Salivary Interleukin 6 is A Valid Biomarker for Diagnosis of Osteoporosis in Postmenopausal Women

Abstract

Background: Interleukin 6 (IL6) is pro-inflammatory cytokine associated with decline in ovarian function during menopause which is involved in the pathophysiology of postmenopausal bone loss.

Objective: To investigate validity of salivary IL6 as a biomarker to diagnose osteoporosis in post-menopausal women.

Patients and Methods: This cross sectional study was conducted on 75 postmenopausal women. Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry (DXA) to diagnose osteoporosis. Salivary IL6 was measured for all postmenopausal women by using Human ELISA kit.

Results: Of a total 75 individual involved in the study, 25 were healthy postmenopausal women, 25 had osteopenia, and 25 had osteoporosis. There was no statistical significant differences between age and body mass index in all groups (p>0.05). Mean level of salivary IL6 was significantly different among healthy controls, osteopenic group, and osteoporotic group (11.66 ± 4.44 vs 14.51 ± 6.5 vs 23.9 ±5.52 pg/ml; p<0.001) respectively. The mean salivary IL-6 was significantly higher in osteoporosis group (23.9 pg/ml) compared to control group (11.66 pg/ml). Salivary IL-6 was a valid parameter to predict osteoporosis in postmenopausal woman (ROC area=0.91, p<0.001).Salivary IL-6 showed positive strong significant linear correlation with bone t- score (r=0.62,     P<0.001). Salivary IL6 at the optimum cut off value ≥19.45 pg/ml has highest accuracy (81.3%) to diagnose osteoporosis in postmenopausal women  with sensitivity was 84.%, specificity 80 %, positive predictive value (PPV) at pretest probability 50% was 80.8%,  and PPV at pretest probability 90% was 97.4 %,  and  negative predictive value (NPV) at pretest  probability 10% was 97.8 %.

Conclusions: Salivary IL6 was a simple, easy, and a valid biomarker to diagnose osteoporosis in postmenopausal women with high accuracy. This may indicate a hopeful measure for early diagnosis and treatment of osteoporosis.

Keywords: Salivary IL6, Menopause, Proinflammatory cytokines, Osteoporosis.