TUG1 and miR-145 as potential biomarkers associating hypothyroidism to cardiovascular risk

RNA based epigenetic modifications and their relations with chronic diseases have been widely studied. The current study aimed to determine the role of long noncoding RNA (lncRNA) TUG1 and microRNA 145 (miR-145) in the pathophysiology and progression of hypothyroidism as well as their impact on subsequent cardiovascular disorders.

Serum levels of TUG1 and miR-145 were measured in three different groups, 40 overt hypothyroid (OHT) patients, 40 subclinical hypothyroid (SHT) patients and 45 healthy controls. All individuals were subjected to a full history investigation and clinical examination. Flow mediated vasodilation of the brachial artery was measured to evaluate endothelial function. Serum samples were also tested for T4, TSH, TG, TC, HDL, LDL, HbA1c, glucose and insulin.

TUG1 level was significantly increased in OHT and SHT patients compared to the healthy controls. TUG1 correlated positively with TC, LDL levels and endothelial dysfunction, while correlated negatively with HDL. Regarding miR-145, its expression level was downregulated only in OHT patients as compared to controls and SHT patients. There were significant negative correlations with TC, LDL and endothelial dysfunction and significant positive correlation with HDL. A significant negative correlation existed between TUG1 and miR-145.

TUG1 could be considered a powerful diagnostic tool to distinguish HT patients, while miR-145 could serve as a negative independent predictor for the progression of HT among subclinical patients. TUG1/miR-145 trajectory could affect the progression of hypothyroidism and the incidence of cardiovascular diseases through impacting patients' lipid profile and endothelial integrity. They could be potential biomarkers and predictors for hypothyroidism pathophysiology.