Relationship between serum leptin levels, non-cardiovascular risk factors and mortality in hemodialysis patients

Introduction. Hemodialysis (HD) patients have higher mortality rate than the general population. Recent studies indicate a significant role of non-cardiovascular risk factors in for mortality in HD patients. Leptin is protein hormone and may indicate malnutrition in HD patients. Its role in mortality in these patients is being examined. This study aimed to investigate the correlation between serum leptin levels and non-cardiovascular risk factors and relationship between leptin level and mortality in HD patients.Methods. The prospective study included 93 patients on maintenance HD and follow-up period was 12 months. We measured leptin level and evaluated non-cardiovascular risk factors: nutritional status, anemia, volemia, parameters of mineral and bone disorder.Results. Out of 93 patients 9 died during study and 1 underwent kidney transplantation. Malnutrition and hypervolemia were two main non-cardiovascular risk factors among deceased subjects. Leptin showed a significant direct correlation with nutritional BMI (r = 0.72, P < 0.001), fat tissue index (r = 0.74, P < 0.001) and statistically significant inverse correlation with leantissue index (r = -0.349, P < 0.05) and inverse correlation with volemic parameters (overhydration / extracellular water ratio (r = -0.38, P < 0.001), but no association with anemia and mineral bone parameters was observed. Elevated leptin levels were associated with better survival. However, no statistically significant difference in survival rates was observed between the study groups (Log-Rank P =0.214, Breslow P =0.211, Tarone-Ware P=0.212).Conclusion. Deceased patients had significantly lower leptin values. Leptin was associated with two non-cardiovascular risk factors for mortality: malnutrition and hypervolemia.