For people with type 1 diabetes (T1D) using multiple daily insulin injections (MDI), we previously reported that maintaining optimal glucose control whilst travelling across multiple time zones is challenging. The aim of this pilot study was to compare flexibly-dosed U100 insulin degludec (DEG) with a structured pre-flight dose algorithm for U100 insulin glargine (GLA) in adults with T1D flying >6 hours. Beginning in Honolulu (HI, UTC -10), subjects flew eastward non-stop for 9.5 hours to New York (NY, UTC -5). After 72 hours in NY, subjects returned to HI (11 hour flight) staying up to 72 hours. After 2 weeks, they switched to the other insulin and repeated the travel. The primary endpoint was inflight Time in Range (TIR, 70-140 mg/dl) using blinded continuous glucose monitoring (CGM-Abbott Freestyle Libre Pro) during eastward and westward travel. Secondary end-points included time above and below range and glycemic variability (coefficient of variation [CV]). Between insulin comparisons were made using Pearson N1 chi-square tests for proportions, mean glucose via two-tailed independent t-tests and glycemic variability via two-sample F-tests. Twenty subjects, (60% female, age 34.9 ± 15.2 [mean ±SD] years, HbA1c 7.5 ± 1.2%) completed the study. Insulin doses during travel were similar (23.0 ± 11.4 for GLA and 21.8 ± 12.0 units for DEG). Overall, mean glucose on GLA was 148.0 ± 73.8 mg/dL (CV 50%) versus 158.5 ± 76.7 mg/dL (CV 48%) on DEG, p=0.01. While aggregate TIR was greater on GLA (44% versus 38% with DEG), there was less hypoglycemia <70 mg/dL on DEG (p<0.01). Significantly less time was also spent below <60 (p<0.01) and >250 mg/dL (p<0.01) during eastward travel and <70 (p<0.01) during westward travel on DEG. Inflight CV on DEG was also less during both eastward (43% vs. 49%, p<0.01) and westward (38% vs. 51%, p<0.0001) travel.
In conclusion, for adults with T1D undertaking long-haul travel, DEG use was associated with less disruption to glucose control compared to GLA.
C. Axelrod: None. K.N. Castorino: Research Support; Self; Abbott, Dexcom, Inc., Medtronic, Mylan, Novo Nordisk Inc. W.C. Bevier: None. G. Haroush: None. C.C. Farfan: None. M.R. Mefford: None. K. Nelson: None. L.A. Spink: None. D. Kerr: Advisory Panel; Self; Novo Nordisk A/S, Sanofi-Aventis. Research Support; Self; Eli Lilly and Company. Stock/Shareholder; Self; Glooko, Inc.