This cross-sectional study by Sato et al. investigates the impact of Sodium-Glucose Co-Transporter-2 (SGLT2) inhibitors on nocturnal polyuria in type 2 diabetic patients, in particular on a comparison between the short-acting inhibitor tofogliflozin and other SGLT2 inhibitors. The sample was 142 patients, divided into two groups: one that received SGLT2 inhibitors and one that received none. Another subgroup analysis was also conducted to compare patients on tofogliflozin with patients on other SGLT2 inhibitors. A questionnaire was used to assess nocturnal voiding frequency, with nocturia operationally defined as the frequency of waking two or more times per night to urinate.
The findings indicated that nocturnal polyuria was felt more frequently in patients on SGLT2 inhibitors compared to their counterparts that were not undergoing these treatments. Among those patients that were not on SGLT2 inhibitors, 40.6% had reported cases of nocturnal polyuria, whereas its occurrence was much higher at 53.4% among those on SGLT2 inhibitors. A statistically significant difference arose when the contrast was drawn between patients on other SGLT2 inhibitors and those that were not on these therapies, since the former group had increased cases of nocturnal polyuria.
Nonetheless, patients that took tofogliflozin had a significantly low incidence of nocturnal polyuria when compared to those patients on other SGLT2 inhibitors. The study clarifies that SGLT2 inhibitors enhance the excretion of glucose through urine, leading to excessive urination. However, tofogliflozin, with its short half-life of 5.4 hours, reduces its effect prior to evening, hence reducing nocturnal excessive urination. Other SGLT2 inhibitors, with longer half-lives, allow continuous glucose excretion during the night, thus leading to increased nocturnal voiding. Since nocturnal polyuria is associated with poor sleep quality, impaired daily activities, and increased risk of falls in older patients, the study suggests that tofogliflozin might be a better option for patients with nocturnal urination.
The findings highlight that tofogliflozin is effective in reducing nocturnal polyuria and has the potential to decrease nighttime hypoglycemia and fractures simultaneously. With these potential benefits, it could be a better SGLT2 inhibitor for elderly patients. However, the study acknowledges its limitations and calls for further studies to confirm the clinical efficacy of tofogliflozin compared with other SGLT2 inhibitors.
