Glucometabolic efficacy of the empagliflozin/metformin combination in people with type 1 diabetes and increased cardiovascular risk

Background/Objectives: People with type 1 diabetes have an unmet need for cardiovascular protection due to the lack of new recommended antidiabetic therapies with cardiovascular benefits. We examined whether the addition of an empagliflozin/metformin combination, and each drug alone, can complement insulin to improve glucometabolic parameters in overweight people with type 1 diabetes at high cardiovascular risk. Methods: This pilot, single-center double-blind randomized controlled trial included 40 people with type 1 diabetes. In addition to insulin, they received empagliflozin (25 mg daily), metformin (2000 mg daily), an empagliflozin/metformin combination, or a placebo. The intervention period was 12 weeks. Glycemic parameters, insulin requirements, and blood and urine samples were analyzed. Indices for liver fibrosis were calculated. Due to potential safety concerns, participants regularly measured blood ketone values. Results: The empagliflozin/metformin combination decreased HbA1c (−0.6%, p < 0.05) and weight (−6.1 kg, p < 0.05). Empagliflozin decreased the urinary albumin-to-creatinine ratio (−31.4 ± 4.9%, p = 0.002). The empagliflozin/metformin combination and empagliflozin decreased the estimated daily proteinuria (−34.6 ± 5.0%, p = 0.006 and −35.9 ± 6.2%, p = 0.03, respectively), the calculated FIB-4 (up to −17.8 ± 5.2%, p = 0.04 and −10.7 ± 3.7%, p = 0.02, respectively), and other liver fibrosis indices and uric acid values. No significant side effects occurred during the study. Conclusions: The empagliflozin/metformin combination improved glycemic control, reduced weight and insulin requirements, and produced several additional beneficial metabolic effects in overweight people with type 1 diabetes with increased cardiovascular risk.