Angiopoietin-like protein 3, 4 and 8 are linked to cardiovascular function in naïve sub-clinical and overt hypothyroid patients receiving levothyroxine therapy
Objective: Angiopoietin-like protein (ANGPTL) 3,4,8 are upcoming cardiovascular biomarkers. Experimental studies showed thyroid hormones altered their levels. We assessed: ANGPTL3,4,8 as predictor of cardiovascular functions among naïve-subclinical and naïve-overt hypothyroidism [SCH and OH]; and altered ANGPTL levels with levothyroxine replacement (LT4) and their association with improved cardiovascular risk factors and cardiovascular function. Design and Methods: Prospective follow-up study assessed ANGPTL3,4,8 levels, vascular status (flow mediated dilation% of brachial artery (FMD%), carotid intima media thickness (CIMT), aortic stiffness index (ASI)), left ventricle (LV) parameters (ejection fraction (EF), myocardial performance index (MPI), LV mass), well-known cardiovascular risk factors and HOMA-IR, at two time points: among naïve -SCH, naïve-OH and healthy subjects groups; and at six months after achieved euthyroid state with LT4 with calculating their increased or decreased delta changes (∆↑ or ∆↓) in longitudinal arm among LT4- hypothyroid groups. Results: Significantly elevated ANGPTL3,4 and 8 among hypothyroid groups than healthy subjects were reduced with LT4. Multivariate analysis revealed ANGPTLs as independent predictors of cardiovascular functions and the contributors for ANGPTL levels: ANGPTL3,4 for impaired FMD% and ANGPTL8 for LVmass among naïve-SCH; ANGPTL3 for EF% and ANGPTL8 for CIMT in naïve-OH; ∆↓ ANGPTL3 for ∆↓ ASI meanwhile ∆↑ freeT4 for ∆↓ ANGPTL3, ∆↓ fasting glucose, ∆↓ triglyceride and ∆↓ thyroid peroxidase antibody for ∆↓ ANGPTL4 among LT4-SCH. ∆↓ ANGPTL4 for ∆↓ MPI and ∆↓ LVmass meanwhile ∆↓ TSH and ∆↓ triglyceride for ∆↓ ntributors for ANGPTL level: ANGPTL3,4 for impaired FMD% and ANGPTL8 for LVmass among naïve-SCH; ANGPTL3 for EF% and g LT4-OH. Conclusion: Elevated ANGPTL3,4,8 levels are differentially independent predictors of endothelial and cardiac function and reduced with LT4 in SCH and OH.