Aging reduces venous distensibility and the venodilatory response to nitroglycerin in normal subjects

To determine if aging alters venous tone, venous distensibility was measured during control conditions and after the administration of nitroglycerin (0.8-mg spray) to 50 subjects ranging in age from 21 to 78 years. The mean arterial pressure decreased and the heart rate increased significantly after nitroglycerin. Control venous distensibility, measured after the inflation of an upper arm cuff to 30 mm Hg above cuff zero (VV[30]) was 2.69 ± 1.26 (standard deviation) cc/100 cc arm. The VV[30] increased to 3.06 ± 1.43 cc/100 cc arm after the administration of nitroglycerin. There was a significant relation between age and baseline venous distensibility (r = 0.53, p < 0.001) and between age and the change in venous distensibility after nitroglycerin (r = 0.56, p < 0.001). Both baseline venous distensibility and the venodilatory response to nitroglycerin decreased with age. There was no significant relation between systemic arterial pressure and baseline venous distensibility or between arterial pressure and the venodilatory response to nitroglycerin. Aging appears to diminish baseline venous distensibility and attenuate the venodilatory response to nitroglycerin.