Childhood sedentariness may be a key factor in elevated cholesterol and premature heart disease

Children who are physically inactive may have high cholesterol in early adulthood and subsequent heart health issues in their mid-forties, according to new research published in The Journal of Clinical Endocrinology & Metabolism.

High cholesterol during childhood has been associated with early signs of heart disease when individuals reach their mid-twenties and an increased risk of premature cardiovascular death in their mid-forties. Several clinical trials aimed at lowering cholesterol levels in the youth population have had minimal or no effect.

Our study shows increased sedentary time in childhood may contribute to two-thirds of the total increase in a person's cholesterol levels before their mid-twenties. This suggests childhood sedentariness may be a major risk factor for elevated cholesterol and subsequent premature heart attack or stroke when individuals reach their mid-forties. We also discovered light-intensity physical activity from childhood may be 5-8 times more effective than moderate-to-vigorous physical activity at reversing the adverse effect of sedentary time on high cholesterol."

Andrew O. Agbaje, M.D., M.P.H., study author of the University of Eastern Finland in Kuopio, Finland

The researchers studied activity tracker data and repeated measures of cholesterol in 11-year-old children followed for up to 13 years from the Avon Longitudinal Study of Parents and Children.

They assessed the association between sedentary time and high cholesterol levels and found sedentary time increased from approximately 6 hours/day in childhood to 9 hours/day in young adulthood, and contributed nearly 70% to the increase in their overall cholesterol levels.

They also determined light physical activity decreased from 6 hours/day in childhood to 3 hours/day in young adulthood but was cumulatively associated with reduced total cholesterol. Increased total body fat slightly reduced the effect of light physical activity on total cholesterol.

Moderate-to-vigorous physical activity was relatively stable around 50 mins/day from childhood until young adulthood and was only associated with reduced total cholesterol, but increased total body fat seriously diminished the effect of moderate-to-vigorous physical activity on total cholesterol.

"Engaging in light physical activity for 3-4 hours/day may be an effective way to reduce high cholesterol and avoid heart health issues later in life," Agbaje said.

The study was funded by the Finnish Cultural Foundation, the Finnish Foundation for Cardiovascular Research, the Yrjö Jahnsson Foundation, the Jenny and Antti Wihuri Foundation, the Orion Research Foundation, the Aarne Koskelon Foundation, the Paulo Foundation, the Paavo Nurmi Foundation, and the Ida Montinin Foundation.