Subclinical hypothyroidism and cardiovascular risk.

Area of Science:

• Endocrinology
• Cardiovascular Medicine
• Clinical Chemistry

Background:

• Subclinical hypothyroidism (SCH) is suspected to increase cardiovascular risk, but studies on risk factors yield conflicting results.
• Understanding these associations is crucial for managing potential cardiovascular complications in SCH patients.

Purpose of the Study:

• To compare cardiovascular risk markers, including lipids, inflammatory markers (plasma viscosity, fibrinogen, CRP), homocysteine (Hcy), and red blood cell distribution width (RDW), between SCH patients and controls.
• To identify which of these markers predict SCH risk and act as independent predictors.

Main Methods:

• Plasma viscosity (PV), Hcy, and routine biochemical/hematological parameters were measured in 58 SCH outpatients and 58 matched controls.
• Standard laboratory methods and a capillary plasma viscosimeter were employed for sample analysis.

Main Results:

• SCH patients exhibited higher body mass index (BMI), thyroid-stimulating hormone (TSH), PV, C-reactive protein (CRP), fibrinogen, Hcy, and RDW compared to controls.
• RDW showed significant correlations with inflammatory markers (PV, fibrinogen, CRP) and leucocytes.
• Logistic regression identified RDW (≥14%) and fibrinogen (≥400 mg/dL) as independent predictors of SCH risk.

Conclusions:

• Subclinical hypothyroidism patients present with increased cardiovascular risk markers, notably elevated PV, fibrinogen, Hcy, and RDW.
• Fibrinogen levels ≥400 mg/dL and RDW ≥14% are identified as independent predictors of subclinical hypothyroidism.