Common Blood Pressure Drug Linked to Higher Kidney Risk in Diabetic Kidney Disease

A commonly prescribed class of blood pressure medication may be linked to worse kidney outcomes in people with type 2 diabetes, even when they are already taking newer drugs designed to protect the kidneys, according to findings presented at the 63rd European Renal Association (ERA) Congress. The drugs, dihydropyridine calcium-channel blockers (DCCBs), lower blood pressure by relaxing blood vessels and are often used as a second-line treatment for diabetic kidney disease (DKD), a leading cause of kidney failure worldwide caused by prolonged high blood sugar damaging small blood vessels in the kidneys.

Researchers examined health data from 31,031 adults with type 2 diabetes between 2016 and 2021, all of whom were taking both renin-angiotensin system (RAS) inhibitors and sodium-glucose cotransporter-2 (SGLT2) inhibitors, two drug classes now considered standard, kidney-protective treatment for DKD. Of these, 12,172 patients (39.2%) were also taking DCCBs and 18,859 (60%) were on other blood-pressure medications, with a median follow-up of about 3.5 years.

After adjusting for differences between patients, DCCB use was associated with a 33% greater risk of a major adverse kidney event, defined as a 40% or greater decline in estimated glomerular filtration rate, or eGFR, the standard measure of kidney function, or progression to dialysis or transplant. "We initially thought the kidney-protective effects of SGLT2 inhibitors might counterbalance the potential harms associated with DCCBs," said Dr. Timna Agur, the study's lead author. "However, the increased risk of kidney disease progression appeared to persist even in this group." Researchers suggest DCCBs may relax the blood vessels carrying blood into the kidney's filtering units more than those carrying blood away, raising internal filtration pressure.

Because the study was observational, the researchers said it cannot prove DCCBs directly cause the poorer outcomes, and called for prospective studies and randomized controlled trials to confirm the findings and clarify the safest blood pressure treatment strategy for patients with DKD.