HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Guest Access | Sign In via User Name/Password

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Gallagher, M. J. Articles by McCullough, P. A. Search for Related Content PubMed PubMed Citation Articles by Gallagher, M. J. Articles by McCullough, P. A.

Comparative Impact of Morbid Obesity vs Heart Failure on Cardiorespiratory Fitness^*

^* From the Department of Medicine (Drs. Gallagher, Franklin, and McCullough, and Mr. deJong), Divisions of Cardiology, Nutrition and Preventive Medicine, William Beaumont Hospital, Royal Oak, MI; and the Preventive Cardiology Unit (Drs. Ehrman and Keteyian, and Mr. Brawner), Division of Cardiovascular Medicine, Henry Ford Heart and Vascular Institute, Detroit, MI.

Correspondence to: Peter A. McCullough, MD, MPH, Divisions of Cardiology, Nutrition, and Preventive Medicine, William Beaumont Hospital, 4949 Coolidge Hwy, Royal Oak, MI 48073; e-mail: pmc975{at}yahoo.com

Background: We are in the midst of an obesity pandemic. Morbid obesity is associated with dyspnea on exertion and higher overall mortality rates. The relations between measures of cardiorespiratory fitness in morbidly obese persons compared to those with heart failure are unknown.

Methods: We compared cardiorespiratory fitness in patients with morbid obesity (n = 43) and established systolic dysfunction heart failure (n = 235), and in age-matched medical control subjects (n = 222) who had been referred for diagnostic exercise testing with simultaneous metabolic measurements. Only patients who completed an adequate test for maximum exertion manifested by a respiratory exchange ratio of 1.10 were included in the study.

Results: The mean (± SD) body mass index (BMI) values for the three groups were 47.8 ± 5.1, 30.1 ± 5.7, and 33.8 ± 9.0, respectively (p < 0.0001 for comparisons between morbidly obese patients and each comparator). The mean left ventricular ejection fraction for the heart failure group was 21.5 ± 8.4%. Despite achieving higher peak heart rate and BP values, the morbidly obese patients had a mean maximum oxygen uptake (O₂max) that was similar to that of those with heart failure (17.8 ± 3.6 vs 16.5 ± 5.6 mL/kg/min, respectively; p = 0.14) and was considerably lower than that of the control group (17.8 ± 3.6 vs 21.3 ± 8.2 mL/kg/min, respectively; p = 0.007). In addition, among subjects in the control group, there was a graded inverse relation between BMI and O₂max.

Conclusions: Morbidly obese individuals have severely reduced cardiorespiratory fitness that is similar to those with established systolic dysfunction heart failure. In addition, in those persons who are referred for stress testing for medical reasons, there is an inverse graded relationship between BMI and cardiorespiratory fitness. These data suggest that the impairment in O₂max in morbidly obese persons is related to BMI and possibly to other factors that impair peak cardiac performance. These findings are consistent with overall higher expected mortality in morbidly obese persons.

Key Words: aerobic capacity (O₂max) • heart failure • morbid obesity

This article has been cited by other articles:

				D. Barker, N. Artis, L.-B. Tan, A. deJong, B. A. Franklin, and P. A. McCullough Correcting data for body size may confound results. Chest, February 1, 2006; 129(2): 493 - 494. [Full Text] [PDF]