Diabetes is a disease that affects more and more Americans every day: Almost 26 million children and adults in the United States now have diabetes, and another 79 million US residents are living with prediabetes, a condition in which blood tests show a blood glucose level that is higher than normal but not high enough for a diagnosis of diabetes. People with prediabetes have an increased risk of developing Type 2 diabetes. Blood relatives of people with either Type 1 or Type 2 diabetes also have a higher risk of developing the same type of diabetes as their family member. And people who have diabetes run the risk of developing long-term complications associated with diabetes.
In some cases, being aware of having a heightened risk for diabetes enables a person to be proactive about reducing the risk. For example, people with prediabetes and blood relatives of people with Type 2 diabetes can reduce their risk of developing Type 2 diabetes by making lifestyle changes, such as increased physical activity, that burn calories, lower blood glucose levels, and encourage weight maintenance or weight loss.
Close relatives of people with Type 1 diabetes can have their risk of developing the condition assessed through blood tests. While no one yet knows how to prevent Type 1 diabetes, people determined to be at high risk can be followed closely, so that if they develop diabetes, they can be diagnosed early and be started on treatment as early as possible.
Diabetes and genetics
The reasons that diabetes runs in families are complex, and they differ between Type 1 and Type 2 diabetes. In both cases, however, it appears that both genetics and environment influence whether a person develops diabetes.
Close relatives of people with Type 2 diabetes, such as siblings or children, have a strong genetic tendency to develop the disease. If you have Type 2 diabetes, the risk of your children developing it is related to the age at which you were diagnosed. If you were diagnosed before age 50, your offspring have a 1 in 7 chance of developing Type 2 diabetes; if you were diagnosed after age 50, they have a 1 in 13 chance.
There is some research that suggests a child’s risk is greater when the parent with Type 2 diabetes is the mother. The risk for getting Type 2 diabetes goes up to about 50% if both parents have it, and if an identical twin has it, the risk is almost 75%.
If you have Type 2 diabetes but can’t think of any relatives who have it, chances are you have some who don’t know they have it, because about 25% of those with Type 2 diabetes are unaware they are living with the disease. Knowing that Type 2 diabetes runs in the family is something to pay attention to, because studies show that it is possible to delay or prevent Type 2 diabetes with exercise and weight loss. The American Diabetes Association has developed a short, online test to help people evaluate their individual risk for Type 2 diabetes. You can find it at www.diabetes.org/diabetes-basics/prevention/diabetes-risk-test.
Having a parent with Type 1 diabetes also raises a child’s risk of developing it, but his level of risk depends on a lot of variables. If the mother has Type 1 diabetes, her age during pregnancy influences the chances of the baby developing it at some point. If the mother with Type 1 diabetes is 25 or older during pregnancy, the child’s chance developing Type 1 diabetes is approximately 1%. If the mother is younger than 25, the child has a 4% chance. If the father has Type 1 diabetes, the child has a 6% chance of having Type 1 diabetes. A child’s risk for Type 1 is doubled if the parent who has it developed the disease before turning 11 years old. And if both parents have Type 1 diabetes, the risk is that the child will develop the disease ranges from 10% to 25%.
Inheriting an increased risk for Type 1 diabetes doesn’t necessarily mean a person will get it. Research suggests that some type of environmental factor is necessary to put the development of Type 1 diabetes in motion. Some studies point to cold weather or viruses as the environmental trigger. Other data suggest that infants who were breast-fed and/or who started solid food at later ages tend to be less likely to develop Type 1 diabetes.
Type 1 diabetes is an autoimmune disorder, which means that the body produces autoantibodies (a type of protein) that attack and destroy the cells in the pancreas that produce insulin, the hormone in the body that lowers blood glucose levels. Relatives of individuals with Type 1 diabetes can have a blood test that screens for these autoantibodies. Information on being screened for Type 1 diabetes is available at www.diabetestrialnet.org. You can also make an appointment to be screened by calling (800) 425-8361.
Can diabetes be prevented?
