Background: Progression of diabetic nephropathy has serious effects on the life expectancy of diabetic patients. Although diagnoses, lifestyle interventions, and treatment of diabetic nephropathy have been often attempted, diabetic nephropathy has not been sufficiently overcome. Previous studies show that periodontitis, the inflammation of oral cavity, might lead to endothelial and renal dysfunction. Moreover, periodontitis does not only negatively affect glycemic control but is also associated with diabetes-related complications. Therefore, we conducted this study to examine the relationship between number of teeth, which is one of the factors associated with periodontal disease markers, and diabetic nephropathy.

Methods: This study included 1767 patients with type 2 diabetes mellitus, grouped according to number of teeth, with cut-off distribution points of 13 and 27. Diabetic nephropathy was defined using albumin-creatinine ratio (albuminuria, ≥30 mg/mmol creatinine, and macroalbuminuria ≥300 mg/mmol creatinine). Adjustment was made for age, sex, body mass index, hemoglobin A1c, and hypertension status.

Results: Patients with diabetic nephropathy had significantly fewer teeth than those without diabetic nephropathy (albuminuria, p < 0.001; macroalbuminuria, p = 0.002). The group with fewer number of teeth was significantly associated with a higher prevalence of diabetic nephropathy; the adjusted odds ratios (95% confidence intervals) for diabetic albuminuria for 27-32 teeth, 13-26 teeth, and 0-13 teeth were 1.00 (reference), 1.219 (0.932-1.596), and 1.509 (1.147-1.988), respectively (p for trend = 0.003), and for diabetic macroalbuminuria were 1.00 (reference), 1.061 (0.644-1.748), and 1.756 (1.1-2.844), respectively (p for trend = 0.015).

Conclusion: The number of teeth is positively associated with diabetic nephropathy for patients with type 2 diabetes mellitus, and could assist clinicians in the identification of patients at high risk for diabetic nephropathy.


W. Kurihara: None. T. Miyake: None. S. Furukawa: None. H. Senba: None. S. Yamamoto: None. Y. Sakiko: None. K. Joko: None. T. Ueda: None. T. Niiya: None. H. Miyaoka: None. B. Matsuura: None. Y. Hiasa: None.

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