Hypoglycaemia

Original Editor - Cindy John-Chu
Top Contributors - Lucinda hampton, Candace Goh, Aminat Abolade, Mohamed A Hassanin and Alexandra Stead  

Introduction

Hypoglycaemia is a condition caused by lowered plasma glucose levels. It is a critical condition that requires rapid management to stop the Blood Glucose Level (BGL) from falling even lower and the person becoming seriously unwell. Typically, neurogenic and neuroglycopenic symptoms of hypoglycaemia occur at a BGL of or below 50 to 55 mg/dL, but this threshold can vary among individuals. This happens because glucose is the primary metabolic fuel for the brain under physiologic conditions. Unlike other tissues of the body, the brain is very limited in supplying its glucose and requires a steady supply of arterial glucose for adequate metabolic function. Potential complications can arise from an interruption in the glucose supply.

Hypoglycaemia is more dangerous than hyperglycemia. One can afford to have increased BGLs sometimes but hypoglycaemia (low BGL) can be life threatening due to glucose role in brain metabolism. Hypoglycaemia is common with type 1 diabetes, particularly in those patients receiving intensive insulin therapy. Individuals with type II diabetes experience hypoglycaemia relatively less frequently compared to patients with type I diabetes.

Classification of Hypoglycaemic events

The following are different classes of a hypoglycaemic event:

Severe Hypoglycaemia: an episode in which someone else must actively deliver glucose, glucagon, or other resuscitation measures. There may be enough neuroglycopenia (less glucose to the brain) linked to these episodes to cause seizures or coma.

Documented Symptomatic Hypoglycaemia: an episode in which a measured plasma glucose concentration of ≤70 mg/dl (3.9 mmol/l) is present together with the usual symptoms of hypoglycaemia.

Probable Symptomatic Hypoglycaemia: an episode in which a plasma glucose measurement does not show hypoglycaemia symptoms, but was likely brought on by a BGL of ≤ 70 mg/dl. Many diabetics opt to treat symptoms with oral carbohydrates rather than a plasma glucose test.

Asymptomatic Hypoglycaemia: An episode in which the measured BGL of ≤ 70 mg/dl but does not exhibit the usual symptoms of hypoglycaemia.

Relative Hypoglycaemia: When a diabetic has any of the common symptoms of hypoglycaemia and interprets them as such, but their measured BGL of > 70 mg/dl.

Pathophysiology

Changes of BGL and Insulin levels during day and night with relations to type of meals administered.

The body has inherent counter-regulatory mechanisms to prevent acute hypoglycaemic episodes including an interplay of hormones and neural signal as follows:

• Insulin regulation: Decreases in insulin production as a response to low serum glucose are the body's first line of defence against hypoglycaemia.

• Pancreatic alpha cell secretion of glucagon is the next line of defence against hypoglycaemia.
• On glucagon failure to achieve normal blood sugar levels, adrenomedullary epinephrine is secreted.

All three counter-regulatory measures occur in the acute stage of hypoglycaemia. Further counter-regulatory measures include growth hormone and cortisol that are seen in prolonged hypoglycaemic states.

Causes

Many causes of hypoglycaemia have been reported, they can be categorized into metabolic, nutritional, psychological, toxic and infective. Here are some of them:

• Iatrogenic hypoglycaemia due to diabetes medications.
• Autoimmune conditions.
• Organ failure e.g. Pancreatic tumours, end-stage liver disease, sepsis, or renal failure.
• Endocrine disease.
• Dietary toxins, Alcohol consumption.
• Stress.
• Infections.
• Starvation as can occur in the eating disorder anorexia nervosa.
• Excessive exercise.

Risk Factors

The risk factors for the hypoglycaemia are diverse and you should be cautious about this, as early identification of the hypoglycaemia rules out many complications related to it. The risk factors of hypoglycaemia are as follow:

• Chronic diabetes.
• History of Prior Hypoglycaemic attack.
• Treatment involving Insulin or Sulfonylureas, both of which lowers BGL.
• Old Age.
• Food insecurities.
• Behavioural like Fasting.

Signs and Symptoms

Some symptoms of Hypoglycaemic episodes

It becomes crucial to identify the signs and symptoms for the treatment of hypoglycaemia, wrong interpretation of the symptoms can have very drastic effects. The signs and symptoms of the hypoglycaemia may include:

• Psychological symptoms e.g. Depression, Discomfort, Anxiety and Fear.
• Physical symptoms e.g. Fatigue, Blurred vision, Seizures or shakiness, Numb cheeks, lips or tongue.
• Cognitive Impairment and Dementia.
• Hormonal imbalance.
• Risk of Cardiovascular events in older persons (Irregular heart beats, Pale skin, Sweating, Hunger).
• Loss of consciousness.

Complications

Difference between symptoms of hypoglycaemic and hyperglycaemic episodes

Normally if elevated insulin levels result in low BGL (50 to 55 mg/dL range), the central nervous system's metabolism is slowed down, then neuronal activity becomes sensitive and the system typically becomes excitable with neuroglycopenic irritability symptoms appear (anxiety, trembles, perspiration, etc.) and may progress to coma (differs from diabetic coma, see image). Thus, this phenomenon known as insulin shock (although may be used as a treatment for other conditions) may develop in individuals with insulin-secreting tumours or in diabetic patients who give themselves excessive amounts of insulin and cause the dramatic symptoms.

Management

Hypoglycaemia management requires careful clinical consideration due to the potential for serious complications. Immediate treatment focuses on restoring normal glucose levels through glucose administration to prevent neurological sequelae. Concurrent identification and treatment of the underlying cause is essential to prevent recurrent episodes. Long-term management involves comprehensive evaluation and treatment of the root cause of hypoglycaemia to ensure sustained glycaemic control.

• Severe hypoglycaemia can be treated with intravenous (IV) dextrose followed by infusion of glucose.
• For conscious patients able to take oral (PO) medications, carbohydrate sources (such as fruit juice) should be given.
• For patients unable to take oral agents, a 1-mg intramuscular (IM) injection of glucagon can be administered.
• Once the patient is more awake, a complex carbohydrate food source should be given to the patient to achieve sustained normal blood glucose levels. More frequent blood glucose monitoring should occur to rule out further drops in blood sugar.

• Sulfonylurea induced Hypoglycaemia can be treated with octreotide instead of glucose as the these kind of hypoglycaemia can be persistent and recurrent.

Prevention

Education remains a pivotal component in the prevention of hypoglycaemic episodes. Focus on preventing hypoglycaemia should include education on signs and symptoms that constitute hypoglycaemia and early recognition of these signs and symptoms. Persons with hypoglycaemia may also need counsel on meal plans and exercise to manage their condition.

Following measures can be taken to prevent the Hypoglycaemia

• Education: Persons with hypoglycaemia must be educated about its effects, risks, management, and prevention.
• Insulin Devices: New insulin formulations and devices are being used to prevent the insulin induced hypoglycaemia in diabetic individuals.
• Technology: Continuous Glucose monitoring (CGM) system can be used to monitor glucose level and administer the Glucose or Insulin accordingly.

Physiotherapy

When treating diabetic clients monitor whilst exercising. The therapist should watch the patient for symptoms of hypoglycaemia see above. Aerobic and anaerobic activities such as short sprints, high-intensity intervals, and resistance exercise can prevent hypoglycaemia during exercise and thus decrease the reliance on excessive carbohydrate consumption during exercise to maintain blood glucose levels.