Blockage or narrowing of the airways, even temporarily, can cause the body to experience lowered oxygen levels in the blood, and these conditions of hypoxia are recurring in those with obstructive sleep apnea (OSAS). Constant hypoxia may cause a variety of changes within the body, such as tissue inflammation, increased insulin resistance, and liver injury. A prospective cohort study found the association between habitual snoring and NAFLD development to be significant, and the trend was noted to be most prominent in lean individuals. Pathophysiology
The primary characteristic of NAFLD is the accumulation of lipids in the liver, largely in the form of triglycerides. However, the mechanisms by which triglycerides accumulate and the reasons that accumulation can lead to liver dysfunction are complex and incompletely understood. NAFLD can include steatosis along with varied signs of liver injury: either lobular or portal inflammation (a form of liver injury) or ballooning degeneration. Similarly, NASH can include histological features such as portal inflammation, polymorphonuclear cell infiltrates, Mallory bodies, apoptotic bodies, clear vacuolated nuclei, microvesicular steatosis, megamitochondria, and perisinusoidal fibrosis. NASH increases hepatocyte death via apoptosis or necroptosis is increased in NASH compared with simple steatosis, and inflammation is a hallmark of NASH.One debated mechanism proposes that hepatic steatosis progresses to steatosis with inflammation following some further injury, or second hit. Oxidative stress, hormonal imbalances, and mitochondrial abnormalities are potential causes of this "second hit" phenomenon.
In his article "Sleep-Related Eating Disorder and Night Eating Syndrome: Sleep Disorders, Eating Disorders, Or both", Winkelman said, "Both [disorders] involve nearly nightly binging at multiple nocturnal awakenings, defined as excess calorie intake or loss of control over consumption." He also reported that both disorders have a common occurrence of approximately one to five percent of adults, have been predominantly found in women, with a young adult onset, have a chronic course, have a primary morbidity of weight gain, sleep disruption, and shame over loss of control over food intake, have familial bases, and have been observed to have comorbid depression and daytime eating disorders. However, Winkelman said, "The most prominent cited distinction between NES and SRED is the level of consciousness during nighttime eating episodes." Therefore, these two disorders are extremely similar with only one distinction between them. Doctors and psychologists have difficulty differentiating between NES and NSRED, but the distinction of a persons level of consciousness is what doctors chiefly rely on to make a diagnosis. One mistake that is often made is the misdiagnosis of NSRED for NES. However, even though NSRED is not a commonly known and diagnosed disease, many people with it in differing ways while doctors work to find a treatment that works for everyone; several studies have been done on NSRED, such as the one conducted by Schenck and Mahowald. These studies, in turn, provide the basic information on this disorder including the symptoms, behaviors, and possible treatments that doctors are using today.