Diseases & Conditions


Diabetes Mellitus (DM)

Diabetes mellitus is a disorder in which blood sugar (glucose) levels are abnormally high because the body does not produce enough insulin.

The symptoms, diagnosis, and treatment of diabetes are similar in children and adults (see Diabetes Mellitus (DM): Diabetes Mellitus ). However, management of diabetes in children may be more complex. It must be tailored to the child's physical and emotional maturity level and to constant variations in food intake, physical activity, and stress.

Insulin Some Trade Names HUMULIN NOVOLIN is a hormone that is released by the pancreas. Insulin Some Trade Names HUMULIN NOVOLIN controls the amount of sugar (glucose) in the blood. A child with diabetes has high blood sugar levels either because the pancreas produces little or no insulin Some Trade Names HUMULIN NOVOLIN (type 1 diabetes, formerly called juvenile-onset diabetes) or because the body is insensitive to the amount of insulin Some Trade Names HUMULIN NOVOLIN that is produced (type 2 diabetes). In either case, the amount of insulin Some Trade Names HUMULIN NOVOLIN available is insufficient for the body's needs.

Type 1 diabetes can develop at any time during childhood, even during infancy, but it usually begins between ages 6 and 13 years. Type 2 diabetes occurs mainly in adolescents but is becoming increasingly common in overweight or obese children.

Up until the 1990s, more than 95% of children who developed diabetes had type 1 diabetes, usually because the immune system attacked the cells in the pancreas that make insulin Some Trade Names HUMULIN NOVOLIN (islet cells). Such an attack may be triggered by environmental factors in people whose genetic make-up leaves them susceptible. Recently, the number of children, especially adolescents, with type 2 diabetes has been steadily increasing. Today, 10 to 50% of children newly diagnosed with diabetes have type 2 diabetes. The increase in childhood type 2 diabetes has been particularly prominent among Native Americans, blacks, and Hispanics. Obesity and a family history of type 2 diabetes are major factors in the development of type 2 diabetes (but not type 1).

Which Children Are at Risk of Type 2 Diabetes?

Children and adolescents meeting these criteria should be tested with a fasting blood sugar test every 2 years beginning at about age 10: Being overweight (weighing more than 85% of children of similar age, sex, and height or weighing more than 120% of the ideal weight for height)

Plus any two of the following factors: Having a close relative with type 2 diabetes Being Native American, black, Hispanic, or Asian/Pacific Islander Having high blood pressure, high blood levels of lipids (fats), or polycystic ovary syndrome

In newborns who are very underweight, blood sugar levels may be elevated transiently, usually because they are given intravenous infusions of glucose too rapidly. The infusions are given to increase the newborn's weight. This problem usually resolves on its own.


High blood sugar levels are responsible for a variety of immediate symptoms and long-term complications.

Symptoms develop quickly in type 1 diabetes, usually over 2 to 3 weeks or less, and tend to be quite obvious. High blood sugar levels cause the child to urinate excessively. This fluid loss causes an increase in thirst and the consumption of fluids. Some children become dehydrated, resulting in weakness, lethargy, and a rapid pulse. Vision may become blurred.

Diabetic ketoacidosis occurs at the beginning of the disease in about one third of children with type 1 diabetes. Without insulin Some Trade Names HUMULIN NOVOLIN , cells cannot use the sugar that is in the blood. Cells switch to a back-up mechanism to obtain energy and break down fat, producing compounds called ketones as by-products. Ketones make the blood too acidic (ketoacidosis), causing nausea, vomiting, fatigue, and abdominal pain. The ketones make the child's breath smell like nail polish remover. Breathing becomes deep and rapid as the body attempts to correct the blood's acidity (see Acid-Base Balance: Introduction ). Some children develop a headache and may become confused or less alert. These symptoms may be caused by accumulation of fluid in the brain (cerebral edema). Diabetic ketoacidosis can progress to coma and death. Children with diabetic ketoacidosis are also dehydrated and often have other chemical imbalances in the blood, such as an abnormal level of potassium and high levels of lipids (fats).

Symptoms in children with type 2 diabetes are milder than those in type 1 diabetes and develop more slowly—over weeks or even a few months. Parents may notice an increase in the child's thirst and urination or only vague symptoms, such as fatigue. Typically, children with type 2 diabetes do not develop ketoacidosis or severe dehydration.


