A new study has opined that women with a history of hypothyroidism are more prone to liver cancer than their counterparts with thyroid glands that function normally.
Hypothyroidism is a disease that could lead to hyperlipidemia and weight gain, and may play a role in the development of nonalcoholic steatohepatitis, which can progress to more severe liver disease.
Many studies have shown that hypothyroidism is linked with hepatitis C, which in turn leads to a rising rate of liver cancer.
Led by Manal Hassan of Anderson Cancer Center at the University of Texas, the research team designed a case-control study to better understand the association between hypothyroidism and the development of liver cancer, also known as hepatocellular carcinoma (HCC), in the U.S.
For their analysis, the researchers recruited 420 patients with liver cancer and 1,104 healthy controls.
From each subject, they gathered demographic data and information about liver cancer risk factors - like smoking, alcohol consumption and family cancer history. The team also questioned them about their history of thyroid conditions and obesity.
They provided blood samples that were tested for hepatitis B and hepatitis C.
About 15 percent of the liver cancer patients were found to have a history of thyroid disease, compared to about 12 percent of the healthy controls.
The researchers found that the subjects with a history of hypothyroidism had twice the risk of liver cancer.
However the relationship was only significant for females.
Women who had a prior history of hypothyroidism for more than 10 years had a three-fold higher risk of liver cancer, compared to those without a history of thyroid disorders.
There was no change in the association even after adjusting for obesity.
"Whether and why hypothyroidism causes HCC is not clear. However, the association between hypothyroidism and NASH can be explained by the underlying hyperlipidemia, decreased fatty acid oxidation insulin resistance and lipid peroxidation in patients with hypothyroidism," wrote the authors.
And these conditions may make the patient susceptible to HCC development.
"Further studies among different populations are warranted to confirm the association between hypothyroidism and HCC and to identify the underlying biological mechanisms and the genetic predisposition factors that may contribute to susceptibility to HCC development in the presence of thyroid disorders," concluded the authors.
The study has been reported in the latest issue of Hepatology.