Self-reported sleep duration is associated with time in work physical activity but not transportation or leisure physical activity among Hispanic/Latino adults in the U.S.: results from the Hispanic Community Health Study/Study of Latinos.

OBJECTIVES: The objective of this study is to test the hypothesis that short sleep duration is associated with fewer minutes of transportation, work, and leisure physical activity (PA). DESIGN: This is a cross-sectional study conducted from 2008 to 2011. SETTING: The study setting included four sites across the U.S. (Bronx, NY; Chicago, IL; Miami, FL; San Diego, CA). PARTICIPANTS: A total of 14,653 Hispanic/Latino adults aged 18-74 years were enrolled as participants for the study. MEASUREMENTS: Respondents reported sleep duration and transportation (including walking and cycling), work (including volunteering, paid work, and household chores), and leisure (including sports) PA domains and sociodemographic characteristics, other sleep characteristics, cardiometabolic health, health behaviors, and depressive symptoms. RESULTS: In analyses weighted to reflect the Hispanic/Latino population of the four cities sampled, 61% had sleep duration 7-9 hours, 19% each had sleep duration < 7 hours and > 9 hours. Those sleeping < 7 hours spent 106 minutes/day in work-related PA, compared with those who spent fewer than 40 minutes/day in transportation-related or leisure-related PA. Sleep duration < 7 hours was associated with 26 minutes more in work-related PA (95% confidence interval [CI]: 16.7, 36.0), compared with sleep duration of 7-9 hours, adjusting for age and sex. Results were similar in employed respondents only, adjusting for occupation class and shift work frequency. Sleep duration was not associated with transportation-related or leisure-related PA. CONCLUSIONS: Short sleep duration is associated with more work-related PA, both in the overall sample and among those employed. Individuals with higher work-related PA may face multiple demands and stressors that negatively influence sleep duration.

Calibration of activity-related energy expenditure in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

OBJECTIVES: Usual physical activity (PA) is a complex exposure and typical instruments to measure aspects of PA are subject to measurement error, from systematic biases and biological variability. This error can lead to biased estimates of associations between PA and health outcomes. We developed a calibrated physical activity measure that adjusts for measurement error in both self-reported and accelerometry measures of PA in adults from the US Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a community-based cohort study. DESIGN: Total energy expenditure (TEE) from doubly labeled water and resting energy expenditure (REE) from indirect calorimetry were measured in 445 men and women aged 18-74years in 2010-2012, as part of the HCHS/SOL Study of Latinos: Nutrition & Physical Activity Assessment Study (SOLNAS). Measurements were repeated in a subset (N=98) 6months later. METHOD: Calibration equations for usual activity-related energy expenditure (AEE=0.90×TEE-REE) were developed by regressing this objective biomarker on self-reported PA and sedentary behavior, Actical accelerometer PA, and other subject characteristics. RESULTS: Age, weight and height explained a significant amount of variation in AEE. Actical PA and wear-time were important predictors of AEE; whereas, self-reported PA was not independently associated with AEE. The final calibration equation explained fifty percent of variation in AEE. CONCLUSIONS: The developed calibration equations can be used to obtain error-corrected associations between PA and health outcomes in HCHS/SOL. Our study represents a unique opportunity to understand the measurement characteristics of PA instruments in an under-studied Hispanic/Latino cohort.