How Does Our DNA Contribute To Certain Types of Diabetes

5 Mins Read


Lawrence Ng
Scientific Advancement Executive at Advanx Health

We can't live without sugars, but having too much sugar in our blood stream is not a good thing either.

What is Diabetes

Diabetes occurs when your system is not able to transport glucose out of the blood stream and hence, increases the blood glucose levels. When you eat food that contain carbohydrates, these carbohydrates are then converted into glucose which is your main source of energy.

The problem arises when insulin, a hormone made by the pancreas, does not perform its job to convert glucose into glycogen, a form of glucose that can be stored in the liver. This can happen when your pancreas does not produce enough insulin or your cells in the body do not respond to insulin. As a result, glucose is not transported to the cells in your body and stays in the bloodstream.

Types of diabetes

Type 1 Diabetes

People with type 1 diabetes means that their body does not produce enough insulin. This may be due to their immune system attacking the cells in their pancreas that are responsible for making insulin. Although Type 1 diabetes can develop at any age, they are more commonly diagnosed in children and young adults. A person with Type 1 diabetes would need to take insulin daily in order to survive. Type 1 diabetes is relatively uncommon.

Type 2 Diabetes

People with type 2 diabetes means that they do not produce insulin efficiently or their bodies do not respond well to insulin. Type 2 diabetes can develop at any age, but the risk increases the older you get. Type 2 diabetes is more common than other types of diabetes.

Other types of diabetes

You are probably familiar with type 1 and type 2 diabetes or have at least heard of them, but did you know that there are other types of diabetes?

  1. Gestational diabetes, as the name suggests, is a diabetes that some women may go through during pregnancy. Gestational diabetes typically goes away after conception, but your risk of type 2 diabetes increases if you’ve had gestational diabetes. A possible misdiagnosis is that the diabetes diagnosed during pregnancy may turn out to be type 2 diabetes.

  2. Monogenic diabetes is a rare type of diabetes that is only affected by a single gene unlike type 1 and type 2 diabetes which may be affected by many genes.

  1. Cystic fibrosis-related diabetes (CFRD) is another rare type of diabetes that may occur when a person is already suffering from cystic fibrosis. CFRD shares some features with both type 1 and type 2 diabetes.

Your risk of diabetes may be in your genes.

As we now know, your genes may play a part in our risks of developing certain diseases. In the case of diabetes, large-scale studies have been done to identify the genes that may be associated with diabetes. The genes found are those that are either responsible for fasting glucose levels, insulin production and secretion or insulin response. Here are several examples of genes that may be responsible for diabetes:

  1. ADCY5, MADD, CRY2, FADS1, GLIS3, SLC2A2 are associated with fasting glucose levels.
  2. TCF7L2 variants affect mean fasting glucose levels (cause high blood glucose levels) and subsequently affect risk for type 2 diabetes.
  3. ADCY5 variants are associated with fasting glucose levels and 2 hour glucose levels and may increase the risk of type 2 diabetes.
  4. ADCY5 and MADD were associated with decreased proinsulin-to-insulin conversion. GLIS3 was might be associated with impaired proinsulin-to-insulin conversion and insulin secretion. (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0023639)
  5. MTNR1B is associated with increased risk of type 2 diabetes. It also worsens the effect of melatonin on glucose tolerance, suggesting the importance of genetic testing and personalized recommendations, especially in people consuming food when melatonin levels are elevated.

You’ve done screening and found out that you are have a genetic predisposition to type 2 diabetes. What’s next?

Is it the end of the world if you find out you have an increased risk of type 2 diabetes? Not to worry, it’s not.

Diabetes is a multifactorial disease which means it is affected not just by your genes but also by your lifestyle and diet. This means that you can take many precautions to minimise those risks.

Since your DNA cannot be changed, the only way to decrease your risk of the disease is to change your lifestyle and diet. The Diabetes Prevention Program states that losing weight may delay or even prevent the onset of diabetes.

In our webinar where we talked about the precautions that can be taken to decrease the risk of diabetes, Dr Ng Zhi Xiang mentioned a few steps that would help you live a healthier lifestyle. Watch the webinar here.

