Cardiovascular responses and endurance during isometric exercise in patients with Type 2 diabetes compared to control subjects.

Background: While it is well documented that diabetes impairs the microcirculation, its effect on isometric exercise has not been determined.

Material/methods: Isometric strength and endurance of the handgrip muscles for a series of 2 fatiguing isometric contractions at a tension of 40% of the maximum strength were assessed in 10 subjects with Type 2 diabetes compared to 10 control subjects; 5 minutes were allowed between the contractions. Blood pressure (BP), heart rate (HR), blood flow (BF) of the whole arm and of the skin on the chest and foot were measured.

Results: Strength and endurance for the first contraction was the same in control subjects compared to subjects with Type 2 diabetes (p>0.05), but endurance of the second contraction was significantly less in subjects with diabetes (p<0.01). HR increased significantly (p<0.01) by over three fold during exercise in control subjects compared to subjects with diabetes. Resting and peak blood pressures were greater in subjects with type 2 diabetes compared to control subjects (p<0.01). Forearm blood flow was significantly lower at rest, during exercise and post exercise in subjects with diabetes compared to control subjects (p<0.01).

Conclusions: The results are probably explained by the damage to the microcirculation seen in subjects with diabetes.