JMIR Publications

ABSTRACT

Background:

The association between physical activity behavior and cardiometabolic risk factors in longitudinal cohort studies has depended largely on questionnaire-based reporting. While there are differences between self-reported activity levels and objectively measured accelerometer-based activity, how these differences manifest in disease risk is unknown. Here, we sought to evaluate these differences and to model the impact in their association with cardiometabolic factors.

Objective:

We sought to evaluate the difference between objective physical activity measured by an accelerometer and self-report physical activity in their association with cardiometabolic factors.

Methods:

We assessed physical activity (PA) using both wrist-word accelerometer data and self-reported questionnaires in 16K participants of the UK Biobank, focusing on walking, sleeping, sedentary, and moderate-to-vigorous physical activity (MVPA). We compared the concordance between self-reported and objective measures of PA. Next, we compared the association between objective measured or self-reported PA and future clinical biomarker levels (e.g., body mass index, pulse rate, glucose control, cholesterol).

Results:

Participants underestimated their weekly sedentary duration on average of 2.86 hours, and that the correlation between subjective and objective activity were respectively r=0.12 for sedentary time, r=0.16 for moderate to vigorous physical activity, r=0.18 for walking, and r=0.13 for sleeping. We found an inverse association between objectively measured moderate-to-vigorous physical activity and cardiometabolic biomarkers such as BMI and pulse rate but found no association for subjectively reported activity.

Conclusions:

These findings provide evidence that the association of self-reported activity is likely underestimated and biased. Clinical Trial: None