Thyroid dysfunction is more common in women than in men.
Female predominance of thyroid dysfunction is attributed to sex difference in immune function, similar to many auto immune diseases.
8-13% of women older than 50 years have biochemical evidence of thyroid dysfunction.
Even mild abnormalities in thyroid function can alter serum cholesterol levels, heart rate and rhythm, ventricular function, coronary artery disease risk and cardiovascular mortality.
Subclinical thyroid disease is a common finding on testing of thyroid function and its management remains controversial.
There is an increased risk of progression to overt hypothyroidism or hyperthyroidism.
The treatment of mild thyroid failure is of importance in optimizing pregnancy outcome.
More than 80% of patients with acute or chronic thyroiditis and resulting hypothyroidism have anti-thyroid auto antibodies, as well as B- cell and T-cell infiltration of the thyroid gland, consistent with an autoimmune etiology.
Prevalence of auto antibodies against thyroid antigen thyroid peroxidase ranges from 3% of teenage males and 7% of teenage females, to 12% of men and 30% of women older than 80 years..
At every age women are twice as likely to have TPO antibodies (thyroid peroxidase).
Black women are half is likely to have TPO antibodies as white women.
TPO antibodies are not specific and occur in the absence of thyroid dysfunction and are present in other autoimmune processes.