In a meta-analysis of ten eligible placebo-controlled trials, the combination of SGLT2-Is with insulin treatment is beneficial in patients with T1DM compared with placebo, providing reduction of HbA1c, mean amplitude of glucose excursions, body weight, and insulin requirements, without increasing the risk of hypoglycemia but increasing that of genital infections and diabetic ketoacidosis. This evidence concerns the gene SLC5A2 and type 1 diabetes mellitus.