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==Historical Perspective== | ==Historical Perspective== | ||
In 1922, Hypoglycemia was first discovered by James Collip when he was working on purifying insulin. Collip discovered that injection of a large dose of insulin into a rabbit, the rabbit got into a coma and died. | |||
==Classification== | ==Classification== | ||
Revision as of 18:40, 25 July 2017
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Mohammed Abdelwahed M.D[2]
Overview
Hypoglycemia is a medical term referring to a pathologic state produced by a lower than normal level of glucose (sugar) in the blood. No single glucose value alone serves to define the medical condition termed hypoglycemia for all people and purposes. Although 60 or 70 mg/dL (3.3 or 3.9 mmol/L) is commonly cited as the lower limit of normal glucose, different values (typically below 40, 50, 60, or 70 mg/dL) have been defined as low for different populations, clinical purposes, or circumstances.
Historical Perspective
In 1922, Hypoglycemia was first discovered by James Collip when he was working on purifying insulin. Collip discovered that injection of a large dose of insulin into a rabbit, the rabbit got into a coma and died.
Classification
Hypoglycemia can be classified by severity into severe hypoglycemia, symptomatic hypoglycemia, asymptomatic hypoglycemia, probable symptomatic hypoglycemia and pseudo-hypoglycemia.
Pathophysiology
Pathogenesis of hypoglycemia depends on the failure of physiological defense mechanisms and hormones such as insulin, glucagon and epinephrine. This leads to low glucose level that affects primarily the brain causing nervous symptoms.
Causes
Causes of hypoglycemia depend on age; neonatal causes are transient neonatal hypoglycemia, Prematurity, intrauterine growth retardation, perinatal asphyxia., sepsis, congenital hypopituitarism, beta sympathomimetic drugs, congenital hyperinsulinism, infant of a diabetic mother, Beckwith-Wiedemann syndrome and inborn errors of carbohydrate metabolism.
Cause of adult hypoglycemia are: Insulin or insulin secretagogue drugs, alcohol, hepatic, renal, or cardiac failure, sepsis, Nonislet cell pancreatic tumors, insulinoma, reactive hypoglycemia, post gastric bypass hypoglycemia, autoimmune hypoglycemia.
Differentiating Hypoglycemia from other Diseases
Hypoglycemia should be differentiated from other causes of autonomic hyper activity symptoms. Physicians should have history, signs and laboratory results sufficient to help them to identify the cause of hypoglycemia. Neonatal hypoglycemia should be differentiated from other causes of neurological symptoms in neonates such as sepsis, metabolic diseases: urea cycle disorders, and branched-chain organic acidemias, hyponatremia and neonatal asphyxia.
Epidemiology and Demographics
- Patients with type 1 diabetes may suffer an average of two episodes of symptomatic hypoglycemia per week, thousands of such episodes over a lifetime of diabetes, and one episode of severe symptoms per year. Hypoglycemia is less frequent in type 2 diabetes than it is in type1.[2] Event rate for severe hypoglycemia range from 40 to 100 percent of those in type 1 diabetes.[4]
Risk Factors
Risk factors of hypoglycemia include diabetic patients with excessive insulin doses especially after missed meals or after exercise, nocturnal or with alcohol. Absolute endogenous insulin deficiency is another risk factor.
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Hypoglycemic symptoms and manifestations can be divided into those produced by the counterregulatory hormones: adrenergic Manifestations: anxiety, nervousness, tremor, Palpitations, Sweating, coldness. Glucagon Manifestations: Hunger, nausea, vomiting. Neuroglycopenic Manifestations: irritability, weakness, apathy, lethargy Confusion, amnesia.
Physical Examination
Main signs of hypoglycemia are attacks of diaphoresis, tachycardia, tachypnea, hypertension, hypothermia and neurological deficits.
Laboratory Findings
Laboratory investigations of hypoglycemia depend on many tests: plasma glucose should be <55 mg/dL, insulin, c-peptide, proinsulin, sulfonylurea screen, beta-hydroxybutyrate, 24-hour fasting then identifying the cause.
Electrocardiogram
There are no EKG findings in hypoglycemia.
Chest X Ray
There is no x-ray findings in hypoglycemia.
CT
Ultrasound, Computed tomography and MRI can differentiate between insulinoma and islet-cell hypertrophy.
MRI
MRI may be indicated for insulinoma in the case of failed CT.
Echocardiography or Ultrasound
Other Imaging Findings
Other Diagnostic Studies
Other tests include: injection of calcium gluconate into splanchnic arteries and venous sampling searching for insulin.
Treatment
Medical Therapy
Medical treatment of hypoglycemia depends on the severity of symptoms and the cause. If asymptomatic, repeating the measurement in short time and avoiding critical tasks. Twenty grams is usually sufficient to raise the blood glucose Severe in symptomatic patients. Subcutaneous or intramuscular injection or 25% dextrose intravenously. If postprandial hypoglycemia, the patient should have frequent small meals or snacks and foods should be high in fiber, avoiding foods high in sugar. Surgery is the best treatment for insulinoma.
Surgery
Surgical removal of the overactive part of the pancreas is curative with minimal risk when hyperinsulinism is focal or due to a benign insulin-producing tumor of the pancreas. When congenital hyperinsulinism is diffuse and refractory to medications, near-total pancreatectomy may be the treatment of last resort, but in this condition is less consistently effective and fraught with more complications.
Primary Prevention
The main issue is patient education about nature, symptoms, how to measure glucose level and how to treat. Reactive hypoglycemia prevention depends on changing eating patterns smaller meals and avoiding excessive sugar.
Secondary Prevention
Secondary Prevention is the same as primary prevention.