Effect of aging on carotid artery stiffness and baroreflex sensitivity during head-out water immersion in man.

摘要: To examine the possible age-related blood pressure (BP) deregulation in response to central hypervolemia, we measured spontaneous baroreflex sensitivity (SBRS), carotid arterial compliance (CC), and R-R interval coefficient of variation (RRICV) during basal thermoneutral resting head-out-of-water immersion (HOWI) 7 young (YG = 24.0 +/- 0.8 years) 6 middle-aged/older (OL 59.3 1.3 healthy men. Compared with conditions 19.6 4.0 vs OL 6.1 1.5 ms/mmHg, P < 0.05), SBRS remained higher YG than rest HOWI 23.6 6.6 9.3 2.1 0.05). The RRICV was significantly different between groups 6.5 1.4 2.8 0.4%, 0.05) under HOWI. group had no increase CC, but a significant systolic BP (basal 115.3 4.4 water 129.3 5.3 mmHg, In contrast, CC 0.16 0.01 0.17 0.02 mm(2)/mmHg, changes BP. positively related (r 0.58, 0.05 for r 0.62, water). Our data suggest that vagal dysfunction reduced may be associated differences groups, elevation older