Associations of nicotine dependence and fat distribution in Chinese male adults: a cross-sectional study in Lanxi, China.

INTRODUCTION: Previous studies have showed association between smoking and central fat distribution. However, the impact of smoking on whole body fat distribution, particularly peripheral fat distribution remains unclear. METHODS: Nicotine dependence was assessed in a total of 1264 male adults aged 18-80 years using the Fagerström Test for Nicotine Dependence (FTND). Smoking status was categorised as non-smokers, former and current smokers with very low, low/moderate, or high FTND scores. Body fat distribution was determined using the dual energy X-ray absorptiometry and anthropometric measurements. Multivariable linear regression models were applied to examine the adjusted associations between body fat distribution and smoking in all participants, and its association with FTND scores in the current smokers. RESULTS: Greater waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), trunk fat percentage (%TF), android fat percentage (%AF) and android-to-gynoid fat mass ratio (AOI); but lower legs fat percentage (%LegF), limb fat percentage (%LimbF) and gynoid fat percentage (%GF) were found in current smokers with high FTND scores compared with non-smokers. In current smokers aged 60 years or older, FTND scores had positive associations with WC, WHR, WHtR, %TF, %AF and AOI, and negative associations with %LegF, %LimbF and %GF. CONCLUSIONS: Nicotine dependence was positively associated with central fat distribution and negatively associated with peripheral fat distribution in Chinese male adults, particularly in those older or heavy smokers, and these associations were independent from body mass index, which might be due to long exposure to smoking.

The Body Fat-Cognition Relationship in Healthy Older Individuals: Does Gynoid vs Android Distribution Matter?

OBJECTIVE: To examine the relationship between regional and whole body fat accumulation and core cognitive executive functions. DESIGN: Cross-sectional study. SETTINGS AND PARTICIPANTS: 78 healthy men and women aged between 65 and 75 years recruited through consumer's database. MEASUREMENTS: DXA measured percentage total body fat, android, gynoid distribution and android/gynoid ratio; inhibition and working memory updating through Random Number Generation test and cognitive flexibility by Trail Making test. First-order partial correlations between regional body fat and cognitive executive function were computed partialling out the effects of whole body fat. Moderation analysis was performed to verify the effect of gender on the body fat-cognition relationship. RESULTS: Results showed a differentiated pattern of fat-cognition relationship depending on fat localization and type of cognitive function. Statistically significant relationships were observed between working memory updating and: android fat (r = -0.232; p = 0.042), gynoid fat (r = 0.333; p = 0.003) and android/gynoid ratio (r = -0.272; p = 0.017). Separating genders, the only significant relationship was observed in females between working memory updating and gynoid fat (r = 0.280; p = 0.045). In spite of gender differences in both working memory updating and gynoid body fat levels, moderation analysis did not show an effect of gender on the relationship between gynoid fat and working memory updating. CONCLUSIONS: Results suggest a protective effect of gynoid body fat and a deleterious effect of android body fat. Although excessive body fat increases the risk of developing CDV, metabolic and cognitive problems, maintaining a certain proportion of gynoid fat may help prevent cognitive decline, particularly in older women. Guidelines for optimal body composition maintenance for the elderly should not target indiscriminate weight loss, but weight maintenance through body fat/lean mass control based on non-pharmacological tools such as physical exercise, known to have protective effects against CVD risk factors and age-related cognitive deterioration.

Regional Fat Measured by DEXA and Metabolic Risk Factors among Women with Central Obesity

BACKGROUND: This study was carried out to determine the usefulness of regional body fat measured by dual energy X-ray absorptiometry (DEXA) by examining the relationship between regional body fat and metabolic risk factors. METHODS: A total of 98 women aged 18~65 years with central obesity (waist circumference > or =80 cm) took the evaluation for metabolic risk factors (blood pressure, fasting glucose, insulin, high sensitive c-reactive protein (hs-CRP), lipid profile, homeostasis model assessment of insulin resistance (HOMA-IR)) and the anthropometric measurement, and regional body fat measurement using DEXA. The relationship of regional body fat with the metabolic risk factors, the metabolic syndrome (MS) defined by the International Diabetes Federation and insulin resistance (IR, defined by HOMA-IR> or =2.48) were assessed. The analyses were conducted using regression and logistic regression analyses. RESULTS: After adjustment for age and total body fat (%), legs fat (%) was significantly and negatively associated with LDL-C, triglyceride, HOMA-IR, and hs-CRP, while positively with HDL-C. The 1% increase of legs fat was associated with the MS by odds ratio of 0.82 (95% C.I 0.71~0.96) and with the IR by odds ratio of 0.80 (95% C.I. 0.67~0.95). Trunk fat (%) was significantly and positively associated with LDL-C, triglycerides, and HOMA-IR. The 1% increase of trunk fat was associated with the MS by odds ratio of 1.32 (95% C.I. 1.03~1.71) and with the IR by odds ratio of 1.33 (95% C.I. 1.01~1.77). The ratio of android fat to gynoid fat was significantly and positively associated with LDL-C, triglycerides, glucose, and HOMA- IR, while negatively with HDL-C. The 0.1 increase of the ratio was associated with the MS by odds ratio of 1.66 (95% C.I. 1.07~2.60). CONCLUSION: The trunk fat, and legs fat, the ratio of android fat to gynoid fat assessed by DEXA seemed to be useful indicators to predict the metabolic risk factors in women with central obesity.