Subclinical hypothyroidism.
OBJECTIVE
Mild or subclinical hypothyroidism is characterized by normal serum free thyroxine concentrations with elevated serum thyroid-stimulating hormone concentrations. Subclinical hypothyroidism is relatively prevalent in the general population, especially among women and the elderly. The main cause of subclinical hypothyroidism is autoimmune chronic thyroiditis. The present report reviews the most important and recent studies on subclinical hypothyroidism, and discusses the most controversial aspects of this topic.


RESULTS
Several studies have demonstrated that subclinical hypothyroidism may affect both diastolic and systolic cardiac function. It may also worsen many risk factors for cardiovascular disease, including hypertension, abnormal endothelial function, and elevated low-density lipoprotein cholesterol concentrations. Furthermore, a growing body of evidence suggests that subclinical hypothyroidism may cause symptoms or progress to symptomatic overt hypothyroidism.


CONCLUSIONS
Prompt treatment of subclinical hypothyroidism in pregnant women is mandatory to decrease risks for pregnancy complications and impaired cognitive development in offspring. Children with subclinical hypothyroidism should be treated to prevent growth retardation. Whether nonpregnant adult patients with subclinical hypothyroidism should be treated, and at what thyroid-stimulating hormone values, is debatable.
Papi
Giampaolo
G
Uberti
Ettore Degli
ED
Betterle
Corrado
C
Carani
Cesare
C
Pearce
Elizabeth N
EN
Braverman
Lewis E
LE
Roti
Elio
E
D002318:Cardiovascular Diseases / Q000209:etiology*; D002675:Child, Preschool; D003072:Cognition Disorders / Q000517:prevention & control; D018450:Disease Progression; D005260:Female; D006130:Growth Disorders / Q000517:prevention & control; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000628:therapy; D011247:Pregnancy; D011248:Pregnancy Complications / Q000517:prevention & control / Q000628:therapy; D012307:Risk Factors