title: Longitudinal study of leptin levels in chronic hemodialysis patients.
abstract: BACKGROUND
  The influence of serum leptin levels on nutritional status and survival in chronic hemodialysis patients remained to be elucidated. We conducted a prospective longitudinal study of leptin levels and nutritional parameters to determine whether changes of serum leptin levels modify nutritional status and survival in a cohort of prevalent hemodialysis patients.
  
  
  METHODS
  Leptin, dietary energy and protein intake, biochemical markers of nutrition and body composition (anthropometry and bioimpedance analysis) were measured at baseline and at 6, 12, 18 and 24 months following enrollment, in 101 prevalent hemodialysis patients (37% women) with a mean age of 64.6 ± 11.5 years. Observation of this cohort was continued over 2 additional years. Changes in repeated measures were evaluated, with adjustment for baseline differences in demographic and clinical parameters.
  
  
  RESULTS
  Significant reduction of leptin levels with time were observed (linear estimate: -2.5010 ± 0.57 ng/ml/2 y; p < 0.001) with a more rapid decline in leptin levels in the highest leptin tertile in both unadjusted (p = 0.007) and fully adjusted (p = 0.047) models. A significant reduction in body composition parameters over time was observed, but was not influenced by leptin (leptin-by-time interactions were not significant). No significant associations were noted between leptin levels and changes in dietary protein or energy intake, or laboratory nutritional markers. Finally, cumulative incidences of survival were unaffected by the baseline serum leptin levels.
  
  
  CONCLUSIONS
  Thus leptin levels reflect fat mass depots, rather than independently contributing to uremic anorexia or modifying nutritional status and/or survival in chronic hemodialysis patients. The importance of such information is high if leptin is contemplated as a potential therapeutic target in hemodialysis patients.
authors.affiliation: Nephrology Division, Assaf Harofeh Medical Center, Zerifin, Affiliated to Sackler Faculty of Medicine Tel Aviv University, Israel. iliab@asaf.health.gov.il
authors.forename: Ilia
authors.initials: I
authors.lastname: Beberashvili
authors.forename: Inna
authors.initials: I
authors.lastname: Sinuani
authors.forename: Ada
authors.initials: A
authors.lastname: Azar
authors.forename: Hila
authors.initials: H
authors.lastname: Yasur
authors.forename: Leonid
authors.initials: L
authors.lastname: Feldman
authors.forename: Zhan
authors.initials: Z
authors.lastname: Averbukh
authors.forename: Joshua
authors.initials: J
authors.lastname: Weissgarten
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001823:Body Composition; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood*; D020738:Leptin / Q000097:blood*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009752:Nutritional Status; D011446:Prospective Studies; D006435:Renal Dialysis; D016019:Survival Analysis
chemical_list: D015415:Biomarkers; D004044:Dietary Proteins; D020738:Leptin