# Exercise as it relates to Disease/The effects of exercise for women post gestational diabetes in the prevention of the development of diabetes later in life
## Gestational Diabetes
### What is it?

Gestational diabetes is a form of diabetes that occurs during pregnancy. Gestational diabetes is diagnosed when higher than normal levels of glucose are detected during pregnancy and displays the same abnormalities that is seen in normal diabetes. Gestational diabetes occurs in 3%-8% of pregnant women around the 24th to the 28th week of pregnancy, although some women may begin to experience this at an earlier stage.

### Cause

Gestational diabetes is caused in pregnant women by two main factors, the increase in maternal adiposity and a decrease in insulin sensitivity due to hormonal changes caused by the placenta. During pregnancy the mother needs to generate 2-3 times more insulin than normal. The hormones created by the placenta prevent the mother from creating enough insulin which results in a decrease in the removal of glucose from the blood.

## Diabetes
### What is it?

When glucose is ingested the body absorbs it into the blood stream and is moved into tissues through a hormone called insulin. If the body does not produce enough insulin or does not respond to insulin efficiently then blood glucose levels increase. This results in diabetes. There are 2 Types of diabetes, type 1 diabetes and type 2 diabetes. Type 1 diabetes is generally developed in early life and is due to an autoimmune dysfunction. Type 2 diabetes is developed later in life, it accounts for 85%-90% of all people with diabetes and is a result of poor lifestyle.

### Cause

Type 1: in this type of diabetes the pancreas does not produce enough insulin for the body to control glucose levels due to an autoimmune pancreatic B cell dysfunction. The cause of this is unknown and there is no current cure for type 1 diabetes. Type 2: type 2 diabetes is the development of insulin resistants in the tissues. this can be caused by several factors such as: family history of diabetes, over 55 Years, overweight, high blood pressure and had gestational diabetes.

## Women at Risk

* Women over 30.
* Family history of type 2 diabetes.
* Women who are over weight.
* Women from Indigenous backgrounds.
* Women suffering from Pancreatic B cell dysfunction.
* Women from certain ethnic backgrounds including:
* South Asian
* Vietnamese
* Chinese
* Middle Eastern
* Polynesian/Melanesian
Women at risk of developing Gestational diabetes have shown Pancreatic B cell dysfunction prior to developing Gestational diabetes when insulin levels and responses are relative to each individual. It is thought that women that develop gestational diabetes have either autoimmune or background of insulin resistance gestational diabetes.

### 1. Autoimmune

Women who suffer from an Autoimmune gestational diabetes have most likely developed Autoimmune damage which decreases the amount of insulin secreted, because of this it will appear that they have developed type 1 diabetes. Women who suffer this damage generally develop diabetes post pregnancy.

### 2. Initial Insulin Resistance (lifestyle)

Women who suffer this form of gestational diabetes usually have a greater resistance to insulin prior to pregnancy. Because of the resistance to insulin caused by pregnancy these women increase their chances of developing gestational diabetes. It has also been found that women who suffer gestational diabetes tend to be obese and therefore have symptoms that lead to the decrease in insulin sensitivity.

## Development of Diabetes Post Gestational Diabetes

Women who have been affected by gestational diabetes are at a higher risk of becoming diabetic after pregnancy. Studies have shown that over a 10 year period women who suffered from gestational diabetes, showed a long term risk of 70% chance of becoming diabetic post pregnancy. Pregnancey has shown to create metabolic stress with in women, this stress has been shown to push someone from a normal glycemic state to a hyperglucimic state. Women who suffer gestational diabetes due to hyperglycemic state double the risk of developing type 2 diabetes within 4 months post pregnancy and having a fasting plasma glucose level of >121 mg/dl increases the chance by 21 times. studies have shown that women are 74% more likely to develop diabetes post gestational diabetes than those who didn't have gestational diabetes with only a 17.1% chance.

