Hypoglycemia

Hypoglycemia, also called low blood sugar or low blood glucose, is a blood-sugar level below 70 mg/dL (3.9 mmol/L). • A low blood glucose measurement is present, typically less than 70 mg/dL (3.9 mmol/L) After the first 48 hours of life, the Pediatric Endocrine Society cites that there is little difference in blood glucose level and the use of glucose between adults and children. Whipple's triad is used to identify hypoglycemia in children who can communicate their symptoms. ==Signs and symptoms==

Hypoglycemic symptoms are divided into two main categories. The first category is symptoms caused by low glucose in the brain, called neuroglycopenic symptoms. The second category of symptoms is caused by the body's reaction to low glucose in the blood, called adrenergic symptoms. Everyone experiences different symptoms of hypoglycemia, so someone with hypoglycemia may not have all of the symptoms listed above. Symptoms also tend to have quick onset. It is important to quickly obtain a blood glucose measurement in someone presenting with symptoms of hypoglycemia to properly identify the hypoglycemic episode. ==Causes==

Hypoglycemia is most common in those with diabetes treated by insulin, glinides, and sulfonylureas. As diabetics experience more episodes of hypoglycemia, the blood glucose level which triggers symptoms of hypoglycemia decreases. Other causes Other causes of hypoglycemia in diabetics include the following: • Fasting, whether it be a planned fast or overnight fast, as there is a long period of time without glucose intake Severe disease of many organ systems can cause hypoglycemia as a secondary problem. Moderate quality evidence implicates the non-steroidal anti-inflammatory drug indomethacin and the anti-malarial quinine. Some people may use insulin to induce weight loss, whereas for others this may be due to malingering or factitious disorder, which is a psychiatric disorder. Inborn errors of metabolism may cause infant hypoglycemia, and much less commonly adult hypoglycemia. as for example in combined malonic and methylmalonic aciduria (CMAMMA), propionic acidemia, and carcinoid tumors. Antibodies are immune proteins produced by the body, that normally attack bacteria and viruses, but sometimes can attack normal human cells, leading to an autoimmune disorder. In autoimmune hypoglycemia, there are two possible mechanisms. In one instance, antibodies bind to insulin following its release associated with a meal, resulting in insulin being non-functional. At a later time, the antibodies fall off insulin, causing insulin to be functional again leading late hypoglycemia after a meal, called late postprandial hypoglycemia. Another mechanism causing hypoglycemia is due to antibodies formed against insulin receptors, called insulin receptor antibodies. The antibodies attach to insulin receptors and prevent insulin breakdown, or degradation, leading to inappropriately high insulin levels and low glucose levels. Neonatal hypoglycemia Low blood sugar may occur in healthy neonates aged less than 48 hours who have not eaten for a few hours. During the 48-hour neonatal period, the neonate adjusts glucagon and epinephrine levels following birth, which may trigger transient hypoglycemia. In children who are aged greater than 48 hours, serum glucose on average ranges from 70 to 100 mg/dL (3.9–5.5 mmol/L), similar to adults, with hypoglycemia being far less common. ==Pathophysiology==

Glucose is the main source of energy for the brain, and a number of mechanisms are in place to prevent hypoglycemia and protect energy supply to the brain. If increased glucagon does not raise blood sugar levels to normal, the adrenal glands release epinephrine. Epinephrine works to also increase gluconeogenesis and glycogenolysis, while also decreasing the use of glucose by organs, protecting the brain's glucose supply. After hypoglycemia has been prolonged, cortisol and growth hormone are released to continue gluconeogenesis and glycogenolysis, while also preventing the use of glucose by other organs. The effects of cortisol and growth hormone are far less effective than epinephrine. In a state of hypoglycemia, the brain also signals a sense of hunger and drives the person to eat, in an attempt to increase glucose. ==Diagnosis==

The most reliable method of identifying hypoglycemia is through identifying Whipple's triad. • Cardiac arrhythmia ==Treatment==

After hypoglycemia in a person is identified, rapid treatment is necessary and can be life-saving. This results in the greatest bioavailability of glucose, meaning the greatest amount of glucose enters the body producing the best possible improvements in blood glucose levels. This same review reported that, based on limited evidence, no difference was found in plasma glucose when administering combined oral and buccal glucose (via dextrose gel) compared to only oral administration. Emergency services should be called for further assistance. If a patient is conscious and able to swallow safely, food or drink may be administered, as well as glucose tabs or gel. Dasiglucagon (brand name Zegalogue) is unique because it is glucagon in a prefilled syringe or auto-injector pen, as opposed to traditional glucagon kits that require mixing powdered glucagon with a liquid. ==Prevention==

Diabetics The prevention of hypoglycemia depends on the cause. Insulin pumps help to prevent high glucose spikes, and help prevent inappropriate insulin dosing. Continuous glucose monitors can sound alarms when blood glucose is too low or too high, especially helping those with nocturnal hypoglycemia or hypoglycemic unawareness. In terms of medication adjustments, medication doses and timing can be adjusted to prevent hypoglycemia, or a medication can be stopped altogether. Non-diabetics In those with hypoglycemia who do not have diabetes, there are a number of preventative measures dependent on the cause. Hypoglycemia caused by hormonal dysfunction like lack of cortisol in Addison's disease or lack of growth hormone in hypopituitarism can be prevented with appropriate hormone replacement. The hypoglycemic episodes associated with non-B cell tumors can be decreased following surgical removal of the tumor, as well as following radiotherapy or chemotherapy to reduce the size of the tumor. In some cases, those with non-B cell tumors may have hormone therapy with growth hormone, glucocorticoid, or octreotide to also lessen hypoglycemic episodes. Post-gastric bypass hypoglycemia can be prevented by eating smaller, more frequent meals, avoiding sugar-filled foods, as well as medical treatment with an alpha-glucosidase inhibitor, diazoxide, or octreotide. Some causes of hypoglycemia require treatment of the underlying cause to best prevent hypoglycemia. This is the case for insulinomas which often require surgical removal of the tumor for hypoglycemia to remit. In patients who cannot undergo surgery for removal of the insulinoma, diazoxide or octreotide may be used. == Epidemiology ==

Hypoglycemia is common in people with type 1 diabetes, and in people with type 2 diabetes taking insulin, glinides, or sulfonylurea. It is estimated that type 1 diabetics experience two mild, symptomatic episodes of hypoglycemia per week. Additionally, people with type 1 diabetes have at least one severe hypoglyemic episode per year, requiring treatment assistance. In terms of mortality, hypoglycemia causes death in 6–10% of type 1 diabetics. In those with type 2 diabetes, hypoglycemia is less common compared to type 1 diabetics, because medications that treat type 2 diabetes like metformin, glitazones, alpha-glucosidase inhibitors, glucagon-like peptide 1 agonists, and dipeptidyl peptidase IV inhibitors, do not cause hypoglycemia. Hypoglycemia is common in type 2 diabetics who take insulin, glinides, or sulfonylurea. Insulin use remains a key risk factor in developing hypoglycemia, regardless of diabetes type. ==History==

Hypoglycemia was first discovered by James Collip when he was working with Frederick Banting on purifying insulin in 1922. ==Etymology==

The word hypoglycemia is also spelled hypoglycaemia or hypoglycæmia. The term means 'low blood sugar' from Greek ὑπογλυκαιμία, from ὑπο- hypo- 'under' + γλυκύς glykys 'sweet' + αἷμᾰ haima 'blood'. == References ==