Accelerometer epoch setting is decisive for associations between physical activity and metabolic health in children

Area of Science:

• Pediatric Exercise Science
• Metabolic Health Research
• Biomedical Data Analysis

Background:

• Accurate assessment of physical activity (PA) intensity is vital for understanding its impact on childhood metabolic health.
• The epoch setting used in accelerometry data processing significantly influences the captured PA intensity levels.
• Previous research has not fully elucidated how varying epoch settings affect the association between PA intensity and metabolic health in children.

Purpose of the Study:

• To investigate the influence of different epoch settings (1, 10, and 60 seconds) on physical activity intensity signatures.
• To examine how these intensity signatures, derived from varying epoch settings, relate to metabolic health indices in a pediatric population.
• To identify optimal intensity intervals associated with metabolic health across different epoch settings.

Main Methods:

• Utilized accelerometry data (ActiGraph GT3X+) from 841 Norwegian children (mean age 10.2 years).
• Collected data on multiple metabolic health indicators including aerobic fitness, abdominal fatness, insulin sensitivity, lipid metabolism, and blood pressure.
• Created composite metabolic health scores and analyzed intensity spectra (0-99 to ≥ 10000 counts per minute) using multivariate pattern analysis for 1, 10, and 60-second epoch settings.

Main Results:

• Significant differences were observed in the association patterns between PA intensity and metabolic health across the tested epoch settings.
• The most impactful intensity intervals for metabolic health were 7000-8000 cpm (1-sec epoch), 5500-6500 cpm (10-sec epoch), and 4000-5000 cpm (60-sec epoch).
• Data aggregation period clearly impacts the relationship between moderate-to-vigorous PA intensities and childhood metabolic health.

Conclusions:

• The choice of epoch setting in accelerometry critically affects the characterization of physical activity intensity and its association with metabolic health in children.
• Different epoch durations reveal distinct intensity thresholds linked to metabolic well-being, highlighting the need for careful consideration in research and practice.
• Findings underscore the importance of standardizing or clearly reporting epoch settings when analyzing PA data to ensure comparability and accurate interpretation of metabolic health associations.