Exercise as it relates to Disease/The Link Between Type 2 Diabetes and Inactivity. A closer look at Inactive Indigenous Australian Men

Article
This wiki page is critically analysing the article by Mendham AE, Duffield R, Marino F, Coutts AJ. A 12-week sports-based exercise programme for inactive Indigenous Australian men improved clinical risk factors associated with type 2 diabetes mellitus.

What is the background to this research?
Diabetes mellitus is a metabolic disease that effects the uptake and use of glucose (sugar) in the body. There are three types; type 1, type 2 and gestational diabetes. They are all complex and require daily management.

Chronic disease rates are much higher in Indigenous and Torres Strait Islander populations, with life expectancy being up to 20 years lower than non-indigenous populations. In the northwest of Australia, diabetes rates are worrying with 40% of all adults and nearly 60% of indigenous people aged over 35 have diabetes. The diagnosis rate for diabetes in children under 17 years, is as high as 18 times more likely than non-indigenous children. Type 2 diabetes mellitus (T2DM), and obesity are increased by a sedentary lifestyle and inactivity which is common in indigenous populations. Both disease states are unreasonably high in this populations. This high prevalence of clinical risk factors highlights the importance of studies like this one, targeting the Australian Indigenous population.

Where is the research from?
The study was developed and supported by the members of the local community, local Aboriginal Medical Centre and Men’s Group. This research was conducted in a regional community in New South Wales. The location of the research is important as the intervention is tailored around the lifestyle and community of the Indigenous Australians population. The Authors come from both; Charles Stuart University (CSU) and the University of technology Sydney (UTS). In the world ranking systems, CSU is ranked at 29 in Australia and 25 from the Excellence in Research Australia (ERA). UTS is renowned for their research covering a range of disciplines. From 2015-17 Quality Standards, (QS) awarded UTS 5 stars of excellence for their eight categories.

What kind of research was this?
This study was a sport based intervention, conducted through a randomised control trial, with a specific population of inactive Indigenous Australian men. A randomised control trial is the gold standard for this type of study.

What did the research involve?
The research took place in 2012 over 4 months. 33 Indigenous Australian men were recruited and separated using block randomisation, into groups of 4 and then allocated either to an exercise group or a control group. The participants who were recruited had to have an inactive lifestyle (less than 60 min per week of exercise) to create and accurate representation of the population being tested. The participants attended 2 pre-intervention and 2 post-intervention tests.

Test 1 (pre/post) Test 2 (pre/post)
 * PAR-Q, Anthropometric measurements (stature, waist circumference, body mass and hip circumference), manual blood pressure, inflammatory markers associated with T2DM, oral glucose tolerance test (OGTT) and fasting blood chemistry.
 * Graded Exercise Tests (GXT) to determined peak O2 (VO2peak) and maximum aerobic workload (Wmax)

Non-exercise control group were specifically asked to continue a non-active lifestyle. This was given with verbal and written consent.

What were the basic results?
Results showed a significant change in clinical risk factors from the exercise group to the control group in;
 * BMI- (has limitations due to the inability to discriminate between lean muscle mass and adiposity)
 * waist circumference
 * decrease in body mass
 * increase in the graded exercise test duration
 * positive changes in; insulin sensitivity, decreases in leptin (strong associations with decreases in adiposity).

The researches confirmed their original hypothesis. The results did confirm this, yet the small number of participants and the low participation rate is an influencing factor to be noted. The results from this study indicated an improvement in fitness variables, anthropometry and metabolic measures. The researchers stated their results as well as understanding the limitations of their study.

Limitations to this study

 * Small number of participants recruited
 * Attendance for the 12-week program had a mean of 69%. This low compliance was also observed in a 12-week intervention program for indigenous and Torres Strait women.
 * No post intervention follow up. Other studies have tested 3 months or more post intervention, to assess compliance and effectiveness of the program.

The methodology was specific, clear and well thought out. There were set days and times and transport available to assist with compliance. The assessments tested are in line with clinical risk factors associated with chronic disease states, which are all a major concern for Indigenous Australians. The different options of sports in weeks 7-12, gives the opportunity to play something that they might enjoy, which could lead to the maintenance of physical activity, encouraging a lifestyle change. Including more cultural games may also incorporate a sense of ownership, new skills and connection to the activity.

What conclusions can we take from this research?
Physical activity can reduce clinical risk factors for T2DM. The indigenous population is at higher risk of this disease then non- indigenous populations. This highlights the importance of more studies focussing on; community run interventions to improve clinical risk factors for Indigenous Australian populations. Other studies have noted that by incorporating cultural and community or group based physical interventions, may be more likely to be successful in this population.

Practical advice
Although the researches recognised the importance of a nutritional intervention in combination with the exercise intervention, this was not part of the study. More studies need to focus on this combination, as the obesity epidemic is a key factor for T2DM and can be influenced by diet. Programs with a focus to link culture and physical activity by incorporate innovative and creative ways to develop community support, cultural identity, cultural pride and self-esteem, will have greater potential to be sustained. There are large health gaps that have been identified in this population. This presents as an opportunity to create health gains through more funding, research and awareness of these issues.

Further information/resources
For more information on diabetes click on the below links:
 * 1) Diabetes Australia - https://www.diabetesaustralia.com.au/pre-diabetes
 * 2) Diabetes video - https://www.youtube.com/watch?v=JAjZv41iUJU
 * 3) Online diabetes assessment tool http://www.health.gov.au/internet/main/publishing.nsf/Content/diabetesRiskAssessmentTool