title: Diagnostic performance of weight loss to predict body fatness improvement in cardiac rehabilitation patients.
abstract: OBJECTIVE
  To determine the diagnostic performance of weight loss to identify fat mass loss in cardiac rehabilitation (CR) patients.
  
  
  METHODS
  We included consecutive patients enrolled in early outpatient CR who underwent air displacement plethysmography with measurements of height, weight, and waist circumference at initiation and completion of CR. We calculated the accuracy of >1 kg of weight loss to predict a >1 kg loss of fat mass.
  
  
  RESULTS
  We analyzed data from 142 patients (mean age ± SD = 60 ± 12 years), 74% male, 94% non-Hispanic whites, and body mass index (BMI) 29.9 ± 5.1 kg/m. Following 87 ± 49 days and 22 ± 9 CR sessions, there was a small but significant change in weight (-1.3 ± 3.8 kg), BMI (-0.4 ± 1.2 kg/m), fat mass (-2.6 ± 3.9 kg), lean mass (+1.3 ± 1.9 kg), and waist circumference (-4.3 ± 5.1 cm), P < .001 for all. Overall, patients who lost weight consistently lost fat mass, positive predictive value 0.91 (95% CI: 0.83-0.96). However, the negative predictive value of lack of weight loss to exclude fat mass loss was poor, 0.59 (95% CI: 0.52-0.64). Among patients who did not lose weight, waist circumference reduction was modestly predictive of fat mass loss (r = 0.33, P = .004.)
  
  
  CONCLUSIONS
  Although weight loss in CR is indicative of fat mass loss in most patients, absence of weight loss, or even weight gain, would not necessarily rule out fat loss in a significant number of patients attending CR. These findings speak to the importance of body fatness measurements beyond BMI in the CR setting.
authors: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
authors: Quinn R
authors: QR
authors: Pack
authors: Juan Pablo
authors: JP
authors: Rodriguez-Escudero
authors: Randal J
authors: RJ
authors: Thomas
authors: Ray W
authors: RW
authors: Squires
authors: Lezlie
authors: L
authors: Johnson
authors: Virend K
authors: VK
authors: Somers
authors: Francisco
authors: F
authors: Lopez-Jimenez
mesh_terms: D000273:Adipose Tissue; D000368:Aged; D001827:Body Height; D001835:Body Weight; D005260:Female; D006331:Heart Diseases / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000534:rehabilitation*; D010045:Outpatients; D010991:Plethysmography; D011237:Predictive Value of Tests; D055105:Waist Circumference; D015431:Weight Loss