Cumulative incidence and risk factors of prediabetes and type 2 diabetes in a Singaporean Malay cohort

Aims: The aim of this work was to determine the cumulative incidence and independent risk factors of prediabetes and type 2 diabetes (T2DM) in a well-characterized cohort of Malays in Singapore.

Methods: We included 1137 participants (mean age [SD]: 55 (10) years; 53.6% female) without diabetes (DM) at baseline from the Singapore Malay Eye Study, a population-based longitudinal study with baseline (2004-2006), and follow-up (2010-2013) examinations. Prediabetes was defined as an HbA1c between 5.7% and 6.4%, with no self-reported DM history or insulin/DM medication use. T2DM was defined as a random glucose level ≥200mg/dL or HbA1c>6.4% or use of insulin/DM medication. Age-standardized cumulative incidence was calculated as the crude 6-year cumulative incidence standardized to Singapore's Malay population census. Multivariable modified poisson regression models were utilized to determine the risk factors of incident prediabetes and T2DM.

Results: The age-standardized 6-year cumulative incidence was 11.2% (95% CI 9.5, 13.1%) for T2DM, and 20.4% (95% CI 16.4, 25.2%) for prediabetes. Hypertension, higher body mass index (BMI) and higher Hba1c levels were associated with increased risk of T2DM, while older age and higher high density lipoprotein (HDL) cholesterol were protective (all P<0.05). Only higher BMI and HbA1c levels were independently associated with incident prediabetes (all P≤0.001).

Conclusions: While only one in ten adult Malays developed T2DM over 6-years, one in five developed prediabetes over the same time period. Our results suggest that evidence-based interventions addressing modifiable risk factors (obesity, prediabetes, hypertension, low HDL cholesterol) are needed to delay or prevent their onset.