The obesity paradox, weight loss, and coronary disease

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] > or =25 kg/m(2)) 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 > or =25 kg/m(2)) than in 136 CRET patients with baseline BMI <25 kg/m(2) (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.