Research Database

Short Sleep Duration Is Independently Associated With Overweight and Obesity in Quebec Children

  • Published on September/October 2011

Objective To investigate the association of sleep duration with adiposity and to determine if caloric intake and physical activity mediate this relationship. Methods The Quebec Adiposity and Lifestyle Investigation in Youth (QUALITY) study is an ongoing longitudinal investigation of Caucasian children with at least one obese biological parent. Children (n=550) ...


Assessing Sleep with Wrist and Hip Actigraphy in young adults-Comparison to Simultaneous Laboratory Polysomnography

  • Added on August 20, 2013

Introduction: Laboratory-based polysomnograpy (PSG) is the gold standard technique for assessment and quantification of sleep. Wrist and hip actigraphy have been widely used to quantify sleep and physical activity, respectively. It remains unclear whether hip actigraphy is also a valid measure of sleep. Purpose: To compare sleep varialbes simultaneously derived ...



Short Sleep Duration in Middle Childhood: Risk Factors and Consequences

  • Published on August 1, 2007

Objectives: To measure sleep duration in 7-year-old children; identify the determinants of sleep duration; and assess the association between short sleep duration and obesity, cognitive functioning, and behaviour. Design: Longitudinal study with disproportionate sampling of the participants. Setting: Community. Participants: 591 seven-year-old children, of whom 519 had complete sleep data. Interventions: Not ...


Seasonal Variation In Objectively Measured Physical Activity, Sedentary Time, And Sleep Duration Among Children

  • Presented on June 17, 2013

Purpose Understanding fluctuations in lifestyle indicators is important to identify relevant time periods to intervene in order to promote a healthy lifestyle; however, objective assessment of multiple lifestyle indicators has never been done using a repeated-measures design. The primary aim was, therefore, to examine between-season and within-week variation in physical ...


Validation of Two Self-Reported Sleep Duration Measures Against Objective Estimates of Sleep Duration in a Large UK Adolescent Cohort

  • Presented on June 3, 2013

Introduction Self-reported sleep duration is widely used but may not provide accurate information. Correlations between objective estimates of sleep and self-reported data only demonstrate if a relationship is present but do not determine if the two measures agree. We sought to determine levels of agreement between two self-reported average weekday ...


Contemporaneous Assessment Of Physical Activity, Sedentary Behavior And Sleep Using An Actigraph GT3X+ Accelerometer

  • Presented on June 18, 2013

Introduction Physical activity (PA), sedentary behavior (SB) and sleep form the behavioral tripartite of energy expenditure and appear inter- and independently related to cardiometabolic disease and cancer. The ability to collect valid data on all three behaviors contemporaneously using one type of accelerometer is important because it may improve our ...


Inferred Time In Bed Independently Predicts Levels Of Daytime Activity And Sedentary Behavior

  • Presented on June 17, 2013

Purpose Increased all-cause mortality has been consistently associated with longer (8-10 hours+) self-reported sleep duration. The possibility that longer sleep may impact survival through inactive lifestyles was proposed by Morgan (2007), and subsequently tested by Hartescu et al (2012) who concluded that, independent of health status, longer sleep duration, and the inevitably ...


Assessing The Bidirectional Relationship Between Physical Activity And Sleep In Elderly Women

  • Presented on May 29, 2013

A physically active lifestyle and quality sleep are associated with lower risk for obesity and cardiovascular disease. Cross-sectional studies demonstrate that greater physical activity (PA) is associated with better quality sleep. However, few studies have examined this relationship using objective measures. Additionally, few studies have examined the directionality of the ...


Sedentary/active Behaviors And Cardiometabolic Risk: Protective Effects Of Sleep Duration, Nhanes 2005-2006

  • Presented on May 29, 2013

Optimal sleep duration (7-8h), moderate-to-vigorous intensity physical activity (MVPA) and light-intensity activity are beneficially associated with cardiometabolic outcomes and related biomarkers, while sedentary time and long (≥9h) or short (<7h) sleep duration are detrimentally associated. Purpose This study examined whether sleep duration modified the relationship between both sedentary/...