Ethnicity affects the postprandial regulation of glycogenolysis

Am J Physiol. 1999 Nov;277(5):E905-14. doi: 10.1152/ajpendo.1999.277.5.E905.

Abstract

We investigated the effect of nutrient intake on glucose metabolism in normal Mexican-Americans (n = 6) and European-Americans (n = 6). Subjects were studied after an 18-h fast and after 5-6 h of ingestion of hourly meals that supplied 6.35 or 12.75 micromol glucose. kg(-1). min(-1). Endogenous glucose production (EGP), gluconeogenesis (GNG), and glycogenolysis (GLY) were estimated by mass isotopomer analysis with [U-(13)C]glucose infusions. Fasting EGP, GNG, and GLY did not differ between the groups. Food ingestion lowered the molar rate of GNG by only 31%. However, while consuming the lower quantity of nutrients, Mexican-Americans had higher plasma glucose (P < 0.05), a 39% higher rate of EGP (P < 0.05), and a 68% (P < 0.025) higher rate of GLY than the European-Americans. At the higher intake, EGP and GLY were suppressed completely in both groups. There was a linear relationship between insulin concentrations, EGP, and GLY in both groups, but the slope of the line was significantly (P < 0.05) greater in the European-Americans. We conclude that the sensitivity of GLY to nutrient intake differs between ethnic groups and that this may play a role in the increased predisposition of Mexican-Americans to type II diabetes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Asian Continental Ancestry Group
  • Blood Glucose
  • Carbon Isotopes
  • Diabetes Mellitus, Type 2 / ethnology
  • Energy Metabolism / physiology
  • European Continental Ancestry Group
  • Genetic Predisposition to Disease
  • Gluconeogenesis / physiology
  • Glucose / biosynthesis*
  • Glucose Tolerance Test
  • Glycogen / metabolism*
  • Humans
  • Hyperglycemia / ethnology*
  • Insulin / blood
  • Kinetics
  • Lactic Acid / blood
  • Male
  • Mexican Americans / genetics
  • Middle Aged
  • Postprandial Period / physiology*

Substances

  • Blood Glucose
  • Carbon Isotopes
  • Insulin
  • Lactic Acid
  • Glycogen
  • Glucose