Background

Several clinical and epidemiological studies have established a relationship between serum bilirubin levels and T2DM .However, prospective longitudinal studies to clarify thecausal relationship between serum bilirubin and diabetes are limited. In this study, the impact of serum bilirubin on new-onset type 2 diabetes mellitus (T2DM) in Korean with impaired glucose tolerance(IGT) was investigated.

Methods

Data were obtained from the Korean Genome and Epidemiology Study (KoGES), a population-based prospective cohort study was used to assess environmental and lifestyle determinants of the prevalence and incidence of chronic degenerative disorders, such as hypertension, diabetes, osteoporosis and CVD.The baseline survey, conducted from 2001 to 2002, included 10,038 adults (5018 men and 5020 women) 40 to 69 years of age. Study participants were invited to attend follow-up visits twice a year. This study included 2147 adults with IGT, aged 40 to 69 years, who underwent a mean follow-up of 8.4 years. IGT was defined based on the following data: a 2-hour plasma glucose was between 140 mg/dl and 199 mg/dl during a 75-g oral glucose tolerance test. The study population was divided into quartiles (Q) of serum bilirubin levels, with cut-off points at 0.39, 0.53 and 0.71 mg/dL for subject with IGT.

Results

Over the mean 8.4-year follow-up, 310 participants (14.4%) developed T2DM. Compared with Q1, the odds ratios (ORs) and 95% confidence intervals (CIs) for T2DM incidence were 0.47 (0.32–0.69) respectively, in the highest Q group after adjusting for possible confounding factors. These significant results persisted in those (0.61 (0.38–0.98)) with impaired fasting glucose(IFG).

Conclusions

The results of this study reveal a protective role for serum total bilirubin on new-onset T2DM in Korean with impaired glucose tolerance . In addition, serum total bilirubin had favorable effects on new-onset T2DM in those with impaired fasting glucose.