Evaluation of the association between sleep duration and tooth loss among Korean adults: Data from the Korean National Health and Nutrition Examination Survey (KNHANES 2012-2014)

Objectives This study assessed the association between sleep duration and tooth loss using nationally representative data. In this study, a cross-sectional analysis was performed using multivariable logistic regression analysis models. Setting The present study analysed data from the Korean National Health and Nutrition Examination Survey between 2012 and 2014. Participants A total of 14 675 respondents over 19 years old without missing values were included in this study. Exposure and primary outcome measures Sleep duration and tooth loss. Results Participants with a sleep duration of 6-8 hours showed the lowest prevalence of diabetes mellitus, hypertension, metabolic syndrome, periodontitis and meeting the waist circumference criteria for metabolic syndrome. Adjusted OR and their 95% CI of male individuals with fewer than 25 natural teeth were 1.426 (1.113 to 1.827), 1.290 (1.074 to 1.548), 0.988 (0.853 to 1.145), 1 (reference), 1.058 (0.907 to 1.235) and 1.620 (1.287 to 2.038) for sleep duration of 4 hours or less, 5 hours, 6 hours, 7 hours, 8 hours and 9 hours or more, respectively (p<0.05), after adjustments for age, sex, smoking, drinking, walking, frequency of tooth brushing per day, body mass index and periodontitis. Conclusions Our findings showed the U-shaped association between sleep duration and tooth loss was suggested by multiple logistic regression analyses after adjusting for confounding factors. Moreover, subgroup analyses showed that short and long sleep duration were associated with greater tooth loss in participants without diabetes mellitus, those without hypertension and those without metabolic syndrome.