Exercise as it relates to Disease/Effects of exercise and its cessation on insulin resistance syndrome in obese children

The following wiki fact sheet is a critique of the article: Effects of exercise and it's cessation on components of the insulin resistance syndrome in obese children from the International Journal of Obesity by MA Ferguson, et al.(1999).

Background of Research
Obesity is defined as a BMI (body mass index) of 30 or greater by the World Health Organisation (WHO) and is measured by weight in kilograms(kg) divided by height in metres squared (m2). Being classified as obese increases your risk greatly of developing a collection of chronic conditions, including cardiovascular disease, cancer, diabetes and insulin resistance syndrome.

Insulin resistance syndrome is a grouping of metabolic issues such as hypertension (high blood pressure), elevated glucose and dyslipidemia (abnormal fats in blood) that increase people's risk of developing type 2 diabetes, cardiovascular disease and other conditions. As can be seen, insulin resistance syndrome is closely related to many chronic diseases and health issues that are of major importance in today's society. For example, in 2011 the leading cause of death in Australia was ischaemic heart disease (14.6% of deaths) which comes under the blanket term cardiovascular disease. Also, the prevalence of diabetes has been growing significantly, from 2002 to 2011 it has moved from rank number 9 to rank number 6 on the leading causes of death in Australia.

Insufficient exercise/physical inactivity has been linked to vast majority of these chronic diseases. The opposite is also true, where the application of exercise/physical activity has been used for treatment and therapeutic benefits of basically all these chronic diseases.

Where did the research come from?
Ferguson MA, et al. from the Medical College of Georgia, USA conducted the research on children from the area close to the Medical College of Georgia.

What kind of research was this?
The research was quantitative with measurements of various insulin resistance syndrome markers, percent body fat and heart rate for cardiovascular fitness.

What did the research involve?
The research involved 79 obese but otherwise healthy children between the ages of 7 and 11 years old. Recruitment was via the sending of flyers to parents of children who went to school near the Medical College and adverts in newspapers in the community and hospitals close by. An information video was then shown to interested parents and children and informed consents were signed. Children were placed into 1 of 2 groups, group 1 underwent 4 months of exercise training followed by 4 months of no exercise training and group 2 underwent 4 months of no exercise training followed by 4 months of exercise training. The subjects undertook exercise training in 40 minute sessions (2x 20 minute halves) 5 days per week and were pushed to maintain heart rates of above 150 beats per minute. Subjects were paid $1 per attended session and prizes were used for motivation. The type of exercises being undertaken were changed regularly to encourage interest and the second half of the session was made up of group games. Heart rate monitors were worn by the participants to help assess energy expenditure. Testing was conducted at the start of the study, at the 4 month halfway point and then at the 8 month finish. Height and weight were recorded with a stadiometer and a balance scale respectively. Body fat percentage was tested with dual energy x-ray absorptiometry (DEXA). The insulin resistance syndrome markers were measured via blood sample analysis and cardiovascular fitness was assessed by sub maximal heart rate testing on a supine ergometer, which would be more comfortable for the obese children than other ergometers.

Results
MA Ferguson, et al. found:

Blood Concentration Markers Groups 1&2 TG = triglycerides  Plasma = blood plasma


 * As plasma triglycerides decreased low density lipoproteins increased in size
 * The greater the fall in triglyceride concentration the greater the increase in low density lipoprotein size
 * Average sub maximal heart rates dropped during periods of exercise training compared to periods of none

Conclusions
From the research from MA Ferguson et al. we can conclude:
 * Regular exercise training/physical activity can help improve some components that make up the insulin resistance syndrome
 * The opposite is also true, cessation of exercise training/physical activity results in the loss of these improvements
 * Decreased body fat percentage is related to lower triglyceride concentration and increased insulin sensitivity

Advice
From this research it can be seen that exercise may play a beneficial role on some markers and components of insulin resistance syndrome in obese children and the cessation of exercise leads to a loss in the improvements. This suggests that obese but otherwise healthy children should undertake regular exercise training/physical activity to reduce their risk of insulin resistance syndrome and in effect, many chronic diseases. This exercise should be maintained over a long period of time as to prevent the recoil of the benefits. A good diet should also accompany regular exercise to promote good health.

Further Information & Resources

 * Exercise Prescription for many chronic diseases: http://www.cardiology.org/recentpapers/Pedersen_ExerciseAsMedicine_ScandJMSS.pdf
 * Obesity Australia: http://www.obesityaustralia.org/
 * Insulin Resistance Facts and Definitions: http://www.medicinenet.com/insulin_resistance/article.htm
 * Childhood Insulin Resistance Syndrome: http://kidshealth.org/en/parents/metabolic-syndrome.html