Relationships of Serum Leptin With Nutrition Status and Insulin Resistance in Non-Diabetic Hemodialysis Patients

Background: Leptin is known as an adipose-derived peptide hormone that has various physiological effects on energy intake and expenditure, glucose homeostasis, the reproductive and circulatory systems, and weight balance. The first goal of this study was to reveal the difference in the blood leptin depending on obesity. The second goal was to uncover the relationship between leptin and inflammatory markers such as homocysteine and C-reactive protein (CRP). The third goal was to demonstrate the relationship of leptin with a non-diabetic hemodialysis (HD) patient’s nutritional status and insulin resistance. Methods: This cross-sectional study included 44 patients with end-stage renal failure on HD for more than 6 months who had not been diagnosed with diabetes mellitus. Insulin resistance was assessed using the homeostasis model assessment method of insulin resistance (HOMA-IR). The serum leptin levels were measured using radioimmunometric assay. The serum pre-albumin, albumin insulin, glucose, and CRP were checked by various methods. Results: Serum leptin has a correlation with factors related to the nutritional status, insulin resistance and inflammation. The bivariate analysis showed that the body mass index (BMI), nPCR, total cholesterol, total protein, albumin, pre-albumin and HOMA-IR were positively correlated with the serum leptin levels, and high-sensitivity C-reactive protein (hsCRP) and tCO 2 were negatively correlated with the serum leptin concentrations. The linear regression analysis also showed that the BMI, nPCR, total protein, pre-albumin and HOMA-IR were positively correlated, and tCO 2 was negatively correlated with the serum leptin level. Conclusions: This study showed that obese non-diabetic HD patients have higher serum leptin. It also revealed that patients with a high serum leptin level have increased insulin resistance. Therefore, it could be expected that patients who have an elevated serum lepin level have an elevated cardiovascular risk. In addition, further study is needed for the relationship between inflammation markers and serum leptin level. World J Nephrol Urol. 2015;4(2):201-206 doi: http://dx.doi.org/10.14740/wjnu217w