Diabetes is a chronic illness, and so far, there is no cure for it. But with careful monitoring, a person with diabetes can maintain good health and live a full and productive life.
While there is still much that isn’t known about diabetes, one thing that is known is that diabetes has a genetic component. That is, blood relatives of people with either Type 1 or Type 2 diabetes have a higher-than-average risk of developing the same type of diabetes as their family member. People with a family history of Type 2 diabetes are also at risk for prediabetes, a condition in which blood glucose is higher than normal but not high enough for a diagnosis of diabetes. Prediabetes is considered a risk factor for Type 2 diabetes and also for cardiovascular disease.
Women with a history of Type 2 diabetes in the family are at risk for gestational diabetes, a type of diabetes that can occur during pregnancy (usually between the 24th and 28th week). Additionally, women with a history of gestational diabetes are at increased risk for developing Type 2 diabetes, and children whose mothers had gestational diabetes while pregnant with them are at increased risk for obesity and Type 2 diabetes.
While you can’t change your family history, knowing that you have a family history of diabetes allows you to be proactive about monitoring your health and, if there’s Type 2 diabetes or gestational diabetes in your family, lowering your risk.
What is diabetes?
Hyperglycemia, or a blood glucose level that is too high, is the hallmark of diabetes. Blood glucose levels become elevated when the body either can’t make insulin, as in Type 1 diabetes, or doesn’t respond properly to insulin, as in Type 2 diabetes. Insulin is a hormone that enables the body to use glucose for energy. When insulin is not available or not working efficiently, glucose accumulates in the bloodstream. As the blood glucose level becomes higher, symptoms such as frequent urination, feeling very thirsty, feeling hungry even though you are eating, tiredness or fatigue, blurry vision, cuts or bruises that are slow to heal, numbness or tingling in the feet and legs, and weight loss despite eating (particularly with Type 1) can occur.
Prediabetes often occurs as a precursor to Type 2 diabetes. In cases of prediabetes or gestational diabetes (diabetes that appears during pregnancy), blood glucose levels are too high but may not be high enough to cause symptoms. Therefore, you cannot count on symptoms as a cue to alert you to seek medical attention. Instead, you need to let your health-care provider know that you have a family history of the condition so that screening can start at the appropriate time.
Strategies to improve glucose levels in prediabetes may help to prevent or at least postpone Type 2 diabetes. In gestational diabetes, optimal control of blood glucose levels is essential to prevent macrosomia, a condition in which the baby gains an excess amount of weight in the uterus, which can make delivery more difficult and affect the baby’s blood glucose levels and risk for Type 2 diabetes later in life.
If you are at risk for prediabetes or gestational diabetes, work with your physician to stay on top of the situation. If you have Type 1 or Type 2 diabetes, be sure to discuss what tests will be routinely done to monitor your diabetes control. In either case, be aware of any test results and what they mean for you.
Screening for diabetes
If a person were to visit his health-care provider with signs or symptoms of hyperglycemia, he would likely have his blood glucose level checked to see if he had diabetes. Even without signs or symptoms, however, the American Diabetes Association recommends screening certain individuals who have risk factors for Type 2 diabetes. Screening for diabetes should be considered in any adult who is overweight (generally defined as having a body-mass index of 25 or greater, although this number may be different for certain ethnic groups) and has at least one of the following risk factors:
• The person is sedentary (physically inactive).
• The person has first-degree relative (a parent, child, or sibling) with diabetes.
• The person is a member of a high-risk ethnic group (for example, African-American, Latino, Native American, Asian American, or Pacific Islander).
• The person is a woman who has delivered a baby weighing nine pounds or more.
• The person is a woman with a history of gestational diabetes.
• The person has high blood pressure.
• The person has low HDL (“good”) cholesterol and/or a high triglyceride level.
• The person has a history of a condition associated with insulin resistance, such as polycystic ovary syndrome in women, severe obesity, or acanthosis nigricans (a darkening of the skin that may occur in certain skin folds, such as the armpits).
• The person has a history of prediabetes.
• The person has a history of cardiovascular disease.
If an adult who is not pregnant has none of the risk factors mentioned above, screening for diabetes should begin at age 45. If the results are normal, then screening for diabetes should occur at least every three years. If a person is found to have prediabetes, he should be screened annually for diabetes. (Click here for some take-away tips on when and how often you should be screened for high blood glucose.)
There are four blood tests that are commonly done to evaluate whether someone has diabetes or prediabetes: the hemoglobin A1c (HbA1c) test; the fasting plasma glucose test; the random, or casual, blood glucose test; and the oral glucose tolerance test. The majority of the time, the test will be repeated (or another of the tests will be done) to confirm a diagnosis of diabetes.
