title: Usefulness of waist circumference as a marker of abdominal adiposity in peritoneal dialysis: a cross-sectional and prospective analysis.
abstract: BACKGROUND
  Waist circumference (WC) has been well recognized as a surrogate marker of abdominal adiposity. In peritoneal dialysis (PD) patients, however, aspects related to this dialysis modality, such as abdominal distension, presence of catheter and frequent hernia, raise questions regarding the reliability of WC measurements. Herein, we investigated for the first time whether WC is a reliable marker of abdominal adiposity in PD population.
  
  
  METHODS
  This study included 107 prevalent PD patients [56% male, age 52 ± 17 years, 35% diabetics, body mass index (BMI) 24.8 ± 3.9 kg/m(2)]. WC measured at umbilicus level was evaluated against the trunk fat assessed by dual-energy x-ray absorptiometry at baseline and after 6 months. All measurements were taken with the empty abdominal cavity.
  
  
  RESULTS
  At baseline, a strong correlation of WC with trunk fat (r = 0.81; P < 0.001) was observed. Adjusting for gender, age, dialysis vintage and BMI, WC was independently associated with trunk fat (β = 0.30; P < 0.001; R(2) = 0.77). The agreement between WC and trunk fat was 0.59 (kappa statistic) and the area under the curve was 0.90. In the prospective evaluation, we observed that changes in WC correlated with changes in trunk fat as well (r = 0.49; P < 0.001). The kappa statistic of 0.48 remained indicative of a moderate agreement between the methods. The receiver operating characteristic curve analysis showed that WC was sensitive to detect changes in trunk fat (area under the curve 0.76). In the logistic regression analysis adjusting for gender, age and BMI, changes in WC were independently associated with changes in trunk fat.
  
  
  CONCLUSIONS
  The simple anthropometric method of WC is a reliable marker of abdominal adiposity in PD patients.
authors.affiliation: Nutrition Program, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Bazanelli
authors.forename: Maria Ayako
authors.initials: MA
authors.lastname: Kamimura
authors.forename: Silvia Regina
authors.initials: SR
authors.lastname: Manfredi
authors.forename: Sergio Antônio
authors.initials: SA
authors.lastname: Draibe
authors.forename: Lilian
authors.initials: L
authors.lastname: Cuppari
mesh_terms: D050153:Abdominal Fat / Q000000981:diagnostic imaging*; D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001774:Blood Chemical Analysis; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000628:therapy*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010530:Peritoneal Dialysis / Q000009:adverse effects / Q000379:methods*; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055105:Waist Circumference
chemical_list: D015415:Biomarkers