Why is thyroid function disturbed in long-standing liver disease?
The liver is an indispensable internal organ. It may lose its potential to function properly when the liver is damaged. The liver is damaged due to long-standing liver diseases such as cirrhosis. The most common reason leading to chronic liver diseases are hepatitis, alcohol abuse, and other viruses. To prevent liver disease one must follow a healthy lifestyle. Dr. Ankur Garg is the best liver doctor in India.
There was a study conducted to relate why thyroid function disturbed chronic liver diseases.
The liver is the most important organ in the body. It plays a vital role in the functioning of the digestive system in the body. Along with it, the liver is also responsible for the metabolism of thyroid hormones in the peripheral conversion of namely T3 and T4 by Type 1 monodeiodinase in the human body. Type 1 is the enzyme responsible for the activation and deactivation of thyroid hormones.
Method of study:
The study was conducted to diagnose thyroid function in long-standing liver disease in which 100 decompensated liver cirrhosis patients were compared with 100 healthy adults. Levels of T3, T4, and TSH were also measured using cilia and detailed analysis between these two groups of patients.
In a long-standing liver disease such as cirrhosis, the functioning of the thyroid is completely altered.
The most common cause of cirrhosis in patients is observed to be alcohol abuse and the presence of gross ascites. For those who don’t know what ascites are, it is the accumulation of fluid in the abdomen causing abdominal swelling.
When a study was conducted on cirrhosis patients, it was observed that T3 (P < 0.0001) and T4 (P < 0.0001) levels were significantly decreased and thyroid-stimulating hormone (TSH) levels were elevated in cirrhosis patients when compared with healthy groups. It was also observed that cirrhosis with Hepatic encephalopathy (HE) had a lower level of T3 compared to cirrhosis without HE. However, there was no significant change in T4 and TSH levels.
The levels of T3, T4, and TSH are correlated with the severity of the long-standing liver disease.
What is Cirrhosis? Cirrhosis is the scarring of the liver tissue leading to liver failure. Long withstanding liver diseases such as cirrhosis, graves disease, and liver problems may disturb the function of the thyroid. In medical terms, cirrhosis is termed as either compensated meaning an increase in the activity of one organ that makes up the loss of another organ. It is also termed decompensated which is the result of complications caused due to hepatic encephalopathy (HE), bleeding, fluid retention, chronic hepatitis B and C, and jaundice.
Decompensated cirrhosis patients will experience ascites followed by hepatorenal syndrome, hyponatremia, and spontaneous bacterial peritonitis while compensated cirrhosis patients will not experience any of these features.
The thyroid gland produces two-related hormones namely:
- Triiodothyronine (T3)
- Thyroxine (T4)
T3 and T4 hormones play a vital role in cell differentiation during the development and maintenance of thermogenic and metabolic homeostasis. The thyroid gland produces T4 in about twentyfold which is an excess of the T3 hormone. Both hormones are bound to plasma proteins as well as thyroxine-binding globulin, thyroxine-binding pre-albumin, and albumin.
The liver is not just responsible for metabolism in thyroid function but also involved in thyroid hormone secretion and synthesis of thyroid-binding globulin.
Hormones T3 and T4 regulate the metabolic rate of all cells including hepatocytes, and thereby modulate hepatic function. The liver metabolizes the TSH levels and also regulates their systematic endocrine effects. Thyroid diseases may interrupt the functioning of the liver. In fact, some liver diseases may affect organs. Liver and thyroid hormones are correlated.
Patients with end-stage liver disease may have thyroiditis, hypothyroidism, or hyperthyroidism. These patients might have an abnormal liver function which may be reversed when thyroid function is improved.
The studies have shown that there are a decrease and increase in T3 levels in patients with cirrhosis. While no studies have proven if T4 and TSH levels have a direct relation with liver damage. However, T4 levels either remain low or at a normal level in cirrhosis patients. Also, the TSH level remains normal or slightly elevated. This is linked with the sensitive effect of liver function.
The factors that influence abnormalities in thyroid hormones include:
Alterations in plasma level of thyroid binding proteins
altered binding of T4 and T3 to their carrier protein
Impaired hepatic clearance of reverse T3
reduced extrathyroidal conversion of T4 to T3
The research is based on a study conducted for one year. Data was collected by studying 100 cirrhosis patients in the age of 18 to 80 years and 100 healthy adults. The diagnosis was based on endoscopy, clinical examination, liver biopsy, and ultrasound. Although liver biopsy was not performed in patients with the complaint of ascites presence. The severity of the liver damage was determined on the basis of a model for end-stage liver disease (MELD) and Child-Pugh grading system.
The result showed the presence of complications in cirrhosis patients:
Upper gastro internal bleeding
Ascites (fluid retention in the abdomen)
Hepatic encephalopathy (HE)
Chronic hepatitis B and C
Wilson disease and others
To ensure thyroid hormones function properly, a regular thyroid function test is suggested in patients with cirrhosis to reduce mortality.
You must log in to post a comment.