The Efficacy and Safety of Sodium-Glucose Co-transporter 2 (SGLT2) Inhibitors in Real-World Clinical Practice: Potential Cautionary Use in Elderly Patients with Type 2 Diabetes (T2D)

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have shown safe and therapeutic efficacy in randomized controlled trials (RCT) to reduce adverse cardiorenal events in high-risk patients with type 2 diabetes (T2D). In this study, we investigated the efficacy and safety of SGLT2 intervention in patients with T2D in a real-world clinical practice to confirm the validity of the RCT results. As a retrospective study, we evaluated medical records from 596 patients with T2D treated with SGLT2 inhibitors (dapagliflozin or empagliflozin) in addition to their prior drug regimen to improve glucose control between 2015 and 2019 in the Endocrinology Department at Chungbuk National University Hospital. No control arm was evaluated to compare the effects of adding SGLT inhibitors to the pre-existing regimen. The primary objective was the measurement of glycated hemoglobin (HbA1c) from each individual patient over a 36-month period at 6-month intervals. The secondary parameters were the measurement of fasting plasma glucose (FPG) and body weight (Bwt) changes, as well as the monitoring of adverse events (AEs) and determining the reasons for drug discontinuation. HbA1c levels were reduced at each of the time points throughout the 36-month period and were significantly reduced by 12.5% (P < 0.01) from time 0 (8.8 ± 1.3%) to 36 months (7.7 ± 1.0%). FPG levels from basal (180 ± 60 mg/dL) to 36 months (138 ± 38 mg/dL) and Bwt from basal (74 ± 15 kg) to 36 months (72 ± 15 kg) were also significantly reduced (P < 0.01) for both measurements in the SGLT2 inhibitor add-on group. Similar to HbA1c profile, the FPG and Bwt were measured at a consistently lower level at 6 months until the end of the study. The most common AEs were hypoglycemia (n = 57), genitourinary infection (GUI) (n = 31), and polyuria (n = 28). In the elderly population (≥ 75 years old), AEs (31%) were generally more prevalent (P < 0.001) than those (21%) in the adult (< 75 years old) patients. Over the study period, 211 (35%) patients either dropped or completely discontinued the use of the SGLT2 inhibitor, and the elderly patients tended to have a higher discontinuation rate (52%; P = 0.005) than the adults (33%). In this study, we demonstrated that SGLT2 inhibitors are an effective and durable hypoglycemic agent to control blood glucose levels with reduced maintenance of Bwt, but their use in the elderly (≥ 75 years old) patients with T2D may warrant some additional caution due to increased probability of AEs and discontinuation of drug use.