Fatty Liver and Body Clock: How Sleep Cycle Regulate Liver Function? - Dr Mohammed Noufal

Fatty liver disease is essentially, as the name suggests, the accumulation of fat in the liver, the largest organ inside the human body.

The chronic liver disease is of two types – alcoholic fatty liver disease caused by heavy usage of alcohol, and secondly, non-alcoholic fatty liver disease (NAFLD), seen more commonly in persons who are obese, who have type-2 diabetes, and report high triglycerides in the blood.

NAFLD is the most common liver disorder in the world today and is accounting for a rise in cases every year, primarily due to sedentary lifestyles.

Over the years, multiple studies have shown that there is a direct correlation between sleep cycles and liver function. Since on average, humans spend a third of their lifetime sleeping, sleep is found to play a key role in the functioning of critical organs like the heart, liver, and kidneys.

Even though sleep renders a person immobile and leads to reduced consciousness for hours, it remains critical to human well-being.

Epidemiological studies on shorter sleep duration in persons pointed to obesity and metabolic syndrome. This is primarily because sleep disorders lead to increased secretion of stress hormones like cortisol, resulting in a higher risk for metabolic syndrome.

And those with disorders like sleep-wake disturbance and insomnia report higher insulin resistance (IR) and risk for inflammation. All of the above conditions, like obesity, IR, and diabetes, are risk factors for NAFLD.

Therefore, any substantial changes in sleep cycles, including poor nighttime sleep and high daytime napping, can have a direct impact on liver function and associated disease.

A study in Guangzhou, China conducted among over 5000 adults with fatty liver showed that they were at increased risk of disease due to snoring, high daytime sleep and late bedtime at night. They found that there was a 29% reduction in liver disease when sleep cycles were ‘moderately improved.’

As per the Pittsburgh Sleep Quality Index (PSQI), 60-80% of persons with cirrhosis stated that they were ‘poor sleepers.’ Additionally, in China, there has been a 9% jump in cases of NAFLD between 2001 and 2018, which has been attributed by researchers to poor lifestyle choices and improper sleep patterns.

Those with fatty liver are advised to stick to a proper bedtime routine, avoid caffeinated drinks in late evenings, stay away from digital devices at night, try journaling and relaxation exercises, and devote at least 30 minutes a day to physical workouts. The British Liver Trust recommends an average of 7-9 hours sleep per night for every adult.