Age-related progressive brachial artery endothelial dysfunction precedes the changed carotid and left ventricular geometry in healthy humans.

In this study the authors evaluated correlation between aging and brachial endothelial and vascular smooth muscle dysfunction, changes in carotid geometry, and left ventricular remodeling. Vasomotor influences of brachial endothelium and brachial smooth muscle function to reactive hyperemia and nitroglycerin (400 microg, sublingual spray) were assessed by noninvasive ultrasound in 66 healthy subjects of different ages (20-82 years). Carotid intima-media thickness and left ventricular mass index were also assessed by ultrasound and compared with brachial hemodynamic parameters. All results were analyzed by linear regression analysis. The response of brachial artery diastolic diameter to reactive hyperemia decreased with aging (p<0.0001). Also, the response of brachial artery diastolic diameter to nitroglycerin increased relative to aging (p<0.004). Age-related correlations between increased carotid intima-media thickness and brachial artery diastolic diameter response to reactive hyperemia (p<0.01) as well as between increased carotid intima-media thickness and increased left ventricular mass index (p<0.001) were found. However, there was no correlation between brachial artery diastolic diameter response to reactive hyperemia and increased left ventricular mass index (p>0.05). The study showed that aging influences not only brachial endothelial vasomotor properties but also vascular and cardiac geometry. The authors believe that modern therapeutic approach should take these results into consideration to establish new vasculo-protective and cardioprotective strategies.