analyze associations between covariates of interest and Pearson's correlation coefficient (PC) was applied to assess the strength of association. RESULTS: 582/676(86%) consecutive patients (age 48 (range 14-89), 56% female) had complete data for analysis. The prevalence of obesity defined by BMI≥30kg.m-2 in males and females was 16% and 23% (p=ns) respectively. More men hadWC≥99cm (M41%:F28%; p<0.001)). %time pH<4 at 5cm above the lower esophageal sphincter (LES) increased with obesity (PC=0.255 and 0.240 for BMI and WC respectively; both p<0.001) and age (PC= 0.162; p<0.001) and was higher in men than women (p=0.014) Increase in %time pH<4 was associated with a reduction in LES pressure and abdominal LES length (PC=-0.327, -0.344 respectively; p<0.001). There was a weak negative association of BMI with LES pressure (PC=-0.140; p=0.005) but no link with abdominal LES length. In contrast, there was a significant negative association of WC with LES pressure (PC=-0.225; p<0.001) and abdominal LES length (PC=-0.213; p<0.001). Overall symptom severity increased with %time pH<4 (PC=0.209; p<0.001); however there was no change in symptom severity with BMI (PC=0.056, p=0.17) and the effect of WC was weak and of borderline significance (PC=0.083, p=0.05). CONCLUSION: In this large cohort of clinical patients referred for investigation of reflux symptoms, gastro-esophageal reflux increased with obesity and was most prevalent in elderly males with central adiposity. WC but not BMI was associated with both reduced LES pressure and abdominal length. These findings confirm the mechanistic link between increasing WC and the risk of reflux via raised intragastric pressure and disruption of the GEJ. In contrast, there was little change in symptom severity despite increased acid exposure in this group. The relative insensitivity to acid reflux may explain the increased prevalence of severe and complicated reflux in obese patients.

The Effects of Central Adiposity on Growth Hormone (GH) Response to GH-Releasing Hormone-Arginine Stimulation Testing in Men

The relative contribution of central adiposity vs. weight on GH response to stimulation testing in obesity is not known. We aimed to assess the contribution of weight and specific measures of central and peripheral adiposity to GH response to GHRH-arginine testing in lean, overweight, and obese men. A total of 75 men [mean age, 44.3+/-1.1 yr; body mass index (BMI), 28.8+/-0.7 kg/m2] were investigated. Subjects were classified as lean (BMI<25 kg/m2; n=23), overweight (BMI>or=25 and <30 kg/m2; n=28), or obese (BMI>or=30 kg/m2; n=24). Subjects were also stratified by waist circumference (WC) (<102 cm, n=47; >or=102 cm, n=28). Body composition and regional adiposity were assessed by anthropometrics, dual-energy x-ray absorptiometry (DEXA), and abdominal computed tomography (CT) scans. Peak stimulated GH was 36.4+/-5.4, 16.6+/-2.9, and 7.6+/-0.9 microg/liter among lean, overweight, and obese subjects, respectively (P<0.001 for all comparisons). Peak stimulated GH was 26.9+/-3.4 microg/liter among subjects with WC less than 102 cm compared to 7.9+/-0.9 microg/liter among subjects with WC of 102 cm or greater (P<0.0001). Separate multivariate models using anthropometric, DEXA, and CT-derived measures of central adiposity demonstrated strong associations between peak stimulated GH and measures of central adiposity including WC, trunk fat by DEXA, and visceral adiposity by CT, controlling for age, BMI, and more general measures of adiposity. WC was independently associated with peak GH response to GHRH-arginine in a model including age, BMI, and hip circumference. In this model, BMI was no longer significant, and peak GH was reduced 1.02 microg/liter for each 1 cm increase in WC (P=0.02). GH response to GHRH-arginine testing is reduced in both overweight and obese subjects and negatively associated with indices of central abdominal obesity including WC, trunk fat, and visceral adipose tissue. The use of waist circumference, as a surrogate for central adiposity, adds predictive information to the determination of GH response, independent of BMI.

Body Size, Weight Cycling, and Risk of Renal Cell Carcinoma among Postmenopausal Women: The Women's Health Initiative (United States)

Although obesity is an established risk factor for renal cell carcinoma, the possible effect of central adiposity and long-term variation in weight has yet to be established. The authors studied 140,057 women aged 50-79 years enrolled in the Women's Health Initiative in the United States to examine the role of obesity, especially abdominal obesity, and weight cycling in relation to risk of renal cell carcinoma among postmenopausal women. Cox models were used to estimate relative risks and their corresponding 95% confidence intervals. During an average of 7.7 years of follow-up through September 12, 2005, a total of 269 incident cases of renal cell carcinoma were identified. Central adiposity, as indicated by waist-to-hip ratio, was an important risk factor for developing renal cell carcinoma (highest vs. lowest quartile: relative risk = 1.8, 95% confidence interval: 1.2, 2.5; p for trend = 0.0003). Moreover, women who had experienced weight cycling more than 10 times were at 2.6 times (95% confidence interval: 1.6, 4.2) increased risk compared with women whose weight was stable. Results add evidence that obesity, particularly central adiposity, is associated with an increased risk of renal cell carcinoma among postmenopausal women. Furthermore, they indicate that weight cycling is independently associated with further increased risk of this malignancy.