Aims/hypothesis: Prediabetes, an early stage in the hyperglycaemic continuum, increases the future risk of developing diabetes and cardiovascular disease (CVD). C-reactive protein (CRP), a marker of inflammation, is associated with diabetes and CVD. However, studies examining the association between CRP and prediabetes among participants without diabetes are limited.
Methods: We analysed data from two large population-based studies in Singapore: the Singapore Prospective Study Programme (SP2, n = 4,252 Chinese, Malay and Indians aged ≥ 24 years) and the Singapore Malay Eye Study (SiMES, n = 2,337 Malays aged 40-80 years), participants of which were free of diabetes mellitus. Prediabetes was defined as glycated haemoglobin of 5.7-6.4% in SiMES (n = 1,231); fasting plasma glucose of 5.6-6.9 mmol/l in SP2 (n = 386).
Results: Elevated high sensitivity CRP (hsCRP) levels were found to be associated with prediabetes after adjusting for age, sex, race-ethnicity, education, smoking, alcohol consumption, hypertension, BMI and total cholesterol. Comparing those with hsCRP <1 mg/l (referent), the OR (95% confidence interval) of prediabetes in persons with hsCRP 1-3 mg/l and >3 mg/l was 1.31 (0.99-1.74) and 2.17 (1.61-2.92), p (trend) < 0.0001 in SP2; 1.23 (1.00-1.52) and 1.31 (1.06-1.64), p (trend) = 0.02 in SiMES. In subgroup analysis, the association was stronger in women, Chinese and Malays, and participants with BMI < 25 kg/m(2).
Conclusions: Data from two population-based Asian cohorts suggest that elevated serum hsCRP levels are associated with prediabetes.