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

Question  Which measures of body composition are associated with major adverse cardiovascular events in patients with colorectal cancer (CRC)?

Findings  In this population-based cohort study of 2839 patients with CRC, body composition measured by visceral adiposity and muscle radiodensity was associated with major adverse cardiovascular events, whereas body composition measured by body mass index was not associated with these events.

Meaning  Body composition measures collected using routine computed tomographic images, including visceral adiposity and muscle radiodensity, can be used to assess cardiac risk in patients with CRC; however, body mass index may have limited use for assessing cardiovascular risk in this patient population.

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.