LINK BETWEEN CHILDREN’S SLEEPING AND OBESITY IN AUSTRALIA.
Is there a link between children’s sleeping patterns and obesity in Australia?
Sleep like diet and physical activity plays a significant role in maturation, growth, and health of adolescent and child. Deprivation of sleep is becoming predominant in both children and adults. A short duration of sleep is connected with glucose tolerance, decreased levels of leptin, insulin insensitivity but the high standard of hunger, ghrelin, and appetite (Spiegel, Leproult & Van Cauter, 1999). It is also linked with behaviors which promote obesity and weight gain involving lower vegetable and fruit consumption and lower physical activity. Research show that short duration of sleep supports risk of obesity (Taheri, 2006). Hence focusing on short duration of sleep may give the effective method of treating and preventing obesity. The habit of childhood sleep may contain a long-term impact on weight. Every one hour in sleep deprivation during childhood is associated with 50% risk of weight gain that would lead to obesity at 32.
An increasing number of studies on obesity and sleep among children are available in the recent years. However, the range of age of the studies published is minimal with the age range of greater than five having few studies. From the recent systematic review, children of less than ten years show a negative relationship between obesity and sleep (Nevare & Rifas-Shiman et al, 2010. A birth cohort study of 32 years indicates that during childhood, short sleep was connected with the high risk of obesity in adults but at 32 years, sleep time was not related wit BMI in the adult. The research does not indicate clearly whether critical cut off in the relation between obesity and sleep in 10 years. Nevertheless, such information is significant to seek intervention from the high-risk group.
The information on duration of sleep and obesity is limited among the Australian children. One research found that an association between obesity and short sleep was among boys only. However, it was not a recent research, and there was no modification of vegetable and fruit consumption and variables of socio-economic. Also, the decline in the duration of sleep was found for both boys and girls in another study (Van Cauter & Knutson , 2008). The obesity prevalence among children also raised at the same time. Thus, there is a need for updated research on the association between sleep and obesity in children. South Australian and Surveillance System also carried out the study to examine the connection between obesity and sleep duration among children of age 5-15. They also determined the link between activity and sleep and the impact of obesity (Taheri , Lin , Austin , Young & Mignot, 2004). They found out that there was a connection between obesity and short duration of sleep. Also, they discovered that there is the collaboration between physical activity and sleep in connection to obesity (Gillman & Rifas-Shiman et al, 2008). Another limitation of the research is that the studies cannot show conclusively how getting enough sleep in children lowers the risks of obesity despite suggesting that there is a connection between obesity and sleep (Magee, Iverson, Huang & Caputi, 2008). Thus, more clear answers may be obtained from randomized clinical trials which examine if increasing childhood or infant sleep lowers the obesity risk. Therefore, the paper explores the association between obesity and sleep duration in children in Australia.
Sample selection and survey design
For this study, data is collected utilizing the South Australian Monitoring and Surveillance (SAMSS). SAMSS is structured to monitor the related health problems, the trend of diseases, risk factors and other issues of health services systematically for all age in the health system in South Australian (Department of Health, 2002). A minimum of 600 people is selected each month randomly to be interviewed. All South Australian households with telephones linked and listed telephone number in the Electronic White Page are suitable for sample selection. A letter of survey introduction is sent to chosen family and the individual with last birthday is selected for an interview. Health interviewers are used to conducting the interviews. SAMSS employs the system of Computer Assisted Telephone Interviewing to carry out the interview. The data are weighted by age, area, and gender and selection probability in the household to the most current data to make the result a representative of South Australian population. Therefore, the interview is conducted with parents with children of age 5 to 15 years. Children with duration of sleep between 4 and 14 are removed from the analysis. All the participants should give knowledgeable agreement.
The data collected included, body mass index, sleep duration, vegetable and fruit consumption, physical inactivity and activity and demographic variables. Sleep duration is assessed by finding numbers of hours spent by the child in sleeping, and the length of sleeping was categorized as ≥10 hours, 9-10 hours and <9 hours. The body mass index was also obtained from reports of a parent on height and weight. Definition of obesity was done according to International Obesity Task Force. The vegetable and fruit consumption was examined by inquiring from the parent the number of vegetables and fruits their children eat each day. Besides, physical inactivity and activity were evaluated by finding the number of hours per day the child use in reading for pleasure, doing organized sport, watching TV, doing homework, playing computer games and watching videos. Finally, the age, sex, residence area and income of the households were involved in the analysis.
