Neutrophil-to-lymphocyte Ratio and Platelet-to-lymphocyte Ratio in the Patients with Euthyroid Hashimoto's Thyroiditis.

Objective: This study aimed to compare the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) values in patients with euthyroid Hashimoto's thyroiditis (HT) with healthy control subjects.

Methods: This was a single-center, retrospective, cross-sectional study conducted on obese patients aged 18 years and over. The medical records of patients who presented with complaints of being overweight at the obesity clinic between April 2017 and May 2019 were examined. Patients and healthy individuals were included in the study consecutively until the sample sizes reached saturation. Patients with diabetes, cardiovascular disease, chronic inflammatory disease, and malignancy were excluded from the study. The patients' anthropometric measurements, smoking status, blood examination, and thyroid ultrasounds were evaluated. The difference in means between the groups was calculated using the Mann-Whitney U test.

Results: The study included 179 participants, consisting of 93 patients and 86 healthy controls. The mean age was 46.6±14.1 years, with most females (91.6%). Although the NLR and PLR values in patients were higher than those in the control group, the difference did not reach statistical significance (p=0.427 and p=0.089, respectively). Furthermore, no significant difference was observed in NLR (p=0.191) and PLR (p=0.668) values between levothyroxine-treated and untreated patients. Correlation analysis revealed weak positive associations between C-reactive protein and thyroid peroxidase antibodies (p<0.05), neutrophils (p<0.01), platelets (p<0.01), and NLR (p<0.05).

Conclusions: The findings of this study suggest that NLR and PLR may not serve as effective indicators of systemic inflammation in patients with euthyroid HT, nor do they adequately assess the impact of levothyroxine usage on systemic inflammation.