People with hepatitis C should be regularly screened for thyroid disorders due to an increased risk for primary and subclinical hypothyroidism. These findings, from a case-control study, were published in Cureus.
Many medical professionals say there is a link between hepatitis C and an increased risk for cirrhosis and hepatocellular carcinoma, as well as a wide range of autoimmune disorders, but little data exists regarding the virus and thyroid disease.
Researchers enrolled 300 people with hepatitis C and 300 people without the infection as a control group from a single center in Pakistan, which has the second-highest number of hepatitis C cases worldwide. The study was conducted between June 2020 and March 2021. Blood samples were collected from each group and assessed for thyroid function.
The hepatitis C and control groups were 57.0% and 56.0% men, aged mean 41±10 and 39±11 years, with thyroid stimulating hormone (THC) levels of 2.1±0.8 and 1.9±0.6 mIU/L, and free thyroxine (FT4) levels of 17.7±4.6 and 18.2±4.2 pmol/L, respectively.
Subtypes of thyroid dysfunction differed between the patients with hepatitis C and controls participants specifically for primary hyperthyroidism (6.0% vs 3.0%), subclinical hyperthyroidism (2.6% vs 1.3%), primary hypothyroidism (10.6% vs 4.6%), and subclinical hypothyroidism (6.0% vs 1.3%), respectively.
Hepatitis C infection significantly increased the risk for primary hypothyroidism (odds ratio [OR], 2.43; 95% CI, 1.27-4.67; P =.0072) and subclinical hypothyroidism (OR, 4.72; 95% CI, 1.57-14.12; P =.005) but not for primary hyperthyroidism (OR, 2.06; 95% CI, 0.91-4.67; P =.07) or subclinical hyperthyroidism (OR, 2.02; 95% CI, 0.60-6.80; P =.24).
The presence of a hepatitis C infection also appeared to significantly decrease the likelihood of having normal thyroid function (OR, 0.33; 95% CI, 0.21-0.53; P <.01). Normal thyroid function was found in 224 people (74.6%) in the hepatitis C group vs 269 people (89.6%) in the control group.
This study was limited by its single-center, case-control design. Additional studies, the researchers acknowledged, are needed to confirm their findings. Longitudinal studies involving multiple centers are also needed to assess the trajectory of thyroid dysfunction among patients receiving treatment for hepatitis C.
“Evidence shows that hepatitis C patients are more frequently seen to have problems related to thyroid, most commonly primary and subclinical hypothyroidism,” the researchers wrote. “Therefore, these patients should be screened at regular intervals for early prognosis [and] treatment modalities that are known to cause thyroid abnormalities should be avoided in such patients.”
Nazary K, Anwar S, Choudhary AY, et al. Prevalence of thyroid dysfunction in patients with hepatitis C. Cureus. 2021;13(9):e18289. doi:10.7759/cureus.18289