Increased risk of non-alcoholic fatty liver disease linked to prolonged sitting

A higher risk of non-alcoholic fatty liver disease (NAFLD) is linked to prolonged sitting, regardless of how much exercise you do at other times, according to new research.
The study, conducted at the Sungkyunkwan University School of Medicine, South Korea, is not the first to link prolonged periods of sitting to health conditions: previous studies have found links to obesity, type 2 diabetes, high blood pressure and heart disease.
Non-alcoholic fatty liver disease is a generic term for conditions that trigger a build-up of fat within the liver. NAFLD is commonly linked to obesity and type 2 diabetes, but this study suggests that people with a healthy BMI also have an increased risk if they spend too much time sitting down. According to the National Health and Nutrition Examination Survey (NHANES), the average adult is sedentary for 55 per cent of the day.
The researchers examined the data of over 140,000 Korean men and women, all of whom were middle-aged. They established how much time each participant spent sitting down and taking part in physical activity using a questionnaire. Ultrasound was used to identify fatty liver.
Both taking part in less physical activity and spending a lot of time sitting down were independently associated with a higher risk of NAFLD. In total, 35 per cent of the participants had NAFLD, with the researchers observing no difference depending on body weight.
“Our findings suggest that both increasing participation in physical activity and reducing sitting time may be independently important in reducing the risk of NAFLD, and underlines the importance of reducing time spent sitting in addition to promoting physical activity,” said Dr. Yoosoo Chang, study co-author, of the Department of Occupational and Environmental Medicine, Kanbgbuk Samsung Hospital, Sungkyunkwan University School of Medicine in South Korea.
Michael I. Trenell, Professor of Metabolism and Lifestyle Medicine at Newcastle University said: “The message is clear, our chairs are slowly but surely killing us. Our body is designed to move and it is not surprising that sedentary behaviour, characterised by low muscle activity, has a direct impact on physiology.
“With a dearth of approved drug therapies for NAFLD, lifestyle changes remain the cornerstone of clinical care. The challenge for us now is to ‘stand up’ and move for NAFLD, both physically and metaphorically.”
The findings were published in the Journal of Hepatology.