Hereditary hemochromatosis (HH) is a disease characterized by the excessive absorption of iron and its deposition in various organs. Late complications of this disease include cirrhosis, hepatocellular carcinoma and endocrine disorders. Data from literature on thyroid disorders in patients with HH are inconsistent and ambiguous and no research has been done to determine the relationship between excessive accumulation of iron and the thyroid volume. Therefore, the aim of this study was to characterize thyroid function and ultrasound image in patients with clinically overt hereditary hemochromatosis.
We studied 40 patients who were diagnosed with hereditary hemochromatosis with one of the mutation of HFE gene and iron deposites in liver in specimen from liver biopsy (graded G2 to G4) or in MRI. To assess the thyroid function, the ultrasound examination of the thyroid gland was performed and serum TSH concentrations were measured.
We showed in our study that patients with HH have diagnosed with nodular goiters statistically less frequent than in control group. We did not reveal any statistically significant differences in TSH concentrations between patients with HH and the general population. However patients with more severe iron deposits in liver showed lower TSH.
Our results indicate that iron overload syndromes and iron deposition could have prevent from formation of focal lesions in thyroid gland. Excess iron may act as a “protective” factor against the formation of nodular lesions in the thyroid gland through the production of peripheral thyroid hormones, i.e. thyroxine (T4) and triiodothyronine (T3), and the reduction of TSH concentration.