Utility of Epicardial Fat Thickness in Subclinical Hypothyroid Children to Determine Existence of Subclinical Atherosclerosis in Them

Abstract

Context:

Adult studies have shown the association of subclinical hypothyroid (SCH) with various cardiovascular dysfunction, which indicates SCH may be a potentially modifiable risk factor of CV disease and mortality. However, there is still controversy about the association of cardiovascular dysfunction in children with SCH. Epicardial fat thickness (EFT) is a reliable and sensitive marker of cardiovascular risk and has become an emerging modality to predict CV risks.

Aims:

To measure the EFT in children with subclinical hypothyroidism and compare with healthy children. To find its correlation with subclinical atherosclerosis. To compare EFT between TPO positive and TPO negative subclinical hypothyroid patients.

Materials and Methods:

Children of subclinical hypothyroidism (TSH >5 mIU/ml with normal FT3, FT4, and age and sex matched control were included as per inclusion and exclusion criteria. Clinical data was collected from all study subjects. Thyroid function tests including FT3, FT4 and TSH, TPO antibody, fasting insulin, hsCRP, Lp(a), USG neck for carotid intima media thickness (CIMT), USG brachial artery for flow mediated dilation (FMD) and echocardiography for epicardial fat thickness (EFT) were done in all patients.

Results:

A total 42 number of SCH and 50 age and sex matched controls were recruited and screened for various parameters of subclinical atherosclerosis. EFT was significantly higher in the cases than in the controls (6.27 mm vs 4.54 mm) with P value < 0.001. Brachial FMD was significantly lower in cases than the cohort (4.5% vs 8.93%, P < 0.001). Difference in CIMT was not significant amongst the cases and controls. EFT failed to correlate with the level of TSH though it had significant positive correlation with hsCRP. The patients who were TPO positive, had higher fasting insulin, HOMAIR, hsCRP, Lp(a) than those who were TPO negative.

Conclusion:

Results of this study show the presence of subclinical atherosclerosis in children with SCH regardless of the aetiologies. The patients of Hashimoto thyroiditis had significantly high insulin resistance and inflammation than the SCH patients of other aetiologies.