title: Comparison of body mass index at diagnosis of diabetes in a multi-ethnic population: A case-control study with matched non-diabetic controls.
abstract: To investigate the probability of developing type 2 diabetes mellitus (T2DM) at different body mass index levels compared to matched non-diabetic controls in a multi-ethnic population.
  
  
  
  This was a case-control study of 90 367 patients with incident diabetes and 362 548 age-sex-ethnicity matched controls from UK primary care. The probability of developing T2DM was estimated.
  
  
  
  Case and control patients were 56 years old at index and 56% were male. Patients with T2DM had significantly higher mean BMI levels by about 5 kg/m2at diagnosis (32.2 kg/m2) compared to the matched controls (27.4 kg/m2). White Europeans (n = 79 270), African-Caribbeans (n = 4115) and South Asians (n = 7252) were 58, 48 and 46 years old with a mean BMI of 32.5, 31.1 and 29.2 kg/m2, respectively, at diagnosis. More South Asians developed T2DM at BMI below 30 kg/m2(38%) than White Europeans (26%) and African-Caribbeans (29%) (all P  < .01). Within the 18 to 70-year age range, South Asian males and females had a significantly higher probability of developing diabetes in the continuously measured BMI range of 18 to 30 kg/m2, compared to White Europeans and African-Caribbeans. Across all age groups <70 years, South Asians and African-Caribbeans had a significantly higher probability of developing T2DM in the normal weight and overweight categories, compared to White Europeans. However, this risk pattern of developing diabetes was reversed amongst the obese in all age groups.
  
  
  
  Risk patterns of developing diabetes at different levels of obesity varies among ethnic groups across all ages, while South Asians and African-Caribbeans carry the highest risk at a younger age and at lower adiposity burden.
authors.affiliation: Clinical Trials and Biostatistics Unit, QIMR Berghofer Medical Research Institute, Brisbane, Australia.|Melbourne EpiCentre, University of Melbourne and Melbourne Health, Melbourne, Australia.
authors.forename: Sanjoy K
authors.identifier: 0000-0003-0848-7194
authors.initials: SK
authors.lastname: Paul
authors.affiliation: Clinical Trials and Biostatistics Unit, QIMR Berghofer Medical Research Institute, Brisbane, Australia.|School of Medicine, The University of Queensland, Brisbane, Australia.
authors.forename: Ebenezer S
authors.initials: ES
authors.lastname: Owusu Adjah
authors.affiliation: Clinical Trials and Biostatistics Unit, QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Mayukh
authors.initials: M
authors.lastname: Samanta
authors.affiliation: University of Warwick, Warwick, UK.|Heart of England NHS Trust, Birmingham, UK.
authors.forename: Kiran
authors.initials: K
authors.lastname: Patel
authors.affiliation: Aston Research Centre for Healthy Ageing, Aston University, Birmingham, UK.
authors.forename: Srikanth
authors.initials: S
authors.lastname: Bellary
authors.affiliation: Department of Diabetes, University Hospital Birmingham, Birmingham, UK.
authors.forename: Wasim
authors.initials: W
authors.lastname: Hanif
authors.affiliation: Department of Health Sciences, University of Leicester, Leicester, Birmingham, UK.
authors.forename: Kamlesh
authors.initials: K
authors.lastname: Khunti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D044383:Black People; D015992:Body Mass Index; D016022:Case-Control Studies; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology / Q000208:ethnology / Q000209:etiology*; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000208:ethnology / Q000503:physiopathology*; D050177:Overweight / Q000150:complications / Q000208:ethnology / Q000503:physiopathology*; D011320:Primary Health Care; D012307:Risk Factors; D013222:State Medicine; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
keywords: body mass index; matched case-control study; multi-ethnic comparisons; probability of developing type 2 diabetes