Splanchnic Blood Flow During Dynamic Moderate-intensity Exercise: Effects Of Aging In Females

Blood flow to the active muscles increases during dynamic exercise, whereas blood flow to inactive organs, which include splanchnic organs and inactive limbs, declines. The splanchnic region receives about 25% of cardiac output at rest but is reduced to 20-25% of basal values during exercise. Splanchnic blood flow during exercise differs between young and old males, but no investigations have confirmed this finding in females. To our knowledge, there are no available data on age differences in females in splanchnic blood flow during dynamic exercise. PURPOSE: To elucidate the effects of aging in females on arterial blood pressure and celiac artery blood flow responses to dynamic moderate-intensity exercise. We hypothesized that the reduction in celiac artery blood flow during dynamic moderate-intensity exercise would be greater in elderly females than in young females. METHODS: Ten young healthy females (YF: 20 ± 2 yrs, mean ± SD) and ten elderly healthy females (EF: 71 ± 5 yrs) performed dynamic knee-extension and -flexion for 4-min at 30% heart rate reserve. The changes from baseline for heart rate (HR; ECG), mean arterial blood pressure (MAP; finger photoplethysmography), celiac artery mean blood flow (MBF; Doppler ultrasound) and vascular conductance (MBF/MAP) were calculated. RESULTS: HR increased in both groups at onset of exercise and was maintained throughout exercise. HR increase was higher in the YF than in EF (+37.3 ± 5.5 vs. 26.0 ± 5.3 beats/min, P < 0.001). The increase in MAP during exercise was greater in the EF than in YF (+27.2 ± 10.3 vs. +12.8 ± 6.9 mmHg, P < 0.001). MBF decreased during exercise in both groups, and there was no significant difference between YF and EF (-100.3 ± 64.5 vs. -84.7 ± 68.9 mL/min, P = 0.61). Celiac artery vascular conductance also decreased during exercise in both groups, and there was no difference in response between YF and EF (-1.8 ± 1.0 vs. -1.5 ± 0.7 mL/min/mmHg, P = 0.33). CONCLUSION: These results indicate that aging in females has minimal effect on changes in blood flow in the celiac artery during dynamic moderate-intensity exercise. Supported by JSPS KAKENHI # 22H03479, # 23 K10633, # 23KJ1072. Supported by JSPS KAKENHI # 22H03479, # 23 K10633, # 23KJ1072