Confirming the Bidirectional Nature of the Association Between Severe Hypoglycemic and Cardiovascular Events in Type 2 Diabetes: Insights From EXSCEL.

OBJECTIVE: We sought to confirm a bidirectional association between severe hypoglycemic events (SHEs) and cardiovascular (CV) event risk and to characterize individuals at dual risk. RESEARCH DESIGN AND METHODS: In a post hoc analysis of 14,752 Exenatide Study of Cardiovascular Event Lowering (EXSCEL) participants, we examined time-dependent associations between SHEs and subsequent major adverse cardiac events (CV death, nonfatal myocardial infarction [MI] or stroke), fatal/nonfatal MI, fatal/nonfatal stroke, hospitalization for acute coronary syndrome (hACS), hospitalization for heart failure (hHF), and all-cause mortality (ACM), as well as time-dependent associations between nonfatal CV events and subsequent SHEs. RESULTS: SHEs were uncommon and not associated with once-weekly exenatide therapy (hazard ratio 1.13 [95% CI 0.94-1.36], P = 0.179). In fully adjusted models, SHEs were associated with an increased risk of subsequent ACM (1.83 [1.38-2.42], P < 0.001), CV death (1.60 [1.11-2.30], P = 0.012), and hHF (2.09 [1.37-3.17], P = 0.001), while nonfatal MI (2.02 [1.35-3.01], P = 0.001), nonfatal stroke (2.30 [1.25-4.23], P = 0.007), hACS (2.00 [1.39-2.90], P < 0.001), and hHF (3.24 [1.98-5.30], P < 0.001) were all associated with a subsequent increased risk of SHEs. The elevated bidirectional time-dependent hazards linking SHEs and a composite of all CV events were approximately constant over time, with those individuals at dual risk showing higher comorbidity scores compared with those without. CONCLUSIONS: These findings, showing greater risk of SHEs after CV events as well as greater risk of CV events after SHEs, validate a bidirectional relationship between CV events and SHEs in patients with high comorbidity scores.