Activity accumulation and cardiometabolic risk in youth : A latent profile approach

Introduction
This cross-sectional study aimed to i) identify and characterize youth according to distinct physical activity (PA) and sedentary (SED) accumulation patterns, and ii) investigate associations of these derived patterns with cardiometabolic risk factors.

Methods
ActiGraph accelerometer data from 7- to 13-yr-olds from two studies were pooled (n = 1219; 843 (69%) with valid accelerometry included in analysis). Time accumulated in ≥5- and ≥10-min SED bouts, ≥1- and ≥5-min bouts of light, and ≥1-min bouts of moderate and vigorous PA was calculated. Frequency of breaks in SED was also obtained. Latent profile analysis was used to identify groups of participants based on their distinct accumulation patterns. Linear and logistic regression models were used to test associations of group accumulation patterns with cardiometabolic risk factors, including adiposity indicators, blood pressure, and lipids. Total PA and SED time were also compared between groups.

Results
Three distinct groups were identified: “prolonged sitters” had the most time in sustained SED bouts and the least time in vigorous PA bouts; “breakers” had the highest frequency of SED breaks and lowest engagement in sustained bouts across most PA intensities; and “prolonged movers” had the least time accumulated in SED bouts and the most in PA bouts across most intensities. Although breakers engaged in less time in PA bouts compared with other groups, they had the healthiest adiposity indicators. No associations with the remaining cardiometabolic risk factors were found.

Conclusion
Youth accumulate their daily activity in three distinct patterns (prolonged sitters, breakers, and prolonger movers), with those breaking up sitting and least time in prolonged PA bouts across the day having a lower adiposity risk. No relationships with other cardiometabolic risk factors were identified.