Oxidative DNA Damage, And Vascular And Physical Function In Healthy Aging

Abstract

Human aging is associated with changes in vascular function that may, at least in part, explain age-related declines in functional capacity. Furthermore, current aging theory suggests that oxidative stress and the resultant damage may contribute to age-related changes in vascular function. PURPOSE To examine the associations among age, oxidative DNA damage, brachial artery flow-mediated dilation (BAFMD), and physical function in older adults. METHODS Analyses were conducted on 22 women (Age: 88±10yrs; BMI: 24.6±4.1) and 26 men (Age: 86±10yrs; BMI: 26.9±4.1) enrolled in The Louisiana Healthy Aging Study. Vascular function was assessed using high-resolution ultrasonography of the brachial artery. Physical function was defined as performance on the reduced Continuous Scale-Physical Functional Performance (CS-PFP10) Test. Levels of oxidative DNA damage were measured using Single Cell Gel Electrophoresis (Comet assay). RESULTS Brachial artery diameter at rest and BAFMD was 4.3±0.7mm (range: 2.7 to 5.5mm), and 2±2% (range: 0% to 11%), respectively. BAFMD and components of the CS-PFP10 were inversely associated with advancing age (BAFMD: r = −0.29, p <0.05; Endurance: r = −0.63, p <0.001; CS-PFP10 total: r = −0.63, p <0.001). Levels of oxidative DNA damage were directly associated with age (r = 0.29, p <0.05), but inversely associated with CS-PFP10 scores (Endurance: r = −0.28, p <.05; CS-PFP10 total: r = −0.27, p <0.05) and BAFMD (r = −0.45, p <0.05). Finally, BAFMD was directly associated with several CS-PFP10 items (Endurance: r = 0.36, p <0.05; CS-PFP10 total: r = 0.35, p <0.05). CONCLUSION These data support the hypothesis that a decline in function may in part be a consequence of a reduction in vasoreactivity and/or amount of DNA damage. Supported by the National Institute on Aging [P01 (AG022064091A1)] and the Louisiana Board of Regents through the Millennium Trust Health Excellence Fund [HEF (2001–06)02].