Diurnal pattern to insulin secretion and insulin action in healthy individuals.

Publication Type:

Journal Article

Source:

Diabetes, Volume 61, Issue 11, p.2691-700 (2012)

Keywords:

Adolescentdigestive disease, digestive deseases Adultdigestive disease, digestive deseases Blood Glucosedigestive disease, digestive deseases Carbon Isotopesdigestive disease, digestive deseases Circadian Rhythmdigestive disease, digestive deseases Cohort Studiesdigestive disease, digestive deseases Cross-Over Studiesdigestive disease, digestive deseases Deuteriumdigestive disease, digestive deseases Femaledigestive disease, digestive deseases Gluconeogenesisdigestive disease, digestive deseases Glucosedigestive disease, digestive deseases Glucose Intolerancedigestive disease, digestive deseases Humansdigestive disease, digestive deseases Insulindigestive disease, digestive deseases Insulin Resistancedigestive disease, digestive deseases Insulin-Secreting Cellsdigestive disease, digestive deseases Maledigestive disease, digestive deseases Middle Ageddigestive disease, digestive deseases Postprandial Perioddigestive disease, digestive deseases Young Adult

Abstract:

Evaluation of the existence of a diurnal pattern of glucose tolerance after mixed meals is important to inform a closed-loop system of treatment for insulin requiring diabetes. We studied 20 healthy volunteers with normal fasting glucose (4.8 ± 0.1 mmol/L) and HbA(1c) (5.2 ± 0.0%) to determine such a pattern in nondiabetic individuals. Identical mixed meals were ingested during breakfast, lunch, or dinner at 0700, 1300, and 1900 h in randomized Latin square order on 3 consecutive days. Physical activity was the same on all days. Postprandial glucose turnover was measured using the triple tracer technique. Postprandial glucose excursion was significantly lower (P < 0.01) at breakfast than lunch and dinner. β-Cell responsivity to glucose and disposition index was higher (P < 0.01) at breakfast than lunch and dinner. Hepatic insulin extraction was lower (P < 0.01) at breakfast than dinner. Although meal glucose appearance did not differ between meals, suppression of endogenous glucose production tended to be lower (P < 0.01) and insulin sensitivity tended to be higher (P < 0.01) at breakfast than at lunch or dinner. Our results suggest a diurnal pattern to glucose tolerance in healthy humans, and if present in type 1 diabetes, it will need to be incorporated into artificial pancreas systems.