title: Can body fat distribution, adiponectin levels and inflammation explain differences in insulin resistance between ethnic Chinese, Malays and Asian Indians?
abstract: OBJECTIVE
  Diabetes in Asia constitutes approximately half of the global burden. Although insulin resistance and incidence of type 2 diabetes differ substantially between ethnic groups within Asia, the reasons for these differences are poorly understood. We evaluated to what extent body fatness, adiponectin levels and inflammation mediate the relationship between ethnicity and insulin resistance in an Asian setting.
  
  
  METHODS
  Cross-sectional population-based study.
  
  
  METHODS
  In total, 4136 adult Chinese, Malays and Asian Indians residing in Singapore.
  
  
  METHODS
  Insulin resistance was assessed using homeostasis model assessment (HOMA-IR) and systemic inflammation by C-reactive protein (CRP). Data were analyzed using path analysis.
  
  
  RESULTS
  HOMA-IR was highest in Asian Indians, intermediate in Malays and lowest in Chinese (P<0.001). The difference in HOMA-IR between Malays and Chinese disappeared after adjusting for body mass index (BMI). For the comparison of Asian Indians with Chinese, the association between ethnicity and HOMA-IR was mediated by BMI (men: 32.9%; women: 48.5%), BMI-adjusted waist circumference (men: 6.1%; women: 3.5%), and CRP (men: 5.1%; women: 5.6%), and unidentified factors (men: 47.2%; women: 26.5%). Part of the mediating effects of body fatness was indirect through effects of body fatness on CRP and adiponectin concentrations.
  
  
  CONCLUSIONS
  Mediators of ethnic differences in insulin resistance differed markedly depending on the ethnic groups compared. General adiposity explained the difference in insulin resistance between Chinese and Malays, whereas abdominal fat distribution, inflammation and unexplained factors contributed to excess insulin resistance in Asian Indians as compared with Chinese and Malays. These findings suggest that interventions targeting excess weight gain can reduce ethnic disparities in insulin resistance among Asian Indians, Chinese and Malays.
authors.affiliation: Department of Epidemiology and Public Health, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: H
authors.initials: H
authors.lastname: Gao
authors.forename: A
authors.initials: A
authors.lastname: Salim
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: E S
authors.initials: ES
authors.lastname: Tai
authors.forename: R M
authors.initials: RM
authors.lastname: van Dam
mesh_terms: D052242:Adiponectin / Q000097:blood*; D044466:Asian People; D001823:Body Composition; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002681:China / Q000208:ethnology; D003430:Cross-Sectional Studies; D005260:Female; D006706:Homeostasis; D006801:Humans; D007194:India / Q000208:ethnology; D007249:Inflammation / Q000097:blood / Q000453:epidemiology / Q000208:ethnology*; D007333:Insulin Resistance / Q000208:ethnology*; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000453:epidemiology / Q000208:ethnology*; D011446:Prospective Studies; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology; D055105:Waist Circumference / Q000208:ethnology; D015430:Weight Gain / Q000208:ethnology; D044465:White People
chemical_list: D052242:Adiponectin; D002097:C-Reactive Protein