Changes in serum potassium in people with type 2 diabetes taking sodium-glucose co-transporter-2 inhibitors.

Study objective: The primary objective of this study was to determine if there was a significant change in potassium levels with sodium-glucose co-transporter-2 (SGLT2) inhibitor therapy in people with type 2 diabetes (T2D). A co-primary objective was to evaluate which factors may predispose a patient to changes in potassium levels.

Design: Multicenter retrospective cohort chart review.

Data source: Study patients were identified through an electronic medical record-generated report if they had T2D and were prescribed an SGLT2 inhibitor from January 2013 to September 2019.

Patients: Patients were included if they had T2D, were receiving care at Advocate Medical Group, and were confirmed to have taken one of the four SGLT2 inhibitors available at the time of study approval, canagliflozin, dapagliflozin, empagliflozin, or ertugliflozin, for at least 7 days. Patients were excluded if they did not have a basic metabolic panel or comprehensive metabolic panel recorded 1 year prior to or 6 months after SGLT2 inhibitor therapy initiation.

Results: Data extraction from the electronic medical record identified 6425 patients receiving an SGLT2 inhibitor, of which 1926 met inclusion criteria. The SGLT2 inhibitor most prescribed was canagliflozin (43.7%), followed by empagliflozin (36.9%) and dapagliflozin (19.4%). Concomitant baseline medications were thiazide diuretics (27.5%); angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, or angiotensin receptor-neprilysin inhibitors (72.1%); and/or mineralocorticoid receptor antagonists (27.2%). A statistically significant change in potassium levels was found with dapagliflozin (p = 0.018); albeit not clinically significant. No other statistically significant changes or patterns were identified. The overall mean change in serum potassium from baseline was 0.021 mmol/L within 3 months; 0.007 mmol/L from 3 to 5.9 months; -0.017 mmol/L within 6-12 months; and 0.004 mmol/L after more than 12 months.

Conclusions: No clinically significant increase or decrease in potassium levels was observed upon initiation of SGLT2 inhibitor therapy in patients with T2D. This was consistent across background medication use and patient-specific factors. Baseline potassium should not be a factor in initiating SGLT2 inhibitor therapy, if clinically indicated, in patients with T2D.