Endocrine Abstracts

Introduction: Denosumab is a new pharmacotherapy option for postmenopausal osteoporosis. It is a human monoclonal antibody against RANKL, acting as an osteoprotegerin (OPG) analog. Recently, osteoprotegerin levels were found to be elevated in type two diabetes while insulin resistance was shown to be positively associated with decreased serum OPG levels, in healthy obese subjects. However, no study has been conducted in order to clarify the effect of anti-RANKL factors administration on insulin resistance, especially in women with postmenopausal osteoporosis.

Methods: The study population consisted of 20 non obese, non diabetic, postmenopausal women with BMI: 22.15±2.16 and age: 64.7±7.96 years. All patients had postmenopausal osteoporosis and were followed in our outpatient clinic for at least 18 months. Serum samples were collected and analyzed for fasting glucose, insulin and c-peptide levels before the initial dose of denosumab and at 6 and 12 months during treatment. HOMA index for insulin resistance (HOMA-IR) and steady pancreatic β cell function (HOMA-β) were calculated. Patients with 25(OH)D deficiency were excluded from the study. Statistical analysis was performed by using SPSS 15.0 software. Comparisons between groups were made by using ANOVA and unpaired t-test.

Results: During the study, patients’ weight and 25(OH)D levels remained unchanged (P=0.749 and P=0.456 respectively). Denosumab treatment did not cause any statistically significant change on HOMA-IR (P=0.194) or HOMA-β values (P=0.507), at all timepoints of the study.

Conclusions: These preliminary data show that in non obese and non diabetic postmenopausal osteoporotic women, treatment with denosumab does not seem to have an effect on insulin resistance or steady pancreatic β cell function.