Relationships among bone turnover, renal function and periodontal disease in elderly Japanese

We hypothesized that renal function is associated with the relationship between periodontal disease and bone metabolism. The present study evaluated the relationship of bone formation and resorption markers to periodontal disease, taking renal function into consideration, in elderly Japanese subjects.

We selected 148 subjects aged 77 years. The periodontal examination included the assessment of clinical attachment level (CAL). We measured two bone formation markers (serum bone-specific alkaline phosphatase and serum osteocalcin) and two bone resorption markers (urinary deoxypyridinoline and urinary cross-linked N-telopeptide of type I collagen). Creatinine clearance per 24 h, as a measure of renal function, was also determined. The correlations between mean CAL or percentage of sites with ≥6mm CAL (6+mm CAL) and bone turnover markers, and between bone turnover markers and creatinine clearance levels, were performed by multiple linear regression analysis.

There were significant negative relationships between mean CAL or 6+mm CAL and serum osteocalcin levels adjusted for gender, smoking habits and oral care habits (β=-0.25, p=0.014 and β=-0.35, p=0.001, respectively). In addition, there was a negative relationship between serum osteocalcin and creatinine clearance levels adjusted for gender and smoking habits (β=-0.45, p<0.0001).

Results from the present study suggest that serum osteocalcin was significantly associated with renal function and periodontal disease. The low systemic bone metabolism, which might be caused by low renal function, is associated with periodontal disease.