Doctors suspect diabetes when children have typical symptoms or when a urine test done during a routine physical examination reveals sugar. The diagnosis is confirmed by measurement of the blood sugar level. Preferably, the blood test is done after the child fasts overnight. A child is considered to have diabetes if the fasting blood sugar level is 126 milligrams per deciliter (mg/dL) or higher. Sometimes, doctors also do tests to see whether the blood is too acidic or contains ketones. Rarely, doctors order a blood test that detects antibodies to islet cells to help distinguish type 1 diabetes from type 2.

Because prompt measures (such as dietary changes, an increase in physical activity, and weight loss) may help prevent or delay the onset of type 2 diabetes, children at risk should be screened with a blood test. Nothing can be done to prevent type 1 diabetes.

Breaking Down Sugar

There are many kinds of sugar. The white granules of table sugar are known as sucrose. Sucrose occurs naturally in sugar cane and sugar beets. Another kind of sugar, lactose, occurs in milk. Sucrose consists of two different simple sugars, glucose and fructose. Lactose consists of the simple sugars glucose and galactose. Sucrose and lactose must be broken down by the intestine into their simple sugars before they can be absorbed. Glucose is the main sugar the body uses for energy, so during and after absorption, most sugars are turned into glucose. Thus, when doctors talk about blood sugar, they are really talking about blood glucose.


The main goal of treatment is to keep blood sugar levels as close to the normal range as can be done safely. To control blood sugar, children with type 1 diabetes take insulin Some Trade Names HUMULIN NOVOLIN , and children with type 2 diabetes take drugs given by mouth. Children with either type of diabetes need to change their diet, exercise regularly, and, if overweight, lose weight.

When type 1 diabetes is first diagnosed, children are usually hospitalized, and those with diabetic ketoacidosis are treated in an intensive care unit. Children with type 1 diabetes are given fluids (to treat dehydration) and insulin Some Trade Names HUMULIN NOVOLIN . They always require insulin Some Trade Names HUMULIN NOVOLIN because nothing else is effective. Those with ketoacidosis require insulin Some Trade Names HUMULIN NOVOLIN intravenously for a brief time. Those without ketoacidosis typically receive two or more daily injections of insulin Some Trade Names HUMULIN NOVOLIN , although some children may need to receive insulin Some Trade Names HUMULIN NOVOLIN continuously by a small infusion pump through a needle under the skin. Insulin Some Trade Names HUMULIN NOVOLIN treatment is usually begun in the hospital so that blood sugar levels can be tested often and doctors can change insulin Some Trade Names HUMULIN NOVOLIN dosage in response. Rarely, treatment is started at home.

Children with type 2 diabetes do not usually need to receive treatment in the hospital. They do require treatment with drugs to lower blood sugar levels (antihyperglycemic drugs), which are taken by mouth. The drugs used for adults with type 2 diabetes (see Oral Antihyperglycemic Drugs ) are safe for children, although some of the side effects—particularly diarrhea—cause more problems in children. Some children with type 2 diabetes need insulin Some Trade Names HUMULIN NOVOLIN . A few children who lose weight, improve their diet, and exercise regularly may be able to stop taking the drugs.

Nutritional management and education are particularly important for all children with diabetes. Because carbohydrates in food are turned into glucose by the body, variations in carbohydrate intake cause variations in blood sugar levels. Large amounts of sugar, as is present in soda, candy, and pastries, are discouraged because blood sugar may rise too high. Parents and older children are taught how to gauge the carbohydrate content of food and adjust what children eat as needed to maintain a consistent daily intake of carbohydrates. Children of all ages may find it difficult to consistently follow a properly balanced meal plan (consumed at regular intervals) and avoid the temptations of sugary snacks. Infants and preschool-aged children present a particular challenge to parents because of the concern arising from the dangers of frequent and very low blood levels sugar (hypoglycemia).

Adolescence: Adolescents may have particular problems controlling their blood sugar levels because of: Hormonal changes during puberty: These changes affect how the body responds to insulin. As a result, higher doses are usually needed during this time. Adolescent lifestyle: Peer pressure, increased activities, erratic schedules, concern about body image, or eating disorders may interfere with the prescribed treatment regimen, particularly their meal plan. Experimentation with alcohol, cigarettes, and illicit drugs: Adolescents who experiment with these substances may neglect their treatment regimen. Conflicts with parents and other authority figures: Such conflicts may make adolescents less willing to follow their treatment regimen.

Thus, some adolescents need for a parent or another adult to recognize these issues and give them the opportunity to discuss problems with a health care practitioner. The practitioner can make sure adolescents remain appropriately focused on keeping their blood sugar levels under control. Parents and health care practitioners should encourage adolescents to check their blood sugar levels frequently.

Support: Emotional issues affect children with diabetes and their families. The realization that they have a lifelong condition may cause some children to become sad or angry, and sometimes even deny that they have an illness. A doctor, psychologist, or counselor needs to address these emotions to secure the child's cooperation in adhering with the required regimen of meal plan, physical activity, blood sugar testing, and drugs. Failure to resolve these issues can lead to difficulties with blood sugar control.

Summer camps for children with diabetes allow these children to share their experiences with one another while learning how to become personally more responsible for their condition.

For the treatment of diabetes, the child's primary care doctor usually enlists the aid of a team of other professionals, possibly including a pediatric endocrinologist, dietitian, diabetes educator, social worker, or psychologist. Family support groups may also help. The doctor may provide parents with information to bring to school so that school personnel understand their roles.

Monitoring Treatment: Children and parents are taught to monitor the blood sugar level at least 4 times a day using a blood sample obtained by pricking a fingertip or the forearm with a small implement called a lancet. Once experience is gained, parents and many children can adjust the insulin Some Trade Names HUMULIN NOVOLIN dose as needed to achieve the best control. In general, by 10 years of age, children start to become interested in testing their own blood sugar levels and injecting insulin Some Trade Names HUMULIN NOVOLIN themselves. Parents should encourage this independence but make sure the child is being responsible. Doctors teach most children how to adjust their insulin Some Trade Names HUMULIN NOVOLIN dosage in accordance with the patterns of their home blood sugar records.

Children with diabetes typically see their doctor 4 times a year. The doctor evaluates their growth and development, reviews blood sugar records that the family member keeps, provides guidance and counseling about nutrition, and measures glycosylated hemoglobin (hemoglobin A 1c )—a substance in the blood that reflects blood sugar levels over the long term. The doctor screens for long-term complications (see Diabetes Mellitus (DM): Complications ) once a year by measuring protein in the urine, assessing function of the thyroid gland, and performing neurologic and eye examinations.

Some children with diabetes do very well and control their diabetes without undue effort or conflict. In others, diabetes becomes a constant source of stress within the family, and control of the condition deteriorates. Adolescents in particular often find it difficult to follow the prescribed treatment regimen given the demands on their schedule and the limitations on their freedom that arise from diabetes. An adolescent benefits if the doctor considers the adolescent's desired schedule and activities and takes a flexible approach to problem solving—working with the adolescent rather than imposing solutions.

Complications of Treatment and Illness: No treatment completely maintains blood sugar at normal levels. The goal of treatment is to avoid blood sugar levels that are too high and too low. The complications of diabetes include coronary artery disease, kidney failure, blindness, peripheral vascular disease, and other serious disorders. Although these events take years to develop, the better the control of diabetes, the less likely that complications will ever occur.

Low blood sugar (hypoglycemia (see Hypoglycemia ) occurs when too much insulin Some Trade Names HUMULIN NOVOLIN or too much of an antihyperglycemic drug is taken or when the child does not eat regularly or engages in unusually vigorous and sustained exercise. Hypoglycemia produces weakness, confusion, and even coma. In adults, adolescents, and older children, episodes of hypoglycemia rarely cause long-term problems. However, frequent episodes of hypoglycemia in children younger than 5 may permanently impair intellectual development. Also, young children may not be aware of the warning symptoms of hypoglycemia. To minimize the possibility of hypoglycemia, doctors and parents monitor young children with diabetes particularly closely and use a slightly higher target range for their blood sugar level.

Children and adolescents with type 1 diabetes who miss insulin Some Trade Names HUMULIN NOVOLIN injections may develop diabetic ketoacidosis within days. The long-term insufficient or inadequate use of insulin Some Trade Names HUMULIN NOVOLIN can lead to a syndrome of stunted growth, delayed puberty, and an enlarged liver (Mauriac syndrome).

Last full review/revision April 2007 by Nicholas Jospe, MD

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Introduction: Hereditary Metabolic Disorders: Merck Manual Home Edition


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