Diabetes Care, Vol 22, Issue 10 1640-1646, Copyright © 1999 by American Diabetes Association
Effects of exercise training on oxygen uptake kinetic responses in women with type 2 diabetes
SL Brandenburg, JE Reusch, TA Bauer, BW Jeffers, WR Hiatt and JG Regensteiner
Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA. suzanne.brandenburg@uchsc.edu
OBJECTIVE: Women with uncomplicated type 2 diabetes have both a decreased
maximal oxygen consumption (VO2max) and slowed oxygen uptake (VO2) kinetics
at the onset of exercise compared with nondiabetic women. These
abnormalities are seen not only at maximal workloads, but also at the onset
of low-level exercise. To evaluate the hypothesis that VO2max and VO2
kinetics would improve with exercise training in untrained people with type
2 diabetes, we measured these parameters in premenopausal sedentary women
before and after 3 months of supervised exercise training. RESEARCH DESIGN
AND METHODS: A total of 8 women with type 2 diabetes, 9 overweight
nondiabetic women, and 10 lean nondiabetic women were studied. At baseline
and after 3 months of exercise training, subjects underwent bicycle
ergometer testing to obtain VO2max and VO2 kinetics data. RESULTS: On
entry, women with type 2 diabetes had the lowest VO2max and slowest VO2
kinetics of the three groups. After exercise training, the women with type
2 diabetes improved their VO2max more than the lean and overweight control
women: 28 vs. 5 and 8%, respectively (P < 0.05 for the diabetic group
vs. both control groups). In the group with diabetes, VO2 kinetics improved
by 39 and 22% at 20 and 30 W, respectively. For the control subjects, VO2
kinetics did not improve at any workload in either group. CONCLUSIONS:
Despite beginning with the lowest VO2max and slowest VO2 kinetics, subjects
with type 2 diabetes benefited more from an exercise training program than
did control subjects. These findings suggest that in addition to its known
metabolic effects, exercise training in individuals with type 2 diabetes
may be an effective therapy to improve the cardiovascular response to
exercise and to overcome low-level exercise impairment as reflected by
improved VO2max and VO2 kinetics. If the ability to make circulatory
adjustments at the beginning of exercise at low workloads is improved by an
exercise training program, as suggested by the VO2 kinetics data, the
clinical significance of exercise for people with type 2 diabetes is clear.