Objectives: To determine the incidence rates of type 2 diabetes and associated factors among professional and office workers in Bangkok.
Material and Method: Data on fasting glucose measurements and physical examination were obtained from a cohort of 6,924 workers in 43 establishments in Bangkok during 1999-2003. Impaired fasting glucose and diabetes were defined according to the American Diabetes Association criteria. The type 2 diabetes incidence rates were calculated based on the person-time of follow-up period.
Results: A total of 136 individuals developed type 2 diabetes during 11,581 person-years (py) of follow-up. The incidence rates of type 2 diabetes in individuals aged 35-60 years was 11.4 per 1000 py Men had a higher incidence rate than women (17.8 vs 9.2 per 1,000 py). The incidence rates increased with age. Factors associated with development of diabetes included baseline fasting plasma glucose (FPG) level, overweight and obesity status. Adjusted incidence rate ratios (IRR, 95%CI) for FPG of 93-99 mg/dl and 100-125 mg/dl were 3.2 [1.1-9.9] and 31.5 [11.4-86.8] respectively, compared to those with FPG < 93 mg/dl. The IRRs for those with BMI of 23-27.5 and > 27.5 kg/m2 were 1.5 [0.9-2.5] and 2.7 [1.6-4.5] respectively, compared to those with BMI < 23 kg/m2.
Conclusion: Findings from the present study could serve as the first marking post for estimating the risk and magnitude of type 2 diabetes in other adult populations in Thailand.

Keywords: Type 2 diabetes, Incidence rate, Risk factor