Effects of combined intervention of isoflavone supplementation and exercise on bone metabolism in growing rats

Abstract

Purpose: This study examined the effects of combined intervention of isoflavones and exercise on bone mineral density, bone mineral content, and biochemical bone markers. Methods: Forty rats were divided into four groups; Control, Isoflavones (IF), Isoflavones + Running (IFR), and Isoflavones + Swimming (IFS). All of the rats in this study were fed an experimental diet and deionized water ad libitum for nine weeks. Bone mineral density (BMD) and bone mineral content (BMC) were estimated using PIXImus (GE Lunar Co, Wisconsin.) in spine and femur nine weeks after feeding or training. Results: The combined intervention did not affect weight gain, mean food intake, or food efficiency ratio. The serum concentrations of ALP and osteocalcin were not significantly different by combined intervention. The urinary DPD crosslinks values were not significantly different by combined intervention. There were no significant differences in serum PTH, calcitonin, and estradiol among all groups. Spine BMD, spine BMC and femur BMC were not significantly different by combined intervention. However, femur BMD was significantly higher in the IFR group than in the control group. Compared with the control group, spine BMD, spine BMC, and femur BMD per weight were markedly increased in the isoflavones supplementation and combined intervention group. In addition, femur BMC per weight was significantly higher in the IFS group than in the control group. Compared with the isoflavones supplemented group, BMD and BMC were not significantly different by combined intervention. Conclusion: It can be concluded that isoflavones supplementation or combined intervention of isoflavone and exercise had a beneficial effect on spine and femur peak bone mass in growing female rats.