Older type 2 diabetic males do not exhibit abnormal pulmonary oxygen uptake and muscle oxygen utilization dynamics during submaximal cycling exercise.
نویسندگان
چکیده
There are reports of abnormal pulmonary oxygen uptake (Vo(2)) and deoxygenated hemoglobin ([HHb]) kinetics in individuals with Type 2 diabetes (T2D) below 50 yr of age with disease durations of <5 yr. We examined the Vo(2) and muscle [HHb] kinetics in 12 older T2D patients with extended disease durations (age: 65 ± 5 years; disease duration 9.3 ± 3.8 years) and 12 healthy age-matched control participants (CON; age: 62 ± 6 years). Maximal oxygen uptake (Vo(2max)) was determined via a ramp incremental cycle test and Vo(2) and [HHb] kinetics were determined during subsequent submaximal step exercise. The Vo(2max) was significantly reduced (P < 0.05) in individuals with T2D compared with CON (1.98 ± 0.43 vs. 2.72 ± 0.40 l/min, respectively) but, surprisingly, Vo(2) kinetics was not different in T2D compared with CON (phase II time constant: 43 ± 17 vs. 41 ± 12 s, respectively). The Δ[HHb]/ΔVo(2) was significantly higher in T2D compared with CON (235 ± 99 vs. 135 ± 33 AU·l(-1)·min(-1); P < 0.05). Despite a lower Vo(2max), Vo(2) kinetics is not different in older T2D compared with healthy age-matched control participants. The elevated Δ[HHb]/ΔVo(2) in T2D individuals possibly indicates a compromised muscle blood flow that mandates a greater O(2) extraction during exercise. Longer disease duration may result in adaptations in the O(2) extraction capabilities of individuals with T2D, thereby mitigating the expected age-related slowing of Vo(2) kinetics.
منابع مشابه
Older type 2 diabetic males do not exhibit abnormal pulmonary oxygen uptake and muscle oxygen utilization dynamics during sub-maximal cycling exercise Running head: Oxygen uptake kinetics in older Type 2 diabetic patients
متن کامل
Skeletal muscle deoxygenation after the onset of moderate exercise suggests slowed microvascular blood flow kinetics in type 2 diabetes.
OBJECTIVE People with type 2 diabetes have impaired exercise responses even in the absence of cardiovascular complications. One key factor associated with the exercise intolerance is abnormally slowed oxygen uptake (VO2) kinetics during submaximal exercise. The mechanisms of this delayed adaptation during exercise are unclear but probably relate to impairments in skeletal muscle blood flow. Thi...
متن کاملSkeletal Muscle Deoxygenation Following the Onset of Moderate Exercise Suggests Slowed Microvascular Blood Flow Kinetics in Type 2 Diabetes
Objective: People with type 2 diabetes (T2DM) have impaired exercise responses even in the absence of cardiovascular complications. One key factor associated with the exercise intolerance is abnormally slowed oxygen uptake ( O2) kinetics during submaximal exercise. The mechanisms of this delayed adaptation during exercise are unclear but likely relate to impairments in skeletal muscle blood flo...
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ورودعنوان ژورنال:
- American journal of physiology. Regulatory, integrative and comparative physiology
دوره 300 3 شماره
صفحات -
تاریخ انتشار 2011