Elevated peak exercise systolic blood pressure is not associated with reduced exercise capacity in subjects with Type 2 diabetes

Abstract

Subjects with Type 2 diabetes without cardiovascular disease have a reduced exercise capacity compared with nondiabetic subjects. However, the mechanisms responsible for this phenomenon are unknown. The purpose of this study was to evaluate the impact of exercise systolic blood pressure (SBP) response on diverse exercise tolerance parameters in Type 2 diabetic subjects. Twenty-eight sedentary men with Type 2 diabetes were recruited for this study. Subjects were treated with oral hypoglycemic agents and/or diet. Evaluation of glycemic control and peak exercise capacity were performed for each subject. The subjects were divided into two groups according to the median value of peak SBP (210 mmHg) measured in each subject. We observed a 13, 13, and 16% reduction in the relative peak oxygen uptake (V(O2 peak)), absolute V(O2 peak), and peak work rate in the low- compared with the high-peak SBP group [26.95 (SD 5.35) vs. 30.96 (SD 3.61) ml.kg(-1).min(-1), 2.5 (SD 0.4) vs. 2.8 (SD 0.6) l/min, and 169 (SD 34) vs. 202 (SD 32) W; all P < 0.05]. After adjusting for age, relative V(O2 peak) was still significantly different (P < 0.05). There were similar peak respiratory exchange ratio (RER) [1.20 (SD 0.08) vs. 1.16 (SD 0.07); P = 0.24] and peak heart rate [160 (SD 20) vs. 169 (SD 15) beats/min; P = 0.18] between the low- compared with the high-SBP group. No difference in glycemic control was observed between the two groups. The results reported in this study suggest that in subjects with Type 2 diabetes without cardiovascular disease, an elevated exercise SBP is not associated with reduced exercise capacity and its modulation is probably not related to glycemic control.