Risk of clinically relevant hyperglycemia with metoprolol compared to carvedilol in older adults with heart failure and diabetes

BACKGROUND: Although prior literature suggests that metoprolol may worsen glucose control compared to carvedilol, whether this has clinical relevance among older adults with diabetes and heart failure (HF) remains an open question. METHODS: This was a US retrospective cohort study utilizing data sourced from a 50% national sample of Medicare fee-for-service claims of patients with part D prescription drug coverage (2007-2017). Among patients with diabetes and HF, we identified initiators of metoprolol or carvedilol, which were 1:1 propensity score matched on >90 variables. The primary outcome was initiation of a new oral or injectable antidiabetic medication (proxy for uncontrolled diabetes); secondary outcomes included initiation of insulin and severe hyperglycemic event (composite of emergency room visits or hospitalizations related to hyperglycemia). RESULTS: Among 24 239 propensity score-matched pairs (mean [SD] age 77.7 [8.0] years; male [39.1%]), there were 8150 (incidence rate per 100 person-years [IR] = 33.5) episodes of antidiabetic medication initiation among metoprolol users (exposure arm) compared to 8576 (IR = 33.4) among carvedilol users (comparator arm) compared to corresponding to an adjusted hazard ratio (aHR) of 0.97 (95% confidence interval [CI]: 0.94, 1.01). Similarly, metoprolol was not associated with a significant increase in the risk of secondary outcomes including insulin initiation: aHR of 0.98 (95% CI: 0.93, 1.04) and severe hyperglycemic events: aHR of 0.98 (95% CI: 0.93, 1.02). CONCLUSIONS: In this large study of older adults with HF and diabetes, initiation of metoprolol compared to carvedilol was not associated with an increase in the risk of clinically relevant hyperglycemia.