Background: Hypothyroidism due to autoimmune thyroiditis leads to atherogenic lipid profile and metabolic changes. The formation of advanced glycation end products (AGEs) increases with hyperglycemia, hyperlipidemia and oxidative stress. Degradation of AGEs after AGEs-receptor 1-mediated intracellular uptake and renal clearance of soluble AGEs generated by certain cells like macrophages play a crucial role in the decrement of circulating AGEs level. Chemerin is an adipokine produced by adipose tissue and liver and acts as a chemoattractant for immune cells and promotes adipocyte differentiation. Chemerin also appears to induce insulin resistance in skeletal muscle. To date, the association of AGEs and chemerin has not been investigated in thyroid disorders.
Subjects and Methods: In our study we investigated the association between thyroid hormone levels, thyroid antibodies, the components of lipid metabolism, renal and liver function, anthropometrical parameters and AGEs. We enrolled one hundred and ten patients (9 men, 101 women, mean age 49.3±16.7 years, mean BMI 27.5±5.8 kg/m2) from the outpatient clinic of Endocrine Department of University of Debrecen, Faculty of Medicine. All patients had autoimmune thyroiditis with various thyroid hormone status from hypo- to hyperthyroidism. Serum AGEs concentrations were determined by autofluorescence. Thyroid hormone levels, anti-thyroperoxidase (aTPO) concentration and lipid parameters were measured by routine laboratory methods. Chemerin levels were measured by ELISA method.
Results: Median serum AGEs level was 10.4 (9.4 11.8) AU/μg protein, median chemerin level was 91.2 (79.8 104.8) ng/ml, while mean total cholesterol level was 5.3±1.1 mmol/l. Mean fT3 and fT4 were 4.56±0.76 and 17.8±3.7 pmol/l, respectively. Significant negative correlation was found between fT3 and log AGEs/total protein levels. There was a significant correlation between log chemerin, total cholesterol, log creatinine, log ApoB100 and log AGEs/total protein levels. However, we could not find correlation between log AGEs/total protein levels and aTPO levels.
Conclusions: The significant negative correlation between log AGEs/total protein levels and fT3 levels might be the consequence of T3 regulatory effect on metabolism. However, further clinical investigations are needed to clarify this relationship.
21 May 2022 - 24 May 2022