| Objective To investigate the effects of different doses of metformin on bone mineral density and body composition in SD rats at different treatment duration. Methods Sixty 3-month-old SD rats were randomly divided into control group, metformin 100mg/kg/day group, metformin 200mg/kg/day group, metformin 300mg/kg/day group and metformin 500mg/kg?day group. The medicine was given by gavage once a day. Bone mineral density (BMD) and body composition of rats were measured before and after intervention. Results After 8 weeks and 12 weeks intervention, BMD of rats in the metformin groups with different doses was increased compared with the control group (P < 0.05). After 8 weeks of intervention, BMD of the metformin groups with different doses was increased compared with that of the 4-week intervention groups (< 0.05). After 12 weeks of intervention, BMD of metformin group (200mg/kg?d) and group (300mg/kg?d) was higher than that of the 8-week groups (P < 0.01). After 12 weeks of intervention, weight of rats in the intervention groups with different doses of metformin was lower than that in the control group (P < 0.01). Weight of rats in the 500mg/kg?d group was lower than that in the 100mg/kg?d group and the 200mg/kg?d group (P<0.05). After 8 weeks of intervention, the fat content of rats in different doses of metformin groups was lower than that in the control group (P < 0.05). After 12 weeks of intervention, the fat content of rats in the metformin groups with different doses was lower than that in the control group (P<0.05); the fat content of rats in the metformin 300mg/kg?d group was lower than that in the metformin 100mg/kg?d group and the metformin 200mg/kg?d group (P<0.01), and the fat content of rats in the metformin 300mg/kg?d group and the metformin 500mg/kg?d group was lower than that in the 8-week groups (P<0.05). After 12 weeks of intervention, the muscle content of metformin group (200mg/kg?d) and group (300mg/kg?d) was higher than that of the control group (P<0.05). Conclusion Metformin can increase bone density and muscle content, decrease fat content and led to weight loss in SD rats, which is related to the time and dose of intervention. |