Ontology highlight
ABSTRACT: Objective
Afternoon exercise increases the risk of nocturnal hypoglycemia (NH) in subjects with type 1 diabetes. We hypothesized that automated feedback-controlled closed-loop (CL) insulin delivery would be superior to open-loop (OL) control in preventing NH and maintaining a higher proportion of blood glucose levels within the target blood glucose range on nights with and without antecedent afternoon exercise.Research design and methods
Subjects completed two 48-h inpatient study periods in random order: usual OL control and CL control using a proportional-integrative-derivative plus insulin feedback algorithm. Each admission included a sedentary day and an exercise day, with a standardized protocol of 60 min of brisk treadmill walking to 65-70% maximum heart rate at 3:00 p.m.Results
Among 12 subjects (age 12-26 years, A1C 7.4±0.6%), antecedent exercise increased the frequency of NH (reference blood glucose<60 mg/dL) during OL control from six to eight events. In contrast, there was only one NH event each on nights with and without antecedent exercise during CL control (P=0.04 vs. OL nights). Overnight, the percentage of glucose values in target range was increased with CL control (P<0.0001). Insulin delivery was lower between 10:00 p.m. and 2:00 a.m. on nights after exercise on CL versus OL, P=0.008.Conclusions
CL insulin delivery provides an effective means to reduce the risk of NH while increasing the percentage of time spent in target range, regardless of activity level in the mid-afternoon. These data suggest that CL control could be of benefit to patients with type 1 diabetes even if it is limited to the overnight period.
SUBMITTER: Sherr JL
PROVIDER: S-EPMC3781513 | biostudies-literature | 2013 Oct
REPOSITORIES: biostudies-literature
Sherr Jennifer L JL Cengiz Eda E Palerm Cesar C CC Clark Bud B Kurtz Natalie N Roy Anirban A Carria Lori L Cantwell Martin M Tamborlane William V WV Weinzimer Stuart A SA
Diabetes care 20130611 10
<h4>Objective</h4>Afternoon exercise increases the risk of nocturnal hypoglycemia (NH) in subjects with type 1 diabetes. We hypothesized that automated feedback-controlled closed-loop (CL) insulin delivery would be superior to open-loop (OL) control in preventing NH and maintaining a higher proportion of blood glucose levels within the target blood glucose range on nights with and without antecedent afternoon exercise.<h4>Research design and methods</h4>Subjects completed two 48-h inpatient stud ...[more]