Black and female patients, and patients of low socioeconomic status, are less likely to receive SGLT2 inhibitor treatment despite the increase in its use between 2015 and 2019, say researchers writing in the April 15 issue of JAMA Open Access.
SGLT2 inhibitors, or sodium-glucose cotransporter 2, are used to improve glycemic control, but the inhibitors also have protective effects against cardiovascular and kidney disease, particularly in patients with diabetes. The inhibitors work by decreasing the reabsorption of kidney glucose which in turn increases the excretion of urinary glucose to improve blood glucose levels.
Studies have shown that in patients with diabetes who are at high risk for cardiovascular events, the SGLT2 inhibitor empagliflozin can significantly reduce mortality from cardiovascular-related injuries and lower the risk of hospitalization for heart failure. Dapagliflozin can slow the progression of kidney disease and decrease mortality among patients with chronic kidney disease. The American Diabetes Association and the American College of Cardiology both recommend the use of SGLT2 inhibitors in patients with diabetes who are at high risk for cardiovascular disease, chronic kidney disease or heart failure regardless of their glycemic control status.
However, in this study, which was led by Lauren A. Eberly, MD, MPH, of the Perelman School of Medicine at the University of Pennsylvania, researchers report that racial/ethnic, gender and socioeconomic status may determine who will receive this life-saving treatment. If left unaddressed, it “may widen disparities in kidney and cardiovascular outcomes in the U.S.,” the authors wrote.
Eberly et al. conducted a 5-year cohort study of 934,737 patients (mean age 65.4 years, 50.7% female; 57.6% White) with type 2 diabetes who were commercially insured. They examined the frequency of SGLT2 inhibitor use finding it has been used more often in recent years, yet not among patients with heart failure, kidney disease and cardiovascular disease. Black patients, female patients and patients of lower household income were among those who used the inhibitors less often due to lack of access.
During the study period, of the 934,737 patients included in the study, 81,007 (8.7%) were treated with an SGLT2 inhibitor. More patients with diabetes received the treatment with usage increasing from 3.8% to 11.9%. For patients with type 2 diabetes and cardiovascular or kidney disease, the rate of SGLT2 inhibitor use increased, but was lower as compared to type 2 diabetes with systolic heart failure (1.9% to 7.6%); atherosclerotic cardiovascular disease (3.0% to 9.8%); and, chronic kidney disease (2.1% to 7.5%).
Black, Asian and female patients were associated with lower rates of SGLT2 inhibitor use as compared to patients with higher median household incomes in excess of $100,000. Similar results were found among patients with systolic heart failure, atherosclerotic cardiovascular disease and chronic kidney disease.
Eberly et al. suggested that the lack of access to quality care among affected patients may be an issue, but they didn’t rule out bias and racism. “Although this finding may reflect differences in specialist consultation and decreased access to providers familiar with the clinical benefits of SLGT2 inhibitor treatment, we found that lower rates of SGLT2 inhibitor prescription persisted even after adjustment for visits to cardiology and endocrinology specialists. This result suggests that racism and bias in care delivery may contribute to the findings of this study as well,” the authors wrote.
The authors highlighted some limitations associated with the study, such as the use of an administrative, insurance claims–based database which made it impossible to differentiate between prescriptions offered and prescriptions filled. “We were also unable to fully understand the detailed decision-making, clinical context, and physician and patient preference regarding each patient’s unique treatment plan,” the authors wrote.
Lauren A. Eberly, MD, MPH; Lin Yang, MS; Nwamaka D. Eneanya, MD, MPH, et al. “Association of Race/Ethnicity, Gender, and Socioeconomic Status With Sodium-Glucose Cotransporter 2 Inhibitor Use Among Patients With Diabetes in the US,” JAMA Open Network. April 15, 2021. doi:10.1001/jamanetworkopen.2021.6139