Insulin resistance, lipid profile and low-grade inflammation in Hashimoto thyroiditis

• Autor(a) principal: Marta Isabel Sousa Faria Afonso
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/10216/128724
• topic: Medicina clínica; Clinical medicine

BACKGROUNDː Hashimoto thyroiditis (HT) may present different levels of thyroid function impairment. It remains unclear how mild thyroid dysfunction, autoimmunity and chronic inflammation contribute to an increased cardiovascular risk in HT. Therefore, this study aims to assess insulin resistance, lipid panel and low-grade inflammation in HT patients. METHODSː A total of 228 patients with HT were enrolled and divided into 3 groups, accordingly to TSH levels - TSH 0.35-2.49 μUI/ml, TSH 2.50-4.94 μUI/ml and TSH>4.94 μUI/ml. We assessed thyroid function tests and antibodies, lipid profile, insulin resistance indexes, high-sensitivity C-reactive protein, vitamin B12, folic acid and homocysteine. Statistical analysis was made using ANOVA, Student's t-test, Pearson's correlations and multiple linear regression. RESULTSː 93.9% of our population were women and mean age was 47.1±15.4 years. No significant differences were found between groups, regarding age, sex and body mass index (BMI). Homeostasis model assessment-insulin resistance (HOMA-IR) levels were significantly different in the three groups (p<0.001). In the total group, higher TSH values were associated to higher levels of triglycerides (r=0.206, p=0.002) and HOMA-IR (r=0.209, p=0.002), even after adjustment for age, sex and BMI. Thyroid peroxidase antibodies titers correlated positively with total cholesterol (r=0.166, p=0.013), LDL-cholesterol (r=0.173, p=0.010), ApoB (r=0.190, p=0.006) and HOMA-IR (r=0.141, p=0.033). Thyroglobulin antibodies correlated positively with triglycerides (r=0.140, p=0.036). CONCLUSIONSː HT patients with mild thyroid dysfunction present a more atherogenic lipid profile and higher resistance to insulin action. Therefore, screening for cardiovascular comorbidities in these patients is essential to provide an early diagnosis and better treatment decisions.