Type 1 and type 2 diabetes mellitus are both life-long conditions that require ongoing care and management. However, while some similarities exist, the two are quite different. Type 1 diabetes is more associated with genetics, while type 2 diabetes is more associated with lifestyle factors and environmental risks, but genetics still plays a role. To understand your risk, we'll review everything you need to know regarding diabetes genetics and your risk of developing the condition.
The Role of Genetics and Type 1 Diabetes
Type 1 diabetes is an autoimmune condition where the immune system mistakenly attacks and destroys insulin-producing beta cells in the pancreas. This results in little to no insulin production, leading to high blood sugar levels that require lifelong insulin therapy for management. The exact cause is unknown, but it involves genetic and environmental factors.
Development of type 1 diabetes typically occurs during childhood (between the ages of 4 to 6) or adolescence (between the ages of 10 to 14). However, type 1 diabetes can occur at any age, even in adulthood.
Which Genes Are Responsible for Type 1 Diabetes?
The risk of type 1 diabetes has been strongly linked to a few specific genes. According to the American Diabetes Association (ADA), most people with type 1 diabetes have mutations in the HLA genes. These genes encode proteins that help the body differentiate between its own cells and foreign invaders. Therefore, mutations in various HLA genes tend to be responsible for autoimmune conditions such as type 1 diabetes.
Are Your Children at Risk for Developing Type 1 Diabetes?
Living with type 1 diabetes may concern individuals who want to become parents one day, but just because you have it doesn't mean your children will get diabetes, too. According to the ADA, a male with type 1 diabetes has a 1 in 17 chance of their child developing the condition, while a female has a 1 in 25 chance.
These numbers are associated with births before the diagnosed parent turns 25. If you have a child after age 25, your child's risk decreases to 1 in 100. If both parents have diabetes, the risk is doubled. If one parent also has a condition called type 2 polyglandular autoimmune syndrome, your child's risk of inheriting both the syndrome and type 1 diabetes is 1 in 2.
The Genetics of Type 2 Diabetes
Type 2 diabetes is a chronic condition in which the body either resists the effects of insulin or doesn't produce enough insulin to maintain normal blood sugar levels. Although type 2 diabetes has some association with family history, environmental factors also play a heavy role.
Is Type 2 Diabetes Hereditary?
Your risk increases if you have a family history of type 2 diabetes, but that doesn't mean you will develop it. The genetic predisposition is strongest if you have an older sibling or parent with it, but again, it's not a guaranteed ticket to diabetes development. So yes, type 2 diabetes does run in families, but there's more to it than that.
The primary issue in understanding the weight of genetics as a risk for type 2 diabetes is the difficulty in separating genetic and environmental risk. For example, parental eating habits tend to be passed on to their children, which can affect body fat, weight, and nutritional makeup. However, genetics can also play a role in weight and obesity, so it's not always a black-and-white answer.
Which Genes Are Responsible for Type 2 Diabetes?
Several different genetic mutations have been linked with a higher risk of type 2 diabetes. Although not everyone with these mutations will develop diabetes, most people who have been diagnosed with type 2 diabetes have been found to have one or more of these mutations.
The mutations occur in the genes that typically help control blood glucose levels. Specifically, the genes most associated with the development of type 2 diabetes are:
- ABCC8 — A gene that regulates insulin within the body
- CAPN10 — The gene that's associated with type 2 diabetes risks in certain ethnic groups like Mexican Americans
- GLUT2 — A gene that helps move glucose into the pancreas.
- GCGR — A hormone that's involved in the regulation of glucose within the body.
- TCF7L2 — A gene that affects insulin secretion and overall glucose production.
Other Risk Factors for Type 2 Diabetes
Several other factors can increase your risk of developing type 2 diabetes. The most important ones to be aware of include the following:
- Age 45 or older
- Overweight
- High blood pressure
- Low levels of HDL (good cholesterol)
- High levels of triglycerides
- Sedentary lifestyle (physically active fewer than three times per week)
- Gestational diabetes
- Given birth to a baby weight over nine pounds
- Family history of diabetes
- One or more gene mutations associated with type 2 diabetes
- History of heart disease or stroke
- Depression
- Polycystic ovary syndrome (PCOS)
- Acanthosis nigricans (skin condition associated with diabetes)
- Prediabetes
Does Genetics Play a Role in Other Types of Diabetes?
