Screen time and metabolic risk factors among adolescents.

Physical Activity, Nutrition, and Obesity Research Group, University of Sydney, Camperdown, NSW 2006, Australia.
JAMA Pediatrics (Impact Factor: 4.25). 07/2010; 164(7):643-9. DOI: 10.1001/archpediatrics.2010.88
Source: PubMed

ABSTRACT To examine the association between screen time (ST) (ie, television/DVD/video and computer use) guidelines and risk factors for cardiovascular disease, type 2 diabetes mellitus, and fatty liver diseases in mid-adolescence.
High schools in Sydney, Australia.
Grade 10 students (N = 496; 58% boys; mean [SD] age, 15.4 [0.4] years).
Body mass index, waist circumference, cardiorespiratory endurance, dietary factors, socioeconomic status, and pubertal status.
Screen time was categorized as less than 2 hours per day or 2 or more hours per day and calculated for weekday, weekend, and the entire week. Fasting blood samples were analyzed for levels of high-density lipoprotein and low-density lipoprotein cholesterol, triglycerides, insulin, and glucose; homeostasis model assessment of insulin resistance (HOMA-IR); levels of alanine aminotransferase, gamma-glutamyltransferase, and high-sensitivity C-reactive protein; and blood pressure. Abnormal results were categorized according to published guidelines.
Mean ST for all students was 3.1 hours per day and for weekdays and weekend days, 2.6 hours per day and 4.4 hours per day, respectively. Boys were more likely to exceed ST guidelines than girls (odds ratio [OR], 2.71; 95% confidence interval [CI], 1.67-4.38). There were no significant associations between ST guidelines and metabolic risk factors among girls. After adjusting for potential confounders, boys who exceeded ST guidelines on weekdays were more likely to have elevated HOMA-IR (adjusted OR, 2.42; 95% CI, 1.11-5.28) and insulin levels (adjusted OR, 2.73; 95% CI, 1.43-5.23).
Adolescent boys with ST of 2 or more hours per day on weekdays have twice the risk of abnormal levels of insulin and HOMA-IR compared with peers with ST less than 2 hours per day on weekdays. These results suggest there is an increased risk of insulin resistance among adolescent boys who do not meet ST guidelines on weekdays.

  • Source
    Cinergis. 10/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Obesity and metabolic syndrome is prevalent among Malaysian adolescents and has been associated with certain behavioural factors such as duration of sleep, screen time and physical activity. The aim of the study is to report the prevalence of overweight/obesity, metabolic syndrome and its risk factors among adolescents. A multi-staged cluster sampling method was used to select participants from urban and rural schools in Selangor, Perak and Wilayah Persekutuan Kuala Lumpur. Participants underwent anthropometric measurement and physical examination including blood pressure measurement. Blood samples were taken for fasting glucose and lipids and participants answered a self-administered questionnaire. Overweight and obesity was defined using the extrapolated adult body mass index (BMI) cut-offs of >25 kg/m2 and >30 kg/m2, according to the International Obesity Task Force (IOTF) criteria. Metabolic syndrome was defined based on International Diabetes Federation (IDF) 2007 criteria. Data were collected from 1361 participants. After excluding incomplete data and missing values for the variables, we analysed a sample of 1014 participants. Prevalence of overweight and obesity in this population was 25.4% (N = 258). The prevalence of metabolic syndrome was 2.6% in the population and 10% among the overweight and obese adolescents. Participants who slept between 7 and 9 hours a day has a lower risk of developing metabolic syndrome OR 0.38(0.15-0.94). Our results provide the prevalence of metabolic syndrome in Malaysian adolescents. Adequate sleep between 7 and 9 hours per day reduces the risk of developing metabolic syndrome.
    BMC Public Health 11/2014; 14 Suppl 3:S7. · 2.32 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Concomitant with the rise in global pediatric obesity in the past decades, there has been a significant increase in the number of children and adolescents with clinical signs of insulin resistance. Given insulin resistance is the important link between obesity and the associated metabolic abnormalities and cardiovascular risk, clinicians should be aware of high risk groups and treatment options. As there is no universally accepted biochemical definition of insulin resistance in children and adolescents, identification and diagnosis of insulin resistance usually relies on clinical features such as acanthosis nigricans, polycystic ovary syndrome, hypertension, dyslipidemia, and nonalcoholic fatty liver disease. Treatment for reducing insulin resistance and other obesity-associated comorbidities should focus on changes in health behaviors to achieve effective weight management. Lifestyle interventions incorporating dietary change, increased physical activity, and decreased sedentary behaviors, with the involvement of family and adoption of a developmentally appropriate approach, should be used as the first line treatment. Current evidence suggests that the primary objective of dietary interventions should be to reduce total energy intake and a combination of aerobic and resistance training should be encouraged. Metformin can be used in conjunction with a lifestyle intervention program in obese adolescents with clinical insulin resistance to achieve weight loss and to improve insulin sensitivity. Ongoing evaluation and research are required to explore optimal protocol and long-term effectiveness of lifestyle interventions, as well as to determine whether the improvements in insulin sensitivity induced by lifestyle interventions and weight loss will lead to a clinical benefit including reduced cardiovascular morbidity and mortality.
    Current Treatment Options in Cardiovascular Medicine 12/2014; 16(12):351.

Full-text (2 Sources)

Available from
May 22, 2014