leptin and Tibial-Fractures

Previously reported fracture rates in patients with spinal cord injury range from 1% to 20%. However, the exact role of spinal cord injury in bone metabolism has not yet been clarified. In order to investigate the effects of serum leptin and bone mineral density on the healing of long bone fractures in men with spinal cord injury, 15 male SCI patients and 15 matched controls were involved in our study. The outcome indicated that at 4 and 8 weeks after bone fracture, callus production in patients with spinal cord injury was lower than that in controls. Besides, bone mineral density was significantly reduced at 2, 4 and 8 weeks. In addition, it was found that at each time point, patients with spinal cord injury had significantly higher serum leptin levels than controls and no association was found between serum leptin level and bone mineral density of lumbar vertebrae. Moreover, bone mineral density was positively correlated with bone formation in both of the groups. These findings suggest that in early phases i.e. week 4 and 8, fracture healing was impaired in patients with spinal cord injury and that various factors participated in the complicated healing process, such as hormonal and mechanical factors.

Topics: Adult; Biomarkers; Bone Density; Femoral Fractures; Fracture Healing; Fractures, Bone; Humans; Leptin; Male; Middle Aged; Spinal Cord Injuries; Spine; Tibial Fractures; Young Adult

To investigate mechanisms behind the faster rehabilitation of limb fractures when associated with traumatic brain injury (TBI).. New Zealand rabbits were divided into TBI group and sham-operation group for four studies as follows: (1) blood and cerebrospinal fluid (CSF) were drawn on days 1, 3, and 7 to demonstrate changes in serum leptin, growth hormone (GH), insulin-like growth factor 1 (IGF-1), and CSF leptin; (2) bone defection was created by drilling in the tibial bone and either leptin or normal saline was injected into rabbit's cerebellomedullary cistern. X-ray was taken at 1 days, 2 weeks, and 5 weeks and evaluated by criteria to determine rate of bone healing; (3) FITC-labeled rabbit leptin was injected into TBI and sham-operation groups, and frozen sections of rabbit brain were observed to identify differences in central nervous system (CNS) leptin by fluorescence; (4) polymerase chain reaction (PCR) was used to evaluate the expression of leptin production by brain tissue.. Serum and CSF leptin, GH, and IGF-1 concentrations were found to be higher in the TBI group than the sham-operation group at days 1, 3, and 7 (P<0·05). CSF leptin of the TBI group was positively correlated with serum leptin on day 1 (P<0·05), and positively correlated with GH and IGF-1 on days 3 and 7 (P<0·05). X-ray criteria demonstrated that leptin administration caused significantly faster healing calluses at 3 and 5 weeks as compared to control animals (P<0·05). FITC-labeled leptin study demonstrated that TBI animals had stronger expression of leptin in the brain than sham-operated animals. However, PCR of brain tissue leptin showed no significant differences between TBI and sham-operated animals in the expression of leptin.. Our study suggests that increased CSF leptin, likely from blood-brain barrier breakdown, combined with elevated serum GH and IGF-1 after TBI, leads to accelerated fracture healing.

Topics: Animals; Brain; Brain Injuries; Fracture Healing; Growth Hormone; Insulin-Like Growth Factor I; Leptin; Male; Rabbits; Tibial Fractures

In this study, we aimed to evaluate possible effects of leptin on fracture healing.. 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.. 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).. Leptin has a positive dose-dependent effect on rat tibial fracture healing.

Topics: Animals; Fracture Healing; Injections, Intraperitoneal; Leptin; Male; Models, Animal; Rats; Rats, Sprague-Dawley; Tibial Fractures; Treatment Outcome