title: Is a body mass index of 23 kg/m² a reliable marker of protein-energy wasting in hemodialysis patients?
abstract: OBJECTIVE
  To evaluate the body composition and inflammatory status in patients on hemodialysis (HD) according to the cutoff of 23 kg/m² for the body mass index (BMI).
  
  
  METHODS
  Forty-seven patients (30 men, 11 diabetics, 53.8 ± 12.2 y of age, 58.2 ± 50.9 mo on HD) were studied. Anthropometric data and handgrip strength were evaluated. C-reactive protein, tumor necrosis factor-α, leptin, and interleukin-6 were measured. Mortality was assessed after 24 mo of follow-up.
  
  
  RESULTS
  Nineteen patients (40.4%) presented BMI values lower than 23 kg/m² and leptin levels, midarm muscle area, and free-fat mass were significantly lower in these patients. The prevalence of functional muscle loss according to handgrip strength was not different between the BMI groups. The sum of skinfold thicknesses, the percentage of body fat, fat mass, the fat mass/free-fat mass ratio, and waist circumference were significantly lower in patients with a BMI lower than 23 kg/m², but the mean values did not indicate energy wasting. Patients with a BMI higher than 23 kg/m² presented a higher prevalence of inflammation and higher waist circumference and body fat values. The adiposity parameters were correlated with C-reactive protein and leptin. A Cox multivariate regression analysis demonstrated that C-reactive protein, tumor necrosis factor-α, and interleukin-6 predict cardiovascular mortality.
  
  
  CONCLUSIONS
  Patients on HD with a BMI lower than 23 kg/m² did not present signs of energy wasting, whereas those with a BMI higher than 23 kg/m² had more inflammation, probably because of a greater adiposity. Thus, the BMI value of 23 kg/m² does not seem to be a reliable marker of protein-energy wasting in patients on HD.
authors.affiliation: Medical Sciences Graduate Program, Universidade Federal Fluminense, Niterói, Brazil. vivianeoleal@yahoo.com.br
authors.forename: Viviane O
authors.initials: VO
authors.lastname: Leal
authors.forename: Cristiane
authors.initials: C
authors.lastname: Moraes
authors.forename: Milena B
authors.initials: MB
authors.lastname: Stockler-Pinto
authors.forename: Julie C
authors.initials: JC
authors.lastname: Lobo
authors.forename: Najla E
authors.initials: NE
authors.lastname: Farage
authors.forename: Luis G
authors.initials: LG
authors.lastname: Velarde
authors.forename: Denis
authors.initials: D
authors.lastname: Fouque
authors.forename: Denise
authors.initials: D
authors.lastname: Mafra
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D001823:Body Composition; D001825:Body Fluid Compartments / Q000378:metabolism; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000150:complications / Q000401:mortality; D048909:Diabetes Complications / Q000097:blood / Q000628:therapy; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood; D018836:Inflammation Mediators / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000628:therapy; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal; D009765:Obesity / Q000097:blood / Q000150:complications; D016016:Proportional Hazards Models; D011502:Protein-Energy Malnutrition / Q000097:blood / Q000209:etiology; D012016:Reference Values; D006435:Renal Dialysis; D015203:Reproducibility of Results; D019282:Wasting Syndrome / Q000097:blood / Q000209:etiology
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; D020738:Leptin; D002097:C-Reactive Protein