The number of children (and adults) with type 2 diabetes mellitus has been growing considerably in recent years. This condition used to be known as "adult-onset diabetes" because it was so uncommon among children and adolescents. Since the 1990s, however, more cases of type 2 diabetes mellitus are being diagnosed in children than ever before.
Type 2 is the most common form of diabetes mellitus in the United States, affecting more than 25 million people. Both type 1 and type 2 diabetes cause high amounts of sugar (glucose) to circulate in the blood. Insulin produced by the pancreas is required to move sugar from the blood into the body's cells, where the sugar is used to create energy. People with type 1 diabetes do not make enough insulin. People with type 2 diabetes initially make plenty of insulin, but their cells are "resistant" to the action of insulin — the cells do not respond properly and high levels of sugar build up in their blood. Persistently high blood sugars make it hard for the body to fight infections and, over time, damage nerves and blood vessels, causing problems with the heart, brain, eyes, kidneys, feet, as well as other parts of the body.
Some people believe it may be related to changes in children's diets, activity levels, and weights. Children, like adults, are eating more calories than ever before. At the same time, children are getting less exercise, both in school and at home. Higher calorie diets and less exercise together means there are more children who are very overweight in the United States (and in many other nations). In fact, it now is estimated that one child out of every three in the United States is at least somewhat overweight.
Studies have shown that being overweight and not active enough (exercising less than three times per week) greatly increase the chance of developing type 2 diabetes. Diabetes tends to run in families; having a parent or sibling with diabetes or being part of certain ethnic groups (African-American, American Indian, Asian-American, Pacific Islander or Hispanic-American/Latino) increases the chance of developing type 2 diabetes.
Most people with type 2 diabetes, including children and adolescents, have no signs or symptoms, or their symptoms are so mild that they are not even noticed. Some people do have symptoms, which may include: increased thirst, increased hunger, increased urination (especially at night, when a child who was previously dry might start to wet the bed), extreme tiredness (fatigue), blurred vision, or cuts and sores that do not heal well. In addition, children may be losing weight without a clear reason why it is happening, while still eating the same amount of calories and exercising as much as before.
Some adolescents with type 2 diabetes, particularly those who are overweight, have areas of dark, thickened, velvety skin in the folds of the neck or abdomen, under the arms, inside the elbow, or on the inner thighs. This condition, called acanthosis nigricans, is associated with persistently high insulin levels in the blood and marked insulin resistance.
High blood pressure, abnormal cholesterol and triglyceride blood levels, and irregular menstrual periods (caused by polycystic ovary syndrome) also may be signs of type 2 diabetes.
Type 2 diabetes mellitus should be treated by improving diet (making wise food choices), exercising more regularly, losing weight, and maintaining normal blood pressure. Many people with type 2 diabetes are able to manage with these lifestyle changes alone, but others may need to take diabetes medicines by mouth or shots of insulin to control how much sugar is in the blood.
Studies suggest that people at high risk of type 2 diabetes can delay or possibly prevent it from ever happening by eating a healthy diet, not allowing body mass index to rise above 25, and getting regular exercise. Losing weight, lowering blood pressure, and lowering cholesterol also can lower the risk of complications should blood sugars begin to rise.
Type 2 diabetes is a serious illness that unfortunately is becoming more common in children. While certain children are more likely to get this disease than others (for example, because of their background), all children (and adults) can lower their risk by eating healthier foods and getting regular exercise.
Children and adolescents who are overweight and who have risk factors for diabetes (as discussed above: family history, ethnic group, acanthosis, polycystic ovary syndrome, high blood pressure or cholesterol problems) should be especially careful to get enough exercise and eat right, and should see their health care professional regularly so that he or she can check for early signs of diabetes.
Henry H. Bernstein, D.O., is is a senior lecturer in Pediatrics at Harvard Medical School. In addition, he is chief of General Academic Pediatrics at Children's Hospital at Dartmouth and professor of pediatrics at Dartmouth Medical School. He is the former associate chief of General Pediatrics and director of Primary Care at Children's Hospital Boston.