Diabetes and thyroid disorders

Abstract

It has long been recognised that thyroid hormones have marked effects on glucose homeostasis. Glucose intolerance is associated with hyperthyroidism and most recently it was shown that hypothyroidism is characterised by insulin resistance. Although autoimmune thyroid disease is more prevalent in type 1 diabetes as a result of their common origin, in patients with type 2 diabetes the prevalence of hypothyroidism and hyperthyroidism is similar to that of the general population. However, in type 2 diabetic patients, the presence of the highly frequent sub-clinical forms of hyperthyroidism and hypothyroidism should be ruled out since they may be associated with higher cardiovascular risk. While there are no doubts about the therapeutic impact of normalising hypothyroidism and hyperthyroidism, the information available about the benefit of treating subclinical thyroid disease in diabetes remains insufficient.