Racial and ethnic disparities in the uptake of SGLT2is and GLP-1RAs among Medicare beneficiaries with type 2 diabetes and heart failure, atherosclerotic cardiovascular disease and chronic kidney disease, 2013-2019

Aims/hypothesis: The aim of this study was to investigate racial and ethnic disparities in the use of sodium-glucose cotransporter 2 inhibitors (SGLT2is) and glucagon-like peptide-1 receptor antagonists (GLP-1RAs) among older adults with type 2 diabetes and cardiorenal conditions.

Methods: Using Medicare fee-for-service data (2013-2019), this retrospective cohort study identified older adults (≥65 years) with type 2 diabetes initiating second-line therapies (SGLT2is, GLP1-RAs, dipeptidyl peptidase-4 inhibitors [DPP4is] and sulfonylureas [SUs]) with (1) heart failure (HF), (2) atherosclerotic cardiovascular disease (ASCVD), (3) chronic kidney disease (CKD) and (4) no recorded cardiorenal conditions. Participants were classified as non-Hispanic White, non-Hispanic Black and Hispanic. Multinomial regressions, adjusting for sociodemographic, clinical and county-level characteristics, were used to model the odds of initiating SGLT2is or GLP-1RAs within each cohort.

Results: Black participants with HF, ASCVD, CKD or no recorded cardiorenal conditions had 35% (adjusted OR 0.65 [95% CI 0.61, 0.68]), 33% (0.67 [0.64, 0.69]), 32% (0.68 [0.64, 0.72]) and 24% (0.76 [0.74, 0.79]) lower odds of initiating SGLT2is, respectively, than White participants. Disparities ameliorated from 50-60% lower odds in 2013 to 17-18% in 2019. Similar patterns were observed for GLP-1RA uptake among Black participants. By contrast, Hispanic participants had similar odds of SGLT2i initiation in the HF and CKD cohorts as White participants, but 6% (0.94 [0.91, 0.98]) lower odds in the ASCVD cohort. Notable disparities for Hispanic participants compared with White participants were observed for GLP-1RA uptake in the HF, ASCVD, CKD and no cardiorenal conditions cohorts: 11% (0.89 [0.84, 0.94]), 16% (0.84 [0.81, 0.87]), 16% (0.84 [0.80, 0.89]) and 25% (0.75 [0.72, 0.78]) lower odds, respectively. Participants had greater odds than White participants of initiating DPP4is, which confer no cardiorenal benefits, across all cohorts (HF 1.25 [1.19, 1.31]; ASCVD 1.36 [1.32, 1.40]; CKD 1.32 [1.26, 1.38). Adjustment for social determinants of health did not meaningfully change the study findings.

Conclusions/interpretation: Compared with White participants, disparities in the uptake of SGLT2is were evident for Black participants, and in the uptake of GLP-1RAs for both Black and Hispanic participants. This study highlights how type 2 diabetes management is evolving, while underscoring historical imbalances that have shown signs of abatement.