학술논문
Metabolic state switches between morning and evening in association with circadian clock in people without diabetes
Document Type
Report
Author
Source
Journal of Cutaneous Immunology and Allergy. September 2022, Vol. 13 Issue 9, p1496, 1505 p.
Subject
Language
English
Abstract
INTRODUCTION The circadian clock plays a critical role in many biological processes, including the sleep–wake cycle, hormone secretions, glucose and lipid metabolism, and body temperature regulation. Increased research attention during [...]
: Aims/Introduction: Understanding morning–evening variation in metabolic state is critical for managing metabolic disorders. We aimed to characterize this variation from the viewpoints of insulin secretion and insulin sensitivity, including their relevance to the circadian rhythm. Materials and Methods: A total of 14 and 10 people without diabetes were enrolled, and underwent a 75‐g oral glucose tolerance test (OGTT) and hyperinsulinemic‐euglycemic clamp study, respectively. Participants completed the OGTT or hyperinsulinemic‐euglycemic clamp at 08.00 hours and 20.00 hours in random order. Before each study, hair follicles were collected. In mice, phosphorylation levels of protein kinase B were examined in the liver and muscle by western blotting. Results: Glucose tolerance was better at 08.00 hours, which was explained by the higher 1‐h insulin secretion on OGTT and increased skeletal muscle insulin sensitivity on hyperinsulinemic‐euglycemic clamp. Hepatic insulin sensitivity, estimated by the hepatic insulin resistance index on OGTT, was better at 20.00 hours. The 1‐h insulin secretion and hepatic insulin resistance index correlated significantly with Per2 messenger ribonucleic acid expression. The change (evening value – morning value) in the glucose infusion rate correlated significantly with the change in non‐esterified fatty acid, but not with clock gene expressions. The change in non‐esterified fatty acid correlated significantly with E4bp4 messenger ribonucleic acid expression and the change in cortisol. In mice, phosphorylation of protein kinase B was decreased in the liver and increased in muscle in the beginning of the active period as, expected from the human study. Conclusions: Glucose metabolism in each tissue differed between the morning and evening, partly reflecting lipid metabolism, clock genes and cortisol levels. Deeper knowledge of these associations might be useful for ameliorating metabolic disorders.
: Aims/Introduction: Understanding morning–evening variation in metabolic state is critical for managing metabolic disorders. We aimed to characterize this variation from the viewpoints of insulin secretion and insulin sensitivity, including their relevance to the circadian rhythm. Materials and Methods: A total of 14 and 10 people without diabetes were enrolled, and underwent a 75‐g oral glucose tolerance test (OGTT) and hyperinsulinemic‐euglycemic clamp study, respectively. Participants completed the OGTT or hyperinsulinemic‐euglycemic clamp at 08.00 hours and 20.00 hours in random order. Before each study, hair follicles were collected. In mice, phosphorylation levels of protein kinase B were examined in the liver and muscle by western blotting. Results: Glucose tolerance was better at 08.00 hours, which was explained by the higher 1‐h insulin secretion on OGTT and increased skeletal muscle insulin sensitivity on hyperinsulinemic‐euglycemic clamp. Hepatic insulin sensitivity, estimated by the hepatic insulin resistance index on OGTT, was better at 20.00 hours. The 1‐h insulin secretion and hepatic insulin resistance index correlated significantly with Per2 messenger ribonucleic acid expression. The change (evening value – morning value) in the glucose infusion rate correlated significantly with the change in non‐esterified fatty acid, but not with clock gene expressions. The change in non‐esterified fatty acid correlated significantly with E4bp4 messenger ribonucleic acid expression and the change in cortisol. In mice, phosphorylation of protein kinase B was decreased in the liver and increased in muscle in the beginning of the active period as, expected from the human study. Conclusions: Glucose metabolism in each tissue differed between the morning and evening, partly reflecting lipid metabolism, clock genes and cortisol levels. Deeper knowledge of these associations might be useful for ameliorating metabolic disorders.