Introduction: Autoimmune thyroid disease is often associated with other autoimmune diseases. Coeliac disease is one of those autoimmune diseases, together with is wide spectrum of intestinal and extraintestinal manifestations. Atrophy of intestinal mucosa, one of the characteristics of coeliac disease, among everything else, leads to poor absorption of l-tyroxine used in therapy of hypothyroidism.
Aim and results: We like to present a clinical case of our patient with Hashimoto thyroiditis who remain hypothyroid in despite of high doses of l-thyroxine during fifteen years of therapy. She was admitted to our Clinic when she was 58 years old with signs of hypothyroidism, hypoalbuminemia and severe anemia. We doubt there is a malabsorption syndrome associated with this signs. We perform a small bowel biopsy and laboratory testing of transglutaminase antibody which was positive for celiac disease. Also, bone mineral density in this moment was in reference range of severe osteoporosis, and biochemical markers of bone were appropriate for secondary hyperparathyroidism. Patient was give the specific gluten free diet. During next 7 months there is an improvement of anemia, hypoalbuminemia, but now we have an iatrogenic hyperthyroidism, and no improvements in bone metabolism. Dose of l-thyroxin was decreased gradually and therapy with vitamin D was started. After 19 months from diagnosing the celiac disease, patient is euthyroid, without anemia or hapoalbuminemia. Parameters of bone metabolism are within normal range and there is no hyperparathyroidism, bone mineral density is improved to level of osteopenia.
Conclusions: Coeliac disease can be a cause of low absorption levels of l-thyroxine in small intestines. Iatrogenic hyperthyroidism could be a consequence of improved absorption. In cases like this, secondary hyperparathyroidism is an reversible and osteoporosis is mainly reversible condition with adequate vitamin D supplementation.