The differences in defined variables were compared using chi-square test. The association between risk of obesity and sleep duration was analyzed by models of logistic regression, regulating many covariates. The model controlled for gender, age, income, physical activity/ inactivity, residence and fruit and vegetable intake (Eisenmann, Ekkekakis & Holmes, 2006). The multiplicative interaction between age and sleep duration was tested by Wald test through the addition of age/sex and product of sleep in the model. The significance of statistics was considered if the value of p was less five. All the analysis was carried out by STATA survey command.
Results and discussion.
The analysis indicated that the connection between obesity and short sleep was stronger in children. The multiplicative interaction between age and sleep duration was not significant as well gender and sleep duration (Patel & Hu, 2008). Also, there was no significant association between risk of obesity and sleep duration among the children of age 13. Physical activity was negatively related to obesity. Gender was also not significant in the model. However, there was an additive connection between physical activity and sleep duration. Children with a low level of physical activity and short sleep had highest obesity risk. Regulating socioeconomic status, fruit and vegetable consumption and lifestyle factor did not alter the association (Stamatakis & Brownson, 1999). In this association, there are several mechanisms involved like decreased insulin sensitivity, glucose tolerance, high evening cortisol concentration, elevated sympathovagal balance, increased ghrelin level, decreased leptin level and increased appetite and hunger. Human studies indicate that short sleep is associated with high fat intake and snacks.
Pros of the study
Determining the association between obesity and sleep is significant in preventing obesity. There is convincing evidence from the research that short sleep duration is a robust and independent factor for obesity in children (Knutson & Lauderdale, 2007). Thus, most of the research has observational studies that teach children and adult ways to get long sleep to help in losing weight and reduce the risk of obesity. Currently, the randomized clinical trials are underway and will offer more answers soon.
Cons of the study.
There is some potential limitation of the study. The study design of the cross-sectional prevents the establishment of a causal association. The puberty status is also not justified which is revealed to be connected with obesity risk (Bell & Zimmerman, 2010). Further, the pattern of the diet was not measured. In a study of population, it has been shown that short duration of sleep is associated with higher fat intake. Although it is frequently used, parental reporting validity of duration of sleep and BMI is not known. Sleep quantity in the study is also not measured. Moreover, there was no examination of the difference in duration of sleep between weekend days and weekdays. However, the study strength is that is founded on population sample that was a representative of the South Australian with a broad range of age.
The gap in knowledge concerning association between sleep and obesity.
The study topic has a minimal range of age from the studies published in the age range of greater than five having few studies. Also, there is no, updated research on the association between sleep and obesity in children. For instance, information on duration of sleep and obesity is limited among the Australian children (Hui, Nelson, Yu, Li & Fok, 2003). One research found that an association between obesity and short sleep was only among boys, but another research found that decline in the duration of sleep was for both boys and girls in another study. Moreover, the studies cannot show conclusively how getting enough sleep in children lowers the risks of obesity despite suggesting that there is a connection between obesity and sleep. Thus, more clear answers may be obtained from randomized clinical trials which examine if increasing childhood or infant sleep lowers the obesity risk (Reilly, Armstrong & Dorosty et al, 2005). Physical activities are also used in most studies as a confounding factor while examining the link between obesity and sleep duration. However, physical activity can be taken as an effect modifier. Thus, the interaction between physical activity and sleep in association to obesity have not been specifically studied.
From the research, there is a link between children’s sleeping patterns and obesity in Australia. The short duration of sleep is linked with obesity in children in Australia particularly boys of age between 5 and 12. Low physical activity level result to the short duration of sleep thus increasing risks of obesity. Adequate sleep has other advantages like improving mood, boosting school alertness and improving the quality of life. Therefore, it is important to encourage children to have an adequate sleep regardless of the effect and cause so as to prevent obesity.
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