Early modification of blood glucose levels during teriparatide treatment in postmenopausal women with severe osteoporosis

Purpose: To analyse the effect on fasting glucose levels after one month of PTH 1-34 treatment in postmenopausal women with osteoporosis. Methods: Twenty-six postmenopausal women treated with PTH 1-34 were enrolled. Patients with glucose ≥ 110 mg/dl and/or glycosylated hemoglobin > 48 mmol/mol were excluded. At baseline and after one month treatment, we measured fasting serum glucose, calcium, creatinine, PTH, 25(OH)vitamin D, OPG, RANKL, and BALP. Standardized questionnaires were administered to assess dietary caloric intake and physical activity. Results: After one month, patients were divided according to the increase (group A) or decrease of glucose (group B). We found no difference between these two groups as regards anthropometric, biochemical evaluation, DXA measurements, dietary caloric intake, physical activity and fractures at baseline. There was no difference between groups in the number of patients treated before with bisphosphonates. Dietary caloric intake and physical activity after one month of therapy were not different in both groups. The mean delta glucose decrease after one month was 7%±4% in group B while the delta increase was 8%±5% in group A, p = 0.001. The only statistically significant difference between these groups, after one month, was an increase in mean delta BALP in group B compared to group A (group B:19 ± 23% vs. group A -0.7 ± 7, p = 0.04). Mean delta vitamin D and OPG increased, while mean delta PTH and RANKL decreased in both groups, without statistically significant differences between groups. Conclusion: PTH 1-34 decreases mean serum glucose levels when bone formation is increased, as suggested by a significant increase in BALP in this group.