Effect of type 2 diabetes on the dynamic response characteristics of leg vascular conductance during exercise.
In this study we tested the hypothesis that type 2 diabetes impairs the dynamic response of leg vascular conductance (LVC) during exercise. LVC (leg blood flow/mean arterial pressure) responses were studied during intermittent contractions of the calf muscle in subjects with type 2 diabetes (n = 9), heavy controls (n = 10) and lean controls (n = 8) using a biexponential function and an estimate of the mean response time (MRT). The time constant of the second phase of LVC was significantly greater in type 2 diabetes (66.4 ± 29.2 s) than the heavy (22.2 ± 13.4 s) and lean (21.8 ± 9.3 s) controls, resulting in a significantly greater MRT in the diabetic group (median [IQR] = 30.7 [24.6-46.5] s versus 16.3 [4.3-23.2] s and 18.4 [13.7-19.3] s). These data support the hypothesis and suggest that a slowed hyperaemic response in the exercising limb might contribute to exercise intolerance in diabetic subjects.
Department of Physiology, Trinity College Dublin, Dublin, Ireland.
Oscar
O
MacAnaney
Heather
H
Reilly
Donal
D
O'Shea
Mikel
M
Egaña
Simon
S
Green
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008875:Middle Aged; D012039:Regional Blood Flow