As Benjamin Franklin said, an ounce of prevention is worth a pound of cure. But can diabetes be prevented?
Type 2 diabetes. Prior to developing Type 2 diabetes, a person will usually have prediabetes, or somewhat elevated blood glucose levels. People with prediabetes often also have high blood pressure and other risk factors for heart and blood vessel disease. However, studies show that many people with prediabetes can lower their risk for Type 2 diabetes by losing approximately 7% of their body weight and performing about 150 minutes of moderate exercise per week, or about 30 minutes of exercise 5 days a week. These same strategies are also usually part of the treatment plan to lower the risks of heart and blood vessel disease.
Knowing you have prediabetes, therefore, is a message to get active, attain a healthy weight, and work with your health-care provider to improve your health.
Type 1 diabetes. There are no known strategies to prevent Type 1 diabetes at this time, but there is a study under way that is evaluating people who are at a higher risk for Type 1 diabetes, with an ultimate goal being the prevention of Type 1. As noted earlier, siblings and children of people with Type 1 diabetes are much more likely to develop the disease than people with no family history. The researchers hope to learn more about how Type 1 diabetes develops.
So if you have Type 1 diabetes, talk with your close family members about participating in this study, called TrialNet Pathway to Prevention Study. Information is available at www.diabetestrialnet.org.
(Click here for some take-away tips for risk reduction.)
Long-term complications from diabetes include disease of the nerves and blood vessels, which can lead to damage of various organs, including the eyes, kidneys, heart, brain, and the feet and legs. Skin disorders such as bacterial and fungal infections, gum disease also occur more often in people with diabetes.
But long-term complications are not inevitable. One key to prevention is having a health-care provider (such as a physician) who is knowledgeable about diabetes and who can coordinate your care to assure that you have the tools you need to manage your diabetes successfully. You should see your diabetes health-care provider at least two to four times a year for regular checkups related to your diabetes management.
Generally, if you are able to control your blood glucose levels over time, your chance of developing the type of nerve and blood vessel damage that contributes to long-term diabetes complications is reduced. Treating high blood pressure and abnormal cholesterol levels, if you have either of these problems, will also help you avoid diabetes complications. Even if your blood pressure is not considered too high, you may be prescribed a medicine that is normally used to treat high blood pressure as a preventive measure against kidney disease.
Managing blood glucose, blood pressure, and blood cholesterol levels usually involves taking medicines, planning healthful meals, and being physically active. It’s also necessary to maintain a balance between these three aspects of treatment.
Your diabetes care team, which usually includes a physician, a nurse, a dietitian, and a pharmacist, can help you to develop a plan to achieve optimal blood glucose and blood pressure control and to stick to it. A diabetes educator (a health-care provider with special training in diabetes care) can help you learn about the prevention and/or treatment of specific long-term complications by working with you individually or in group sessions such as diabetes education classes.
You should also see a physician who specializes in eye care for annual eye examinations to monitor the health of your eyes and to treat any problems that arise. You may also need to see other specialists, as recommended by your primary diabetes care provider.
Bringing it all home
When one person in a family has diabetes, it’s good for the whole family to know about it, both so they can help and support the person who has it, and also so they are aware of the impact it may have on them. One great way to support the person with diabetes is to join him in his healthy lifestyle, and if Type 2 diabetes runs in the family, this can possibly prevent or delay a diagnosis of prediabetes or Type 2 diabetes among family members. (Click here to learn about how one family worked on reducing diabetes risks.)
Learning about diabetes together is another way to support the person who has it and also to inform family members about their risks. Most diabetes education programs welcome the participation of family members in diabetes education classes. It can also be helpful for adult siblings or adult children to accompany their sibling or parent to medical appointments to act as a second set of ears, help to remember to bring up any questions or concerns, and also learn more about what they can do to support their relative in his daily diabetes management efforts.
When families tackle a problem like diabetes together, the benefits can be many, from improved health for everyone, to less of a feeling of isolation for the person with diabetes. It can feel enormously empowering to take charge of your health, and enormously comforting to know you have the support you need at home.