Table 3

BMI-specific incidence (cases/1000 person-years) of diabetes by sex and ethnicity

BMI categoriesSouth Asians (SA)PimaIncidence rate ratioIncidence risk difference
New casesPYRIncidence
(95% CI)*
New casesPYRIncidence
(95% CI)*
Pima vs South Asians (ref)Pima minus South Asians
Men
 <2568662210.6 (8.1 to 13.1)15032.0 (0 to 6.0)0.19 (0, 1.12)−8.3 (–12.9, –3.7)
 25–29.962284620.6 (15.4 to 25.8)21131415.9 (9.1 to 22.7)0.73 (0.42, 1.22)−5.8 (–14.5, 2.9)
 ≥303675245.6 (30.6 to 60.5)154315948.1 (40.4 to 55.8)1.02 (0.7, 1.51)0.9 (–16.6, 18.3)
Women
 <255267748.3 (6.0 to10.6)55918.9 (1.1 to 16.9)1.10 (0.34, 2.74)0.8 (–6.9, 8.5)
 25–29.991470518.2 (14.5 to 22)31145320.8 (13.5 to 28.1)1.10 (0.71, 1.67)2.0 (–6.5, 10.5)
 ≥3098261034.1 (27.2 to 40.9)298607646.5 (40.9 to 52.0)1.31 (1.04, 1.66)11.5 (2.2, 20.8)
  • IRR (ratio of incidence rates) calculated as Pima (incidence rate) divided by SA (incidence rate). IRD (risk difference, cases/1000 person years) calculated as Pima (incidence rate) minus SA (incidence rate).

  • Incidence rate ratio and incidence risk difference calculated from crude incidence rates.

  • Diabetes defined as FPG≥7.00 mmol/L (126 mg/dL) or HbA1c ≥ 48 mmol/mol (6.5 %) or self-reported/physician diagnosed diabetes or medication.

  • *Age adjusted.

  • BMI, body mass index; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin; IRD, incidence risk difference; IRR, incidence rate ratio; PYR, person years; ref, reference category.