A recent finding of a clinical trial published in Endocrine Abstracts has shown that “In patients with subclinical hypothyroidism substitution with levothyroxine is not associated with lower all-cause mortality.”
The study is based on a fact that “Subclinical hypothyroidism is associated with a number of cardiovascular risk factors such as hypertension, hypercholesterolemia, and diastolic dysfunction, but only limited data exist on long-term outcome of levothyroxine substitution therapy.” It was a historical cohort study.
Subclinical hypothyroidism is a condition in which patient has normal levels of thyroid hormones T3 and T4 along with normal levels of Free T3 (FT3) and Free T4 (FT4). But the condition is associated with high level of Thyroid Stimulating Hormone (TSH) which is secreted by the pituitary to maintain a normal level of T3 and T4.
Treatment of Subclinical hypothyroidism is controversial as there is not enough data whether starting Levothyroxine therapy in patients is helpful or not. Some doctors recommend starting therapy if the patient is symptomatic, the patient is positive for antithyroid antibodies and if TSH levels are above 10. Signs and symptoms include Weakness, lethargy, fatigue, Dry skin, Coarse hair, Cold intolerance, Constipation, Weight gain, Muscle cramps, Edema of eyelids, face, legs (nonpitting), Hoarseness, Hearing loss, Menorrhagia, Slowing of return phase of reflexes (e.g., knee jerk) and Bradycardia.
