Effect of preoperative SGLT2 inhibitor use on postoperative acute kidney injury in patients with type 2 diabetes undergoing surgery: A causal inference study using routinely collected data

AIMS: To assess whether preoperative sodium-glucose co-transporter 2 inhibitor (SGLT2i) use reduces the odds of postoperative acute kidney injury (AKI) in patients with type 2 diabetes undergoing surgery. METHODS: We conducted a target trial emulation using inverse probability of treatment weighting, utilising routinely collected data from a tertiary centre in Australia. Patients with type 2 diabetes were included. We compared patients undergoing surgery under general anaesthesia who were taking SGLT2i preoperatively with patients undergoing surgery who were not taking SGLT2i preoperatively. The primary outcome was postoperative AKI within 7 days of surgery. We estimated the average treatment effect on the treated and calculated adjusted odds ratios (ORs) and standardised risk differences. RESULTS: We included 2499 patients (738 taking SGLT2i preoperatively and 1761 not taking SGLT2i preoperatively). Over half of patients underwent emergency surgery. Postoperative AKI occurred in 18.6% taking SGLT2i preoperatively and 25.8% not taking SGLT2i preoperatively. Odds of postoperative AKI were significantly lower in those who used SGLT2i preoperatively (adjusted OR 0.71, 95% CI 0.56-0.91, p = 0.007). Effects were consistent across subgroup and sensitivity analyses. CONCLUSIONS: In patients with type 2 diabetes who used SGLT2i preoperatively, its use reduced the odds of postoperative acute kidney injury.