Diagnosing Type 2 Diabetes in Children

Doctors at Hassenfeld Children’s Hospital at NYU Langone have extensive experience diagnosing type 2 diabetes in children. This chronic condition is characterized by excess blood sugar.

After you eat, the body breaks down sugars and starches into glucose, the main source of energy for cells. When glucose enters the bloodstream, the pancreas releases a hormone called insulin, which signals the liver, muscles, and fat cells to remove the glucose from the blood and store it until the body needs energy.

If the body becomes less responsive to the effects of insulin—a condition known as insulin resistance—the pancreas compensates and produces more insulin. With insulin resistance, the body has difficulty absorbing sugar from the bloodstream, leading to an increase in blood sugar levels, a condition known as prediabetes.

Type 2 diabetes occurs when the body stops responding to the insulin signal and the pancreas can no longer make enough insulin to compensate for rising blood sugar levels.

Causes and Risk Factors

Once referred to as adult-onset diabetes, type 2 diabetes has become increasingly common during childhood and adolescence. This trend appears to be linked to an increase in obesity and sedentary habits among children and teens.

Although the exact cause of insulin resistance is not completely understood, evidence suggests that being overweight plays an important role. This is because fat cells—especially those found in the abdomen—produce hormones and other substances that increase inflammation in the body, which can lead to insulin resistance.

Being inactive, which can contribute to weight gain and lower muscle mass, may be another cause of insulin resistance.

Girls with a hormone condition called polycystic ovary syndrome—which can cause facial hair and the development of noncancerous growths in the ovaries—are at higher risk for insulin resistance. As with type 2 diabetes, being overweight or obese is a risk factor for polycystic ovary syndrome.

Type 2 diabetes is more common in children and teens from certain ethnic groups. Risk factors include being an African American, Hispanic, indigenous American, and Asian American. Doctors aren’t exactly sure why these ethnic groups are more susceptible to type 2 diabetes, but higher rates of obesity among these populations may be a factor.

Although the condition can develop in the preteen years, the risk is greater during puberty, when an increase in sex hormones and growth hormone can lead to insulin resistance.

If a child had a low birth weight or a mother had diabetes during pregnancy—both of which can affect pancreas development—the child may have a higher risk of developing type 2 diabetes. Many children with the condition have a family history of diabetes, suggesting there may be a genetic predisposition.

Signs and Symptoms

Because type 2 diabetes often develops slowly, you and your child may not notice symptoms at first. The most common symptoms are frequent urination, which is caused by the kidneys’ efforts to eliminate excess sugar, and increased thirst, due to the loss of fluid through urination. In some instances, high blood sugar and low insulin levels may cause swelling in blood vessels in the eyes, which can make your child’s vision blurry.

Insulin resistance can make your child feel tired, because the body’s cells are not getting the energy they need. Girls may develop yeast infections, which are fueled by excess sugar in the body.

Insulin resistance can also lead to the development of pseudoacanthosis nigricans, which are noncancerous, dark patches of skin that may appear under the arms, on the back of the neck, over finger and toe joints, and in the groin.

Some children with insulin resistance or type 2 diabetes may develop metabolic syndrome, which is a group of conditions. These include hypertension, or high blood pressure, and hyperlipidemia, an abnormally high concentration of fats or lipids in the blood.

Over time, children with metabolic syndrome have an increased risk of developing medical conditions that are more common in adults, such as heart disease, a buildup of fatty deposits in the blood vessels known as atherosclerosis, kidney disease, liver inflammation, and damage to nerves and blood vessels throughout the body.

In fact, more than 10 percent of children diagnosed with type 2 diabetes develop hypertension. Nearly 7 percent have early signs of kidney damage. More than 3 percent have higher-than-normal levels of low-density lipoproteins, a type of cholesterol that can lead to heart disease.

Children with type 2 diabetes who can no longer make insulin may develop diabetic ketoacidosis, which occurs when the body’s cells don’t get the sugar they need for energy. Symptoms of the condition include a fruity breath odor, difficulty breathing, confusion, and a loss of appetite or vomiting. Without immediate treatment, ketoacidosis can be life threatening.

Pediatric endocrinologists at NYU Langone use a variety of tests to diagnose type 2 diabetes.

