A latest research shows that the activity among neurons that keeps heart rate low is low among the people with common sleep breathing disorder.
Researchers at the George Washington University state that in obstructive sleep apnoea (OSA), the neurons in the brainstem that controls heart rate experience a reduced activity. This diminished neuronal activity then activates increased heart rate, blood pressure and also the risk of adverse cardiovascular events in OSA patients.
Researchers explain that OSA, a common cardiovascular problem, occurs in men than women (24 percent men and 9 percent females). The condition leads to repetitive blocking in breathing during sleep. Lack of oxygen during these incidents puts the sufferers in lighter state of sleep or brief wakefulness for restoration of normal breathing. Cycles of interrupted breathing and arousal from sleep can occur as frequently as once per minute.
"Lack of sleep leaves the mind and body tired, leading to poor mental and physical performance, and if untreated OSA increases a person's risk of developing hypertension and irregular heartbeats. Therefore it is very important that we have discovered some of the underlying mechanisms that could injure the heart and other cardiovascular tissues," lead study author Dr David Mendelowitz, said in a news release
The researchers examined this mechanism in rats by replicating OSA for four weeks and then analysing the blood pressure, heart rate and synaptic activity in parasympathetic neurons that regulate heart rate.
"Our study shows that progression of blunted cardiovascular reflexes is accompanied, and likely maintained by, inhibition of neurons in the brainstem that protect the heart and normally maintain a low resting heart rate. This study would predict that patients who have OSA, and also take sleep medicines, might be at heightened risk for an exaggerated reduction of essential neuronal activity that protects the heart," he said.
The finding was published the journal of Physiology.
