Ethnicity modifies the relationships of insulin resistance, inflammation, and adiponectin with obesity in a multiethnic Asian population.

OBJECTIVE: The development of obesity-related metabolic disorders varies with ethnicity. We examined whether ethnicity modifies the relationship between BMI and three metabolic pathways (insulin resistance, inflammation, and adiponectin) that are involved in the pathogenesis of diabetes and cardiovascular disease (CVD). RESEARCH DESIGN AND METHODS: We analyzed data from 4,804 Chinese, Malay, and Asian-Indian residents of Singapore with complete data on insulin resistance (IR), C-reactive protein (CRP), and total adiponectin levels. Linear regression models with an interaction term ethnicity*BMI were used to evaluate whether ethnicity modifies the association between BMI and IR, CRP, and adiponectin. RESULTS: In both uni- and multivariate analyses, BMI was directly associated with IR and CRP and inversely with adiponectin across all ethnic groups. When compared with Chinese and Malays, Asian-Indians had higher IR and CRP and lower adiponectin levels. The associations between BMI and its metabolic pathways were significantly stronger in Chinese than in other ethnic groups. The increase in IR and CRP and the decrease in adiponectin for each unit increase in BMI were greater in Chinese than in other ethnic groups. The findings were similar when waist circumference was used in the analyses instead of BMI. CONCLUSIONS: The impact of BMI on IR, CRP, and adiponectin appears greater in Chinese as compared with other major Asian ethnic groups. This may partly explain the rapid increase in the prevalence of diabetes and CVD in Chinese populations and highlights the importance of weight management in Asian ethnic groups despite the apparently low levels of obesity.

The relevance of the metabolic syndrome.

INTRODUCTION: To review the definitions of the metabolic syndrome according to various expert groups and assess their relevance to clinical practice. MATERIALS AND METHODS: Medline searches were conducted to identify studies which addressed: (i) the utility of the metabolic syndrome compared to multivariable predictive functions for the identification of individuals at high risk of type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), (ii) the importance and definition of obesity in the definition of the metabolic syndrome and (iii) the impact of lifestyle and pharmacological interventions designed to reduce the risk of cardiovascular disease in those with and without the metabolic syndrome. RESULTS: Although inferior to multivariable risk scores in predicting T2DM and CVD, the metabolic syndrome represents a simple clinical tool, particularly for the prediction of T2DM. Obesity is not a critical component of the metabolic syndrome for identifying those at increased risk of CVD but may be important for predicting T2DM. If anything, pharmacological therapy, especially lipid lowering is as, if not more, effective in those with the metabolic syndrome than in those without. CONCLUSIONS: Although the metabolic syndrome appears to have limited utility for the identification of individuals at increased risk of T2DM or CVD, the diagnosis of the metabolic syndrome presents an opportunity to rationalise health services to deliver coordinated care to those with metabolic syndrome.