Risk for recurrent kidney stones was lower with SGLT-2 inhibitors than with GLP-1 agonists.

Diabetes and gout both predispose patients to nephrolithiasis. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors, which promote both uric acid excretion and urinary flow, have been associated with lower risks for kidney stones and gout attacks in observational studies (NEJM JW Gen Med Mar 15 2024 and JAMA Intern Med 2024; 184: 265-274; NEJM JW Gen Med Aug 15 2023 and Ann Intern Med 2023; 176: 1067-1080). Risk for recurrent nephrolithiasis with these drugs has not been studied extensively.

In this latest observational study using Canadian population databases, researchers identified 20,000 adults with diabetes and previous nephrolithiasis who initiated SGLT-2 inhibitors (14,000 patients) or glucagon-like peptide-1 (GLP-1) receptor agonists (6000 patients) between 2014 and 2022. Twenty-two per cent of the study population had concurrent gout.

After a mean 1.3 years of follow up and extensive adjustment for potential confounders, patients who took SGLT-2 inhibitors had a significantly lower rate of recurrent nephrolithiasis than those who took GLP-1 agonists (156 vs 103 per 1000 person-years; number needed to treat [NNT], 20). Similar results were seen in a variety of subgroup and sensitivity analyses. In patients with recent nephrolithiasis, the NNT for SGLT-2 inhibitors versus GLP-1 agonists was five. Among patients with gout, those who started SGLT-2 inhibitors developed significantly fewer urinary stones and had fewer gout flares than those who started GLP-1 agonists.

Comment: Clinicians currently have several different options for add-on drug therapies in patients with type 2 diabetes; sometimes the choice is a toss-up. The findings of this study suggest that, when we are considering additional drug therapy for a patient with diabetes, a history of recurrent gout or nephrolithiasis could be a factor that pushes in the direction of prescribing an SGLT-2 inhibitor.

Bruce Soloway, MD, Associate Professor Emeritus of Family and Social Medicine, Albert Einstein College of Medicine, Bronx, New York, USA.

McCormick N, et al. Comparative effectiveness of sodium-glucose cotransporter-2 inhibitors for recurrent nephrolithiasis among patients with pre-existing nephrolithiasis or gout: target trial emulation studies. BMJ 2024; 387: e080035.

This summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine.