Hyperglycemia Health Article

Definition

Hyperglycemia is a complex metabolic condition characterized by abnormally high levels of blood sugar (blood glucose) in circulating blood, usually as a result of diabetes mellitus (types 1 and 2), although it can sometimes occur in cystic fibrosis and near-drowning (submersion injury).

Description

Hyperglycemia, also known as diabetic ketoacidosis, is a condition that develops over a period of a few days as the blood glucose levels of a type 1 or type 2 diabetic gradually rise. Ketoacidosis occurs when increasing glucose levels are met by a lack of sufficient or effective insulin production, starting a sequence of physiologic events as follows:

• The combination of excess glucose production and low glucose utilization in the body raises levels of blood glucose, which leads to increased urinary output (diuresis) followed quickly by a loss of fluid and essential mineral salts (electrolytes) and, ultimately, dehydration. The loss of fluid may finally result in dehydration. If the entire process is severe enough over several hours (serum glucose levels over 800mg/dL), swelling can occur in the brain (cerebral edema), and coma can eventually result.
• In a metabolic shift to a catabolic (breaking down) process, cells throughout the body empty their electrolytes (sodium, potassium, and phosphate) into the bloodstream. Electrolytes control the fluid balance of the body and are important in muscle contraction, energy generation, and almost all major biochemical reactions in the body. As a result of electrolyte imbalance, many functions can become impaired.
• Free fatty acids from lipid stores are increased, encouraging the production of ketoacids in the liver, leading to an over-acidic condition (metabolic acidosis) that causes even more disruption in body processes.

Without effective treatment of the hyperglycemic episode, the child can lapse into a diabetic coma, which sometimes leads to death.

In diabetes type 2, which is characterized by insulin resistance, enhanced glucose production in the liver and decreased insulin secretion can be aggravated by low physical activity and/or a high-calorie, high-fat diet. Over time as glucose production accelerates, the child develops hyperglycemia or glucotoxicity and lipotoxicity (hyperlipidemia or high fat levels in the blood) as well. It is primarily thought to be a disease affecting sedentary, obese adults over age 40, but it is found in young people as well, most of them obese at the time of diagnosis. Pediatric type 2 diabetes is increasing in the early 2000s among adolescents and has become the fastest growing form of diabetes. Therefore, hyperglycemic episodes are also noted to be increasing in frequency among young people admitted to hospitals for treatment of diabetes.

Demographics

The incidence of hyperglycemia approximately parallels the incidence of diabetes type 1 cases, which represents about 70 percent of all diabetes cases (17 million Americans diagnosed) in the United States. It occurs more in whites than blacks or Asians. About 30 percent of all new cases of diabetes are children with diabetes type 2. Diabetes type 2 occurs more often in African American youth but also in Native Americans, white Americans, and Hispanic youth between ages 10 and 19. Those with type 2 have fewer symptoms and are not treated as frequently for hyperglycemia.

Causes and symptoms

Diabetes is a chronic metabolic disorder with hyperglycemia, gradually rising levels of glucose, as its primary characteristic. As diabetes develops and symptoms increase, hyperglycemia becomes progressive but will occur only occasionally in the carefully managed diabetic patient. Hyperglycemia can be triggered by irregular self-administration of insulin, by insulin resistance or defective insulin response in the body, by stress or infection, and by the activation of certain autoimmune processes characteristic of type 1 diabetes. It occurs in 20 to 40 percent of children newly diagnosed with diabetes and in children who are not yet successfully managed. Many young type 2 diabetics do not have symptoms because their hyperglycemia is moderate compared to type 1 diabetics, and they are not taking insulin.

The first signs of hyperglycemia or ketoacidosis are frequent urination and increased thirst. The child may then show any of the following symptoms:

• flushed face
• dry skin
• dry mouth
• headache
• abdominal pain
• nausea and vomiting
• drowsiness and lethargy
• blurred vision
• fruity-smelling breath
• rapid heartbeat
• deep and labored breathing

When to call the doctor

The pediatrician or family doctor should be consulted about any sudden change in the child's urinary output, frequency of urination, or increased thirst, especially if accompanied by dry skin or mouth, flushed face, headache, abdominal pain, nausea or vomiting, unusual drowsiness and lack of movement, rapid heartbeat, or difficulty breathing. Parents should be aware of the last insulin injection if the child is on insulin therapy.