Subclinical hypothyroidism – Quick review card

Subclinical hypothyroidism is elevated serum thyroid stimulating hormone ( TSH ) levels combined with normal levels of serum free thyroid hormone

a biochemical diagnosis - mostly picked on routine testing incidence between 3 % & 15 % ( Nazma et al report a prevalence of 3% to 8 % in the general population , this can be up to 15 % to 18 % in women > 60 ) incidence increases with age incidence of SCH varies by sex , age , race / ethnicity and geographic location higher rates of SCH are reported for women & older individuals it may be a transient phenomena ( change in TSH without thyroid disease ) it is not clear how SCH impacts general health ( for e.g relationship between SCH and adverse cardiac events or cardiac dysfunction , cognitive impairment , depression and the risk of fractures )

rate of progression for women with + ve TPO antibodies & a baseline TSH between 2.5 and 4 mIUl/ml is about 1 % other papers quote a rate of progression to clinically overt hypothyroidism at 2.6 % if TPO antibodies absent and 4.3 % if they are present rate of progression is significantly higher...