## Effect of Exercise in Preventing Type 2 Diabetes Post Gestational Diabetes

Studies have shown that performing 150 mins of exercise a week could reduce the risk of developing diabetes. It has also been seen that exercise alone, diet alone and exercise and diet were all found to have an equal effect on impaired glucose tolerance. Exercise has been shown to have an effect on HbA1c which is the amount of Glycated Haemoglobin in the blood and has been shown to be significantly reduced with exercise. This is due to a glucose transporter called GLUT 4 that is present during exercise and Aids in the movement of glucose from the blood to the muscles without the use of insulin there by reducing the amount of A1c. It has been found that GLUT4 levels are high in those who are trained compared to sedentary people. Therefore performing regular exercise will increase the amount of glucose removed from the blood without the aid of insulin. As the evidence shows it is therefore important for women who developed gestational diabetes to perform regular exercise.

### Recommendations

Aerobic exercise: 150min/wk of moderate exercise at 40%-60% of VO2 max or 50%-70% of max heart rate or 90 mins/wk of vigorous exercise at >60% of VO2 max or >70% of max heart rate.
Resistance exercise: 3 times a week at 3 sets of 8-10 reps.

## Conclusion

Due to the effect that pregnancy and gestational diabetes have and the stress that it places on the metabolic system its is very important to be mindful of the development of type 2 diabetes post Gestational diabetes. The evidence shows the positive effects that exercise can have on controlling blood glucose levels and preventing the development of diabetes.

## Further reading

Exercise, GLUT4, and Skeletal Muscle Glucose Uptake: http://physrev.physiology.org/content/93/3/993
Physical Activity in the Prevention of Type 2 Diabetes:http://diabetes.diabetesjournals.org/content/54/1/158.full.pdf
Exercise in the Management of Non–Insulin-Dependent Diabetes Mellitus:http://content.ebscohost.com.ezproxy.canberra.edu.au/ContentServer.asp?T=P&P=AN&K=9593753&S=R&D=s3h&EbscoContent=dGJyMNLr40Seqa440dvuOLCmr0yepq9Ssai4S7SWxWXS&ContentCustomer=dGJyMPGptFC3qLNMuePfgeyx44Dt6fIA

## References

* 1 2 3 4 5 6 7 8 National Diabetes Service scheme, 2010, Gestational Diabetes Caring for yourself and your baby, [internet] http://www.diabetesqld.org.au/media/33447/gestational_diabetes_booklet.pdf cited:30th sep 2014
* 1 2 3 4 5 6 7 8 9 10 Buchanan,T. Xiang, A. 2005, Gestational diabetes mellitus, Journal of Clinical Investigation. vol 115(3),pg 485-491
* ↑ Diabetes Australia, 2014, Gestational Diabetes, http://www.diabetesaustralia.com.au/Living-with-Diabetes/Gestational-Diabetes/
* 1 2 Diabetes Australia,2013, Type 2 Diabetes, http://www.diabetesaustralia.com.au/Understanding-Diabetes/What-is-Diabetes/Type-2-Diabetes/
* 1 2 Diabetes Australia, 2013, Type 1 Diabetes, http://www.diabetesaustralia.com.au/Understanding-Diabetes/What-is-Diabetes/Type-1-Diabetes/
* 1 2 3 Ratner,R.2007,Prevention of Type 2 Diabetes in Women With Previous Gestational Diabetes,American Diabetes Association, Diabetes Care vol 30, pg 242-245
* 1 2 3 4 5 Sigal,R, et al.2006, Physical Activity/Exercise and Type 2 Diabetes, American Diabetes Association, vol 29,no. 6, pg 1433-1438
* ↑ Richter,E. Hargreaves,M. 2013,Exercise, GLUT4, and Skeletal Muscle Glucose Uptake, Physiological Reviews,vol 93. no.3, pg 993-1017
* ↑ Rincon, J. et al. 1998,Exercise in the Management of Non–Insulin-Dependent Diabetes Mellitus, Sports Med, vol 25, no.1, p25-35