SGLT2 inhibitors and mortality in older adults with diabetic kidney disease: A target trial emulation study

Randomized controlled trials on sodium-glucose cotransporter 2 (SGLT2) inhibitors have yielded inconsistent findings regarding mortality benefits. It remains unclear whether, and in which subgroups, SGLT2 inhibitors confer survival benefits in older adults with diabetic kidney disease (DKD).

We emulated a target trial using a nationwide claims and health checkup database in Japan to compare all-cause mortality between SGLT2 and dipeptidyl peptidase-4 (DPP4) inhibitor initiators among 5371 adults aged ≥65 years with DKD. The primary outcome was all-cause mortality. Hazard ratios (HRs) were estimated using propensity score overlap weighting and Cox proportional hazards models in an intention-to-treat analysis. A per-protocol analysis with inverse probability of censoring weighting was conducted as sensitivity analysis. Effect modification by age, body mass index (BMI) and Charlson comorbidity index (CCI) was assessed using restricted cubic spline models.

During a median follow-up of 2.23 (IQR, 1.07-3.49) years, 437 deaths occurred. SGLT2 inhibitor use was associated with significantly lower all-cause mortality than DPP4 inhibitors (HR, 0.51; 95% confidence interval, 0.38-0.70), with consistent results in the per-protocol analysis (HR, 0.50; 95% confidence interval, 0.35-0.73). Survival benefit was evident up to about 80 years of age and among individuals with BMI ≥22 kg/m², irrespective of CCI.

In this target trial emulation study, SGLT2 inhibitors were associated with lower mortality in older adults with DKD, particularly those under 80 years and with BMI ≥22 kg/m². These findings support personalized treatment decisions for this high-risk population in clinical practice.