About a decade ago, it was assumed that the cause of high blood sugar levels in children was type 1 diabetes, which was then known as juvenile diabetes. But today, more and more children and teenagers are being diagnosed with type 2 diabetes. While type 1 diabetes results from an autoimmune problem, type 2 diabetes, formally known as adult onset diabetes, often develops when people are overweight and inactive.
It's thought that the startling rise in type 2 diabetes is tied to the increase in obesity among children. This health trend is particularly worrisome because it raises children's risk of life-threatening medical problems such as heart disease and kidney disease. Early management of diabetes in children and teenagers, however, can help bring blood sugar levels down and delay diabetes complications.
"I remember one of my first cases of type 2 diabetes in children, when there was a lack of knowledge amongst the pediatric endocrinologists," says Wendy Brickman, MD, an assistant professor at the Feinberg School of Medicine at Northwestern University and an attending physician in the division of endocrinology at Children's Memorial Hospital in Chicago. "This used to be primarily an adult disease, but now type 2 diabetes and its complications is something pediatricians and pediatric endocrinologists need to know about."
Below, Dr. Brickman discusses how type 2 diabetes appears in children and teenagers, how families can learn to prevent it, and how endocrinologists are learning to treat it.
How does type 2 diabetes differ from type 1?
Glucose, or blood sugar, levels are controlled by the hormone insulin, which is secreted by one type of cell in the pancreas. The insulin sends signals to cells in certain tissues, such as muscle, and in response the cells use glucose for energy or store it for later use.
There are at least two problems with insulin in type 2 diabetes. One is insulin resistance, when your cells do not respond properly to the insulin signal and blood sugar is not stored or used, and the other is poor insulin secretion, where the cells of the pancreas cannot make enough insulin to overcome the insulin resistance. In type 1 diabetes, there is an autoimmune process that destroys the cells that make insulin, so it's purely a problem with insulin production and secretion.
There are differences in the way these diseases appear. In type 2 diabetes, the disease can be present while the kids feel completely asymptomatic. With type 1 diabetes, children usually have an increase in thirst and urination. When a child makes so little insulin that the body starts to use fats for energy, s/he starts to get very sick very quickly.
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How do you know which type of diabetes a child has?
In determining the type of diabetes a child has, we look at many factors, including a family history of diabetes, weight, a physical exam and laboratory studies. Sometimes the diagnosis can be made right away, but sometimes it can only be determined by watching the progression of the disease.
In what age are you starting to see type 2 diabetes develop in children?
It's been reported in 8 year olds. But 12 to 13 years is a very common age for presentation.
What do you attribute the rise in diabetes rates among children to?
At least part of the rise is due to the presence of insulin resistance in some kids today, probably from obesity and being less active. Some youth don't have the ability to make more insulin to compensate for this resistance, and therefore they develop diabetes. According to a nationwide survey, 15 percent of kids are obese. And there's an even larger population that's at risk of becoming obese or overweight. We also know that we live in an environment where exercise is not always a part of daily life.
Whether the environment we live in, the food we eat or genetics cause some children to have problems with making insulin is being studied right now.
What are risk factors for diabetes in children?
There are several risk factors for kids who have type 2 diabetes. Being overweight is a risk factor, as is having high blood pressure and/or high cholesterol. Native Americans, Hispanics, African Americans and perhaps Asian Americans are at higher risk. There seem to be more female adolescents who have type 2 diabetes than males. Kids who have family histories of type 2 diabetes are at risk. Another risk factor is maternal gestational diabetes. So if a child's mother had diabetes while she was pregnant, that child is at higher risk of diabetes.
Which kids should be screened for diabetes?
The American Diabetes Association recommends screening for kids who have a body mass index (BMI) greater than the 85th percentile for their age and sex and who have at least two other risk factors. For these children, testing should be done every two years in children starting at age 10 or earlier if puberty begins sooner. This recommendation is being adopted by some institutions but was never tested. At the very least, youth with multiple risk factors and those who have symptoms should be screened.
How is type 2 diabetes diagnosed in children and teenagers?
There are two different ways to test. One of them is with a fasting glucose, which is when blood sugar values are measured after an eight hour fast. The fasting glucose will tell you if someone has a normal blood sugar levels, impaired levels or levels consistent with diabetes. But we know in pediatrics that someone can have a normal fasting glucose, but still have diabetes. So often children are given what's called an oral glucose tolerance test to see if they have diabetes. The children come in and drink a sweet solution, and then they have their blood sugar tested later. We use the same blood sugar cut-offs that are used in adults.
Do adolescents develop diabetes-related complications?
I personally can say that we're seeing some complications, and nationwide there have been reports that just because you're a teenager with type 2 diabetes, that doesn't mean you're immune to the complications. In our clinic, we see high blood pressure, high levels of LDL, the bad cholesterol, and low levels of HDL, the good kind of cholesterol. There is also evidence that some kids are losing protein in their kidneys, which is called proteinuria, which can be predictive of future renal disease in some cases.
How do you treat children with type 2 diabetes?
In kids who come in very critically ill and with very high blood sugars, you begin with insulin therapy. Once you get the blood sugar under control with insulin, you then begin lifestyle changes and oral medication and try to wean them off the insulin.
With the kids in whom diabetes is found incidentally on a routine physical, or who have a few mild symptoms, we start with just exercise and nutrition if it's safe. Then we continue with lifestyle management and add oral medication as needed. And then, as the disease progresses, we may need to start insulin therapy.
There are many different types of insulin therapy. Insulin is only effective when given as an injection just under the skin. There's fast-acting, intermediate-acting and long-acting, and it really depends on the family as to what regimen will work best for them. Most youth are started on three injections a day. For some families, a regimen with two injections a day works best and ensures the best compliance. Other children may want more flexibility in their eating and sleeping schedule, and those kids do best with a regimen that includes five injections a day.
Are there any treatment issues specific to children and adolescents?
We're using some of the same therapies, but we don't have the same experience that we have in adults. Kids tolerate the side effects of medication differently than adults, so you have to adapt the treatments. And compliance with medications is difficult at that age. For instance if a medication causes some abdominal discomfort, you really need to convince kids to stick with it because those symptoms will go away. It's hard for kids to understand their vulnerability and that taking medications can make a difference.
Adolescents also have challenges that are particular to adolescents. One of them is that the impression of their peers is very important. When kids go out to the store to get the snacks after school, the pressure is there often to get the junk food, not the fruit.
What diabetes symptoms should a parent be on the alert for?
If they notice that the child is drinking more or going to the bathroom more, they should contact their pediatrician. Some kids will complain of blurry vision or vague abdominal pain and females may have yeast infections. In severe cases, nausea, vomiting, abdominal pain, and extreme fatigue or confusion can develop.
Many children don't have these symptoms, so the parents of children with excessive weight gain or something called acanthosis nigricans (a darkening or thickening of the skin in the back of the neck or under the arms, thought to be due to high insulin levels), should contact their pediatrician to see if they should be screened for diabetes.
How can parents help their children avoid type 2 diabetes?
The best thing for your family is to be active, eat healthy foods and try to stay within a normal weight for their age and height. This will not only help reduce risk factors for diabetes, but also other health problems that can arise in overweight youth.
My experience as a doctor at Children's Memorial Hospital suggests that gearing healthy foods and activity to just the person who needs to lose weight does not often succeed. So the role of the parents and family cannot be underestimated. Parents set an example for their kids, by making time in their own lives to eat healthy and incorporate exercise into their daily life. Starting young kids off in the right direction with healthy eating and living habits is also important; there is no need to wait until the kids are heavy to make changes.
