title: High-calorie supplementation increases serum leptin levels and improves response to rHuEPO in long-term hemodialysis patients.
abstract: BACKGROUND
  Dialysis patients with a high body mass index are less likely to experience severe anemia. Leptin, a hormone secreted by adipocytes, may have a role in protecting against renal anemia. The aim of the present study is to determine the effect of an increase in serum leptin levels by increasing energy intake on recombinant human erythropoietin (rHuEPO) response in long-term hemodialysis (HD) patients.
  
  
  METHODS
  We enrolled 65 long-term HD patients to explore the association between leptin level and rHuEPO response by classifying them as either high- or low-leptin individuals (phase 1). Thereafter, 39 patients with malnutrition by means of Subjective Global Assessment were randomly assigned to high-energy and high-protein (an extra 475 kcal and 16.6 g of protein daily; group A; n = 12) or standard-energy, but high-protein (an extra 67.2 kcal and 16.8 g of protein daily; group B; n = 27), supplementation for 12 weeks. Serial serum leptin levels, nutritional measures, and hematologic parameters were obtained. Age- and sex-matched well-nourished patients (group C; n = 16) not administered extra nutritional supplementation served as control subjects (phase 2).
  
  
  RESULTS
  In phase 1, a significantly lower erythropoietin dose, greater hematocrit, and better nutritional measures were observed in the high-leptin group (P < 0.001). In phase 2, there was a significant increase in body fat mass (P = 0.001) and median serum leptin levels (P < 0.001) in response to 12 weeks of high-energy supplementation in group A, accompanied by markedly improved erythropoiesis (P < 0.05) compared with groups B and C.
  
  
  CONCLUSIONS
  Hyperleptinemia reflects better nutritional status and rHuEPO response in long-term HD patients. Increasing energy intake improves erythropoiesis, which may be mediated in part by an increase in serum leptin levels.
authors.affiliation: Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Szu-Chun
authors.initials: SC
authors.lastname: Hung
authors.forename: Tsui-Yin
authors.initials: TY
authors.lastname: Tung
authors.forename: Chung-Shih
authors.initials: CS
authors.lastname: Yang
authors.forename: Der-Cherng
authors.initials: DC
authors.lastname: Tarng
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism / Q000473:pathology; D000368:Aged; D000740:Anemia / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control*; D001823:Body Composition; D003430:Cross-Sectional Studies; D004044:Dietary Proteins / Q000008:administration & dosage*; D019587:Dietary Supplements; D004351:Drug Resistance; D002149:Energy Intake; D004920:Erythropoiesis; D004921:Erythropoietin / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications*; D020738:Leptin / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011502:Protein-Energy Malnutrition / Q000097:blood / Q000150:complications / Q000517:prevention & control / Q000628:therapy; D011994:Recombinant Proteins; D006435:Renal Dialysis / Q000009:adverse effects; D016896:Treatment Outcome
chemical_list: D004044:Dietary Proteins; D006454:Hemoglobins; D020738:Leptin; D011994:Recombinant Proteins; C103998:epoetin beta; D004921:Erythropoietin