Target Trial Emulation: SGLT-2 Inhibitors May Reduce Recurrent Nephrolithiasis in Patients with Type 2 Diabetes and Pre-existing Nephrolithiasis
10 Nov, 2024 | 18:17h | UTCBackground: Sodium-glucose cotransporter-2 (SGLT-2) inhibitors, initially approved for glycemic control in type 2 diabetes, have demonstrated multiple cardiometabolic and renal benefits, including reducing serum urate levels and lowering gout flare-ups. However, data on the effectiveness of SGLT-2 inhibitors in preventing recurrent nephrolithiasis, especially among patients with concomitant gout, are limited.
Objective: To evaluate the comparative effectiveness of SGLT-2 inhibitors versus glucagon-like peptide-1 (GLP-1) receptor agonists in reducing the recurrence of nephrolithiasis among patients with type 2 diabetes and pre-existing nephrolithiasis, including those with concomitant gout.
Methods: A target trial emulation study was conducted using a population-based cohort from British Columbia, Canada, between January 2014 and June 2022. Adults with type 2 diabetes and pre-existing nephrolithiasis who initiated an SGLT-2 inhibitor or a GLP-1 receptor agonist were included. The primary outcome was recurrent nephrolithiasis events identified from emergency department visits, hospital admissions, or outpatient diagnoses. Inverse probability of treatment weighting was applied to adjust for baseline differences.
Results: After weighting, 14,456 patients initiating SGLT-2 inhibitors and 5,877 initiating GLP-1 receptor agonists were analyzed. The incidence of recurrent nephrolithiasis was significantly lower among SGLT-2 inhibitor users (105.3 per 1000 person-years) compared to GLP-1 receptor agonist users (156.4 per 1000 person-years), with an adjusted rate ratio of 0.67 (95% CI 0.57 to 0.79) and a rate difference of –51 per 1000 person-years (number needed to treat [NNT] = 20).
Conclusions: SGLT-2 inhibitor use is associated with a significant reduction in recurrent nephrolithiasis among patients with type 2 diabetes and pre-existing nephrolithiasis, including those with concomitant gout. These findings suggest that SGLT-2 inhibitors may offer dual benefits in managing nephrolithiasis recurrence and gout comorbidities.
Implications for Practice: In patients with type 2 diabetes and a history of nephrolithiasis, particularly those with concomitant gout, SGLT-2 inhibitors may be a valuable addition to current treatment strategies to reduce the recurrence of kidney stones and manage comorbid conditions.
Study Strengths and Limitations: Strengths include the use of a large, population-based cohort and rigorous statistical methods to emulate a target trial, enhancing causal inference. Limitations involve potential residual confounding due to unmeasured factors such as body mass index and laboratory measures, and the inability to capture nephrolithiasis events not requiring medical attention.
Future Research: Further studies are warranted to explore the mechanisms underlying the nephrolithiasis protective effects of SGLT-2 inhibitors, assess their impact in patients without diabetes, and investigate the effects on different types of kidney stones.