Male obstructive sleep apnea patients more prone to cardiovascular stress and diseases, finds study

There are many types of sleep disorders that affect people; obstructive sleep apnea (OSA) is one that could have a long-term effect on your health. According to the US National Sleep Foundation, OSA occurs when the airway at the back of your throat becomes blocked and causes temporary lapses in breathing. OSA is typically a long-term disease and people who suffer from it often wake up the next day not feeling rested enough. While this might seem like a small problem, OSA usually snowballs into more severe health issues. In fact, a recent study in Sleep Medicine Reviews even suggests that people with severe OSA are also likely to suffer from severe COVID-19 disease and its complications. Sleep apnea and cardiovascular disease risks Johns Hopkins Medicine reveals that people with OSA also tend to suffer from hypertension, type 2 diabetes and obesity, all of which contribute to a higher risk of cardiovascular disease. A study published in the Journal of Clinical Sleep Medicine suggests that the link between OSA and cardiovascular diseases is not that well-understood but the increased risk of metabolic syndrome and disorders like obesity, high cholesterol, hypertension and diabetes may be the biggest contributing factors. This study also indicates that other intermediary mechanisms like oxidative stress, endothelial damage, platelet activation and increased inflammatory mediators may also account for the connection between OSA and cardiovascular diseases. The findings of a new study published in the journal Scientific Reports throws much better light on these intermediary mechanisms that link OSA to cardiovascular diseases. This study shows that the nocturnal respiratory events in people with OSA cause a cardiovascular load and long-term experience of uncontrolled OSA can exacerbate this load to the extent of causing cardiovascular diseases. Heart rate variability in patients of OSA The study, conducted by researchers at the University of Eastern Finland, is based on the premise that the low long-term heart rate variability (HRV) observed in OSA patients is known to be a risk factor for cardiovascular diseases. However, it is not known how the type and duration of nocturnal respiratory events in OSA can lead to these changes in HRV and heartbeat intervals (RR intervals). To understand this mechanism, the researchers recorded the electrocardiography signals of 758 patients with suspected OSA. The researchers observed the average RR intervals and HRV parameters of the participants for different respiratory event durations as they slept. The different durations were set at 10-20 seconds, 20-30 seconds and more than 30 seconds for apneas (cessation of breathing) and hypopneas (decreased amount of air movements in the lungs that leads to a drop in blood oxygen levels). The researchers found that the longer the duration of these respiratory events, the lower the long-term HRV was. They also found that the changes in RR interval were more pronounced during longer respiratory events, especially after apneas. The researchers also found that apneas cause more oxygen desaturation than hypopneas and severe desaturation of oxygen levels in the blood (also known as hypoxemia) is a significant risk factor for cardiovascular diseases. These respiratory events, therefore, not only affect HRV and RR intervals but also increase cardiovascular stress in the body. The frequency and severity of longer respiratory events increase especially towards the mornings and this increases the probability of cardiogenic sudden death between midnight and 6 am, especially due to desaturation and arrhythmias. This association was found to be stronger in the male participants. The scientists thus concluded that longer respiratory event durations, more apneas during said events and male sex increased the risk of cardiovascular stress and diseases in OSA patients. The researchers pointed out that while more studies into respiratory event severity, durations, desaturations and HRV need to be conducted, their findings can also aid healthcare professionals to assess the cardiovascular disease and death risks of OSA patients in a more detailed manner. For more information, read our article on Sleep apnea. Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.