Why Not Screen Everyone?
For many conditions, like HIV or different types of cancer, the US Preventive Services Task Force (USPSTF) recommends broad screening of asymptomatic individuals so that early treatment can improve outcomes.
But when the USPSTF considered the question in 2012 of whether adults should be screened for CKD regardless of symptoms, it found little evidence that early detection could change the course of their illness. At that time, the standard of care for treating early stages of CKD generally focused on treating the comorbid conditions, such as diabetes, hypertension, and cardiovascular disease.
But the equation has changed with the availability of new drugs to treat CKD, such as sodium-glucose cotransporter 2 (SGLT2) inhibitors and mineralocorticoid receptor antagonists (MRAs).
“I consider these blockbuster drugs,” Dr. Bansal said. “For the first time in decades, we’re showing that this class of medications, the SGLT2 inhibitors, substantially reduce risk of loss of kidney function.”
Expressed in the lumen of the proximal renal tubules, SGLT2 reabsorbs filtered glucose from the tubular lumen. Inhibition of SGLT2 promotes urinary glucose excretion and reduces sodium reabsorption, increasing delivery of sodium to the distal tubule. The first SGLT2 inhibitor, canagliflozin, was approved in 2013 for use as an antihyperglycemic agent but subsequently was shown to have serendipitous benefits for the heart and kidneys.
Clinical trials have documented reductions in the risk for cardiovascular events in patients with type 2 diabetes, as well as decreases in the risk for progression to end-stage renal disease, cardiovascular mortality, and hospitalization for heart failure. Updated international guidelines from 2022 recommend treating all patients with type 2 diabetes and CKD with an estimated GFR ≥ 20 mL/min/1.73 m2 with an SGLT2 inhibitor.
But several trials of SGLT2 inhibitors also demonstrated benefits in reducing the risk for cardiovascular-related death or hospitalization for heart failure, even in patients without diabetes. Although initial approval from the US Food and Drug Administration was limited to patients with diabetes and heart failure, the agency has recently expanded its indications to include adults with CKD who do not have diabetes.
Dr. Bansal said she was happy to see this widening of the indications, which makes more patients eligible to receive SGLT2 inhibitors. “I really think this early CKD group is a great group to consider for those medications,” she said.
Dr. Bansal also pointed out that MRAs are another class of drugs with an interesting history. Earlier steroidal MRAs were found to have anti-inflammatory and antifibrotic properties, and in 1960 spironolactone was approved for use as a diuretic for the management of edema, primary aldosteronism, and hypertension. But even as their use in cardiology rose, MRAs had less utility for CKD, given adverse events such as hyperkalemia and hormonal effects like gynecomastia.
But the latest generation of nonsteroidal MRAs (nsMRAs) has higher selectivity for the mineralocorticoid receptor than sex-steroid hormone receptors, reducing androgenic side effects and preventing elevated potassium. Finerenone, the only nsMRA approved in the United States, has been shown in clinical trials to reduce the incidence of cardiovascular events (death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure) and CKD outcomes, including kidney failure, decrease in estimated GFR, or death from renal causes.