Associations of sphingosine-1-phosphate with thyroid function and structure: a cross-sectional population-based study

Area of Science:

• Endocrinology
• Immunology
• Lipid Metabolism

Background:

• Sphingosine-1-phosphate (S1P) is an immunomodulatory lipid mediator impacting immune and cardiovascular systems.
• S1P has demonstrated effects on thyroid health, particularly in inflammatory conditions like Graves' disease.

Purpose of the Study:

• To investigate the associations between circulating S1P levels and key thyroid markers.
• To explore the relationship between S1P and thyroid ultrasound findings.

Main Methods:

• Quantified S1P using LC-MS/MS in 4,034 participants from the 'Study of Health in Pomerania'.
• Measured serum thyrotropin (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) via chemiluminescent immunoassays.
• Assessed thyroid volume, nodules, and echogenicity using ultrasonography; analyzed associations with multivariable regression.

Main Results:

• A higher S1P level was associated with lower TSH and higher fT3 levels, independent of thyroid status or medication.
• No significant association was found between S1P and fT4 levels.
• Elevated S1P levels correlated with increased thyroid volume, presence of nodules, and hypoechogenic patterns on ultrasound.

Conclusions:

• Circulating S1P shows an inverse relationship with TSH and a positive relationship with fT3.
• These findings suggest S1P may play a modulatory role in thyroid function and morphology.