The relation of serum leptin to body mass index and to serum cortisol in men with spinal cord injury

OBJECTIVE: To investigate the relations among serum leptin, body mass index (BMI), and various hormone levels in men with spinal cord injury (SCI). DESIGN: Cross-sectional. SETTING: University hospital that is a tertiary referral center. PARTICIPANTS: Forty-seven men with traumatic neurologically complete SCI and 47 age- and BMI-matched male controls. MAIN OUTCOME MEASURES: Baseline levels of various hormones were measured in subjects with SCI. Serum leptin and cortisol levels and BMI were measured in both groups. RESULTS: Serum leptin was significantly higher in the group with SCI than in the control group. A linear relation was found between serum leptin and BMI in both groups separately. A polynomial relation was found between serum leptin level and BMI in the group with SCI. A "J" phenomenon is noted at the lowest BMI. Serum cortisol correlated significantly with serum leptin level in the group with SCI. CONCLUSION: Sympathetic denervation, peripheral nerve palsy, recurrent infections, and possible central neurotransmitter alterations after SCI may contribute to the elevation of serum leptin level in men with SCI.