Effect Of Aerobic Exercise On Bone Mineral Density And Biomechanical Index In Type 2 Diabetes Model Rat

ObjectiveThis study was based on the establishment of the type 2 diabetes rat model and by aerobic exercise plan in 8 weeks.The purpose was to study the effect of aerobic exercise on bone mineral density (BMD) and biomechanical index in type 2 diabetes model rats, and to provide experimental and theoretical basis for the prevention and treatment of type 2 diabetes and its complications.Methods52 male SD rats of 8 months old were divided into normal control group(n=10) and type 2 diaberes model group(n=42)randomly.The rats of diabetes model group were feed by high fat, glucose and energy food in 4 weeks, then streptozotocin with a does of 30mg/kg weight was given by a bout of intraperitoneal injection for establishing type 2 diabetes model rats.30 successful type 2 diabetic model rats were randomly divided into diabetes control group, diabetes lower-intensity exercise group, and diabetes moderate-intensity exercise group. Exercise proposal:Exercise intensities were 12m/min and 20m/min in the lower and moderate exercise groups respectively. The total duration of exercise proposal was 8 weeks. Exercise time and frequency of the proposal were 60 minutes a day and 6 days each week. BMD were measured by using solid physic density instrument, bone biomechanical index was measured by using mechanics of materials instrument and three-point bending theory.Results1) The mean of blood glucose level in type 2 diabetes model rats was 28.09±6.48 mmol/L.Success rate of model rats was 95.24%.2) Effect of aerobic exercise on blood glucose level in type 2 diabetes model rats.Compared with normal control group,blood glucose level increased significantly in diabetes control, lower and moderate intensity exercise groups(P<0.01).Compared with diabetes control group,blood glucose level decreased significantly in lower and moderate intensity exercise groups(P<0.01).There was no difference between lower and moderate intensity exercise groups.3) Effect of aerobic exercise on BMD in type 2 diabetes model rats.Compared with normal control group,BMD in diabetes moderate exercise group was a significant increased, but in diabetes control and lower-intensity exercise group were significantly decreased respectively(p<0.05).Compared with the diabetes control group, BMD was a significant increased in diabetes moderate-intensity exercise group(p<0.01).Compared with the diabetes lower-intensity group, BMD was a significant increased in diabetes moderate-intensity exercise group(p<0.01).There was no significant difference on BMD between the diabetes control group and the diabetes lower-intensity exercise group.4) Effect of aerobic exercise on bone biomechanical index in type 2 diabetes model rats.Compared with normal control group, maximum load and energy in diabetes control group was a significant decreased(p<0.01), but there was no significant difference on maximum stress and module in diabetes control; maximum load in lower-intensity was a significant decreased(p<0.05),maximum stress and energy in lower-intensity was a significant increased (p<0.05) and module was a significant decreased(p<0.01); maximum stress and module in moderate-intensity exercise control was a significant increased(p<0.05),but there was no significant difference on maximum load and energy. Compared with the diabetes control group, maximum load,maximum stress and module was a significant increased in diabetes lower-intensity exercise group(p<0.05),but there was no significant difference on energy; maximum load and energy in diabetes moderate-intensity exercise group was a significant increased(p<0.01), maximum stress was a significant increased (p<0.05),module was no significant difference.Compared with the diabetes lower-intensity group, maximum load and energy was a significant increased in diabetes moderate-intensity exercise group(p<0.05); There was no significant difference on maximum stress and module.Conclusions1) Aerobic exercise can decrease high glucose signficantly, make it stability, regulate and improve glucose metabolism. Aerobic exercise was suitable exercise way for type 2 diabetes.2) BMD and bone biomechanical function of the type 2 diabetic model rats was less than the normal rats, type 2 diabetes was a high-risk for osteoporosis.3) The effects of aerobic exercise on bone mineral density and bone biomechanical index in type 2 diabetes model rats related to the exercise intensity. Suitable exercise intensity can improve bone metabolism, increase bone mineral density, improve better bone biomechanical function, and have benefit significance for the rehabilitation of type 2 diabetes and prevention and treatment its complications.