The correlation of lipid profile with subclinical and overt hypothyroidism: A cross-sectional study from Syria

Abstract

We proceeded with this study to investigate the relationship between hypothyroidism and lipid profile disturbance. A cross-sectional study at Al- Mowasat University Hospital in Damascus was conducted from March 2021 to March 2022, and included 324 adults. For each participant with abnormal thyroid stimulating hormone (TSH), free thyroxine (FT4) was requested. The participants were categorized into 3 groups: euthyroid (226 participants), subclinical hypothyroidism (SCH) (75 participants), and overt hypothyroidism (23 participants). Fasting lipid profile was tested as: cholesterol (Chol), triglycerides (TG), low density lipoprotein (LDL), and high density lipoprotein (HDL). A significant relationship between hypothyroidism and dyslipidemia was noticed. LDL, TG, and Chol but not HDL showed a significant difference between study groups (euthyroidism, subclinical, and overt hypothyroidism). The lowest levels of these parameters were in euthyroidism and increased in subclinical and overt hypothyroidism subsequently. Overt hypothyroidism showed a significant difference in LDL, TG, and Chol compared to euthyroidism, however, we did not find a difference in lipid parameters in SCH compared to euthyroidism. LDL and Chol showed significant differences between subclinical and overt hypothyroidism. TSH had a positive weak correlation with LDL, TG, and Chol, however, there was no correlation with HDL. Also, FT4 had a negative weak correlation with LDL, TG, and Chol, however, there was a positive correlation with HDL. Our findings suggest a higher level of lipids (LDL, TG, and Chol) among SCH and overt hypothyroidism compared to general population. A weak correlations of lipid parameters with TSH and FT4 were detected. It is not well evident whether a restoration of euthyroidism might influence the morbidity and mortality, especially cardiovascular comorbidities, in this population, which mandates future studies.