Levels of endothelial cell-specific molecule-1 (ESM-1) in overt hypothyroidisim

Endothelial cell-specific molecule-1, endocan, is a proteoglycan that is expressed by the vascular endothelium. Endocan can be a biomarker of endothelial dysfunction caused by endothelial cell-dependent disorders. Endothelial dysfunction is an early step of atherosclerosis and is developed in hypothyroid patients, which indicates an association between hypothyroidism and atherosclerosis. Therefore, we aimed to investigate whether circulating endocan levels are associated with endothelial dysfunction in overt hypothyroid patients.

Forty patients with hypothyroidism diagnosed in the last 5 years and 30 healthy subjects were recruited.

The mean endocan value in all patients was 0.63 ± 0.26 pg/ml, which was higher than that in controls (0.36 ± 0.10 pg/ml, p < 0.05). When we subgrouped the patients as hypothyroid and euthyroid, all groups demonstrated significantly different endocan levels, and hypothyroid patients had the highest endocan levels. A correlation analysis demonstrated that endocan levels were positively correlated with body mass index (BMI), thyroid-stimulating hormone (TSH), anti-thyroid peroxidase, and anti-thyroglobulin and negatively correlated with free thyroid hormone 4 (FT4) and vitamin D levels. In addition, in the patient group, endocan levels were correlated with FT4 levels independently in a covariance analysis.

The circulating endocan level increased in hypothyroid patients, suggesting that endocan levels may be an early biomarker of the development of endothelial dysfunction in patients with hypothyroidism. They may also prove useful in the prediction of cardiovascular diseases after further studies using cardiovascular disease biomarkers. In addition, targeting endocan levels to decrease cardiovascular risk may be a new treatment strategy in these patients.