The extent of periodontal disease and the IL-6−174 genotype as determinants of serum IL-6 level

Aim: To study the extent of periodontal disease and the IL‐6−174 genotype as determinants of serum and mouthwash IL‐6 concentration in subjects with moderate to severe periodontal disease. Material and Methods: Fifty‐two generally healthy subjects volunteered to participate. Probing pocket depth (PD) and periodontal attachment level (AL) were clinically examined and alveolar bone level (BL) was measured on orthopantomographs. IL‐6 concentrations in mouthwash, collected by rinsing with 3 ml saline for 30 s and in serum, obtained by venipuncture, were measured using ELISA. IL‐6−174 polymorphism was studied using a polymerase chain reaction. Results: Eleven subjects carried the GG genotype, and 41 subjects, carried the CG/CC genotype. The mean (± SD) concentration of IL‐6 in serum was 1.6 (± 1.5) pg/ml and, 2.8 (± 5.04) pg/ml in mouthwash. The serum concentration of IL‐6 was higher in subjects with the GG genotype than with the CG/CC genotype. In regression analyses the percentages of sites with PD6 mm, AL6 mm and BL8 mm, the IL‐6−174 genotype, body mass index and gender associated significantly with serum IL‐6 concentration. Conclusions: The extent of moderate to severe periodontal disease and the IL‐6−174 genotype contribute significantly to serum IL‐6 concentration.