Clinical research study
The Obesity Paradox, Weight Loss, and Coronary Disease

https://doi.org/10.1016/j.amjmed.2009.06.006Get rights and content

Abstract

Purpose

Because obesity is a cardiovascular risk factor but is associated with a more favorable prognosis among cohorts of cardiac patients, we assessed this “obesity paradox” in overweight and obese patients with coronary heart disease enrolled in a cardiac rehabilitation and exercise training (CRET) program, making this assessment in patients classified as overweight/obese using both traditional body mass index (BMI) and percent body fat assessments. Additionally, we assessed the efficacy and safety of purposeful weight loss in overweight and obese coronary patients.

Patients and Methods

We retrospectively studied 529 consecutive CRET patients following major coronary events before and after CRET, and compared baseline and post program data in 393 overweight and obese patients (body mass index [BMI] ≥25 kg/m2) divided by median weight change (median = −1.5%; mean +2% vs −5%, respectively). In addition, we assessed 3-year total mortality in various baseline BMI categories as well as compared mortality in those with high baseline percent fat (>25% in men and >35% in women) versus those with low baseline fat.

Results

Following CRET, the overweight and obese with greater weight loss had improvements in BMI (−5%; P <.0001), percent fat (−8%; P <.0001), peak oxygen consumption (+16%; P <.0001), low-density lipoprotein cholesterol (−5%; P <.02), high-density lipoprotein cholesterol (+10%; P <.0001), triglycerides (−17%; P <.0001), C-reactive protein (−40%; P <.0001), and fasting glucose (−4%; P = .02), as well as marked improvements in behavioral factors and quality-of-life scores. Those with lower weight loss had no significant improvements in percent fat, low-density lipoprotein cholesterol, triglycerides, C-reactive protein, and fasting glucose. During 3-year follow-up, overall mortality trended only slightly lower in those with baseline overweightness/obesity who had more weight loss (3.1% vs 5.1%; P = .30). However, total mortality was considerably lower in the baseline overweight/obese (BMI ≥25 kg/m2) than in 136 CRET patients with baseline BMI <25 kg/m2 (4.1% vs 13.2%; P <.001), as well as in those with high baseline fat compared with those with low fat (3.8% vs 10.6%; P <.01).

Conclusions

Purposeful weight loss with CRET in overweight/obese coronary patients is associated with only a nonsignificant trend for lower mortality but is characterized by marked improvements in obesity indices, exercise capacity, plasma lipids, and inflammation, as well as behavioral factors and quality of life. Although an “obesity paradox” exists using either baseline BMI or baseline percent fat criteria, these results support the safety and potential long-term benefits of purposeful weight loss in overweight and obese patients with coronary heart disease.

Section snippets

Patients

We retrospectively reviewed the case records of 529 consecutive patients with coronary heart disease (44% percutaneous intervention, 35% bypass surgery, and 30% myocardial infarction; some patients had more than 1 event) who completed a 3-month formal program of CRET between January 2000 and July 2005 to ascertain relevant anthropometric, lipid, clinical, and psychological data as previously described.24, 25, 27, 28, 29, 30, 31, 32, 33, 37 We have previously demonstrated that our patients who

Baseline Characteristics

Baseline data describing patients with low and high BMI are demonstrated in Table 1. At baseline, patients with high BMI averaged to be 4 years younger (P <.0001), and this group had significantly higher levels of percent body fat (P <.0001), triglycerides (P <.001), fasting glucose (P <.01), and prevalence of diabetes (P = .054), and lower levels of high-density lipoprotein (HDL) cholesterol (P <.0001) compared with those with low BMI. Only 5 of the 529 patients were active smokers, including 3

Discussion

This study has several important and practical clinical findings. First, this study confirms the “obesity paradox” for the first time among patients enrolled in formal CRET programs, in that overweight and obese coronary patients by BMI criteria have more adverse baseline coronary risk profile yet have considerably lower overall mortality during follow-up. Second, even when coronary patients were divided by the gold standard percent body fat criteria for obesity, patients with higher baseline

Conclusions

Although an obesity paradox exists, in that coronary heart disease patients with higher BMI or higher percent body fat have lower mortality than those with less obesity, these results support the safety and potential long-term benefits of purposeful weight loss in overweight and obese patients with coronary heart disease.

