Background: Among South Asians, women have higher prevalence of diabetes than men, but few studies have examined gender differences in incidence.
Methods: We analyzed data from 2714 adults aged ≥20 years, enrolled in the Chennai site of prospective Cardiometabolic risk reduction in South Asia (CARRS) study. We defined normal glucose tolerance (NGT) , isolated impaired fasting glucose (iIFG) , impaired glucose tolerance (IGT) , and diabetes based on ADA criteria. We estimated incidence densities for: NGT (n=2205) to iIFG and iIFG (n=641) to diabetes; NGT (n=2205) to IGT; and IGT (n=341) to diabetes.
Results: Prevalence of iIFG was higher in women (20.5% vs. 11.8%) , while prevalence of IGT was lower (6.6% vs. 8.5%) than in men. During median 2.6 y (IQR: 0.7, 5.8) of follow-up, 316 individuals progressed from NGT to iIFG, 239 from NGT to IGT, 155 from iIFG to diabetes, and 135 from IGT to diabetes. Overall, incidence (95% CI) of NGT to iIFG was higher than incidence of NGT to IGT (36.3 [32.5, 40.5] vs. 27.4 [24.1, 31.1] per 1,000 person-years [PYR], respectively) . However, the incidence of iIFG to diabetes was lower than incidence of IGT to diabetes (47.3 [40.4, 55.4] vs. 77.1 [65.1, 91.3] per 1,000 PYR, respectively) . Compared with men, women had higher conversion from NGT to iIFG (42.1 [36.9, 48] vs. 27.7 [22.7, 33.8]) , but lower incidence of NGT to IGT, 22.9 (19.2, 27.4) vs. 34.2 (28.5, 40.9) . Women had higher conversation both from iIFG to diabetes [49.0 (40.8,58.8) vs. 43.1 (31.6,58.7) ] and IGT to diabetes (87.7 [70.5,109.0] vs. 65.3 [50.0,85.2]) . In Cox models adjusting for age, BMI and family history of diabetes, women were 1.41 times (95% CI: 1.07,1.84) likely to convert from NGT to iIFG compared to men, but, men are 1.76 (1.33, 2.34) times at risk from NGT to IGT. There was no gender difference for conversion from iIFG or IGT to diabetes.
Conclusion: Prevalence and incidence of iIFG is higher in South Asian women than men, while prevalence and incidence of IGT is higher in men. Conversion from iIFG or IGT to diabetes is similar among genders.
K.Narayan: n/a. H.H.Chang: None. N.Tandon: None. V.Mohan: None. D.Kondal: None. L.R.Staimez: None. R.Anjana: None. U.Gujral: None. M.Deepa: None. S.A.Patel: Research Support; Johnson & Johnson. M.K.Ali: Advisory Panel; Bayer AG, Research Support; Merck & Co., Inc. D.Prabhakaran: None.
The National Heart, Lung, and Blood Institute (NHLBI) , National Institutes of Health (HHSN268200900026C)