Smoking may impair blood pressure autocorrect system
Smoking may increase the risk of developing hypertension by impairing the body's blood pressure autocorrect system, warn researchers.
"The human body has a buffering system that continuously monitors and maintains a healthy blood pressure. If blood pressure drops, a response called muscle sympathetic nerve activity (MSNA) is triggered to bring blood pressure back up to normal levels," said Lawrence Sinoway from Penn State University in the US.
An additional system -- called the baroreflex -- helps correct if blood pressure gets too high, he added.
According to Sinoway, the study found that after a burst of MSNA, the rise in blood pressure in a chronic smoker was about twice as great as in a non-smoker, pushing blood pressure to unhealthy levels. The researchers suspect that impairment of baroreflex may be the culprit.
"When the sympathetic nervous system fires, like with MSNA, your blood pressure rises and then a series of things happen to buffer that increase, to try to attenuate it," Sinoway said.
"We think that in smokers, that buffering -- the baroreflex -- is impaired."
The results suggest that this impairment may be connected to hypertension, said Jian Cui, Associate Professor at Penn State College of Medicine.
"The greater rise in blood pressure in response to MSNA may contribute to a higher resting blood pressure level in smokers without hypertension," Cui said.
"It's possible that this higher response to MSNA could also contribute to the eventual development of hypertension," Cui added.
The researchers said that while previous research has found a link between chronic smokers and higher levels of MSNA bursts, less was known about what happened to blood pressure after these bursts.
For the study, the researchers examined 60 participants -- 18 smokers and 42 non-smokers. None of the participants had hypertension.
The results were published in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.IANS