Effects of Resistance Training, Estrogen Therapy, and Calcium Chitosan Supplement Containing Vitamin D on Bone Turnover in Ovariectomized Rats: An Experimental-Comparative Study

Abstract

Background: Hormone therapy is a highly effective method for treating menopausal disorders. However, its side effects may include an increased risk of cancer, heart disease, and pulmonary embolism. Previous research has demonstrated that both exercise and nutrition separately have positive effects on menopausal symptoms. Therefore, we suggest that combining exercise and nutrition interventions may provide a synergistic effect, yielding results at least similar to those of estrogen (Est) therapy. Objectives: This study aims to compare the independent and combined effects of resistance training (RT), Est therapy, and vitamin D calcium chitosan (Vit D + Ca++ + Chit) supplementation on markers of bone turnover in ovariectomized (OVX) rats. Methods: Forty-two female Wistar rats were randomly divided into seven groups (n = 6 per group): (1) healthy-control (He-Co), (2) OVX-Vit D + Ca++ + Chit + RT, (3) OVX-saline (Sal) + Est + RT, (4) Sal + RT, (5) OVX-Vit D + Ca++ +Chit, (6) OVX-Sal + Est, and (7) OVX-Control (OVX-Co). Bone samples were extracted 48 hours after the final session. Two-way ANOVAs were used to determine differences in intervention effects between groups. The alpha level was set to 0.05. Results: Ovariectomy (OVX) decreased bone tissue expression of alkaline phosphatase (ALP) and osterix (OSX) while increasing peroxisome proliferator-activated receptor gamma (PPAR-γ) gene expression. Ovariectomy also decreased the number of osteocytes and osteoblasts while increasing the number of osteoclasts. Resistance training (RT) and Vit D + Ca++ + Chit intake increased bone tissue expression of ALP, OSX, and PPAR-γ gene expression. Additionally, RT and Vit D + Ca++ + Chit supplementation increased the number of osteocytes and osteoblasts and decreased the number of osteoclasts. Conclusions: The combined interventions had synergistic effects compared to each intervention separately on ALP, osteocyte, osteoblast, and osteoclast observations. Therefore, combining RT with Vit D + Ca++ + Chit could be a non-pharmacological approach to address bone turnover alterations caused by OVX.