Association Between Tooth Loss, Body Mass Index, and All-Cause Mortality Among Elderly Patients in Taiwan

To date, the effect of tooth loss on all-cause mortality among elderly patients with a different weight group has not been assessed. This retrospective cohort study evaluated the data obtained from a government-sponsored, annual physical examination program for elderly citizens residing in Taipei City during 2005 to 2007, and follow-up to December 31, 2010. We recruited 55,651 eligible citizens of Taipei City aged 65 years, including 29,572 men and 26,079 women, in our study. Their mortality data were ascertained based on the national death files. The number of missing teeth was used as a representative of oral health status. We used multivariate Cox proportional hazards regression analysis to determine the association between tooth loss and all-cause mortality. After adjustment for all confounders, the hazard ratios (HRs) of all-cause mortality in participants with no teeth, 1 to 9 teeth, and 10 to 19 teeth were 1.36 [95% confidence interval (CI): 1.15-1.61], 1.24 (95% CI: 1.08-1.42), and 1.19 (95% CI: 1.09-1.31), respectively, compared with participants with 20 or more teeth. A significant positive correlation of body mass index (BMI) with all-cause mortality was found in underweight and overweight elderly patients and was represented as a U-shaped curve. Subgroup analysis revealed a significant positive correlation in underweight (no teeth: HR=1.49, 95% CI: 1.21-1.83; 1-9 teeth: HR=1.23, 95% CI: 1.03-1.47; 10-19 teeth: HR=1.20, 95% CI: 1.06-1.36) and overweight participants (no teeth: HR=1.37, 95% CI: 1.05-1.79; 1-9 teeth: HR=1.27, 95% CI: 1.07-1.52). The number of teeth lost is associated with an increased risk of all-cause mortality, particularly for participants with underweight and overweight.