Age Reduces Microvascular Function in the Leg Independent of Physical Activity.
Age Reduces Microvascular Function in the Leg Independent of Physical Activity.
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DOI：
10.1249/mss.0000000000001281
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发表时间：
2017-08
影响因子：
4.1
通讯作者：
Slade JM
中科院分区：
文献类型：
--
作者：
Tonson A;Noble KE;Meyer RA;Rozman MR;Foley KT;Slade JM
The microvasculature is critical in the control of blood flow. Aging and reduced physical activity may both decrease microvascular function. The primary aim was to evaluate the influence of age on microvascular function in adults with similar physical activity levels (PA). Secondary aims were to assess the reliability of muscle functional MRI in older adults and the relationship between physical activity and microvascular function in older adults. Microvascular BOLD responses were measured in young adults (YA, n=12, 21±1 (±SD) years old, PA=239±73×103 counts/day) and older adults (OA, n=12, 64±4 years old, PA=203±48×103 counts/day). Functional MR images (3T, echo planar blood-oxygen-level dependent (BOLD)), of the leg were acquired following brief (1s) maximal voluntary isometric contractions. Test-retest reliability of BOLD responses and the Pearson correlation between peak BOLD and PA was assessed in a group of older adults (OA-r) with a broad range of PA (66±5 years old, n=9, PA range = 54×103 count/day to 674×103 counts/day). Peak BOLD microvascular responses were reduced for OA compared to YA. OA peak BOLD was 27% lower in the soleus (OA: 3.3±0.8% vs. YA: 4.5±1.4% YA, p=0.017) and 40% lower in the anterior compartment (1.6±0.6% OA vs. 2.7±1.1% YA, p=0.006). Coefficient of variation was 8.6% and 11.8% for peak BOLD in the soleus and anterior compartment, respectively, with an intraclass correlation of 0.950 for both muscle regions. The correlation between peak BOLD and PA was r ≥ 0.715, p ≤ 0.030. Aging was associated with reduced microvascular function in leg muscles, independent of physical activity. The findings also revealed good reliability for BOLD MRI in older adults for the soleus and anterior compartment muscles.
