Edinburgh Napier University

  Aging is associated with endothelial dysfunction, reduced angiogenic capabilities, and an increase in arterial stiffness. Additionally, regular exercise is known to offset the age-related decline in blood vessel number and function. Circulating angiogenic cells are known to play an important role in vascular repair, and hence further investigation of the effect of age and cardiorespiratory fitness (CRF) on these cells, and on subsets of these cells, for example angiogenic T cells (TANG), is required. This should allow us to more fully understand the apparent protective mechanisms offered by exercise within the aging process.

PURPOSE: To determine the influence of age and CRF on TANG number and function.

METHODS: CRF was estimated in 62 male participants aged 18-65 through the use of a submaximal cycling ergometer test (YMCA). TANG were quantified by flow cytometry in a resting blood sample, defined as co-expression of CD3 and CD31. In addition, expression of C-X-C Chemokine Receptor 4 (CXCR4) was also quantified as an indicator of migratory capacity. Linear regressions were performed to examine association between TANG and age, and CRF individually, and where appropriate, step-wise comparisons were made. Comparisons were made between young (50 yrs) men, in addition to fitness subcategories (low CRF and high CRF). Age and CRF comparisons were made using two-way Analysis of Variance (ANOVA).

RESULTS: Age was inversely associated with TANG number (r=-0.337, p