What is Hypoglycemia?
Hypoglycemia, or low blood sugar, typically occurs when your blood sugar level drops below 70 mg/dL. Sometimes, you might not notice any symptoms until your blood sugar goes under 55 mg/dL. Doctors often use the “Whipple’s triad” – a three-step process – to diagnose hypoglycemia: identifying the symptoms, confirming low blood sugar levels, and seeing if symptoms improve when the blood sugar is raised. The brain, unlike the rest of the body, relies heavily on sugar, and needs a constant supply for it to function properly. Therefore, our bodies have developed ways to prevent blood sugar from dropping too low.
When we haven’t eaten for a while, our bodies maintain our blood sugar levels in two ways: gluconeogenesis and glycogenolysis, both of which happen in the liver. Gluconeogenesis is the creation of sugar from other materials in the body like proteins, fats, pyruvate (a molecule from sugar), or lactate (a molecule from lactic acid). But, glycogenolysis is the process where our body breaks down stored sugar, called glycogen, and transforms it into usable sugar products. This step mostly happens in the liver and muscle cells.
Most people who experience hypoglycemia have diabetes and are treating it with medication. There’s a higher risk for patients with type 1 diabetes; they’re three times more likely to have hypoglycemia compared to those with type 2 diabetes when both groups are on treatment.
What Causes Hypoglycemia?
For people who don’t have diabetes, low blood sugar or hypoglycemia is quite rare but can still happen. If someone not living with diabetes experiences hypoglycemia, it could be because of a few reasons: medications, drinking alcohol, severe illnesses, hormonal imbalances, and certain types of tumors.
In most cases, low blood sugar episodes are common in people with diabetes who are taking certain medications like meglitinides, sulfonylureas, or insulin, making medication the usual cause of hypoglycemia. Some other diabetes medications, such as Metformin, GLP-1 receptor agonists, SGLT-2 inhibitors, and DPP-4 inhibitors, rarely lead to hypoglycemia.
It’s unusual for people without diabetes and with healthy liver function to experience low blood sugar when fasting thanks to safety measures our body has in place to prevent it. If a non-diabetic experiences true hypoglycemia, it might be due to medical causes like improper insulin use. Other possible causes might include severe illness, alcohol, a lack of cortisol, or malnourishment.
Alcohol can interfere with glucose production in the body but doesn’t affect the breakdown of glucose stores. That’s why low blood sugar can happen if someone drinks alcohol for several days straight and depletes their glucose stores.
In serious illnesses such as end-stage liver disease, sepsis, starvation, or kidney failure, the body might use up glucose faster than it can take it in or produce it. This imbalance might lead to low blood sugar. Some people might have rare hormonal imbalances that can lead to low blood sugar. Certain tumors might cause hypoglycemia by increasing a hormone that helps the body use glucose, which can lead to low blood sugar levels.
Insulinomas are a type of tumor that can overproduce insulin and lead to low blood sugar first thing in the morning. While these tumors are very rare, they should be considered if hypoglycemia is suspected.
Risk Factors and Frequency for Hypoglycemia
People with type 1 diabetes, especially those on intensive insulin treatment, often experience low blood sugar, also known as hypoglycemia. In type 1 diabetes patients, serious low blood sugar incidents can range from 62 to 320 occurrences for every 100 patients yearly. On the other hand, people with type 2 diabetes have relatively fewer incidents of hypoglycemia. This might be due to the regular use of treatments like metformin, which generally do not cause low blood sugar. Cases of hypoglycemia in type 2 diabetes patients are thought to be around 35 occurrences for every 100 patients yearly. It’s important to note that these incidents are not found to vary based on whether the patient is male or female.
Signs and Symptoms of Hypoglycemia
Hypoglycemia, or low blood sugar, can cause two types of symptoms: neuroglycopenic and neurogenic. Neuroglycopenic symptoms occur when there isn’t enough glucose for the brain to function correctly. These symptoms can include behavioral changes, confusion, tiredness, seizures, coma, and even death if not treated right away. Neurogenic symptoms come from the body’s response to low blood sugar and can be divided into two categories: adrenergic symptoms (like tremors, heart palpitations, and anxiety) and cholinergic symptoms (like hunger, sweating, and tingling sensations).
When looking into possible hypoglycemia, doctors need to gather a detailed history from the patient. This includes:
- A detailed overview of the patient’s medications
- Whether the patient uses alcohol or drugs
- Any history of mental health disorders
- Whether the patient or their family has diabetes or hormone disorders called multiple endocrine neoplasia syndromes (MEN)
- Any recent changes in weight
- Changes in medications
- Possibility of kidney injury or failure
- Signs of hormone deficiencies
- When low blood sugar episodes occur in relation to meals or exercise
Hypoglycemia is diagnosed if someone has low blood sugar symptoms and a blood sugar reading below 70 mg/dL. But it’s not just about the numbers; symptoms matter too. Symptoms usually start when blood sugar falls below 50 to 55 mg/dL, but this can vary from person to person.
