Does comorbidity influence the risk of myocardial infarction or diabetes during androgen-deprivation therapy for prostate cancer?

Abstract

Background: Androgen-deprivation therapy (ADT) for prostate cancer (PCa) may be associated with cardiovascular disease and diabetes. Some data suggest that men with certain conditions may be more susceptible to developing cardiovascular disease than others.

Objective: To assess whether the risk of myocardial infarction (MI) or diabetes during ADT is modified by specific baseline comorbidities.

Design, setting, and participants: We conducted a population-based observational study of 185 106 US men ≥66 yr of age diagnosed with local/regional PCa from 1992 to 2007. We assessed comorbidities monthly over the follow-up period.

Outcome measurements and statistical analysis: Cox proportional hazards models with time-varying variables assessing incident diabetes or MI.

Results and limitations: A total of 49.9% of the men received ADT during follow-up. Among men with no comorbidities, ADT was associated with an increase in the adjusted hazard of MI (adjusted hazard ratio [AHR]: 1.09; 95% confidence interval [CI], 1.02-1.16) and diabetes (AHR: 1.33; 95% CI, 1.27-1.39). Risks of MI and diabetes were similarly increased among men with and without specific comorbid illnesses (p>0.10 for all interactions, with one exception). Previous MI, congestive heart failure, peripheral arterial disease, stroke, hypertension, chronic obstructive pulmonary disease, and renal disease were associated with new MI and diabetes, and obesity and rheumatologic disease were also associated with diabetes. Limitations include the observational study design, reliance on administrative data to ascertain outcomes, and lack of information on risk factors such as smoking and family history.

Conclusions: Traditional risk factors for MI and diabetes were also associated with developing these conditions during ADT but did not significantly modify the risk attributable to ADT. Strategies to screen and prevent diabetes and cardiovascular disease in men with PCa should be similar to the strategies recommended for the general population.