Use of metformin, newer drugs on the rise in patients with diabetic kidney disease
Between 2007 and 2016, researchers observed that use of metformin and newer glucose-lowering medications increased significantly for patients with chronic kidney disease and type 2 diabetes.
“Our findings reflect updated [American Diabetes Association] ADA guidelines and results of clinical trials,” Julie Z. Zhao, MPH, of the department of pharmaceutical care and health systems at the University of Minnesota, College of Pharmacy, and colleagues, wrote. “Kidney Disease: Improving Global Outcomes (KDIGO) provides more specific clinical guidelines for patients with CKD and type 2 diabetes. For patients at CKD stage 3 or higher (eGFR 30 mL/min/1.73 m2), metformin is the recommended first-line treatment choice because of its safety, low cost, and potential cardiovascular benefits. An SGLT2 inhibitor is recommended in the glucose-lowering treatment regimen.”
For patients who are unable to achieve glycemic targets with this combination, the researchers added, a GLP-1 receptor agonist is frequently recommended.
To investigate trends in medication use in this patient population, researchers identified Medicare beneficiaries who used glucose-lowering medications in 2007, 2012 and 2016. Adjustments were made for age, sex, race/ethnicity, CKD stage and low-income subsidy status.
Results showed metformin use increased significantly from 32.7% in 2007 to 48.7% in 2016. Significant increases were also seen in the use of newer classes of glucose-lowering medications. These included dipeptidyl peptidase 4 inhibitors (5.6%, to 21.7%), glucagonlike peptide 1 receptor agonists (2.3% to 6.1%) and sodium-glucose cotransporter 2 inhibitors (0.2%, to 3.3%).
Zhao and colleagues noted that while newer insulin analogue use increased from 37.2% in 2007 to 46.3% in 2013, it has since remained steady.
Insulin was the most highly used, single medication class, with use being higher in patients who received a low-income subsidy. The researchers attribute this finding to high out-pocket-costs that patients not receiving a low-income subsidy would have to pay.
“The Medicare Part D program offers low-income subsidy benefits to enrollees with limited assets and income,” they wrote. “The low-income subsidy provides full or partial waivers for out-of-pocket cost-sharing requirements, including premiums, deductibles and copayments.”
According to Zhao and colleagues, future studies utilizing real-world data are required to further test the safety and efficacy of these medications.
“It is important to understand these trends and why they are occurring, especially given emerging data showing that sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists can reduce albuminuria and slow CKD progression,” they concluded.