Toothbrushing, Blood Glucose and HbA1c: Findings from a Random Survey in Chinese Population

Both diabetes and periodontal disease are prevalent in China. Poor oral hygiene practice is the major cause of periodontal disease. An association between oral hygiene practice and blood glucose level was reported in individuals with diabetes, but not in the general population. We examined the association in a population-based random survey recruiting 2,105 adults without previously diagnosed diabetes in Chongqing city, China. Plasma glucose and hemoglobin A1c (HbA1c) were measured, and a 2-hour oral glucose tolerance test was conducted for each respondent. Self-reported toothbrushing frequency was used as a proxy for oral hygiene practice. In a linear model controlling for potential confounders (demographic characteristics, socio-economic status, lifestyle risk factors, BMI, dental visit frequency, etc.), urban residents who barely brushed their teeth had an increase of 0.50 (95% CI: 0.10–0.90) mmol/L in fasting plasma glucose, and an increase of 0.26% (0.04–0.47%) in HbA1c, relative to those brushing ≥twice daily; for rural residents, the effects were 0.26 (0.05–0.48) mmol/L in fasting plasma glucose and 0.20% (0.09–0.31%) in HbA1c. Individuals with better oral practice tended to have lower level of blood glucose and HbA1c. Establishing good oral health behavioral habits may be conducive to diabetes prevention and control in the general population.