Outcomes of “diabetes‐friendly” vs “diabetes‐unfriendly” β‐blockers in older nursing home residents with diabetes after acute myocardial infarction

AIMS: To assess whether nursing home (NH) residents with type 2 diabetes mellitus (T2D) preferentially received "T2D-friendly" (vs "T2D-unfriendly") β-blockers after acute myocardial infarction (AMI), and to evaluate the comparative effects of the two groups of β-blockers. MATERIALS AND METHODS: This new-user retrospective cohort study of NH residents with AMI from May 2007 to March 2010 used national data from the Minimum Data Set and Medicare system. T2D-friendly β-blockers were those hypothesized to increase peripheral glucose uptake through vasodilation: carvedilol, nebivolol and labetalol. Primary outcomes were hospitalizations for hypoglycaemia and hyperglycaemia in the 90 days after AMI. Secondary outcomes were functional decline, death, all-cause re-hospitalization and fracture hospitalization. We compared outcomes using binomial and multinomial logistic regression models after propensity score matching. RESULTS: Of 2855 NH residents with T2D, 29% initiated a T2D-friendly β-blocker vs 24% of 6098 without T2D (P < 0.001). For primary outcomes among residents with T2D, T2D-friendly vs T2D-unfriendly β-blockers were associated with a reduction in hospitalized hyperglycaemia (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.21-0.97), but unassociated with hypoglycaemia (OR 2.05, 95% CI 0.82-5.10). For secondary outcomes, T2D-friendly β-blockers were associated with a greater rate of re-hospitalization (OR 1.26, 95% CI 1.01-1.57), but not death (OR 1.06, 95% CI 0.85-1.32), functional decline (OR 0.91, 95% CI 0.70-1.19), or fracture (OR 1.69, 95% CI 0.40-7.08). CONCLUSIONS: In older NH residents with T2D, T2D-friendly β-blocker use was associated with a lower rate of hospitalization for hyperglycaemia, but a higher rate of all-cause re-hospitalization.