Research Database

Identifying Children's Nocturnal Sleep Using 24-h Waist Accelerometry

  • Published on Sept. 8, 2014

Purpose: The purposes of this study were (1) to add layers and features to a previously published fully automated algorithm designed to identify children's nocturnal sleep and to exclude episodes of nighttime non-wear/wakefulness and potentially misclassified day time sleep episodes, and (2) to validate this refined sleep algorithm (RSA) against sleep ...


Interrelationships among sedentary time, sleep duration, and the metabolic syndrome in adults

  • Published on June 30, 2014

Background: The study objectives were to examine whether: 1) sedentary time is associated with sleep duration, 2) sedentary time predicts the metabolic syndrome (MetS) independent of sleep duration and vice versa, and 3) sedentary time and sleep duration have an interactive effect on the MetS. Methods: This cross-sectional study is based on the 2003–2006 ...


Sleep Variability and Cardiac Autonomic Modulation in Adolescents: The Penn State Child Cohort

  • Presented on June 2, 2014

Introduction: The association between habitual sleep patterns and cardiac autonomic modulation (CAM) in adolescents is not fully understood. We investigated such association in the population-based Penn State Child Cohort (PSCC) follow-up examination. Methods: An actigraph (GT3X) and a sleep diary were used in 421 adolescents for 7 consecutive nights to calculate ...


Sleep Variability and Nutrition Intake in Adolescents: The Penn State Child Cohort

  • Presented on June 2, 2014

Introduction: The association between habitual sleep patterns and nutrition intake is not fully understood, especially in adolescents. We investigated the association between habitual sleep duration and its variability with nutrition intake in population-based adolescents of the Penn State Child Cohort (PSCC) follow-up examination. Methods: An actigraph (GT3X) and a ...


Sleep Variability and Abdominal Obesity in Adolescents: The Penn State Child Cohort

  • Presented on June 2, 2014

Introduction: Chronic sleep problems in adults have been associated with abdominal obesity and cardiometabolic disorders. However, associations between habitual sleep patterns and central obesity have not been fully understood, especially in adolescents. We investigated the associations between habitual sleep duration and its variability and body fat distribution in population-based adolescents ...


Factors Associated with Night-to-Night Variability in Sleep Duration During Adolescence

  • Added on August 13, 2014

Introduction: Night-to-night variability of sleep variables derived from actigraphy or sleep diary data appears to be a novel risk factor associated with physical and mental health. However, little is known about factors associated with night-to-night sleep variability. The aim of this study was to assess the association of sociodemographic and ...


Increased Physical Activity Improves Sleep and Mood Outcomes in Sedentary People with Insomnia: A Randomized Controlled Trial

  • Presented on June 2, 2014

Introduction: Lower levels of regular physical activity are an independent risk factor for insomnia incidence and prevalence. The impact of public health initiatives to increase physical activity on sleep outcomes of people with chronic sleep disorders remains mainly unexplored. The present trial was designed to investigate the effects on sleep ...


Summertime changes in sleep, physical activity, and BMI in urban minority girls

  • Presented on May 21, 2014

Purpose: Seasonal variations in weight gain among children are well documented. Urban minority and overweight youth are at higher risk for weight gain during the summer months, which may result from decreases in physical activity (PA) and sleep. While research has established links between PA, sleep, and BMI, the current ...


Objective measurements of free-living sleep and activity patterns in older Icelandic men and women

  • Presented on May 21, 2014

Purpose: To identify cross-sectional and seasonal sleeping and physical activity (PA) patterns in a community-dwelling Icelandic healthy aging population using accelerometers. Methods: Participants (n=244, male/female 110/134, age 79.7±4.9 years, BMI 26.9±4.8 kg/m2) wore an Actiwatch Spectrum on the non-dominant wrist to assess sleep and an Actigraph GT3X on the right ...


Parent-adolescent correlation of physical activity, sedentary behaviors, and sleep

  • Presented on May 21, 2014

Purpose: The purpose of this study was to examine the correlation between parent and adolescent levels of physical activity, sedentary behaviors, and sleep among a group of overweight and obese adolescents. Methods: Baseline data of parent-adolescent pairs who enrolled in an E-health lifestyle modification intervention were analyzed for this paper (...