Assessment of early vascular dysfunction in drug-naïve hypothyroid patients and its correlation with serum endocan: a case–control study

Abstract Background Atherosclerosis risk is increased in hypothyroidism, largely due to early endothelial dysfunction. Non-invasive markers such as carotid intima-media thickness (CIMT), flow-mediated dilatation (FMD), and pulse wave velocity (PWV) are useful for detecting subclinical vascular changes. Endocan, a proteoglycan secreted by endothelial cells, has emerged as a potential biomarker of endothelial dysfunction. This study aimed to assess endothelial function and arterial stiffness in clinical and subclinical hypothyroidism using CIMT, PWV, and FMD, and to explore their correlation with circulating endocan levels. Methods The study comprised ninety-six Egyptian adult females ranging from 18 to 60 years of age, enrolled from the endocrinology department at Kasralainy hospital between March 2023 and July 2024. Participants were stratified into three distinct groups: Group (I) consisted of 32 individuals with clinical hypothyroidism, Group (II) included 32 patients presenting subclinical hypothyroidism (SCH), and Group (III) encompassed 32 euthyroid healthy controls matched for age and gender. Anthropometric parameters encompassing weight, height, and body mass index were documented, along with systolic and diastolic blood pressure measurements, fasting glucose concentrations, lipid profiles, TSH levels, and serum Endocan values. Furthermore, carotid intima-media thickness (CIMT) assessment was conducted using high-resolution color-coded Doppler ultrasonography, endothelial function evaluation was performed via flow-mediated dilatation (FMD) testing, and arterial stiffness assessment was accomplished through carotid-femoral pulse wave velocity (cfPWV) determinations. Results Carotid intima-media thickness (CIMT) demonstrated significantly elevated values in both clinical hypothyroid and SCH group relative to the control population (P< 0.001). Carotid-femoral pulse wave velocity (cf-PWV) measurements revealed statistically significant elevation in the clinical hypothyroid group when compared with control subjects (P= 0.037). Circulating endocan concentrations showed no statistically significant variations across clinical hypothyroid (34.43±42.76), SCH (31.88±28.55), and healthy control groups (33.85±34.39), P= 0.442. Furthermore, endocan levels exhibited no correlations with age, BMI, fasting plasma glucose, HbA1C, lipid parameters, thyroid function markers, CIMT, FMD, or cf-PWV measurements. Summary: Endothelial dysfunction, arterial stiffness, and vascular wall thickening manifest in hypothyroid patients. Additionally, endothelial dysfunction and arterial wall thickening emerge during the subclinical phase. Flow-mediated dilatation (FMD), cf-PWV, and CIMT represent non-invasive diagnostic modalities suitable for early identification of vascular impairment in hypothyroid individuals. Endocan does not constitute an appropriate biomarker for endothelial dysfunction assessment within the context of hypothyroidism among Egyptian female populations.