Sitting Time Associated With Risk of Chronic Diseases

The more you sit, the higher your risk of chronic diseases.

Richard Rosenkranz, PhD, an assistant professor of human nutrition and a researcher at Kansas State University, examined the associations of sitting time and chronic diseases in middle-aged Australian males in a study published in the International Journal of Behavioral Nutrition and Physical Activity. The study’s sample included 63,048 males aged 45 to 65 from the Australian state of New South Wales. Study participants reported the presence or absence of various chronic diseases along with their daily sitting time, categorized as less than four hours, four to six hours, six to eight hours, or more than eight hours.

Compared with those who reported sitting four or fewer hours per day, those who sat for more than four hours per day were significantly more likely to report having a chronic disease such as cancer, diabetes, heart disease, or high blood pressure. The reporting of chronic diseases rose as participants indicated they sat more. Those sitting for at least six hours were significantly more likely to report having diabetes.

“We saw a steady stair-step increase in risk of chronic diseases the more participants sat,” Rosenkranz says. “The group sitting more than eight hours clearly had the highest risk.”

The study is relevant for office workers sitting at desks and those sitting for long periods of time, such as truck drivers, Rosenkranz says. “We know with very high confidence that more physically active people do better with regard to chronic disease compared with less physically active people, but we should also be looking at reducing sitting,” he says. “A lot of office jobs that require long periods of sitting may be hazardous to your health because of inactivity and the low levels of energy expenditure.”

Researchers discovered consistent findings in those who had a similar physical activity level, age, income, education, weight, and height. Participants who sat more reported more chronic diseases compared with those who sat less, even if they had a similar BMI.

In general, people should get more physical activity and sit less, Rosenkranz says. “It’s not just that people aren’t getting enough physical activity, but it’s that they’re also sitting too much,” he says. “And on top of that, the more you sit, the less time you have for physical activity.”

The study focused on men because they have higher rates of diabetes and heart disease, but it’s probably applicable in adults across sex, race, and ethnicity, Rosenkranz says. Little is known about children and sitting with regard to chronic disease.

Researchers say that although most of the current evidence suggests a causal connection, they can’t be certain in this study whether volumes of sitting time led to the development of chronic diseases or whether the chronic diseases influenced sitting time.

Source: Kansas State University