Association between physical activity based on wearables and self-reported health status among adolescents: NHANES 2011–2014.

Background: Physical activity (PA) was strongly associated with health status, with fewer related studies in adolescents (12–19 years). Most current studies using questionnaires to assess PA levels were not objective enough. So, this study used a wearable device to assess PA levels quantitatively and focused on the association between PA levels and self-reported 4 health status among adolescents. Methods: Data were obtained from adolescents (2241) with both PA and health status assessments from two cycles of NHANES, 2011–2014, using a wearable accelerometer-based device to assess PA levels quantitatively, MIMS-units as the metric, averaging over all valid days of wear (MIMS-units average). There were 4 health statuses, including (1) whether or not flu, pneumonia, or ear infection, (2) whether or not stomach or intestinal illness, (3) whether or not head cold or chest cold, and (4) general health condition, from the past 30 days self-reported. Weighted multiple logistic regression was used to analyze the association between the 4 health statuses and the MIMS-units average and MIMS-units average quartiles respectively. Subgroup analyses were also conducted on age, sex, BMI, and race. Results: After controlling confounding factors, there was no significant correlation between the MIMS-units average and the four physical health conditions in Table 3 model 3. While MIMS-units average quartiles results showed that compared to lower PA levels (Q1), higher PA levels (Q4) were linked to a lower incidence of "flu"(OR = 0.94, 95% CI [0.91, 0.99], P < 0.001). Furthermore, Q3 was linked to a decrease in the incidence of "head cold" (OR = 0.91, 95% CI [0.85, 0.96], P < 0.001), while Q2 showed a decrease in "stomach illness" (OR = 0.95, 95% CI [0.92, 0.99], P = 0.003) in Table 3 model 3. Subgroup analyses showed that higher PA levels significantly reduced "flu" risk among 12–15 year-olds, girls, obese, and Non-Hispanic White; decreased "head cold" risk among 16–19 year-olds, boys, obese, and Non-Hispanic White; significantly lower risk of "stomach illness" in girls. Conclusions: Enhancing PA levels can help prevent flu, head cold, and stomach or intestinal illness in US adolescents. Further studies are needed to determine whether adolescents in other regions have similar results, and high-quality cohort studies are needed to further validate the causal association. [ABSTRACT FROM AUTHOR]