title: Increased risk of type 2 diabetes with ascending social class in urban South Indians is explained by obesity: The Chennai urban rural epidemiology study (CURES-116).
abstract: OBJECTIVE
  The aim of this study is to determine the factors responsible for differences in the prevalence of diabetes mellitus (DM) in subjects of different social class in an urban South Indian population.
  
  
  METHODS
  Analyses were based on the cross-sectional data from the Chennai Urban Rural Epidemiology Study of 1989 individuals, aged ≥20 years. Entered in the analyses were information obtained by self-report on (1) household income; (2) family history of diabetes; (3) physical activity; (4) smoking status; (5) alcohol consumption. Biochemical, clinical and anthropometrical measurements were performed and included in the analyses. Social class was classified based on income as low (Rs. <2000) intermediate (Rs. 2000-5000`) and high (Rs. 5000-20000).
  
  
  RESULTS
  The prevalence rates of DM were 12.0%, 18.4% and 21.7% in low, intermediate and high social class, respectively (P < 0.001). A significant increase in the risk of diabetes was found with ascending social class (Intermediate class: Odds ratio [OR], 1.7 [confidence interval [CI], 1.2-2.3]; High class: OR, 2.0 [CI-1.4-2.9]). The multivariable adjusted logistic regression analysis revealed that the effect of social class on the risk of diabetes remained significant (P = 0.016) when age, family history of diabetes and blood pressure were included. However, with the inclusion of abdominal obesity in the model, the significant effect of social class disappeared (P = 0.087).
  
  
  CONCLUSIONS
  An increased prevalence of DM was found in the higher social class in this urban South Indian population, which is explained by obesity.
authors.affiliation: Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Mette
authors.initials: M
authors.lastname: Skar
authors.affiliation: Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Anne Berg
authors.initials: AB
authors.lastname: Villumsen
authors.affiliation: Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Dirk Lund
authors.initials: DL
authors.lastname: Christensen
authors.affiliation: Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Joergen Holm
authors.initials: JH
authors.lastname: Petersen
authors.affiliation: Department of Epidemiology, Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non Communicable Diseases Prevention and Control, International Diabetes Federation Centre of Education, Gopalapuram, Chennai, Tamil Nadu, India.
authors.forename: Mohan
authors.initials: M
authors.lastname: Deepa
authors.affiliation: Department of Epidemiology, Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non Communicable Diseases Prevention and Control, International Diabetes Federation Centre of Education, Gopalapuram, Chennai, Tamil Nadu, India.
authors.forename: Ranjit Mohan
authors.initials: RM
authors.lastname: Anjana
authors.affiliation: Department of Epidemiology, Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non Communicable Diseases Prevention and Control, International Diabetes Federation Centre of Education, Gopalapuram, Chennai, Tamil Nadu, India.
authors.forename: Rajendra
authors.initials: R
authors.lastname: Pradeepa
authors.affiliation: Department of Epidemiology, Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non Communicable Diseases Prevention and Control, International Diabetes Federation Centre of Education, Gopalapuram, Chennai, Tamil Nadu, India.
authors.forename: Viswanathan
authors.initials: V
authors.lastname: Mohan
keywords: Asian Indians; South Asians; diabetes; obesity; social class; socio-economic status; urban