Relationship between obesity and maximal insulin-stimulated glucose uptake in vivo and in vitro in Pima Indians

J Clin Invest. 1984 Mar;73(3):800-5. doi: 10.1172/JCI111274.

Abstract

Previous studies have left unanswered whether human obesity, independent of glucose intolerance, is associated with a "postreceptor" defect in insulin action. We have studied the relationship between the degree of obesity (as estimated by underwater weighing) and the maximal insulin-stimulated glucose disposal rate (M) in vivo in 52 glucose-tolerant Pima Indian males. The relationship was examined independently of differences in age and maximal oxygen uptake (an estimate of "physical fitness"). The maximal insulin-stimulated glucose transport rate (MTR) was also measured in isolated abdominal adipocytes from the same subjects to determine whether differences in M could be explained by differences in glucose transport. The results showed that there was a large variance in M and MTR among these glucose-tolerant subjects. M was better correlated with glucose storage rates than with oxidation rates, as estimated by indirect calorimetry. The most obese subjects had only a 20% lower mean M and 30% lower MTR than the most lean subjects. The lower M in the obese subjects was due to both lower glucose oxidation and storage rates. There was no significant, independent correlation between age or degree of obesity and M or MTR. The maximal oxygen uptake (VO2 max) appeared to independently account for 20% of the variance observed in M. MTR was only weakly correlated with M (r = 0.36, P less than 0.02). We concluded that differences in M in these glucose-tolerant subjects must be explained by factor(s) other than maximal oxygen uptake, age, maximal insulin-stimulated glucose transport in vitro, or degree of adiposity per se.

MeSH terms

  • Adipose Tissue / metabolism*
  • Adolescent
  • Adult
  • Aging
  • Arizona
  • Biological Transport
  • Blood Glucose / metabolism*
  • Body Composition
  • Calorimetry, Indirect
  • Glucose / metabolism*
  • Humans
  • Indians, North American*
  • Insulin* / pharmacology
  • Male
  • Obesity / metabolism*
  • Oxygen Consumption

Substances

  • Blood Glucose
  • Insulin
  • Glucose