Leptinemia and its relation to sex hormones and obesity in patients with chronic renal failure.

Abstract

Background: Chronic renal failure is a predominant reduction in glumerular filtration rate (GFR) sufficient to produce alterations in well-being and organ function. Endocrine abnormalities common in chronic renal insufficiency is the association of higher serum leptin levels in their patients. Leptin is a protein hormone produced mainly by adyposites. Serum leptin concentrations positively correlate with body mass index (BMI) and body fat content. Changes of androgens synthesis and metabolism develop early after the onset of renal insufficiency and are likely to be caused by primary hypogonadism and /or disturbances of the hypothalamic pituitary –axis.Aim: The aim of the present work is to analyze the contribution of serum testosterone and astradiol concentrations with leptinemia in hemodialyzed patents together with waist circumference and BMI. In order to shed some light on the mechanism of biodegradation of leptin by the kidneys in both genders and how it is affected by body composition and weight.Subjects and Methods: A total of 45 subjects were involved in this study, 30 of them had chronic renal failure and the remaining 15 subjects were normal healthy individuals served as a control. Five mls of blood were withdrawn from each subject by vein puncture, patients and control. ELISA technique was used for the measurement of serum leptin level while RIA technique was used for the measurements of testosterone and estradiol levels. Data were expressed as mean±SD. results were evaluated using the student t-test for paired data. Conventional methods were used for the correlation and regression analyses.Results:Results obtained showed that the level of serum leptin and serum estradiol in patients with chronic renal failure were significantly higher than that in healthy subjects, whereas testosterone level was significantly lower in patients than in healthy subjects.The anthropometrical measurement in patients with chronic renal failure had significantly higher values of waist but significant lower values of BMI. Male with chronic renal failure showed a significant lower level of serum leptin concentration than in females. However the anthropometrical measurements (BMI & waist) of males were significantly higher than those in the females. Serum leptin level was positively correlated with serum estradiol whereas it had an inverse correlation with testosterone. Leptin had positive correlation with each of the studied anthropometrical measurements (BMI & waist). All results are thoroughly discussed in the text. Conclusion :Increased levels of serum leptin and estradiol in CRF patients is a reflection of the increased waist circumference and the poor ability of the kidney for biodegradation of both these hormones. On the other hand testosterone had a significant effect on serum leptin levels as can be shown through its positive effect in males rather than in females.