Exercise as it relates to Disease/Can increased participation in physical activity reduce the risk of developing type 2 diabetes?

The following article is a critical analysis of 'A National Effort to Prevent Type 2 Diabetes: Participant-Level Evaluation of Centres for Disease Control National Diabetes Prevention Program' by Elizabeth K.Ely (2017).

What is the background to this research?
The impact diabetes has on the United States health care system is vast and costly with an estimated 29 million American adults diagnosed with diabetes. According to the American Diabetes Association it is estimated that approximately 86 million adults experience high blood glucose levels linked to prediabetes but not high enough to warrant a diagnosis. High blood glucose levels can not only increase the risk of developing type 2 diabetes but increase the risk of developing heart disease and/or stroke. Physically inactive or overweight or obese individuals also have an increased risk of developing diabetes. The aim of the study was to evaluate participant-level results from the first 4 years of implementation of the national diabetes prevention program and how increased physical activity participation can reduce the risk of developing type 2 diabetes.

Where is the research from?
The research was conducted in the Division of Diabetes Translation, Centres for Disease Control and prevention in Atlanta, United States. The article was also guided by the Hubert Department of Global Health, Rollins school of public health, Emory University in Atlanta, United States. The Data used in the research came from participants of the National Diabetes Prevention Program. The study was funded mainly by the Centres for Diabetes Control. It was partially funded by the Georgia Centre for Diabetes Translation Research and the National Institute of Diabetes and Digestive and Kidney Diseases.

The following authors contributed to the study concept and design, conducted and statistical analysis, and contributed to the interpretation and discussion of data and editing.


 * Elizabeth K. Ely
 * Stephanie M. Gruss
 * Elizabeth T. Luman
 * Edward W. Gregg
 * Mohammed K. Ali
 * Kunthea Nhim
 * Deborah B. Rolka
 * Ann L. Albright

What kind of research was this?
The research article is an evaluation and continuation of analysis based off the core data provided in the randomised controlled trial conducted by the Centres for Disease Control National Prevention Program. The article was designed to support the original Diabetes Prevention Programs findings. Randomised controlled trials have minimal bias and provide a high level of evidence. Evaluation is used to understand the specific issues within a study to ensure practicality for real-world settings. It also assesses the strengths and areas of improvement for the study. However, there are some limitations to the study. Physical activity was reported by the participants which could create bias from individuals over reporting. Also due to not having glycemic markers, the study was unable to provide additional information on whether weight loss will continue to decrease the risk of developing diabetes.

What did the research involve?
The primary study included 14,747 eligible participants aged 18 years or older. The average age of the participants was 55.1 years old and 19.7% were male and 80.3% were female. To be eligible for the study participants had to have an increased risk of developing diabetes. To determine eligibility participants were asked to participate in a blood-based test resulting in high blood glucose levels, have a history of gestational diabetes mellitus, or score on the Centres of diabetes control or American Diabetes Association as having increased risk of developing diabetes. The diabetes prevention program consisted of sessions conducted by coaches. Each session's objective was to provide information regarding diabetes, recommend physical activities and offer feedback to the participants. Program attendance was based on the total number of sessions the person attended during the 12-month program. The participants were encouraged to attend a minimum of four sessions. Sex, age, race/ethnicity, baseline BMI and eligibility category, average initial weight, and average number of days in the program were recorded. A two-sample t test was employed to measure the difference in participants baseline weight and the number of days they contributed to the program. Number of months in the program was calculated as the number of days from first session attended to last session attended. Physical activity was also calculated based on the number of minutes recorded each week. It was suggested that individuals participate in moderate to vigorous physical activity for at least 150 minutes per week.

What were the basic results?
The main findings in the study were:


 * 75% of participants were discovered to have obesity and 22.5% were overweight.
 * Participants reported an average of 152 minutes of physical activity a week throughout the study.
 * Median body weight loss usually increased as the number of sessions attended increased.
 * Significantly less females reached the 5% weight loss goal compared to men.
 * The average weight loss percentage was 4.2%.
 * 35.5% of participants achieved the >5% weight loss goal.

What conclusions can we take from this research?

 * Participants that persisted with the program were more successful than participants who quit early. For example, with each additional session attended the participants lost an average 0.31% of their body weight. This suggests that increased participation in physical activity has a positive relationship with weight loss.
 * A large portion of participants are not participating in the whole program suggesting that the current study lacks engagement.
 * Limitations to the study are identifying individuals at risk of developing diabetes and engaging them to participate in diabetes prevention programs.

Practical advice
It would be beneficial for participants to break up long periods of sedentary behaviour as individuals that experience large periods of sedentary behaviour have an increased risk of weight gain or developing diabetes and other chronic diseases. Obesity is a major risk factor for diabetes because it causes insulin resistance and b cell impairment. Encouraging individuals to participate in sporting teams and exercise groups will increase participation and keep their engagement. It is also important for physical activity to work around your lifestyle. For example, do you have more free time at night or in the morning.

Further information/resources
Additional organisations in the United States and Australia supporting individuals with diabetes and working to prevent diabetes nationwide.

[https://www.cdc.gov/diabetes/prevention/index.html#:~:text=The%20National%20Diabetes%20Prevention%20Program,risk%20of%20type%202%20diabetes. https://www.cdc.gov/diabetes/prevention/index.html#:~:text=The%20National%20Diabetes%20Prevention%20Program,risk%20of%20type%202%20diabetes.]

https://www.mayoclinic.org/diseases-conditions/type-2-diabetes/in-depth/diabetes-prevention/art-20047639

https://www.niddk.nih.gov/

https://www.diabetesaustralia.com.au/for-health-professionals/key-diabetes-organisations/