[Subclinical thyroid disease]

Area of Science:

• Endocrinology
• Internal Medicine
• Cardiology

Background:

• Subclinical thyroid disease (STh) is defined by abnormal thyroid-stimulating hormone (TSH) levels with normal thyroxine (T4).
• This includes subclinical hypothyroidism (SH) with elevated TSH and subclinical hyperthyroidism (STx) with suppressed TSH.
• Individuals with STh have a 2-3 times higher risk of developing overt clinical disease compared to those with normal TSH levels.

Purpose of the Study:

• To discuss the current understanding and clinical relevance of subclinical thyroid disease.
• To highlight the potential risks and effects associated with both SH and STx.

Main Methods:

• Literature review and synthesis of existing research on subclinical thyroid disease.
• Analysis of laboratory definitions and clinical implications.

Main Results:

• SH is linked to lipid metabolism disturbances, reduced vascular elasticity, impaired endothelial function, and increased atherosclerosis risk.
• STx is associated with myocardial electrical instability, heightened arrhythmia risk, and osteoporosis.
• The most significant impacts of STh are observed in cardiology, reproductive medicine, and gynecology.

Conclusions:

• The clinical significance of subclinical thyroid disease, particularly its long-term effects, remains incompletely evaluated.
• Further research is needed to definitively assess the clinical importance of SH and STx across various medical fields.