Type 2 Diabetes and Bone Disease

Effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors, dapagliflozin and canagliflozin, on the musculoskeletal system in an experimental model of diabetes induced by high-fat diet and streptozotocin in rats

The effect of SGLT2 inhibitors, a new group of antidiabetic drugs, on the skeletal system is a matter of debate. There are concerns that they may unfavorably affect bones. The aim of the study was to investigate the effects of dapagliflozin and canagliflozin on musculoskeletal system in an experimental rat model of type 2 diabetes induced by a high-fat diet (HFD) and streptozotocin (STZ). The experiments were carried out on mature female rats. To induce diabetes, STZ was administered 2 weeks after the introduction of HFD. Administration of dapagliflozin (1.4 mg/kg p.o.) or canagliflozin (4.2 mg/kg p.o.) started 1 week after the STZ injection, and lasted 4 weeks. Skeletal muscle mass and strength, serum bone turnover marker concentration and other biochemical parameters, and bone mass, density, histomorphometric parameters and mechanical properties were determined. Diabetes induced decreases in skeletal muscle mass and osteoporotic changes, including decreases in bone density, and worsening of the histomorphometric parameters and cancellous bone mechanical properties. The SGLT2 inhibitors decreased glycemia and other diabetes-induced metabolic changes, and counteracted only some unfavorable effects of diabetes on bones. The effects of dapagliflozin and canagliflozin on metabolic parameters were similar, whereas there were some differences in their effects on the skeletal system. The study demonstrated possibility of differential skeletal effects of different SGLT2 inhibitors in diabetic conditions, indicating the need for caution concerning their use in patients at risk of bone fractures.

Effects of Platelet-Rich Fibrin on Bone Healing Around Implants Placed in Maxillary Sinuses: A Histomorphometric Assessment in Rabbits

This study investigated the effect of platelet-rich fibrin (PRF) on bone healing around implants placed in elevated sinus cavities. Forty New Zealand albino rabbits were divided into eight groups, based on the time of sacrifice (14 or 40 days) and the material used: blood clot (control), hydroxyapatite (HA) from bovine bone, HA combined with PRF, and PRF alone. Each group consisted of five animals (n = 5). A histological analysis measured bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). The results showed significant increases in the BIC and BAFO values at 40 days compared to 14 days in most groups. At day 14, the HA+PRF group had higher BIC than the clot and the PRF alone groups. At 40 days, HA+PRF maintained the highest BIC across all groups (p < 0.05), though it did not show an advantage for BAFO. These findings indicate that combining HA with PRF promotes better osseointegration around implants placed immediately in maxillary sinus augmentation. Given the limited research on PRF's biological impact, these results underscore the importance of evaluating PRF's role in peri-implant healing and its potential benefits for clinical use in sinus augmentation.

Exploring the Interplay between Vitamin D, Insulin Resistance, Obesity and Skeletal Health

Vitamin D (ViD), plays an important role in calcium absorption and bone mineralization, is associated with bone mineral density. Severe deficiency in ViD has long been linked to conditions such as rickets in children and osteomalacia in adults, revealing its substantial role in skeletal health. Additionally, investigations show an existing interconnection between ViD and insulin resistance (Ins-R), especially in patients with type 2 diabetes mellitus (T2DM). Obesity, in conjunction with Ins-R, may augment the risk of osteoporosis and deterioration of skeletal health. This review aims to examine recent studies on the interplay between ViD, Ins-R, obesity, and their impact on skeletal health, to offer insights into potential therapeutic strategies. Cochrane Library, Google Scholar, and Pubmed were searched to investigate relevant studies until December 2023. Current research demonstrates ViD's impact on pancreatic β-cell function, systemic inflammation, and insulin action regulation. Our findings highlight an intricate association between ViD, Ins-R, obesity, and skeletal health, providing a perspective for the prevention and/or treatment of skeletal disorders in patients with obesity, Ins-R, and T2DM.