Sleep Apnea, Obesity, and Hypertension: What Is the Link?
Obesity is known to be the common cause of a wide range of health problems. The link between obesity and problems such as heart failure, hypertension, and sleep apnea is undeniable. Here is what patients should know.
Many people around the world are conscious of being overweight and decide to take action by following a healthy diet and exercising regularly. Nevertheless, in America especially, obesity can a very difficult problem to overcome, taking into account that someone's daily diet could contain lot of unhealthy fats, carbs, and saturated sugars.
Also, obstructive sleep apnea already affects 10% of the population, and there is at least half of that percentage who may not even know that they suffer from it. In some cases, patients can suffer from up to 20 to 30 breathing stops per hour and each of these stops can last up to 30 seconds. These 30 seconds in which the body stops absorbing oxygen can cause severe damage to the human body, and they can also lead to the activation of many different problems in systems that may not even be related to respiratory processes.
Regarding obesity, it can usually affect the muscles that keep the upper airway open. It causes the muscles to work poorly, which leads to more freqent respiratory arrest. The lack of oxygen then causes metabolic disorders that can end up affecting the production of hormones responsible for regulating appetites, such as leptin and ghrelin.
Furthermore, respiratory obstructions while sleeping do not allow the affected patient to rest properly throughout the night, so their actions during the day are reduced, which can make the person more prone to develop extra weight.
Obesity as a risk factor for obstructive sleep apnea (OSA)
Obesity is an important risk factor for OSA, because there is a dose-response relationship between OSA and the Body Mass Index.
What underlies this association is not clear, although numerous possibilities have been proposed:
- Excessive body weight can result in an increase in soft tissue mass located around the neck area, resulting in a reduction in the size of the throat and causing additional tension in the throat muscles so that they are more prone to collapse. The increase in body mass around the abdomen can put pressure on the chest wall so that breathing is affected, especially in the supine position.
- Gastroesophageal reflux disease (GERD) often occurs at the same time as OSA and both conditions are common in obese people. GERD is most often caused by weakness or functional abnormality of the lower esophageal sphincter, a valve located at the junction of the esophagus with the stomach. There is some evidence to suggest that GERD can cause episodes of OSA by activating laryngeal spasms (vocal cords) that restrict the flow of air to the lungs. However, other studies have not observed this type of obstructive episode related to GERD and an alternative mechanism has also been proposed whereby OSA exerts repetitive effort in the gastroesophageal junction, in such a way that it weakens with time.