View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by PubMed Central Android Fat Depot Is More Closely Associated with Metabolic Syndrome than Abdominal Visceral Fat in Elderly People Seon Mee Kang1, Ji Won Yoon1, Hwa Young Ahn1, So Yeon Kim2, Kyoung Ho Lee2, Hayley Shin3, Sung Hee Choi1, Kyong Soo Park4, Hak Chul Jang1, Soo Lim1* 1 Department of Internal Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea, 2 Department of Radiology, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea, 3 Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America, 4 Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea Abstract Background: Fat accumulation in android compartments may confer increased metabolic risk. The incremental utility of measuring regional fat deposition in association with metabolic syndrome (MS) has not been well described particularly in an elderly population. Methods and Findings: As part of the Korean Longitudinal Study on Health and Aging, which is a community-based cohort study of people aged more than 65 years, subjects (287 male, 75.968.6 years and 278 female, 76.068.8 years) with regional body composition data using Dual energy X-ray absorptiometry for android/gynoid area, computed tomography for visceral/subcutaneous adipose tissue (VAT/SAT), and cardiometabolic markers including adiponectin and high-sensitivity CRP were enrolled. We investigated the relationship between regional body composition and MS in multivariate regression models. Mean VAT and SAT area was 131.4665.5 cm2 and 126.9655.2 cm2 in men (P = 0.045) and 120.0646.7 cm2 and 211.8665.9 cm2 in women (P,0.01). Mean android and gynoid fat amount was 1.860.8 kg and 2.560.8 kg in men and 2.060.6 kg and 3.360.8 kg in women, respectively (both P,0.01). VAT area and android fat amount was strongly correlated with most metabolic risk factors compared to SAT or gynoid fat. Furthermore, android fat amount was significantly associated with clustering of MS components after adjustment for multiple parameters including age, gender, adiponectin, hsCRP, a surrogate marker of insulin resistance, whole body fat mass and VAT area. Conclusions: Our findings are consistent with the hypothesized role of android fat as a pathogenic fat depot in the MS. Measurement of android fat may provide a more complete understanding of metabolic risk associated with variations in fat distribution. Citation: Kang SM, Yoon JW, Ahn HY, Kim SY, Lee KH, et al. (2011) Android Fat Depot Is More Closely Associated with Metabolic Syndrome than Abdominal Visceral Fat in Elderly People. PLoS ONE 6(11): e27694. doi:10.1371/journal.pone.0027694 Editor: Gian Paolo Fadini, University of Padova, Italy Received June 2, 2011; Accepted October 22, 2011; Published November 11, 2011 Copyright: ß 2011 Kang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was supported by the Ministry of Science and Technology (2006-2005410), Seoul R&BD Program, Republic of Korea (10526), Seoul National University Bundang Hospital to S. Lim, and Korean Diabetes Association grant (2006) to S.H. Choi. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: [email protected] Introduction greater risk of developing diabetes and future cardiovascular events than the peripheral area [8]. There are differences Obesity is a heterogeneous disorder characterized by multi- between adipose tissue present in subcutaneous areas and in the factorial etiology. Obese individuals vary in their body fat abdominal cavity. These include anatomical, cellular, molecular, distribution, their metabolic profile and the degree of associated physiological, clinical and prognostic differences [2,7,9]. Many cardiovascular and metabolic risks. There is substantial evidence studies have suggested that visceral adipose tissue (VAT) com- providing that fat distribution is a better predictor of cardiovas- pared with subcutaneous adipose tissue (SAT) is more cellular, cular disease than the degree of obesity [1–5]. An excess of vascular and innervated with a larger number of inflammatory abdominally located fat, even without manifestations of obesity, is and immune cells, lesser preadipocyte differentiating capacity, associated with metabolic disturbances that indicate an increased and a greater percentage of large adipocytes [9]. Similar findings risk of atherogenesis and of higher morbidity and mortality, were also observed across different races/ethnicities including possible due to inherent characteristics of abdominal adipocytes Japanese where an independent association with VAT was found [3,4,6,7]. Thus, regional fat distribution rather than overall fat even after accounting for multiple risk factors [7]. Therefore, fat volume has been considered to be more important in under- distribution rather than its magnitude may be more significant in standing the link between obesity and metabolic disorders. understanding metabolic risk, particularly the varying impacts of Among fat depots, fat accumulation in the abdominal area has a VAT and SAT. PLoS ONE | www.plosone.org 1 November 2011 | Volume 6 | Issue 11 | e27694 Android Fat and Metabolic Syndrome in Elderly In a different context, truncal fat depot can be partitioned into Physical activity was divided into two categories; none or regular upper body (android or central) and lower body (gynoid or exercise. Regular exercise was defined as exercising more than peripheral) area. Empirically, android or central fat deposition is three times a week (each session should be at least 30 min long). known to be more associated with cardiometabolic risk than The homeostasis model assessment of the insulin resistance gynoid or peripheral fat deposition. Many studies with simple (HOMA-IR) was calculated as reported previously [17]. Several anthropometric measurements such as waist circumference or metabolic markers including adiponectin and high-sensitivity CRP waist-to-hip ratio have given more weight to the central adiposity (hsCRP) which are known to be associated with MS were mea- [6,10–12]. More advanced technology with computed tomogra- sured. Detailed information about measurement method was phy (CT) or dual energy X-ray absorptiometry (DXA) has been published previously [16]. MS was defined according to the NCEP used to measure the regional fat mass. CT has an advantage in guideline as the presence of at least three of the following com- distinguishing between VAT and SAT while DXA can measure ponents: abdominal obesity (waist circumference $90 cm for men compartment body compositions such as android and gynoid area. and $80 cm for women), triglyceride level $150 mg/dL, high- However, there are limited studies investigating the implication of density lipoprotein cholesterol level ,40 mg/dL for men and android/gynoid fat deposition assessed by advanced technology in ,50 mg/dL for women, blood pressure $135/85 mmHg, and/or determining cardiometabolic risks. fasting blood glucose level $110 mg/dL [18]. All the assessments Metabolic syndrome (MS) increases cardiovascular morbidity were performed at Seoul National University Bundang Hospital and mortality, and all cause of mortality [13]. MS also increases (SNUBH). This was approved by the Institutional Review Board the risk of developing diabetes mellitus with its components re- of SNUBH. The written, informed consent for subjects undergo- presenting major risk factors for impaired glucose metabolism ing CT procedure to inform them of radiation hazard and possible [14]. Obesity, particularly abdominal obesity, is a key feature of a contrast toxicity was obtained from each individual as a routine cluster of atherothrombotic and inflammatory abnormalities procedure. associated with MS [15]. There is substantial evidence linking central obesity with cardiovascular disease and the other MS Regional body composition by DXA components as well as its critical role in the etiological cascade DXA measures were recorded using a bone densitometer leading to full-blown manifestations of MS. (Lunar, GE Medical systems, Madison, WI). DXA is quantified by Thus, assessment of fat distribution may be important in the body tissue absorption of photons that are emitted at two energy clinical evaluation of cardiometabolic risks. However, there has levels to resolve body weight into bone mineral, lean and fat soft been no comprehensive study on fat distribution related risks tissue masses. In vivo precision for body composition measure- particularly in elderly Asian populations whose physical and meta- ments using DXA was proven previously [19]. In this study, bolic characteristics differ from those of Caucasians. We evaluated precision was excellent for lean tissue mass (root mean square of the association between clustering of components constituting MS 0.21 kg; coefficient of variation (CV) of 0.4%) and precision error and the whole and regional body composition measured by com- for the total fat mass had a CV 0.86% and 0.88% for the prehensive methods including DXA and CT