Urinary glycosaminoglycans in patients with hypothyroidism and in healthy subjects

Although the changes in urinary glycosaminoglycans have been investigated in several endocrinopathies, no information was hitherto available on the content and composition of urinary glycosaminoglycans in hypothyroidism. Urinary glycosaminoglycans were therefore investigated in patients with hypothyroidism and in healthy subjects. The total daily excretion of urinary glycosaminoglycans was found to be significantly increased (by 41%) in hypothyroidism. Two electrophoretic bands were always detected in both examined groups: a major band of chondroitin sulphate and a minor band of heparan sulphate. Heparan sulphate and chondroitin sulphate levels were respectively 114% and 42% higher in patients with hypothyroidism than in controls. The respective increases in chondroitin-4-sulphate and chondroitin-6-sulphate were 31% and 41%. The relative quantities of chondroitin-4-sulphate, dermatan sulphate, chondroitin-6-sulphate and non-sulphated chondroitin sulphate were unchanged in the two examined groups. The changes observed in the levels of the excreted glycosaminoglycans may reflect the altered metabolism of connective tissue in hypothyroidism.