Abnormal oxygen uptake kinetic responses in women with type II diabetes mellitus

Abstract

Persons with type II diabetes mellitus (DM), even without cardiovascular complications have a decreased maximal oxygen consumption (VO2 max) and submaximal oxygen consumption (VO2) during graded exercise compared with healthy controls. We evaluated the hypothesis that change in the rate of VO2 in response to the onset of constant-load exercise (measured by VO2-uptake kinetics) was slowed in persons with type II DM. Ten premenopausal women with uncomplicated type II DM, 10 overweight, nondiabetic women, and 10 lean, nondiabetic women had a VO2 max test. On two separate occasions, subjects performed 7-min bouts of constant-load bicycle exercise at workloads below and above the lactate threshold to enable measurements of VO2 kinetics and heart rate kinetics (measuring rate of heart rate rise). VO2 max was reduced in subjects with type II DM compared with both lean and overweight controls (P < 0.05). Subjects with type II DM had slower VO2 and heart rate kinetics than did controls at constant workloads below the lactate threshold. The data suggest a notable abnormality in the cardiopulmonary response at the onset of exercise in people with type II DM. The findings may reflect impaired cardiac responses to exercise, although an additional defect in skeletal muscle oxygen diffusion or mitochondrial oxygen utilization is also possible.

Meta-analysis of the effect of structured exercise training on cardiorespiratory fitness in Type 2 diabetes mellitus

“…It has also been hypothesized that the lower VO 2max might be a consequence of a reduced rate of circulatory adjustments to an increased workload (i.e. cardiac output) [8,65], or poor diffusion and utilization of oxygen at the level of skeletal muscle [12]. Despite this, our present analysis suggests that people with Type 2 diabetes respond to exercise training with similar increases in VO 2max as those reported in older healthy adults [66].…”

“…Furthermore, many characteristics of skeletal muscle are associated with both low insulin sensitivity and low cardiorespiratory fitness (i.e. decreased capillary density, decreased proportion of Type 1 muscle fibres, higher glycolytic to oxidative enzyme ratio) [8,9,10,11,12,13,14,15].…”

Kinetics of Post-Exercise Excess CO2 Production and Substrate Oxidation in Two Dysglycemic and Euglycemic Older Women A Case Study.

“…The interest stems from the fact that excess CO 2 production is a hallmark of metabolic acidosis and was linked to a number of pathologies [4][5][6][7]. However, results linking type 2 diabetes and amount of excess post-exercise CO 2 are very limited and related to anaerobic threshold (AT) only [8][9][10][11]. Abnormal respiratory exchange has been reported in women with type 2 diabetes mellitus [8], specifically, their CO 2 kinetics was slower than controls.…”

“…However, results linking type 2 diabetes and amount of excess post-exercise CO 2 are very limited and related to anaerobic threshold (AT) only [8][9][10][11]. Abnormal respiratory exchange has been reported in women with type 2 diabetes mellitus [8], specifically, their CO 2 kinetics was slower than controls. To date, there have been no attempts to analyze and contrast excess post-exercise CO 2 production between normoglycemic and dysglycemic subjects.…”

Attenuation of the Muscle Metaboreflex in Patients with Type 2 Diabetes

“…Exercise intolerance is a major manifestation in diabetic patients [1][2][3] , and is related to increased mortality 4) . For example, maximum tolerable workload and oxygen uptake have been shown to be reduced in diabetic subjects compared with healthy subjects matched for age, weight, and physical activity level [1][2][3] . Although the reasons for this exercise intolerance are not well understood, one potential mechanism is impaired autonomic regulation of the cardiovascular system.…”