Hemoglobin A1c. The hemoglobin A1c test gives an estimate of your average blood glucose level over the past two to three months. The test can be done at any time of day, and you do not have to fast before the blood sample is taken. When a person’s hemoglobin A1c test result is 6.5% or higher, diabetes is diagnosed. A diagnosis of prediabetes occurs if the hemoglobin A1c is between 5.7% and 6.4%.
Fasting plasma glucose. For a fasting plasma glucose test, a person needs to not eat or drink anything (except water) for at least eight hours before the blood sample is taken. This test is usually done first thing in the morning in a laboratory setting, before a person eats breakfast. A normal, nondiabetic, range for this test is a blood glucose level between 65 and 99 mg/dl. If the fasting glucose is between 100 and 125 mg/dl, a diagnosis of prediabetes may be made. If the test result is greater than 126 mg/dl on two separate occasions, diabetes is diagnosed.
Random blood glucose. A random or casual blood glucose test is a check done at any time during the day, without regard to when the person last ate. Typically, a random blood glucose test is done when a person has signs or symptoms of hyperglycemia. A random blood glucose level of 200 mg/dl or higher indicates diabetes.
Oral glucose tolerance test. The oral glucose tolerance test (OGTT) is generally used for the diagnosis of gestational diabetes. While the method of conducting the test can vary somewhat, generally, the pregnant woman fasts before the test, has her fasting blood glucose measured when she arrives at the lab, drinks a premeasured glucose solution, and then has her blood glucose measured again one hour, two hours, and sometimes three hours after drinking the glucose.
Some physicians prefer to do a “screening” first, before ordering an OGTT. This may be done for woman at high risk for gestational diabetes. In this case, the woman drinks a premeasured glucose solution, and her blood glucose level is measured one hour later. If the result is higher than the high end of the recommended range (usually 130 mg/dl or 140 mg/dl), she is referred for the OGTT.
Sometimes people who are not pregnant are advised to have an OGTT to see how their body responds to the glucose solution. This type of OGTT is done by first checking a person’s fasting blood glucose level, having him drink a premeasured glucose solution, then checking the blood glucose level again two hours later. A blood glucose of 200 mg/dl or higher at the two-hour mark is indicative of diabetes; a blood glucose level between 140 and 199 mg/dl means a person has prediabetes.
If you are scheduled for an OGTT, it is important to ask your physician why the test has been recommended and how it will be conducted. You should request an outline of the testing procedure so you will have the details should any questions come up.
Most people who are diagnosed with diabetes are advised to monitor their blood glucose level regularly. How often and when during the day depends on a number of variables, including what type of diabetes a person has, how he manages his blood glucose levels, and how stable his blood glucose levels are.
Most people with Type 1 or Type 2 diabetes are also advised to have an HbA1c test two or more times a year to give them and their diabetes care providers a broader look at their level of blood glucose control. Your target HbA1c depends on the type of diabetes you have, the length of time you have had diabetes, your age, and the presence of any other health conditions.
Regular home monitoring and HbA1c tests give you and your diabetes care provider the information you need to make decisions about adjusting your diabetes regimen. Fine-tuning your regimen when needed improves your chances of avoiding long-term diabetes complications.
There is pretty much no argument when it comes to the importance of healthful eating and staying active to good health. For people with Type 1 and Type 2 diabetes, learning to eat healthfully, determining an optimal level of carbohydrate intake, maintaining portion control, and participating in physical activity will help to maintain blood glucose and weight control. For overweight people who have diabetes, moderate weight loss and regular physical activity can improve blood glucose control.
For people who are overweight but don’t have diabetes, losing 5% to 7% of body weight (for example, 10 pounds if you weigh 200 pounds) and performing at least 150 minutes per week of moderate physical activity (such as walking, bicycling, or swimming) can help to prevent or delay the onset of Type 2 diabetes.
If you had gestational diabetes during pregnancy, work with a registered dietitian to lose any excess weight gained with pregnancy. Try to reach your pre-pregnancy weight 6 to 12 months after delivery. Breast-feeding your baby may help you reach your post-pregnancy weight goal as well as lower your child’s risk for Type 2 diabetes. Achieving moderate weight loss and getting regular physical activity after gestational diabetes can help reduce your risk of having gestational diabetes again with a future pregnancy as well as developing Type 2 diabetes later in life.
Knowing your family history can help you help yourself as well as your family members when you share what you’ve learned. (Click here to read about how one family explored its history.) Together you can make healthy lifestyle habits as much a part of your family history as diabetes or any other condition.