Serum Leptin Concentration In Patients With Chronic Renal Failure And Its Relation To Their Nutritional Status

Objective To investigate the leptin in chronic renal failure(CRF) and its effects on nutritional status.Methods Serum leptin was measured by radioimmunoassay in 115 individuals in groups of non-dialysed(ND,n=55), hemodialysed patients(HD,n=30) and healthy controls(n=30). Non-dialysed patients included ND1 group(n=29,body mass indeces(BMI)<20kg/m2) and ND2 group(n=26,BMI≥20kg/m2).BMI, triceps skin-fold thickness(TSF), mid-arm muscle circumference (MAMC),total protein(TP),serum albumin(Alb),prealumin(Pre-A), transferrin(TRF), total cholesterol(TC),triglycerides(TG), highdensity lipoprotein cholesterol(HDL-C),lowdensity lipoprotein cholesterol(LDL-C),blood urea nitrogen(BUN),serum creatinine(Scr),fasting insulin(FINS),insulin sensitivity index(ISI),fasting blood glucose(FBG) were also determined. The relationship between serum leptin concentration and these indeces was analysed.Results ⑴Mean serun leptin concentration was significantly higher in the ND2 group than that in the control(P<0.05),and so in the ND1 group when BMI was corrected by covariance analysis.The difference in serun leptin concentration between the HD group and the control was not statistically significant although BMI wascorrected by covariance analysis. ⑵ Each group in CRF had significantly higher concentrations of BUN,Scr(P<0.001) and lower concentrations of Alb,Pre-A,TRF(P>0.05)than control group.⑶Multiple regression analysis showed that the leptin concentration in CRF was significantly correlated to BMI, MAMC , FBG, age, sex ( the standardized regression coefficients were 0.674,-0.401,-0.312,0.214,0.164 repectively) and unrelated to BUN,Scr,Alb Pre-A,TRF,dialysis therapy,etal.Pearson correlation analysis showed leptin concentration in HD group significantly positively correlated to FINS,but no significant correlation was observed between leptin and ISI in CRF.Conclusions ⑴There is presence of hyperleptinemia in CRF.⑵Serun leptin concentration is highly correlate to BMI,and BMI may be the index in nutritional assessment. ⑶Serun leptin concentration in CRF is influenced by multiple factors,such as BMI,renal fuction,sex,age,FINS.⑷Leptin may contribute to the consumption of skeletal muscles and influence metabolism of blood sugar.⑸Hyperleptinemia is not correlated with markers of protein malnutrition in CRF.