title: Diurnal pattern to insulin secretion and insulin action in healthy individuals.
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.
authors: Division of Endocrinology and Metabolism, Mayo College of Medicine, Rochester, MN, USA.
authors: Ahmed
authors: A
authors: Saad
authors: Chiara
authors: C
authors: Dalla Man
authors: Debashis K
authors: DK
authors: Nandy
authors: James A
authors: JA
authors: Levine
authors: Adil E
authors: AE
authors: Bharucha
authors: Robert A
authors: RA
authors: Rizza
authors: Rita
authors: R
authors: Basu
authors: Rickey E
authors: RE
authors: Carter
authors: Claudio
authors: C
authors: Cobelli
authors: Yogish C
authors: YC
authors: Kudva
authors: Ananda
authors: A
authors: Basu
mesh_terms: D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D002247:Carbon Isotopes; D002940:Circadian Rhythm; D015331:Cohort Studies; D018592:Cross-Over Studies; D003903:Deuterium; D005260:Female; D005943:Gluconeogenesis; D005947:Glucose / Q000378:metabolism*; D018149:Glucose Intolerance / Q000097:blood / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002247:Carbon Isotopes; D007328:Insulin; D003903:Deuterium; D005947:Glucose