Methods: Untreated patients with periodontitis (N=73) and periodontally healthy controls (N=41) were recruited. Fasting insulin, HOMA-IR (fasting insulin x fasting glucose/22.5),and Insulin sensitivity index, which is inversely proportional to insulin resistance, (ISI= exp (2.63 - 0.28ln [insulin]-0.31ln [triglycerides]) was measured as marker for insulin resistance. Plasma levels of C-reactive protein (CRP) and leukocyte count were measured as indicators of inflammation.
Results: Mean values of HOMA-IR were 1.88 and 2.41 (p= 0.044), fasting insulin 7.22 and 9.40 mmol/L (p=0.033) and ISI 8.05 and 7.40 (p= 0.017) respectively in controls in patients. Adjusted means, after correcting for education, age, gender, ethnicity, smoking and BMI, for HOMA-IR were 2.17 and 2.60 (p=0.157), for fasting insulin 8.12 and 10.19 (p=0.052), and for ISI 7.69 and 7.29 (p=0.266) respectively in controls and patients. In each analysis BMI showed to be the strongest covariant. Higher levels of CRP (p=0.033) and elevated numbers of leukocytes (p=0.007) in patients compared to controls, confirmed that patients had signs of systemic inflammation.
Conclusions: Our results do not support the hypothesis that periodontits contributes to insulin resistance. Furthermore it is suggested that BMI should be corrected for in studies on the relationship between periodontitis and systemic aspects of general health.