Low blood sugar, or hypoglycemia, occurs when blood glucose drops below a healthy range, typically under 70 milligrams per deciliter (mg/dL). This condition can cause various uncomfortable symptoms and, if left untreated, can become serious. Liver disease, particularly severe liver damage or certain critical illnesses affecting the liver, can indeed lead to low blood sugar.
The Liver’s Role in Blood Sugar Balance
The liver plays a central role in maintaining stable blood sugar levels throughout the day and night. It acts as the body’s primary glucose reservoir, balancing the uptake, storage, and release of glucose to meet the energy demands of various organs. After a meal, when blood glucose rises, the liver converts excess glucose into glycogen, a stored form of glucose, through glycogenesis. This stored glycogen can then be accessed when needed.
When blood glucose levels begin to fall, such as between meals or during periods of fasting, the liver initiates glycogenolysis. This process breaks down its stored glycogen back into glucose and releases it into the bloodstream. This mechanism helps prevent sudden drops in blood sugar and ensures a continuous supply of energy.
The liver also creates new glucose from non-carbohydrate sources like amino acids, lactate, and glycerol, a process called gluconeogenesis. This becomes important during prolonged fasting or when glycogen reserves are depleted. Hormones like insulin and glucagon signal the liver to store or release glucose, ensuring precise blood sugar regulation.
Liver Conditions Linked to Low Blood Sugar
Damage or dysfunction of the liver can significantly impair its ability to manage blood sugar, leading to hypoglycemia. One prominent condition is cirrhosis, which involves scarring of the liver. In cirrhosis, the damaged liver cells have reduced capacity for glycogen synthesis and storage, meaning less glucose can be kept in reserve. This depletion of glycogen reserves makes individuals more susceptible to low blood sugar, especially during fasting periods.
Cirrhosis also compromises the liver’s ability to perform gluconeogenesis effectively, meaning it struggles to produce new glucose from other sources when glycogen stores are low. Additionally, cirrhosis can lead to increased insulin levels in the bloodstream because the liver becomes less efficient at clearing insulin. Elevated insulin then promotes excessive glucose uptake by other tissues, further lowering blood sugar.
Acute liver failure, a life-threatening condition where the liver rapidly loses function, also frequently results in hypoglycemia. In this severe state, the liver’s capacity for gluconeogenesis is significantly impaired. The injured liver may also have a decreased ability to take up insulin, leading to higher levels of insulin circulating in the blood and consequently, lower blood sugar. Studies indicate that hypoglycemia is a common complication in patients with acute-on-chronic liver failure.
Certain liver tumors, such as hepatocellular carcinoma (HCC), can also cause hypoglycemia. This can occur through a rare syndrome known as non-islet cell tumor hypoglycemia (NICTH), where the tumor produces excess insulin-like growth factor 2 (IGF-2). Less common conditions, like specific glycogen storage diseases, are inherited metabolic disorders that directly affect the enzymes involved in the liver’s glucose metabolism, leading to impaired glycogen breakdown or synthesis and subsequent blood sugar imbalances.
Recognizing and Addressing Low Blood Sugar
Symptoms of low blood sugar can appear quickly and vary. Common indicators include:
Shakiness
Sweating
Rapid heartbeat
Dizziness
Confusion
Extreme hunger
Irritability
Pale skin
Headaches
Weakness
Tingling in the lips or tongue
If blood sugar drops significantly, severe symptoms like seizures or loss of consciousness can occur.
For mild to moderate hypoglycemia, the “15-15 rule” is recommended: consume 15 grams of fast-acting carbohydrates, then recheck blood sugar after 15 minutes. Repeat if the level is still below 70 mg/dL. Examples of fast-acting carbohydrates include:
4 ounces of fruit juice or regular soda
1 tablespoon of sugar or honey
Glucose tablets
Avoid foods high in fiber or fat, as they slow sugar absorption. Once blood sugar normalizes, eat a balanced snack or meal to help prevent another drop.
For severe hypoglycemia, if an individual is unconscious or unable to swallow, a glucagon injection is the appropriate treatment. Seek emergency medical attention immediately.
For individuals with liver disease, ongoing management may involve dietary adjustments, such as frequent small meals to prevent prolonged fasting, and careful monitoring of blood glucose levels. A healthcare provider can diagnose the underlying cause of hypoglycemia and tailor a management plan, which may also involve treating the liver condition itself.