Physical Exam

During a physical exam, the doctor measures your child’s height and weight and looks to see whether your child carries most of his or her fat around the belly. This information allows the doctor to calculate your child’s body mass index, or BMI—a measure of body fat based on a person’s height and weight.

The doctor takes your child’s blood pressure and may shine a small light into your child’s eyes to look for swelling in the blood vessels that nourish the retina. A skin exam can reveal if your child has dark patches of skin, called pseudoacanthosis nigricans.

Blood Tests

Our doctors perform several blood tests, using blood samples drawn in the doctor’s office, to diagnose type 2 diabetes and identify complications. Blood test results are available within 24 hours. The doctor typically starts with the random or fasting blood sugar test and a hemoglobin A1C test.

Random Blood Sugar Test

A test to measure blood sugar using a blood sample obtained at any time of day, regardless of when your child has eaten, is known as a random blood sugar test. A blood sugar level of 200 (expressed in milligrams per deciliter) or higher means your child has diabetes.

Fasting Blood Sugar Test

In a fasting blood sugar test, the doctor measures the amount of sugar in your child’s blood after he or she has not eaten or had anything to drink but water for several hours, usually overnight. A fasting blood sugar level of 100 to 125 milligrams per deciliter suggests that your child has prediabetes. A fasting blood sugar level of 126 or higher confirms that your child has type 2 diabetes.

Hemoglobin A1C Blood Test

The hemoglobin A1C test measures a person’s average blood sugar level over a period of two or three months. Specifically, this test measures the percentage of blood sugar that is attached to hemoglobin, a protein in red blood cells.

Because the sugar remains attached to hemoglobin for up to four months, it’s a good indicator of average blood sugar levels. A result of 5.7 percent on two separate tests suggests that your child has prediabetes. A result of 6.5 percent or higher indicates that your child has type 2 diabetes.

Insulin Test

If your child has high blood sugar, the doctor may suggest another blood test that measures insulin levels to distinguish between type 1 and type 2 diabetes. This can also help to determine the most effective treatment.

Type 1 diabetes is an autoimmune condition that prevents the pancreas from making insulin. In people with type 2 diabetes, however, the pancreas generally makes more insulin to compensate for insulin resistance. Eventually, however, overproduction of insulin stops, as the pancreas is no longer able to produce enough insulin.

Additional Blood Tests

Our doctors may perform additional blood tests to rule out other conditions that may cause similar symptoms and to determine your child’s risk of complications.

For example, a thyroid function test can rule out hypothyroidism, a condition in which the body doesn’t produce enough thyroid hormone. This can cause weight gain. A blood lipid test may determine if your child has hyperlipidemia. A blood urea nitrogen test, often called the BUN test, may be used to see how well your child’s kidneys are filtering wastes from the blood.

A liver enzyme test can look for signs of nonalcoholic fatty liver disease, an accumulation of fat in the liver that can occur in people who are obese. Over time, this condition can cause inflammation and scarring in the liver.

Oral Glucose Tolerance Test

Doctors may recommend an oral glucose tolerance test to determine whether your child has prediabetes or diabetes.

After your child has fasted overnight, a doctor or nurse takes a blood sample and measures your child’s blood sugar level. Your child then drinks a sugary liquid. About two hours later, the staff takes another blood sample to see how much your child’s blood sugar level has changed.

A level of 200 milligrams per deciliter or higher after 2 hours confirms a diagnosis of diabetes. A level of 140 to 199 suggests prediabetes.

Urine Tests

The doctor may request a urine test to look for signs of ketoacidosis if your child has been diagnosed with diabetes and has had an unexplained, rapid weight loss or a recent illness.

A staff member gives you a sterile cup to obtain a sample of your child’s urine and inserts a paper test strip or a tablet into the urine to look for the presence of ketones. These are acids from fats that the body tries to use for energy when insulin production stops.

Doctors may also recommend other tests. For instance, your doctor may want to determine whether albumin, a type of protein found in the blood, has leaked into your child’s urine. Albumin in the urine may indicate that the kidneys are not filtering the blood properly, which can lead to hypertension and kidney disease.

Our specialists use the results of these tests to determine the best treatment for your child. During follow-up visits, they may perform additional blood and urine tests as well as check your child’s height, weight, and blood pressure.

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