Systemic Inflammation (C-Reactive Protein) in Type 2 Diabetic Patients Is Associated With Ambient Air Pollution in Pune City, India

OBJECTIVE-To study the association between ambient air pollutants and serum C-reactive protein (CRP) concentration in 1,392 type 2 diabetic patients in Pune, India. RESEARCH DESIGN AND METHODS-A cross-sectional study was conducted that linked daily time series of ambient air pollution data (obtained from central monitoring sites) and plasma CRP concentration in type 2 diabetic patients from the Wellcome Trust Genetic (Well-Gen) Study, recruited between March 2005 and May 2007. Air pollution effects on CRP concentration were investigated with delays (lags) of 0-7 days and multiday averaging spans of 7, 14, and 30 days before blood collection adjusted for age, sex, BMI, hemoglobin, fasting plasma glucose, treatment with agents with anti-inflammatory action, season, air temperature, and relative humidity. RESULTS-Median CRP concentration was 3.49 mg/L. For 1 SD increase in SO2 and oxides of nitrogen (NO) concentrations in ambient air, a day before blood collection (lag(1)), we observed a significant increase in CRP (9.34 and 7.77%, respectively). The effect was higher with lag(2) (12.42% for SO2 and 11.60% for NOx) and wore off progressively thereafter. We also found a significant association with multiday averaging times of up to 30 and 7 days for SO2 and NOx, respectively. No significant associations were found between particulate matter with an aerodynamic profile <10 mu m (PM10) and CRP concentration except in summer. The association was significantly higher among patients with a shorter duration of diabetes, and in those not on statin and thiazolidinedione treatment. CONCLUSIONS-We demonstrate, for the first time, a possible contribution of ambient air pollution to systemic inflammation in Indian type 2 diabetic patients. This may have implications for vascular complications of diabetes. Diabetes Care 36:625-630, 2013