【Objective】Chronic kidney disease (CKD) is characterized by proteinuria and renal function decline, which ultimately lead to renal failure and dialysis. Tooth loss may be associated with renal function; however, previous studies on the relationships among renal function, periodontal disease, and the number of remaining teeth mainly focused on CKD patients or those receiving dialysis. Limited information is currently available on these relationships in healthy individuals or those with mildly impaired renal function. Nevertheless, interventions from the early stage of renal function decline are considered to be essential for the early detection and treatment of CKD. Therefore, the present study investigated the relationship between the number of current teeth and mild or severe renal impairment in local residents aged 40 years or older.
【Methods】The baseline survey of the Uonuma Cohort Study was conducted between 2012 and 2014 among residents aged 40 years or older in Minami-uonuma and Uonuma cities. In the present study, 5,477 individuals (2,666 males and 2,811 females) with complete data from a physical examination and blood test values were included in the analysis.
Impaired renal function was defined as eGFR <60 mL/min/1.73 m2, mild proteinuria, or microalbuminuria. The number of current teeth was classified into two groups: 0–19 and 20 or more teeth. The number of current teeth was independent variable, presence or absence of impaired renal function was the dependent variable, and age, sex, hemoglobin A1c, body mass index, systolic blood pressure, low-density lipoprotein cholesterol, smoking, and family history of CKD were covariates, which were analyzed using logistic regression analysis.
【Results】Among the 5,477 participants, 1,642 (30.0%) were defined as having mild or severely impaired renal function.
The logistic regression analysis revealed that renal impairments were significantly greater in participants with 19 or fewer teeth than in those with 20 or more teeth (odds ratio=1.23, 95% confidence interval=1.08–1.39, p<0.001).
【Conclusion】Following adjustments for community demographics and related factors, an association was observed between the number of current teeth and impaired renal function.
