Alveolar bone loss associated with glucose tolerance in Japanese men

Aims Type 2 diabetes is known to affect alveolar bone loss (ABL). The purpose of this study was to examine whether impaired glucose tolerance (IGT) is associated with ABL, as is diabetes. Methods A case-control study was performed with 664 Japanese men aged 46-57 years. Panoramic radiographs revealed 513 severe ABL cases, 22 moderate ABL cases, and 129 controls with good alveolar bone. Diabetes status was classified into normal glucose tolerance (NGT), impaired fasting glucose (IFG), IGT, and newly diagnosed diabetes according to the fasting plasma glucose and 75-g oral glucose tolerance test (OGTT). Diabetes under treatment was excluded. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from ordinal logistic regression analysis. Statistical adjustment was made for total cholesterol, HDL-cholesterol, triglyceride, rank in the Self Defence Forces (SDF), cigarette-years, alcohol use, body mass index, previous 10 years' brushing habits and instrument use other than toothbrush, and history of periodontal treatment. Results A significant, approximately three-fold increase in the crude OR (crude OR = 3.28; 95% CI = 1.16-9.27) and non-significant 2.6-fold increase in the adjusted OR (adjusted OR = 2.55; 95% CI = 0.86, 7.54) of ABL was observed among men with newly diagnosed Type 2 diabetes compared with the reference group (NGT combined with IFG). However, there was no association between IGT and ABL (adjusted OR = 0.99; 95% CI = 0.59,1.64). Conclusions Type 2 diabetes, but not IGT, was positively associated with ABL. Preventive maintenance against periodontitis is important in middle-aged men with diabetes.