Sleep duration and severe periodontitis in middle-aged Japanese workers

Aim To evaluate the association between sleep duration and severe periodontitis in Japanese workers. Materials and methods This cross-sectional study included 1130 workers (mean age 43.0 years) who underwent full-mouth periodontal examinations and health check-ups and completed a self-administered questionnaire that included questions on sleep duration. Logistic regression and a restricted cubic spline model were used to analyse the data. Results Severe periodontitis was identified in 6.3% of the study population. Those with <5, 5-5.9, 6-6.9, 7-7.9, and >= 8 hr of sleep were 6.7%, 17.4%, 40.3%, 26.3%, and 8.9%, respectively. After adjusting for potential confounders, study participants who slept <5 hr were more likely to have severe periodontitis (adjusted odds ratio = 2.64; 95% confidence interval = 1.06-6.60) than those who slept 7-7.9 hr. The spline model, with a reference value of 399 min (the median sleep duration), showed a non-linear association between sleep duration and severe periodontitis, where an increased prevalence of severe periodontitis was observed only among those with a shorter sleep duration. The prevalence of severe periodontitis did not increase with longer sleep duration. Conclusions Short sleep duration was associated with severe periodontitis in this cohort of Japanese adults.