SGLT2 Inhibitors in Type 1 Diabetes and CKD: A Safe and Promising Option? A Case Series

Introduction: Diabetic kidney disease (DKD) remains a serious and prevalent complication of type 1 diabetes mellitus (T1DM), contirbuting to the development of end-stage kidney disease (ESKD). Despite advances in glycaemic control and blood pressure management, patients with T1DM face limited therapeutic options to slow the progression of CKD. SGLT2 inhibitors have demonstrated compelling renal and cardiovascular benefits in patients with type 2 diabetes and CKD, as well as in non-diabetic CKD and heart failure. Their mechanisms—reducing intraglomerular pressure, promoting natriuresis, and improving metabolic and cardiovascular outcomes—offer potential benefit across a range of conditions. However, their use in T1DM remains controversial due to safety concerns, particularly regarding the risk of DKA. Nonetheless, emerging evidence suggests that with careful patient selection, education, and monitoring, SGLT2 inhibitors may offer renal protection in selected patients with T1DM. Case Description: Methods: This retrospective case series describes the use of SGLT2 inhibitors in four patients with T1DM and CKD at a tertiary referral centre in Ireland. Patients were initiated on dapagliflozin or empagliflozin. Estimated glomerular filtration rate (eGFR), urinary albumin-creatinine ratio [uACR] or protein-creatinine ratio [uPCR], HbA1c, and adverse events including DKA and hospitalisation were assessed. All patients received structured education on ketone monitoring and DKA prevention. Results: All 4 patients demonstrated a reduction in proteinuria following SGLT2 initiation, with uACR/uPCR improving in each case. HbA1c remained stable or modestly increased. eGFR remained stable in 3 patients; one with advanced CKD showed a decline, potentially reflecting natural disease progression. Notably, no episodes of DKA or hospital admissions occurred during follow-up. One patient with heart failure and CKD stage IIIb experienced stable renal function and reduced proteinuria. Discussion: This case series demonstrates the potential renal benefits of off-label SGLT2 inhibitor use in select T1DM patients with CKD, particularly in reducing proteinuria. Despite longstanding concerns about DKA, no events occurred, likely reflecting careful patient selection and education. These findings support emerging evidence that SGLT2 inhibitors may be a safe and effective adjunct therapy in selected individuals with T1DM and CKD.