The obesity paradox in stable chronic heart failure does not persist after matching for indicators of disease severity and confounders.
OBJECTIVE
To verify whether controlling for indicators of disease severity and confounders represents a solution to the obesity paradox in chronic heart failure (CHF).


RESULTS
From a cohort of 1790 patients, we formed 230 nested matched triplets by individually matching patients with body mass index (BMI) > 30 kg/m(2) (Group 3), BMI 20-24.9 k/m(2) (Group 1) and BMI 25-29.9 kg/m(2) (Group 2), according to NT-proBNP, age, sex, and NYHA class (triplet = one matched patient from each group). Although in the pre-matching cohort, BMI group was a significant univariable prognostic indicator, it did not retain significance [heart rate (HR): 0.91, 95% CI: 0.78-1.05, chi(2): 1.67] when controlled for group propensities as covariates. Furthermore, in the matched cohort, 1-year mortality and 3-year mortality did not differ significantly. Here, BMI again failed to reach statistical significance for prognosis, either as a continuous or categorical variable, whether crude or adjusted. This result was confirmed in the patients not selected for matching. NT-proBNP, however, remained statistically significant (log(NT-proBNP): HR: 1.49, 95% CI: 1.13-1.97, chi(2): 7.82) after multivariable adjustment.


CONCLUSIONS
The obesity paradox does not appear to persist in a matched setting with respect to indicators of disease severity and other confounders. NT-proBNP remains an independent prognostic indicator of adverse outcome irrespective of obesity status.
Frankenstein
Lutz
L
Department of Cardiology, Angiology, Pulmonology, University of Heidelberg, Heidelberg, Germany. lutz.frankenstein@med.uni-heidelberg.de
Zugck
Christian
C
Nelles
Manfred
M
Schellberg
Dieter
D
Katus
Hugo A
HA
Remppis
B Andrew
BA
D000368:Aged; D015992:Body Mass Index; D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000401:mortality* / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D009765:Obesity / Q000150:complications*; D010446:Peptide Fragments / Q000097:blood; D011379:Prognosis; D012044:Regression Analysis
D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain