Hypoglycemia, or low blood sugar, occurs when the glucose level in the bloodstream drops below 70 milligrams per deciliter (mg/dL). This condition is concerning for individuals with liver disease because the liver is the body’s central organ for maintaining stable blood sugar levels. When the liver is impaired by chronic illness or acute failure, its ability to regulate glucose is compromised, leading to drops in blood sugar. Understanding this connection requires reviewing the liver’s normal processes for glucose management.
The Liver’s Role in Glucose Regulation
The liver acts as a reservoir for glucose, ensuring a steady supply of energy for the brain and other vital organs, especially during periods without food. After a meal, when blood sugar rises, the liver takes up excess glucose and converts it into a storage form called glycogen through a process known as glycogenesis. This glycogen is the body’s short-term energy reserve.
When the body is fasting, such as overnight or between meals, the liver switches to releasing this stored energy to prevent blood sugar from falling too low. It accomplishes this through glycogenolysis, which is the breakdown of stored glycogen back into glucose that is then released into the bloodstream. This mechanism is the first line of defense against hypoglycemia.
If fasting continues for a longer time, the liver engages its second, more sustained defense: gluconeogenesis, or the creation of new sugar. The liver synthesizes glucose from non-carbohydrate sources, such as amino acids from muscle and glycerol from fat tissue. This process becomes the primary source of glucose after glycogen stores are depleted, which typically happens after about 30 hours of fasting.
Why Liver Impairment Causes Hypoglycemia
The link between liver disease and low blood sugar is the failure of the liver’s regulatory mechanisms. As liver disease progresses, healthy, functional tissue is often replaced by scar tissue, a process known as fibrosis or cirrhosis. This physical damage reduces the mass of functional liver cells (hepatocytes) available to conduct metabolic processes.
With less functional tissue, the liver’s ability to store glucose effectively is severely reduced, meaning glycogen reserves are often low or depleted even after meals. This failure leaves the body vulnerable because it lacks the immediate fuel reserve needed to sustain blood sugar between eating periods. Consequently, the reliance on gluconeogenesis becomes greater.
In advanced liver disease, the machinery for gluconeogenesis is also severely impaired, as the necessary enzymes and pathways cannot function correctly in the damaged cells. The body loses its ability to manufacture new glucose from non-carbohydrate sources, eliminating the long-term backup system. This combined failure of glycogenolysis and gluconeogenesis is the primary reason hypoglycemia occurs, often signaling severe hepatic dysfunction.
Other contributing factors compound this metabolic failure, including malnutrition, which is common in advanced liver disease and depletes the substrates needed for gluconeogenesis. Additionally, a failing liver may not clear the hormone insulin from the bloodstream efficiently, leading to higher circulating insulin levels. This reduced insulin clearance can push blood sugar levels down further, contributing to hypoglycemia.
Recognizing and Treating Low Blood Sugar
Recognizing the symptoms of hypoglycemia is important for anyone with underlying liver disease, as prompt action is necessary to prevent complications. Early signs often include physical symptoms like shakiness, sweating, and a rapid or pounding heartbeat. As blood sugar drops further, neurological symptoms can appear, such as confusion, difficulty concentrating, dizziness, and unusual behavior.
Immediate Treatment
The standard immediate treatment for mild or moderate hypoglycemia involves the “Rule of 15,” which uses fast-acting carbohydrates to quickly raise blood sugar. This protocol instructs a person to consume 15 grams of a simple carbohydrate, such as a half-cup of juice or regular soda, or glucose tablets. After consuming the carbohydrate, the blood sugar level should be rechecked in 15 minutes.
If the blood sugar level remains below 70 mg/dL after the initial treatment, the person should repeat the process of consuming another 15 grams of carbohydrate and rechecking the level after 15 minutes. Once the blood sugar returns to a safe range, a small snack containing protein and carbohydrates can help stabilize the level for a longer period. For severe hypoglycemia, where a person is unconscious or unable to swallow, specialized emergency treatment like a glucagon injection or calling emergency services is necessary.
Proactive Management
For individuals managing liver disease, proactive measures can help reduce the frequency of hypoglycemic episodes. Due to the compromised glucose storage, eating frequent, small meals throughout the day and a bedtime snack is often recommended to prevent long periods of fasting. Continuous glucose monitoring (CGM) can also be a valuable tool to track trends and catch dips in blood sugar before symptoms become severe. Any patient experiencing recurrent hypoglycemia must consult with a healthcare provider to adjust diet, review medications, and address the severity of the underlying liver condition.