Skeletal Manifestations of Hypothyroidism in Twelve Cases from Switzerland

Abstract

Hypothyroidism is caused by a deficiency in the synthesis of thyroid hormone. Dwarfism is the most obvious skeletal manifestation, but most people with hypothyroidism do not have any skeletal evidence of the disease. When the skeleton is affected, the severity of this manifestation depends on the degree of the deficiency and age of onset. Endemic hypothyroidism typically is linked to specific ecological settings such as the high mountains where iodine is absent, or else it occurs with very low concentrations in water and soil. In these areas, the prevalence may be as high as 8%. The disease can be expected to occur in archaeological human skeletal samples from endemic regions. Sporadic hypothyroidism is caused by a deficiency in the thyroid gland itself, and is not linked to any specific environmental context. The disease may be the result of a genetic defect, but can also be caused by other pathological conditions that may affect the thyroid gland, including infection and cancer. The skeletal abnormalities of the two variants will be indistinguishable in archaeological human remains. In order to identify hypothyroidism in archaeological skeletal samples, one must be aware of the differences in pathological skeletal changes seen in hypothyroidism in comparison with other diseases, such as achondroplasia, that can cause similar abnormalities. Twelve clinically documented cases of hypothyroidism provide data for understanding the skeletal abnormalities associated with this disease. All 12 are modern documented cases from Switzerland, where endemic hypothyroidism occurred in the iodine-deficient Alpine regions. However, at least one case in the sample was caused by a defect in the thyroid gland itself