Other forms of diabetes also have genetic components, especially gestational diabetes. Gestational diabetes develops during pregnancy when blood sugar levels become elevated. This is often caused by the hormones present in pregnancy, which can decrease the effects of insulin and cause resistance. Your chance of getting gestational diabetes typically begins around 20 to 24 weeks of pregnancy, so your doctor will screen you at this time.
Like type 1 and type 2 diabetes, gestational diabetes seems to have a genetic link. These mutations may be similar to those responsible for an increased chance of developing type 2 diabetes. Its onset is closely related to family history, and gestational diabetes tends to run in families. But that doesn't mean you're guaranteed to develop it.
Should You Undergo Diabetes Genetic Testing?
Individuals interested in learning about the genetic risk of developing diabetes can get tested for the gene mutations associated with both. However, with type 2 diabetes, you're more likely to develop the condition based on other factors in your life. Namely, your blood pressure, body mass, cholesterol, triglyceride levels, and whether you're relatives of people with type 2 diabetes.
For some, getting tested for the mutation may cause unnecessary anxiety, which can lead to unhealthy coping mechanisms that increase your risk for diabetes. Talk to your doctor about your options to determine if genetic testing is right for you, and try to stay positive regardless of the results.
Can You Prevent Diabetes?
Unfortunately, there is no way to know for sure if you or your child will develop type 1 diabetes, and there's no way to prevent it. It's an autoimmune condition that affects your pancreas and destroys the cells responsible for producing insulin. If you have a family history or confirmed genetic mutations, the best thing to do is active surveillance and prompt treatment if your doctor makes a diagnosis.
You can, however, help prevent type 2 diabetes and gestational diabetes by adopting a healthier lifestyle. Some of the best things you can do to prevent or delay type 2 diabetes include the following:
- Maintain a Healthy Weight — Achieve and sustain a healthy weight.
- Engage in Regular Physical Activity — Aim for at least 150 minutes of moderate aerobic exercise, such as brisk walking, or 75 minutes of vigorous activity, such as running each week.
- Adopt a Balanced Diet — Eat a diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats while limiting processed foods, sugary drinks, and high-fat foods.
- Monitor Blood Sugar Levels — Regularly check blood sugar levels if you are at high risk or have prediabetes.
- Avoid Smoking — Quit smoking, as it increases the risk of type 2 diabetes and other serious health issues.
- Get Regular Health Checkups — Have regular checkups to monitor for risk factors and early signs of diabetes.
- Manage Stress — Practice stress-reducing techniques such as mindfulness, meditation, or yoga to help maintain a healthy lifestyle.
To help you prevent gestational diabetes, consider the following:
- Maintain a Healthy Weight Before Pregnancy — Try to achieve a healthy weight before conception.
- Eat a Balanced Diet — Focus on a diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats, and avoid excessive sugary and processed foods.
- Engage in Regular Physical Activity — Incorporate moderate exercise into your routine before and during pregnancy, with activities such as walking, swimming, or prenatal yoga.
- Monitor Carbohydrate Intake — Be mindful of carbohydrate consumption, aiming for complex carbohydrates with a low glycemic index to maintain stable blood sugar levels.
- Avoid Excessive Weight Gain During Pregnancy — Follow your doctor's guidelines for healthy weight gain.
- Regular Prenatal Care — Attend all prenatal appointments to monitor your health and the baby's development, allowing for early detection and management of any issues.
- Screen for Diabetes Early — If you have risk factors for gestational diabetes, get screened early in your pregnancy.
- Stay Hydrated — Drink plenty of water to help maintain healthy blood sugar levels and overall health.
To help you manage your diabetes, Byram Healthcare carries a wide range of high-quality diabetes supplies. We also offer educational materials and other resources to help you proactively approach management and care.
