چكيده لاتين :
ubclinical hypothyroidism (SCH) is defined as a normal serum Ff4 and a
high serum thyrotropin (TSH) concentration.
Up to 30% of patients with SCH may have vague, non-specific
symptoms of hypothyroidism, but attempts to identify the patients on the basis of clinical finding have not been successful, so the diagnosis
can only be made with laboratory testing.
The causes of SCH are the same as those of overt hypothyroidism. Most patients have Hashimotoיs thyroiditis. The worldwide prevalence
of SCH ranges from 1-10%. A substantial proportion of patients with SCH develop overt hypothyroidism. Serum TSH concentration and
positive antithyroid antibodies (ATA) are significant predictors of progression to clinical hypothyroidism.
Some patients with SCH have some symptoms of hypothyroidism, while some studies show significant improvement in hypothyroid
symptom scores and psychometric testing; others found no improvement in symptoms with levothy roxine therapy.
There is consensus that SCH in pregnancy is a risk factor for poor developmental outcomes inthe offspring and the condition should be
treated in women who wish to become pregnant. There is also agreement that patients with SCH and TSH levels over 10 mUlL, or with goiter should be treated. Population-based screening for SCH is not warranted, but thyroid function should be tested in high risk groups, e.g. in women aged over 60 yr, persons with previous radiation therapy of thyroid gland or external.radiation, those with previous thyroid surgery of
thyroid dysfunction, type 1 diabetes mellitus patients and those with a family history of autoimmune disease. Evidence documenting routine
determination of TSH in pregnant women or women planning to become pregnant are insufficient, and it would be reasonable to consider
TSH measurement in those at high risk for thyroid dysfunction.