Here are some tips to decrease your likelihood of getting type 2 diabetes:

1. Start an exercise programme

Of course, this doesn’t mean that you should immediately join a marathon or a weight-lifting tournament. Slowly incorporate physical activity in your daily routine, take the stairs instead of the lift, park further away from your office, take a leisure walk after lunch. All these subtle changes would no doubt help you lose the required amount of weight. Then, slowly start adding more intense exercises such as weight training and cardio. Try to aim for 150 minutes of exercise per week.

2. Practice a healthy meal plan

This means decreasing your fat and calorie intake. Yes, it may be hard to avoid carbohydrates in our food heaven of a country especially when eating out. Therefore, cooking your own meal is the easiest way to make healthy choices. This way, you’ll know exactly what goes into your meal. It may be time consuming to cook everyday so it is suggested to plan out a menu for the week and prepare a meal prep. Stock up on ingredients and cook ahead of time!

3. Healthy snacking

By eating smaller meals throughout the day, you’re bound to be hungry in between meals. It can be very tempting to reach for the nearest bag of chips or a candy bar but try to restrain yourself! Instead, try stocking up on healthier alternatives to keep yourself satiated. Examples of healthy snacks are fruits, vegetable sticks like carrots and celeries and different types of nuts. Even popcorn can be used as a low calorie alternative as long as you mind the salt and butter!

4. Avoid smoking

Smoking is also a known contributor to getting type 2 diabetes. Diabetes is not the only disease that can be caused by cigarette smoke. Other disease such as lung cancer, emphysema and chronic bronchitis. So, quit smoking now!

5. Get enough sleep

This study also found that the amount of sleep you get can also be a factor of preventing diabetes. The study found that getting 6-9 hours of sleep per night is optimal for preventing diabetes as well as other diseases. Sleeping for more than 9 hours and less than 5 hours are associated with higher risk of type 2 diabetes.




References:
1. Ley, S. H. et al. (2016) 'Contribution of the Nurses' Health Studies to Uncovering Risk Factors for Type 2 Diabetes : Diet , Lifestyle , Biomarkers , and Genetics’, 106(9), pp. 1624–1630. doi: 10.2105/AJPH.2016.303314.
2. Hang, L. U. Z. (2011) 'Smoking and Incident Type 2 Diabetes', (November 2010). doi: 10.2337/dc10-2087.Garaulet, M. et al. (2015) 'Common type 2 diabetes risk variant in MTNR1B worsens the deleterious effect of melatonin on glucose tolerance in humans', Metabolism. Elsevier Inc., pp. 1–8. doi: 10.1016/j.metabol.2015.08.003.
3. Saxena, R. et al. (2010) 'Genetic variation in GIPR influences the glucose and insulin responses to an oral glucose challenge', Nature Genetics, 42(2). doi: 10.1038/ng.521.
4. Ivarsdottir, E. V et al. (2017) 'Effect of sequence variants on variance in glucose levels predicts type 2 diabetes risk and accounts for heritability', Nature Genetics. Nature Publishing Group, (August), pp. 1–8. doi: 10.1038/ng.3928.
5. These, R. and Genome-wide, R. (2010) 'New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk', Nature Genetics, 42(2). doi: 10.1038/ng.520.
6. Machicao, F. et al. (2011) 'Glucose-Raising Genetic Variants in MADD and ADCY5 Impair Conversion of Proinsulin to Insulin', PLoS ONE, 6(8). doi: 10.1371/journal.pone.0023639.
7. Cystic Fibrosis Foundation (no date) Cystic Fibrosis-Related Diabetes. Available at: https://www.cff.org/Life-With-CF/Daily-Life/Cystic-Fibrosis-related-Diabetes/ (Accessed: 20 December 2018).
8. NIDDK (2017) Monogenic Diabetes (Neonatal Diabetes Mellitus & MODY). Available at: https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/monogenic-neonatal-mellitus-mody (Accessed: 20 December 2018).
9. NIDDK (2017) Gestational Diabetes. Available at: https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/gestational/definition-facts (Accessed: 20 December 2018).
10. NIDDK (2016) What is Diabetes? Available at: https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes (Accessed: 20 December 2018).

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