Acknowledgements

The authors greatly appreciate the excellent medical care and data collection provided by the cardiovascular physicians, exercise physiologists, nurses, and dietitians working with cardiac rehabilitation at Ochsner Medical Center. In addition, Ms. Barbara Siede prepared the figures and Ms. Patricia Taylor prepared and edited the submission.

References (65)

  • O. Cortés et al.

    Determinants of referral to cardiac rehabilitation programs in patients with coronary artery disease: a systematic review

    Am Heart J

    (2006)
  • M.A. Williams et al.

    Clinical evidence for a health benefit from cardiac rehabilitation: an update

    Am Heart J

    (2006)
  • C.J. Lavie et al.

    Patients with high baseline exercise capacity benefit from cardiac rehabilitation and exercise training programs

    Am Heart J

    (1994)
  • C.J. Lavie et al.

    Effects of cardiac rehabilitation and exercise training on low density lipoprotein cholesterol in patients with hypertriglyceridemia and coronary artery disease

    Am J Cardiol

    (1994)
  • R.V. Milani et al.

    Reduction in C-reactive protein through cardiac rehabilitation and exercise training

    J Am Coll Cardiol

    (2004)
  • D. Lucini et al.

    Effects of cardiac rehabilitation and exercise training on autonomic regulation in patients with coronary artery disease

    Am Heart J

    (2002)
  • T.S. Church et al.

    Improvements in blood rheology after cardiac rehabilitation and exercise training in patients with coronary heart disease

    Am Heart J

    (2002)
  • C.J. Lavie et al.

    Prevalence of hostility in young coronary patients and effects of cardiac rehabilitation and exercise training

    Mayo Clin Proc

    (2005)
  • C.J. Lavie et al.

    Prevalence of anxiety in coronary patients with improvements following cardiac rehabilitation and exercise training

    Am J Cardiol

    (2004)
  • R.V. Milani et al.

    Impact of cardiac rehabilitation on depression and its associated mortality

    Am J Med

    (2007)
  • C.J. Lavie et al.

    Effects of cardiac rehabilitation, exercise training, and weight reduction on exercise capacity, coronary risk factors, behavioral characteristics, and quality of life in obese coronary patients

    Am J Cardiol

    (1997)
  • G.C. Fonarow et al.

    Obesity, weight reduction and survival in heart failure: reply

    J Am Coll Cardiol

    (2002)
  • R.V. Milani et al.

    Understanding the basics of cardiopulmonary exercise testing

    Mayo Clin Proc

    (2006)
  • P. McAuley et al.

    Body mass, fitness and survival in veteran patients: another obesity paradox?

    Am J Med

    (2007)
  • M.R. Mehra et al.

    Obesity and suppressed B-type natriuretic peptide levels in heart failure

    J Am Coll Cardiol

    (2004)
  • A.F. Osman et al.

    The incremental prognostic importance of body fat adjusted peak oxygen consumption in chronic heart failure

    J Am Coll Cardiol

    (2000)
  • AOA Fact Sheets: Obesity in the U.S.

    (2002)
  • C.J. Lavie et al.

    Cardiac rehabilitation and exercise training programs in metabolic syndrome and diabetes

    J Cardiopul Rehab

    (2005)
  • M.T. Miller et al.

    Impact of obesity on the pathogenesis and prognosis of coronary heart disease

    J Cardiometab Syndr

    (2008)
  • H.B. Hubert et al.

    Obesity as an independent risk factor for cardiovascular disease: a 26-year follow-up of participants in the Framingham Heart Study

    Circulation

    (1983)
  • J.P. Curtis et al.

    The obesity paradox: body mass index and outcomes in patients with heart failure

    Arch Intern Med

    (2005)
  • C.J. Lavie et al.

    Obesity and heart failure prognosis: paradox of reverse epidemiology?

    Eur Heart J

    (2005)
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    Funding: None.

    Conflict of Interest: The authors have no conflict of interest regarding this study.

    Authorship: This is an original work and all authors meet the criteria for authorship, including acceptance of responsibility for the scientific content of this manuscript. All authors had access to the data and had roles in writing and revising the manuscript.

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