Effect of type 2 diabetes mellitus on exercise intolerance and the physiological responses to exercise in peripheral arterial disease

Abstract

Aims/hypothesis There are conflicting data about the effect of type 2 diabetes mellitus on exercise tolerance in peripheral arterial disease. To elucidate this problem, we compared the tolerance and physiological responses to treadmill and cycle exercise in 31 patients with peripheral arterial disease and intermittent claudication. Materials and methods One group of these patients had type 2 diabetes (n=12) and its members were matched for sex and age with a group of patients who did not have diabetes (n=12). Since BMI and body weight were greater in the diabetic group (28.4±3.7 vs 25.2±2.4 kg/m 2 ; 84.0± 14.6 vs 73.8±8.0 kg), we also studied a third, 'heavy' group of non-diabetic patients with claudication of similar age (n=7; BMI = 30.9±5.3 kg/m 2 ; body weight = 85.2± 8.2 kg). Results Compared with the 'light' non-diabetic group, maximum treadmill times were shorter for the diabetic and heavy non-diabetic groups (1,448 vs 845 and 915 s; ANOVA p=0.01); maximum cycle time also tended to be shorter (ANOVA, p=0.08) in the diabetic and heavy nondiabetic groups (median = 1,231 vs 730 and 797 s). The majority of physiological responses assessed were not different between the groups, although the time constant of oxygen uptake during submaximal treadmill and cycle exercise was significantly larger (ANOVA p<0.05) for the diabetic group. Conclusions/interpretation These data demonstrate that exercise tolerance is lower in diabetic than non-diabetic patients with claudication, but that this difference is due to obesity rather than diabetes itself.

Obesity Decreases Time to Claudication and Delays Post-Exercise Hemodynamic Recovery in Elderly Peripheral Arterial Disease Patients

“…Peak VO 2 values are in agreement with the ones reported by other authors in PAD patients [19,20] , they are lower than the ones expected for the age and gender of subjects, and are similar to the ones observed in patients with other diseases, such as congestive heart failure or heart transplant [21] . Thus, these values confirm the poor aerobic condition of PAD patients.…”

Similar level of impairment in exercise performance and oxygen uptake kinetics in middle-aged men and women with type 2 diabetes

“…Excess body weight, reflected in a higher body mass index, contributes to exercise intolerance in diabetic subjects and more so for weight-bearing (treadmill) than nonweight-bearing (cycling) exercise (11). In the former study (34) body weight was 10% higher in diabetic subjects, raising the possibility of a greater difference in body weight in females than males and it contributing to a relatively larger reduction in exercise tolerance in females.…”

“…Each subject was tested on two occasions, separated by 72 h, and at the same time of day. Four female subjects were premenopausal (2 from each female group) and were tested during the midfollicular phase of their menstrual cycle (days [5][6][7][8][9][10][11][12]. Subjects refrained from consuming caffeine and alcohol in the 24 h before testing and limited their exercise to normal activities of daily living.…”

Reliability of the Vascular Claudication Reporting in Diabetic Patients With Peripheral Arterial Disease

“…No significant differences in functional performance between patients having PAD with and without DM were reported, 25 while a lower exercise tolerance, attributable to obesity rather than DM, was reported in another study. 26 Finally, a higher deoxygenation and a lower performance in diabetic patients were found. 19 The discrepancy between these results and our findings in terms of exercise capacity can be related to the severity of the disease, which was mild in their study (ABI ¼ 0.86) and more serious (ABI ¼ 0.61) in the present study.…”