Endocrine Abstracts

Background and aims: Recent studies shows that SGLT-2 inhibitors affect phosphorus and calcium homeostasis in healthy individuals, but their effects in patients with type 2 diabetes are still unclear. The aim of this study was to evaluate effects of empagliflozin on parameters of calcium and phosphorus metabolism in patients with type 2 diabetes mellitus (T2DM) and preserved kidney function.

Materials and methods: The subjects were 30 patients with T2DM, who had inadequate glycemic control despite their therapy. Patients were between 45 and 65 year old and had eGFR>60 ml/min per 1.73 m², and glycated hemoglobin >7. 5% to 9.0%. Patients were administered empagliflozin at a dose of 10 mg every day for 12 weeks. We measured circulating phosphorus (P), calcium (Ca) and fibroblast growth factor 23 (FGF23) levels at baseline and after 12 weeks of treatment.

Results: Mean serum Ca was 1.19±0.13 mmol/l and serum P was 1.02±0.24 mmol/l. Median FGF23 before treatment was 1.87 pmol/l (1.13 2.65). Compared with baseline, no statistically significant differences were obtained in Ca concentrations after 12 weeks of treatment (0.6%; 95% CI −0.5% to 1.8%; P=0.32). Empagliflozin increased serum P by 13% (95% confidence interval, 8% to 19%; P=0.0034), FGF23 by 17% (9% to 25%; P=0.002) at the end of treatment. No correlation was found between the change in FGF23 and the change in serum P (r 0.1, P=0.31).

Conclusion: Empagliflozin increases serum P and FGF23 after 12 weeks of treatment in patients with T2DM. The lack of a significant correlation between the concentration of FGF23 and P may be due to differences in the availability of vitamin D, glycemia and body weight of patients.