Hemoglobin A1c stratifies risk of adverse cardiovascular outcomes in prostate cancer survivors in the UK Biobank: a cohort study.

Cardiovascular mortality is a major cause of death in prostate cancer (PCa) survivors, yet tools for cardiovascular risk stratification in this population are lacking. Although hemoglobin A1c (HbA1c) is routinely utilized for risk stratification in the general population, the value of HbA1c for cardiovascular risk stratification in patients with PCa is unknown. Leveraging data from the UK Biobank, we analyzed the association of HbA1c and adverse cardiovascular outcomes in 2,270 men diagnosed with PCa. Over a median follow-up of 13.4 (IQR 1.7) years, 172 cardiovascular death or non-fatal myocardial infarction (MI) events occurred. When compared to participants with an HbA1c < 5.7% in competing-risk regression analysis accounting for non-cardiovascular death, HbA1c ≥ 6.5% was the strongest predictor of cardiovascular death or non-fatal MI (sHR 1.88, 95% CI 1.01-3.48, P < 0.001) after insulin use in a risk model adjusted for demographics, traditional cardiovascular risk factors, and insulin use. Furthermore, when compared to age-matched male UK Biobank participants without PCa, continuous HbA1c levels were a stronger predictor of adverse cardiovascular outcomes in PCa survivors (P-interaction = 0.011). Our findings highlight HbA1c as a robust predictor of cardiovascular risk in men with PCa. Further prospective studies are needed to discern if improving glycemic control could decrease the risk of adverse cardiovascular outcomes in this population.