Body Composition and Cardiovascular Events in Patients With Colorectal Cancer: A Population-Based Retrospective Cohort Study.

IMPORTANCE: Patients with colorectal cancer (CRC) are up to 4-fold more likely than individuals without a history of cancer to develop cardiovascular disease. Clinical care guidelines recommend that physicians counsel patients with CRC regarding the association between obesity (defined using body mass index [BMI] calculated as weight in kilograms divided by height in meters squared) and cardiovascular disease risk; however, this recommendation is based on expert opinion.
OBJECTIVE: To determine which measures of body composition are associated with major adverse cardiovascular events (MACEs) in patients with CRC. DESIGN, SETTING, AND PARTICIPANTS: Population-based retrospective cohort study of 2839 patients with stage I to III CRC diagnosed between January 2006 and December 2011 at an integrated health care system in North America. EXPOSURES: The primary exposures were BMI and computed tomography-derived body composition measurements (eg, adipose tissue compartments and muscle characteristics) obtained at the diagnosis of CRC. MAIN OUTCOMES AND MEASURES: The primary outcome was time to the first occurrence of MACE after diagnosis of CRC, including myocardial infarction, stroke, and cardiovascular death.
RESULTS: In this population-based cohort study of 2839 participants with CRC (1384 men and 1455 women), the average age (SD) was 61.9 (11.5) years (range, 19-80 years). A substantial number of patients were former (1127; 40%) or current smokers (340; 12%), with hypertension (1150; 55%), hyperlipidemia (1389; 49%), and type 2 diabetes (573; 20%). The cumulative incidence of MACE 10 years after diagnosis of CRC was 19.1%. Body mass index was positively correlated with some computed tomography-derived measures of body composition. However, BMI was not associated with MACE; contrasting BMI categories of greater than or equal to 35 vs 18.5 to 24.9, the hazard ratio (HR) was 1.23 (95% CI, 0.85-1.77; P = .50 for trend). Visceral adipose tissue area was associated with MACE; contrasting the highest vs lowest quintile, the HR was 1.54 (95% CI, 1.02-2.31; P = .04 for trend). Subcutaneous adipose tissue area was not associated with MACE; contrasting the highest vs lowest quintile, the HR was 1.15 (95% CI, 0.78-1.69; P = .65 for trend). Muscle mass was not associated with MACE; contrasting the highest vs lowest quintile, the HR was 0.96 (95% CI, 0.57-1.61; P = .92 for trend). Muscle radiodensity was associated with MACE; contrasting the highest (ie, less lipid stored in the muscle) vs lowest quintile, the HR was 0.67 (95% CI, 0.44-1.03; P = .02 for trend). CONCLUSIONS AND RELEVANCE: Visceral adiposity and muscle radiodensity appear to be risk factors for MACE. Body mass index may have limited use for determining cardiovascular risk in this patient population.