People with diabetes may show low blood sugar symptoms even when their blood sugar is in the normal range. This is due to long-term high blood sugar changing the level at which these symptoms occur. This is called “pseudohypoglycemia”.
Testing for Hypoglycemia
As stated before, Whipple’s triad is a possible sign of hypoglycemia, a condition where your blood sugar levels are too low. The first step in any test for hypoglycemia should be to confirm low blood sugar levels. Other important tests that should be considered include checking insulin, proinsulin, and C-peptide levels in any episode of suspected low blood sugar.
If there are high levels of insulin but low levels of C-peptide, it might suggest the patient has received insulin from an external source. This is because C-peptide and proinsulin (the precursor to insulin) are connected when insulin is produced naturally in the body. The body separates C-peptide from proinsulin to create functioning insulin.
If both C-peptide and insulin levels are high, it could be because of medications like sulfonylureas or insulin secretagogues which stimulate the body to produce more insulin.
It’s important to note that once the supply of insulin from an external source has been ruled out, the possible causes of high insulin production within the body (endogenous hyperinsulinemia) need to be considered. Tests such as an abdominal CT scan or MRI are usually done to locate the source.
Treatment Options for Hypoglycemia
Identifying a person with low blood sugar levels, known as hypoglycemia, is very important due to the serious consequences it can cause, including falling into a coma or potentially dying. Severe cases of hypoglycemia can be managed by injecting a type of sugar called dextrose directly into the bloodstream. If the patient is awake and can swallow, they can consume easily digestible sources of carbohydrates, such as fruit juice. For patients who can’t swallow, a hormone called glucagon can be given via an injection or nasal spray. Once the person has regained consciousness, they should consume a meal rich in complex carbohydrates to keep blood sugar levels stable. Blood sugar should be monitored frequently to make sure it doesn’t drop again.
Education and lifestyle changes are also essential parts of managing repeated episodes of hypoglycemia. Some people are not aware of the serious risks of persistent low blood sugar. Therefore, it’s important that the individual understands the importance of regularly monitoring their blood glucose and knowing their personal symptoms of hypoglycemia. If lifestyle changes aren’t enough to prevent further episodes, medications might need to be adjusted. To be prepared for future episodes, it can be helpful to wear a medical identification bracelet or necklace and carry a source of glucose such as gel, candy, or tablets. Reviewing blood sugar readings and meal logs can help identify potential problem areas.
Controlling blood sugar levels is an important aspect of treating type 2 diabetes due to its link to heart-related problems. However, intensive therapy to aggressively lower blood sugar levels has not been directly linked to a significant reduction in major heart-related events and can even increase the risk of hypoglycemia and mortality. It’s important to note that in one study, a medication called rosiglitazone was used more frequently in the intensive therapy group, which could have contributed to an increase in heart-related problems.
Another study focused on veterans with poorly controlled type 2 diabetes found that strict control of blood sugar levels did not significantly affect heart-related outcomes. Still, it did improve a condition known as microalbuminuria, which is a sign of kidney disease. However, since the majority of the participants were male, the results may not apply to women.
When it comes to conditions that naturally increase insulin levels in the body, like insulinomas, these are often managed through surgery. If there is evidence of an insulinoma, it’s important to investigate the possibility of multiple hormone-related disorders.
What else can Hypoglycemia be?
If low blood sugar (hypoglycemia) is verified, it’s crucial to address it promptly and figure out what’s causing it. When investigating hypoglycemia, it’s important to consider the following:
- Are you sticking to your recommended diet and taking your medication correctly?
- Have there been any changes to your medication lately?
- Could there be a possibility of sudden kidney damage?
- Have you noticed any unusual changes in your weight, especially rapid weight loss?
What to expect with Hypoglycemia
Severe reactions to insulin can be life-threatening, so it’s crucial to call emergency services straight away if someone becomes confused or loses consciousness. If you have diabetes and start to have low blood sugar episodes often, it’s important to talk to your doctor. They may need to tweak your medication, food, or exercise routine.
People without diabetes who show signs of low blood sugar should also see a doctor for further examination. Remember, severe or long-lasting low blood sugar can be very dangerous. In people with diabetes, it has been associated with higher rates of death. However, for those without diabetes who experience reactive low blood sugar, the prospects are generally positive.
Possible Complications When Diagnosed with Hypoglycemia
If hypoglycemia, or low blood sugar, is not treated promptly, it can lead to serious complications affecting the brain. These could include seizures, potential brain damage, and in severe cases, it can be fatal.
Preventing Hypoglycemia
Teaching patients about their condition is an essential part of preventing low blood sugar events. This means that patients should know the signs and symptoms of low blood sugar, and be able to recognize them early. Low blood sugar, or hypoglycemia, can cause symptoms like feeling shaky, hungry, or tired. Patients should also be given advice on what types of food to eat and how much exercise to do, to make sure they’re managing their condition as effectively as possible.