Diabetes Care, Vol 18, Issue 4 490-497, Copyright © 1995 by American Diabetes Association
Relationship between habitual physical activity and insulin area among individuals with impaired glucose tolerance. The San Luis Valley Diabetes Study
JG Regensteiner, SM Shetterly, EJ Mayer, RH Eckel, WL Haskell, J Baxter and RF Hamman
Section of Vascular Medicine, University of Colorado School of Medicine, Denver, USA.
OBJECTIVE--To determine whether higher levels of physical activity are
associated with lower fasting insulin levels and lower insulin areas under
the oral glucose tolerance curve in individuals with impaired glucose
tolerance (IGT) in a community setting. RESEARCH DESIGN AND METHODS--Data
from a cross-sectional study of a population consisting of 219 Hispanic and
non-Hispanic white men and women with IGT (by World Health Organization
criteria) in two rural Colorado counties were analyzed. Total physical
activity was assessed by a 7-day physical activity recall, from which
metabolic equivalents (METs) were estimated (expressed as MET h/week).
Relationships of MET h/week with fasting insulin levels and insulin areas
were assessed while considering obesity, age, and other risk factors known
to influence fasting insulin level and insulin area. RESULTS--Among all
subjects, univariate analyses showed that higher physical activity levels
were associated with lower mean insulin areas and fasting insulin levels
(both P < 0.05). Multiple linear regression showed that higher levels of
physical activity were significantly associated with lower values of of the
insulin area (P < 0.001) but not with fasting insulin levels. The
relationship between insulin area and habitual physical activity was
independent of obesity, fat distribution, and age. CONCLUSIONS--On the
basis of cross-sectional data, we conclude that higher levels of habitual
physical activity are associated with lower insulin areas in a population
of individuals with IGT. Understanding the impact of physical activity on
markers of insulin action in individuals with IGT is important because of
the greatly enhanced risk of non-insulin-dependent diabetes mellitus and,
hence, cardiovascular disease in this population.