Evaluation of monocyte / HDL and neutrophil / lymphocyte ratios in patients with hashimoto's thyroiditis

EVALUATION OF MONOCYTE / HDL AND NEUTROPHIL / LYMPHOCYTE RATIOS IN PATIENTS WITH HASHIMOTO'S THYROIDITIS SUMMARY Hashimoto's thyroiditis is one of the most common causes of hypothyroidism in areas with adequate iodine intake and is characterized by chronic inflammatory processes alongside the development of autoantibodies against the thyroid gland. It is believed that the increase in systemic inflammation observed in this disease contributes to oxidative stress, endothelial dysfunction, and an elevated risk of cardiovascular diseases. Parameters such as the neutrophil/lymphocyte ratio and the monocyte/HDL ratio, which are inexpensive and easily measurable, are utilized to assess subclinical inflammation in diseases characterized by systemic inflammation. In this study, we aimed to indirectly evaluate the increased cardiovascular risk associated with systemic inflammation, endothelial dysfunction, and oxidative stress by using the neutrophil/lymphocyte and monocyte/HDL ratios in patients with Hashimoto's thyroiditis. In this retrospective study, we examined the laboratory data of patients aged 18-80 who were diagnosed with Hashimoto's thyroiditis and presented to the internal medicine outpatient clinics of Namık Kemal University Hospital between January 1, 2020, and February 10, 2023. A total of 203 patients meeting the inclusion criteria were divided into two subgroups: 99 with overt hypothyroidism and 103 with subclinical hypothyroidism. The hemogram, TSH, T3, T4, anti-TPO, anti-TG, CRP, and lipid levels of these patients were compared with a control group of 122 completely healthy individuals. The relationship between the neutrophil/lymphocyte ratio and the monocyte/HDL ratio among the overt hypothyroidism, subclinical hypothyroidism, and control groups was evaluated. The overt hypothyroidism, subclinical hypothyroidism, and control groups exhibited similar characteristics in terms of age, sex, smoking status, CRP, sedimentation rate, triglycerides, and LDL levels. No statistically significant differences were found between the groups regarding the neutrophil/lymphocyte ratio and the monocyte/HDL ratio (p=0.507 and p=0.064, respectively). The levels of anti-TPO and anti-TG autoantibodies were found to be significantly higher in patients with subclinical hypothyroidism compared to those with overt hypothyroidism (p=0.001 for both). There was no significant correlation between the neutrophil/lymphocyte ratio and the monocyte/HDL ratio within the overt and subclinical hypothyroidism groups, nor was there a significant relationship between these parameters and the autoantibodies. The neutrophil/lymphocyte ratio in the overt hypothyroidism group was found to be higher than that in the subclinical hypothyroidism group; however, this difference was not statistically significant. The monocyte/HDL ratio, considered another indicator of inflammation, was similar across the groups. In diseases characterized by chronic inflammation, such as Hashimoto's thyroiditis, there is a need for larger-scale, prospectively designed studies to establish the utility of the neutrophil/lymphocyte and monocyte/HDL ratios as indicators of increased inflammation, endothelial dysfunction, and oxidative stress. Keywords: Hashimoto's Thyroiditis, Neutrophil-to-Lymphocyte Ratio, Monocyte-to- HDL Cholesterol Ratio