The study has a multicenter, open-label, 2-arm design; 60
type 1 diabetes mellitus patients are being recruited from 7 hospitals. Study subjects have been stratified into 2 groups based on the ratio of basal
insulin daily dose (Basal) to total daily
insulin dose (
TDD). The subjects whose Basal/
TDD ratio is <0.4 are instructed not to reduce Basal but to reduce bolus
insulin dose by 10% (group A), and subjects with a Basal/
TDD ratio >0.4 will be instructed to reduce Basal by 10% (group B). The primary outcome is the daily frequency of
hypoglycemia during the intervention period (
SGLT2 inhibitor administration), as determined by self-monitoring of
blood glucose. We aimed to confirm a greater reduction in frequency of
hypoglycemia in group B (reduced Basal), than in group A (non-reduction of Basal and reduced
insulin effect levels by 10%). Baseline
hypoglycemia was set at 7 ± 6 times/month. The minimum sample size required to achieve a significance of .05 for a 1-sided t-test with a statistical power at 80% is determined. When the sample size is 26 patients in 1 group, the percentage increase in
hypoglycemia exceeds 60%, and the sample size is considered sufficient.
DISCUSSION: