Hyperglycemia
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| ICD-10 | R73.9 |
|---|---|
| ICD-9 | 790.6 |
Hyperglycemia, hyperglycaemia, or high blood sugar is a condition in which an excessive amount of glucose circulates in the blood plasma. Hyperglycemia is primarily a symptom of diabetes in which there are elevated levels of blood sugar, or glucose, in the bloodstream. In type I diabetes, hyperglycemia results from malfunctioning in the supply of insulin, the chemical that enables cells to receive energy from glucose; type II diabetes is due to a combination of defective insulin secretion and defective responsiveness to insulin, often termed reduced insulin sensitivity. The term's origin is Greek: hyper-, meaning excessive; -glyc-, meaning sweet; and -emia, meaning "of the blood". It is usually, but not always, associated with diabetes. Chronic hyperglycemia leads to organ damage; acute hyperglycemia can result in life-threatening ketoacidosis. Six million US hospitalizations per year are accompanied by hyperglycemia.[1]
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[edit] Causes
[edit] Diabetic hyperglycemia
Hyperglycaemia is one of the classic symptoms of diabetes mellitus, along with frequent and excessive thirst accompanied by frequent and excessive urination. Hyperglycemia is not exclusive to diabetes mellitus, however, and can often occur independently in the context of many other medical conditions.
Diabetes mellitus occurs in two forms: Type I diabetes, which has peak incidence around puberty and can be caused by a variety of problems, most frequently including an auto-immune disease (in which the body's own antibodies attack and destroy the insulin-producing ß-cells in the islets of Langerhans, which are specialised endocrine tissue in the pancreas), but also other conditions including pancreatitis (which frequently results in digestion of all or part of the pancreas by pancreatic enzymes), a viral infection of the pancreas, or mechanical damage. Type II diabetes is due to a combination of defective insulin secretion and defective responsiveness to insulin, often termed reduced insulin sensitivity.
The most common cause of Type II diabetes and its associated hyperglycemia is obesity, the treatment for which is weight reduction and exercise to reduce the body's excess white fat reserves. These fat reserves interfere with the body's ability to properly absorb and use insulin that is otherwise produced in sufficient quantity. Acute or chronic non-diabetic hyperglycemia can produce the same medical complications as diabetic hyperglycemia.
[edit] Non-diabetic hyperglycemia
Certain eating disorders can produce acute non-diabetic hyperglycemia, as in the binge phase of bulimia nervosa, when the subject consumes a large amount of calories at once, frequently from foods that are high in simple and complex carbohydrates. Certain medications increase the risk of hyperglycemia, including beta blockers, thiazide diuretics, corticosteroids, niacin, pentamidine, protease inhibitors, L-asparaginase,[2] and some antipsychotic agents.[3]
A high proportion of patients suffering an acute stress such as stroke or myocardial infarction may develop hyperglycemia, even in the absence of a diagnosis of diabetes. Human and animal studies suggest that this is not benign, and that stress-induced hyperglycemia is associated with a high risk of mortality after both stroke and myocardial infarction.[4]
[edit] Measurement and definition
Glucose levels are measured in either:
1. Milligrams per deciliter (mg/dL), in the United States and other countries (e.g., Japan, France, Egypt, Columbia); or
2. Millimoles per liter (mmol/L).
Scientific journals are moving towards using mmol/L; some journals now use mmol/L as the primary unit but quote mg/dl in parentheses.[5]
Comparatively:[6]
- 72 mg/dL = 4 mmol/L
- 90 mg/dL = 5 mmol/L
- 108 mg/dL = 6 mmol/L
- 126 mg/dL = 7 mmol/L
- 150 mg/dL = 8 mmol/L
- 180 mg/dL = 10 mmol/L
- 270 mg/dL = 15 mmol/L
- 300 mg/dL = 16 mmol/L
- 360 mg/dL = 20 mmol/L
- 400 mg/dL = 22 mmol/L
- 600 mg/dL = 33 mmol/L
Glucose levels vary before and after meals, and at various times of day; the definition of "normal" varies among medical professionals. In general, the normal range for most people (fasting adults) is about 80 to 120 mg/dL or 4 to 7 mmol/L. A subject with a consistent range above 126 mg/dL or 7 mmol/L is generally held to have hyperglycemia, whereas a consistent range below 70 mg/dL or 4 mmol/L is considered hypoglycemic. In fasting adults, blood plasma glucose should not exceed 126 mg/dL or 7 mmol/L. Sustained higher levels of blood sugar cause damage to the blood vessels and to the organs they supply, leading to the complications of diabetes.
Chronic hyperglycemia can be measured via the HbA1c test. The definition of acute hyperglycemia varies by study, with mmol/L levels from 8 to 15.[7][8]
[edit] Symptoms of hyperglycemia
The presence of these symptoms is associated with hyperglycemia:
- Polyphagia - frequent hunger, especially pronounced hunger
- Polydipsia - frequent thirst, especially excessive thirst
- Polyuria - frequent urination, especially excessive urination
- Blurred vision
- Fatigue
- Weight loss
- Poor wound healing (cuts, scrapes, etc.)
- Dry mouth
- Dry or itchy skin
- Impotence (male)
- Recurrent infections such as vaginal yeast infections, groin rash, or external ear infections (swimmer's ear)
Frequent hunger without other symptoms can also indicate that blood sugar levels are too low. This may occur when people who have diabetes take too much oral hypoglycemic medication or insulin for the amount of food they eat. The resulting drop in blood sugar level to below the normal range prompts a hunger response. This hunger is not usually as pronounced as in Type I diabetes, especially the juvenile onset form, but it makes the prescription of oral hypoglycemic medication difficult to manage.
Symtoms of acute hyperglycemia may include:
- Ketoacidosis
- A decreased level of consciousness or confusion
- Dehydration
- Acute hunger and/or thirst
- Impairment of cognitive function, along with increased sadness and anxiety[9][10]
[edit] Treatment
The treatment of this disease involves lifestyle-directed interventions, insulin, sulfonylurea-based medications, metformin, repaglinide, nateglinide, glucosidase inhibitors, and thiazolidinediones.[11]
[edit] Medical intervention for acute hyperglycemia
Since careful administration of insulin is the principal treatment, immediate medical intervention is advised.
[edit] References
- ^ Hospital admissions accompanied by hyperglycemia
- ^ L-asparaginase-induced hyperglycemia
- ^ JAMA: Drug-induced hyperglycemia
- ^ Stress-induced hyperglycemia
- ^ What are mg/dl and mmol/l? How to convert?
- ^ Mg/dL to mmol/L Conversions
- ^ Acute Stress Hyperglycemia
- ^ Treatment of Acute Hyperglycemia with L-Arginine
- ^ NIH: Mood and cognitive functions during acute euglycaemia and mild hyperglycaemia in type 2 diabetic patients
- ^ Acute Hyperglycemia Alters Mood State and Impairs Cognitive Performance in People with Type 2 Diabetes
- ^ Management of Hyperglycemia in Type 2 Diabetes
