Levothyroxine and Non-alcoholic Fatty Liver Disease: A Mini Review

Abstract

Levothyroxine or l-thyroxine is artificially manufactured thyroxine, which is used as a drug to treat underactive thyroid conditions in humans. The drug, levothyroxine, is consumed daily in a prescribed dose to replace the missing thyroid hormone thyroxine in an individual with an underactive thyroid, and it helps to maintain normal physiological conditions. Though it is a life-maintaining drug, it replaces the missing thyroid hormone and performs the necessary daily metabolic functions in our body. Like all other allopathic drugs, it comes with certain side effects, which include joint pain, cramps in muscle, weight gain/loss, hair loss, etc. The thyroid hormone, thyroxine, is known to mobilize fat in our body, including the ones from the hepatic system. An underactive thyroid may cause an accumulation of fat in the liver, leading to a fatty liver, which is clinically termed Non-Alcoholic Fatty Liver Disease (NAFLD). The correlation between hypothyroidism and NAFLD is now well-studied and recognized. As levothyroxine performs the functions of the missing thyroxine, it is anticipated, based on certain preliminary studies, that the drug helps to mobilize hepatic fat and thus may have a crucial role in mitigating the condition of NAFDL.

Association between thyroid function and nonalcoholic fatty liver disease: a dose-response meta-analysis

“…The inner relationship between NAFLD and thyroid hormones was then questioned and studied nowadays. Interestingly, in some clinical traials, thyroxine supplementation has been found to improve obesity and NAFLD to some extent ( 33 , 34 ). High dosages of T3 were also previously used to promote weight loss in obese patients and to treat hypercholesterolemia ( 4 ).…”

The Pathophysiology and Management of NAFDL in Post-menopausal Women: An Updated Short Review

“…The same estrogen-deficient mice are also reported to have increased body weight, abdominal fat weight, and increased serum triglycerides [10]. Several genes are associated with the coding of various peptide molecules directly related to fat metabolism and the development and progression of NAFDL [4,15]. These genes and different transcription factors are affected and regulated by certain hormones like the thyroid, insulin, and estrogen.…”

“…NAFDL may go unnoticed and undetected as it doesn't give any significant early-stage symptoms. Hence, intermittent checking and superficial ultrasonography of the upper abdomen is recommended for recognition of the condition of the liver [4]. In post-menopausal women, Regular check-ups and diagnostic tests for other physiological parameters are needed.…”

“…If the state goes unrecognized, undiagnosed, and untreated for a long, it may worsen to steatosis of the liver, cirrhosis of the liver, and even cause death. Certain genetic predispositions and other pathological conditions of the body, like hypothyroidism, diabetes etc., have been found to be linked to the occurrence and progression of NAFDL [4]. Menopause, which comes with a vast hormonal turmoil in the women's body, has been reported to be intimately associated with causing, worsening, and progression of NAFDL and thus significantly contributes to the morbidity of post-menopausal women [1,2].…”

DataSheet_1.doc

“…The inner relationship between NAFLD and thyroid hormones was then questioned and studied nowadays. Interestingly, in some clinical traials, thyroxine supplementation has been found to improve obesity and NAFLD to some extent (33,34). High dosages of T3 were also previously used to promote weight loss in obese patients and to treat hypercholesterolemia (4).…”