AHI Rating :* Obesity (frequent causal factor and possible, albeit low-specificity, sign both direct and indirect): Obesity frequently involves accumulation of fat below the chin and around the neck, depressing the trachea when one is in the supine position, and central obesity can, depending on an individual's fat distribution, lead to increased direct pressure on the thoracic cavity and/or compressive anterior (headward) displacement of the abdominal organs, in the second case reducing space for and increasing difficulty of the motion of the diaphragm. Poor breathing during sleep a reduces oxygen available for metabolism and may therefore depress basal metabolic rate during sleep, increasing the difference between supply of food energy and demand for it during that time and thereby promoting weight gain, and b reduces sleep quality and recovery per time unit of sleep, resulting in sleepiness and/or fatigue that may prompt sufferers to eat more in an attempt to increase short-term energy levels. :* Correlation with cardiac disorders: ::* Atrial fibrillation (AF): A study in the medical journal Sleep found that the prevalence of atrial fibrillation among patients with idiopathic<unk>  was significantly higher than the prevalence among patients with obstructive sleep apnea or no sleep apnea (27%, 1.7%, and 3.3%, respectively). The study was based on 180 subjects with 60 people in each of the 3 groups. Possible explanations for the association between<unk>  and AF include a causal relationship in one direction or the other between the two conditions or a common cause involving an abnormality of central cardiorespiratory regulation. ::* Adults suffering from congestive heart failure are at risk for a form of central apnea called Cheyne-Stokes respiration, which manifests itself both during sleep and during waking hours. Cheyne-Stokes respiration is characterized by periodic breathing featuring recurrent episodes of apnea alternating with episodes of rapid breathing. There is good evidence that replacement of the failing heart (heart transplant) cures central apnea in these patients. Temporary measures (e.g., those taken pending the availability of an organ donor) include the administration of drugs whose effects include respiratory stimulation, although these drugs are not universally effective in reducing the severity of Cheyne-Stokes apneas. Congenital central hypoventilation syndrome Congenital central hypoventilation syndrome (CCHS), often referred to by its older name "Ondine's curse," is a rare and very severe inborn form of abnormal interruption and reduction in breathing during sleep. This condition involves a specific homeobox gene, PHOX2B, which guides maturation of the autonomic nervous system; certain loss-of-function mutations interfere with the brain's development of the ability to effectively control breathing. There may be a recognizable pattern of facial features among individuals affected with this syndrome. Once almost uniformly fatal, CCHS is now treatable. Children who have it must have tracheotomies and access to mechanical ventilation on respirators while sleeping, but most do not need to use a respirator while awake. The use of a diaphragmatic pacemaker may offer an alternative for some patients. When pacemakers have enabled some children to sleep without the use of a mechanical respirator, reported cases still required the tracheotomy to remain in place because the vocal cords did not move apart with inhalation. Persons with the syndrome who survive to adulthood are strongly instructed to avoid certain condition-aggravating factors, such as alcohol use, which can easily prove lethal.
Central sleep apnea
Sleep apnea
Obstructive sleep apnea
Hyperventilation syndrome
Obesity hypoventilation syndrome
Central hypoventilation syndrome
Sleep-related breathing disorder
Shift work sleep disorder