Research Database


Short sleep duration is associated with increased obesity markers in European adolescents: effect of physical activity and dietary habits. The HELENA study

  • Published on July 26, 2011

Background Adequate sleep is a critical factor for adolescent’s health and health-related behaviors Objective (a) to describe sleep duration in European adolescents from nine countries, (b) to assess the association of short sleep duration with excess adiposity and (c) to elucidate if physical activity (PA), sedentary behaviors and/or ...


Seasonal variation in objectively measured physical activity, sedentary time, cardio-respiratory fitness and sleep duration among 8–11 year-old Danish children: a repeated-measures study

  • Published on Sept. 8, 2013

Background 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 ...


An Investigation into the Strength of the Association and Agreement Levels between Subjective and Objective Sleep Duration in Adolescents

  • Published on Aug. 9, 2013

Study Objectives The majority of adolescent sleep research has utilized self-reported sleep duration and some have based information on a solitary question. Whilst some have claimed to have validated sleep survey data with objective actigraphy measures in adolescents, the statistical approach applied only demonstrates the strength of the association between ...


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 ...