Purpose: Bone remodeling has been linked to glucose metabolism in animal studies, but the results of human trials were inconclusive. Bisphosphonates may play a role in glucose metabolism through their impacts on bone remodeling enzymes. In this study, we aimed to examine the influence of alendronate usage on the incidence of type 2 diabetes mellitus (DM) among osteoporotic patients.
Methods: A retrospective cohort study was designed to include osteoporotic patients without DM from a population-based cohort containing 1,000,000 subjects. Patients treated with alendronate (exposed group, N=1,011) were compared with those who received no treatment (age and gender matched non-exposed group, N=3,033). Newly diagnosed DM was identified from medical records by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9CM) code. The incidence of DM in both groups was calculated for comparison.
Results: The non-exposed group had a significantly higher incidence of DM (Odds ratio 1.21, 95% confidence interval 1.03~1.41) when compared with the exposed group. In subgroup analysis, the DM risk reduction in exposed group was only significant among those younger than 65 years and those without hypertension or dyslipidemia. Patients who were prescribed alendronate more than or equal to 3 times had demonstrated a significant reduction in DM risk.
Conclusions: Our study showed alendronate might yield a protective effect for incident DM. This effect became insignificant in patients with older age, dyslipidemia or hypertension. The underlying mechanism needs further exploration with prospective data for confirmation of the observed findings.