title: Body mass index and the risk of recurrent coronary events following acute myocardial infarction.
abstract: Although excess adiposity appears to increase the risk of coronary heart disease in the general population, its importance in patients with established coronary disease is less defined. We evaluated a population-based inception cohort of survivors to hospital discharge following first acute myocardial infarction (AMI) (n = 2,541) to assess the association between body mass index (BMI) and the risk of recurrent coronary events and to explore the mechanisms for this relation. Using Cox proportional-hazards regression, we assessed the risk of recurrent coronary events associated with levels of adiposity as defined by BMI and then investigated potential mechanisms through which adiposity conferred risk by examining how adjustment for diabetes mellitus, systemic hypertension, and dyslipidemia affected the association. Forty-one percent of the cohort were overweight (BMI 25 to 29.9), and 27.8% were obese (BMI > or =30). After adjustment for other risk factors, the risk of recurrent coronary events (n = 418) increased as BMI increased, especially among those who were obese. Using a BMI of 16 to 24.9 as the reference group, for mildly overweight patients (BMI 25 to 27.4), the relative risk (RR) was 0.93 (95% confidence interval [CI] 0.70 to 1.24); it was 1.16 for more severe overweight patients (BMI 27.5 to 29.9; 95% CI 0.87 to 1.55). For patients with class I obesity (BMI 30 to 34.9), the RR was 1.49 (95% CI 1.12 to 1.98), and for class II to III obesity (BMI > or =35), the RR was 1.80 (95% CI 1.30 to 2.48). We estimated that clinical measurements of diabetes, hypertension, and dyslipidemia explained approximately 43% of this risk. Thus, excess adiposity as measured by BMI was associated with an increased risk of recurrent coronary events following AMI, particularly among those who were obese.
authors.affiliation: Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, Washington 98101, USA. rea123@u.washington.edu
authors.forename: T D
authors.initials: TD
authors.lastname: Rea
authors.forename: S R
authors.initials: SR
authors.lastname: Heckbert
authors.forename: R C
authors.initials: RC
authors.lastname: Kaplan
authors.forename: B M
authors.initials: BM
authors.lastname: Psaty
authors.forename: N L
authors.initials: NL
authors.lastname: Smith
authors.forename: R N
authors.initials: RN
authors.lastname: Lemaitre
authors.forename: D
authors.initials: D
authors.lastname: Lin
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D015897:Comorbidity; D016001:Confidence Intervals; D003327:Coronary Disease / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000453:epidemiology; D006801:Humans; D006949:Hyperlipidemias / Q000175:diagnosis / Q000453:epidemiology; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology*; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D015996:Survival Rate; D014481:United States / Q000453:epidemiology