Plasma leptin concentration in kidney transplant patients during early post-transplant period

Background: Leptin, is produced by adipose tissue andis presumed to be involved in the regulation of appetite and energybalance. The kidneys are involved in the inactivation of circulatingleptin, and elevated plasma leptin concentrations were reported in uraemicpatients. Finally, glucocorticosteroids as used in transplanted patientsstimulate leptin secretion. Methods: The present studyaimed to assess the relationship between plasma leptin concentration andkidney graft function in the early post-transplant period. We studied 40successfully transplanted haemodialysed uraemic patients (27 males, 13females, mean age 34.3±1.6 years, mean body mass index22.5±0.5 kg/m²). The circadian rhythm ofleptinaemia and insulinaemia was assessed twice: 2-4 days after kidneytransplantation and 1 day before discharge from the hospital when graftfunction was good. Plasma leptin concentration was measured at 8 am, 4 pm,and 12 pm. The control group consisted of 21 healthy subjects (13 males, 8females, mean age 39.4±2.5 years, mean body mass index24.1±0.7 kg/m²).Results: Before kidney transplantation, patients hadelevated plasma leptin and insulin levels. A positive correlation was foundbetween BMI and leptinaemia and BMI and insulinaemia respectively. Aninverse relationship was found between leptinaemia and age. Successfulkidney transplantation was followed by a significant decline of leptinaemiai.e. from 21.5±0.1 vs 7.1±1.3ng/ml. Kidney transplantation did not influence the circadian rhythm ofleptinaemia. Conclusion: Leptinaemia was not relatedto the excretory graft function or immunosuppression. In addition to renalexcretory function, other factors must be involved in the post-transplantdecline of leptinaemia.