Effect of gastric distension on cardiovascular parameters: gastrovascular reflex is attenuated in the elderly

Abstract

Stretching the stomach wall in young healthy subjects causes an increase in muscle sympathetic nerve activity and in blood pressure, the gastrovascular reflex. We compared healthy elderly subjects with healthy young subjects to find out whether the gastrovascular reflex attenuates in normal ageing and we studied whether there was a difference in autonomic function or gastric compliance that could explain this possible attenuation. Muscle sympathetic nerve activity, finger blood pressure and heart rate were continuously recorded during stepwise isobaric gastric distension using a barostat in eight healthy young (6 men and 2 women, 27 ± 3.2 years, mean ± s.e.m.) and eight healthy elderly subjects (7 men and 1 woman, 76 ± 1.5 years). Changes in cardiac output and total peripheral arterial resistance were calculated from the blood pressure signal. The baseline mean arterial pressure and muscle sympathetic nerve activity were higher in the elderly group (both P < 0.05) and muscle sympathetic nerve activity increase during the cold pressor test was lower in the elderly group (P = 0.005). During stepwise gastric distension, the elderly subjects showed an attenuated increase in muscle sympathetic nerve activity compared to the young subjects (P < 0.01). The older group tended to show a higher increase in mean arterial pressure (P = 0.08), heart rate (P = 0.06) and total peripheral arterial resistance (P = 0.09) The cardiac output rose slightly in both groups without significant difference between groups. The fundic compliance did not differ between groups. We conclude that stepwise gastric distension caused an increase in muscle sympathetic nerve activity in both groups, but the increase in the elderly was attenuated.

Comparative effects of glucose and water drinks on blood pressure and cardiac function in older subjects with and without postprandial hypotension

“…Gastric distension induced by a balloon increases muscle sympathetic nerve activity, the so‐called “gastrovascular reflex,” a response known to be attenuated in the healthy elderly (van Orshoven et al. 2004). Water drinking also increases peripheral resistance (Cariga and Mathias 2001) and may attenuate orthostatic tachycardia in patients with idiopathic orthostatic intolerance (Shannon et al.…”

“…While direct stimulation of sympathetic activity triggered by visceral stretch is likely to be important, as evidenced by the response to distension of the stomach with a balloon (van Orshoven et al. 2004), changes in intravascular volume may also be relevant (Cariga and Mathias 2001). There is also evidence that hypo‐osmotic signaling via hepatic afferent fibers may influence sympathetic outflow directly via a local spinal reflex (May et al.…”

Hemodynamic effects of liquid food ingestion in mid-thoracic paraplegia: is supine postprandial hypotension related to thoracic spinal cord damage?

“…Gastric distension by the volume of the fluid-meal, which increases BP in healthy people, 20 more so in older than in younger ones, 21 could also have attenuated the drop in BP in tetraplegia. However, this effect was manifested with a 600 ml but not with a 200 ml fluid load, 20 and the 300 ml fluid load of the meal in the present experiment is unlikely to have had different effects, if any, on the study groups.…”

Ingestão De Água No Sistema Nervoso Autônomo: Uma Revisão Sistemática E Meta-Análise

“…No entanto, a distensão gástrica 18,19 e a osmolalidade 20 são duas vertentes importantes que buscam explicar estes fenômenos. A primeira evidencia que após a IA ocorra estimulação dos mecanorreceptores presentes no estômago, ocasionando aumento da atividade nervosa simpática muscular através de fibras aferentes do nervo esplâncnico 35 .…”

“…Já é demonstrado que o consumo de água tem se tornado um fator profilático e terapêutico para pacientes que sofrem de hipotensão ortostática [14][15][16] , e tendo em vista que o tratamento medicamentoso é dispendioso e o efeito bastante questionado 17 , percebeu-se a necessidade de encontrar os reais estímulos fisiológicos causados pela IA que induzem as respostas autonômicas, na qual duas vertentes vêm sendo alvo de maiores estudos para esclarecer tal fenômeno como a distensão gástrica 18,19 e a osmolalidade 20, 21 .…”