Relationship between 25-Hydroxyvitamin D and Newly Diagnosed Type 2 Diabetes Mellitus in Postmenopausal Women with Osteoporosis

OBJECTIVE: The aim of the study was to determine a correlation between the level of 25-hydroxivitamin D (25-OHD) and the incidence of diabetes. SUBJECTS AND METHODS: In this prospective observational study, 97 (out of an initial 100) Caucasian women with osteoporosis (OS) were monitored for 2 years for the incidence of diabetes. Logistic regression analysis was used to establish an association with and prognostic value of vitamin D for the onset of type 2 diabetes mellitus, as well as insulin resistance, body mass index (BMI), total cholesterol and triglyceride levels in the development of diabetes. The serum level of 25-OHD was measured using immunochemiluminescence in March and April 2011. RESULTS: Of the 97 patients (mean age 51.64 ± 5.86 years, range 36.0-73.0), 21 (21.65%) were diagnosed with diabetes during the observational period. The study showed that the 22 patients with low levels of vitamin D were more susceptible to diabetes (odds ratio = 0.958). The cut-off value of vitamin D using a receiver operating characteristic curve was 62.36 nmol/l with a sensitivity of 39.5% and a specificity of 90.5%. With an increase in BMI and triglyceride levels, women were, respectively, 1,591 and 2,821 times more likely to get diabetes than those without an increase. CONCLUSION: This study showed that the patients with postmenopausal OS and hypovitaminosis D, besides a high BMI, elevated triglyceride levels and insulin resistance, had an increased risk of developing type 2 diabetes.