Serum Leptin and Bone Mineral Density in Hemodialysis Patients with or without Liver Diseases

Introduction: Leptin is a hormone secreted by adipocytes that plays an important role in regulating appetite and energy expenditure. Our aim was to evaluate serum leptin level in hemodialysis (HD) patients with or without chronic liver disease (CLD) and study the relationship between serum leptin level and bone mineral density in these groups of patients. Methods: we recruited 20 healthy volunteers as controls (group I), 20 patients on regular HD with normal liver function (group II), 20 CLD patients with normal kidney function (group III) and 20 patients on regular HD with CLD (group IV). We measured serum calcium, phosphorus, parathyroid hormone (PTH), total alkaline phosphatase (ALP), serum leptin, 24-hours urinary hydroxyproline and bone mineral density (BMD) of the lumber spine and femoral neck by DEXA scan. Results: Serum leptin level was significantly higher (P <0.001) in HD patients and CLD patients compared to controls. Its level was also significantly elevated in HD patients without liver disease (group II) compared to patients with CLD who had no renal failure (group III). Urinary hydroxyproline level was increased in both HD patients and CLD patients. We detected a positive correlation between serum leptin level and urinary hydroxyproline in all patient groups. There was a significant decrease in BMD in HD and CLD patients. BMD was significantly lower in HD patients without CLD compared to HD patients with CLD. There was a significant negative correlation between serum leptin level and BMD in CLD patients without renal disease but not in other groups (r = - 0.6, P = 0.01). Conclusion: Serum leptin is elevated in HD patients with or without liver disease and in CLD patients. Serum leptin level is inversely correlated with BMD in CLD patients without renal disease.