Overnight Insulin Requirements More Variable in Type 1 Diabetes

(HealthDay News) — For individuals with type 1 diabetes, overnight insulin requirements are significantly more variable than daytime and total daily insulin requirements during closed-loop insulin delivery, according to a study published in Diabetes Care.

Yue Ruan, from the Wellcome Trust-MRC Institute of Metabolic Science at the University of Cambridge in the United Kingdom, and colleagues retrospectively analyzed overnight, daytime, and total daily insulin amounts delivered during a multicenter closed-loop trial. Over 12 weeks, 32 adults with type 1 diabetes applied hybrid day-and-night closed-loop insulin delivery under free-living home conditions. Data were analyzed from 1918 nights, 1883 daytime periods, and 1564 total days. Variability of insulin requirements in individual subjects was measured by adopting the coefficient of variation.

The researchers found that the variability of overnight insulin requirements was nearly 2-fold higher than the variability of total daily requirements (mean coefficient of variation, 31% vs 17%; P<.001). Variability of overnight insulin was also higher than variability of daytime insulin requirements (31% vs 22%; P<.001).

“Overnight insulin requirements were significantly more variable than daytime and total daily amounts,” the researchers wrote. “This may explain why some people with type 1 diabetes report frustrating variability in morning glycemia.”

Several authors disclosed financial ties to the pharmaceutical industry.


  1. Ruan Y, Thabit H, Leelarathna L, et al; for the [email protected] consortium. Variability of Insulin Requirements Over 12 Weeks of Closed-Loop Insulin Delivery in Adults With Type 1 Diabetes. Diabetes Care. 2016. doi:10.2337/dc15-2623.