Sedentary Profiles: A New Perspective on Accumulation Patterns in Sedentary Behavior.

Purpose: The purpose of this study is to introduce SB profiles (i.e., groups of similar SB accumulation patterns) as a new approach to pattern-focused SB research.

Methods: Data came from the National Health and Nutrition Examination Survey (2003-2006). The SB bouts were determined from hip-worn accelerometer data, and k-medoid clustering was used to define three SB profiles (interrupted, intermediate, and prolonged). These were used as the exposure in logistic regression models to examine odds ratios (OR) of having high (>20%) predicted-10-yr risk of cardiovascular disease (CVD). For comparison, the models were also fitted using standard metrics (i.e., tertiles of mean SB bout duration and daily total SB time).

Results: Those with interrupted profile (n = 1740) were typically sedentary ~32% of the time, in bouts ≤15 min. Those with intermediate profile (n = 2453) were typically sedentary ~47% of the time, in bouts ≤20 min. Those with prolonged profile (n = 1302) were typically sedentary ~61% of the time, frequently in bouts >20 min. The fully adjusted model showed that high CVD risk was more common for the intermediate (OR, 1.87) and prolonged (OR, 4.65) profiles than the interrupted profile (all P < 0.001). For standard metrics, OR ranged from 1.46 (middle tertile of daily total SB time) to 4.11 (upper tertile of mean bout duration) with all P < 0.002.

Conclusions: The SB profiles represent a promising new avenue for understanding and combating adverse SB trends. The value of the approach was highlighted by the strong associations with CVD risk.