KCNQ1 rs2237892 polymorphism modify the association between short-term ambient particulate matter exposure and fasting blood glucose: A family-based study

Background: The association between particulate matter and fasting blood glucose (FBG) has shown conflicting results. Genome-wide association studies have shown that KCNQ1 rs2237892 polymorphism is associated with the risk of di-abetes. Whether KCNQ1 rs2237892 polymorphism might modify the association between particulate matter and FBG is still uncertain. Methods: Data collected from a family-based cohort study in Northern China, were used to perform the analysis. A gen-eralized additive Gaussian model was used to examine the short-term effects of air pollutants on FBG. We further con-ducted interaction analyses by including a cross-product term of air pollutants by rs2237892 within KCNQ1 gene. Results: A total of 4418 participants were included in the study. In the single pollutant model, the FBG level increased 0.0031 mmol/L with per 10 mu g/m3 elevation in fine particular matter (PM2.5) for lag 0 day. After additional adjustments for nitrogen dioxide (NO2) and sulfur dioxide (SO2), similar results were observed for lag 0-2 days. As for particulate mat-ter with particle size below 10 mu m (PM10), the significant association between the daily average concentration of the pol-lutant and FBG level was observed for lag 0-3 days. Additionally, rs2237892 in KCNQ1 gene modified the association between PM and FBG level. The higher risk of FBG levels associated with elevations in PM10 and PM2.5 were more evident as the number of risk allele C increased. Individuals with a CC genotype had the highest risk of elevation in FBG levels. Conclusion: Short-term exposures to PM2.5 and PM10 were associated with higher FBG levels. Additionally, rs2237892 in KCNQ1 gene might modify the association between the air pollutants and FBG levels.