AJP - Endocrinology and Metabolism, Vol 251, Issue 3 306-E310, Copyright © 1986 by American Physiological Society
Insulin sensitivity in adipocytes from subjects with varying degrees of glucose tolerance
J. E. Foley, P. Thuillez, S. Lillioja, J. Zawadzki and C. Bogardus
Previous studies showed that the sensitivity of glucose transport to
insulin is lower in adipocytes isolated from subjects with
noninsulin-dependent diabetes mellitus and impaired glucose tolerance
compared with subjects with normal glucose tolerance. This study analyzed
the relationship between insulin sensitivity of glucose transport and
glycemia in a large group of nondiabetic-nonglucose-intolerant subjects
with a wide range of glycemic response to oral glucose. Seventy-four Pima
Indians with 2-h postglucose load glucoses between 77 and 197 mg/100 ml,
fasting plasma glucoses between 76 and 108 mg/100 ml, and no postload
glucoses less than 199 mg/100 ml were studied. Isolated adipocytes were
prepared in vitro after an abdominal fat biopsy, ED50 of insulin for
glucose transport was correlated with 2-h postload glucoses, but not
between insulin binding per cell or per cell surface area or in ED50 of
insulin for antilipolysis and 2-h postglucose load glucoses. Although only
17% of the variation in glucose tolerance could be explained by a change in
the sensitivity of glucose transport to insulin, the data suggests that a
postinsulin-binding defect in the coupling of insulin binding to glucose
transport may be an early step in the development of insulin resistance in
human adipocytes.
