Tooth loss and risk of end-stage renal disease: A nationwide cohort study

Background: The association between renal disease and oral health has been studied in previous researches. The purpose of this study is to evaluate whether oral health, depicted by number of natural teeth was associated with an increased risk of kidney diseases. Methods: The present study analysed data from the Korean National Health Insurance from 2007 to 2008. Database of 4,544,610 individuals who received routine health checkups and dental examinations were included in this study. Results: There was an increase in end-stage renal disease with lower number of natural teeth and longer follow-up periods. Hazard ratios and their 95% confidence intervals for end-stage renal disease in participants with a number of natural teeth of 28, 24 to 27, 20 to 23, and <20 were one (reference), 1.066(0.997,1.139), 1.285(1.161,1.422), and 1.285(1.155,1.429), respectively. The association was significantly noted with age and body mass index (P < 0.05). In general, the substantial increase in hazard ratios is seen with loss of teeth and smoking. Hazard ratios and their 95% confidence intervals for end-stage renal disease in male smoking participants with a number of natural teeth <28 is 1.631(1.339,1.988). However, this association was not noted in female group. Conclusions: The association between number of natural teeth and end-stage renal disease was suggested after adjusting for confounding factors by using multiple logistic regression analyses from the entire South Korean population. Oral health, depicted by the number of tooth loss showed strong and dose-dependent association with end-stage renal disease in a large population-based cohort.