Predictors of weight change in overweight patients with myocardial infarction

Background Weight loss is recommended among overweight survivors of myocardial infarction (MI). This study describes patterns of weight change among overweight patients with MI and identifies factors associated with weight change. Methods A prospective cohort of 1253 overweight or heavier (body mass index [BMI] ≥25 kg/m2) post-MI patients were enrolled in the 19-center PREMIER study and followed up for 1 year to determine changes in weight. Patients were categorized at 1 month as overweight (BMI = 25-29.9 kg/m2), obese (BMI = 30-39.9 kg/m2), or morbidly obese (BMI ≥40 kg/m2). Unadjusted percent weight change was assessed at 1 year, and multivariable linear regression was used to identify independent correlates of change. Results Mean weight change was −0.2% and varied by the severity of baseline obesity (+0.4% for overweight patients, −0.5% for obese patients, and −3.7% for morbidly obese patients [P < .001]). Multivariable analyses revealed the following to be significantly associated with weight change: depression 1 month post-MI (+2.7%, P = .001), lack of health insurance (+2%, P = .01), smoking cessation 1 month post-MI (+2.7% vs current smokers, P < .001), morbid obesity (+4.7% vs overweight patients, P < .0001), and increasing age (−0.8% per decade, P = .001). An interaction between smoking cessation and weight class was detected in that overweight patients who quit had a mean increase of 5.3% (95% CI 3.1%-7.4%), whereas no significant change was observed among obese and morbidly obese patients who quit. Conclusions Although post-MI patients had negligible weight loss over 1 year, several sociodemographic, clinical, and lifestyle characteristics were associated with weight change. New, targeted interventions will likely be needed to improve weight management after an MI.