Effects of leptin on fracture healing in rat tibia.

OBJECTIVES In this study, we aimed to evaluate possible effects of leptin on fracture healing. MATERIALS AND METHODS Between November 2009 and May 2010, 54 male Sprague Dawley rats with a mean age of 16 weeks and a mean body weight of 323 g (range; 295-352 g) were included and randomly divided into three equal groups. Standardized tibial fractures were created to all rats. Group 1 was treated with 0.5 mL physiological saline, group 2 was treated with 0.1 µg/kg leptin within 0.5 mL physiological saline, and group 3 was treated 0.3 µg/kg leptin within 0.5 mL physiological saline for 14 days intraperitoneally. Each group was divided into three subgroups including six rats for the evaluation at second, third and fifth weeks. RESULTS Radiological evaluation showed that fracture healing of group 3 was better than group 1 (p=0.014) only at fifth week. Histological evaluation revealed fracture healing of group 3 was better than group 1 at third week (p=0.011). At fifth week, both group 2 and group 3 had better fracture healing than group 1 (p=0.006, p=0.002, respectively). There was no statistically significant difference in fracture healing between group 2 and 3 at fifth week (p=0.176). CONCLUSION Leptin has a positive dose-dependent effect on rat tibial fracture healing.