Modern glucose-lowering treatment effect on bone remodeling in experimental diabetes mellitus and surgical menopause

Abstract

BACKGROUND: Diabetes mellitus (DM) is an independent risk factor for low-traumatic fractures. On the other hand, hypoglycemic drugs can have both positive and negative effects on bone remodeling.THE AIM: Тo investigate bone metabolism parameters during surgical menopause and experimental DM under the treatment with glucagon-like peptide receptor agonist type 1 (arGLP-1) liraglutide (LIRA) and sodium-glucose cotransporter type 2 inhibitor (iSGLT-2) canagliflozin (CANA).MATERIALS AND METHODS: Female Wistar rats have been subjected to bilateral ovariectomy at the beginning of the experiment. Diabetes mellitus (DM) was modelled using a high-fat diet and streptozotocin+nicotinamide. Four weeks after the following groups were formed: “OE+DM” (females after ovariectomy with DM and without any therapy, n=4) «OE+DM+CANA» (females after ovariectomy with DM under treatment with CANA, n=4), «OE+DM+LIRA» (females after ovariectomy with DM under treatment LIRA, n=5). The treatment or observation period were continuing for 8 weeks. Calcium, phosphorus and bone turnover markers (fibroblast growth factor-23 (FGF-23), osteocalcin, sclerostin, osteoprotegerin (OPG), nuclear factor-kappa-B receptor activator ligand (RANKL), were measured in the end of experiment. Bone histomorphometry was performed after euthanasia.RESULTS: Treatment with both CANA and LIRA did not significantly affect the phosphorus-calcium metabolism, sclerostin and osteocalcin concentrations. At the same time, the level of OPG was the highest in «OE+DM ‘’ group (9.1 [7.81; 10.045] pmol/l). The differences were significant compared with «OE+DM+CANA’’ (2, 33 [1.84; 5.84] pmol/l, p = 0.003) and «OE+DM+LIRA» (1.7 [1; 2] pmol/l, p = 0.003) groups. There were no differences in OPG levels between animals treated with different drugs. Similarly, the OPG/RANKL ratio was similarly reduced with both types of treatment. In “OE+DM+CANA’’ group the bone trabeculae number of   the femur epiphysis (p=0.042) were decreased in comparison to «OE+DM» group. LIRA did not change the histoarchitectonic parameters.CONCLUSION: Bone metabolism markers did not differ when using as canagliflozin as liraglutide. Besides, canagliflosin can lead to the activation of bone resorption, which is expressed in the femur epiphyseal trabeculae number decreasing.