“Changes in hemogram-derived inflammatory markers before and after treatment in different etiologies of thyrotoxicosis: a retrospective cohort study”

Hemogram-derived inflammatory indices, including the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV), have been investigated in thyroid and systemic inflammatory disorders. However, their longitudinal patterns across different etiologies of thyrotoxicosis remain incompletely characterized. This study aimed to evaluate changes in these indices over 12 months according to thyrotoxicosis etiology. This retrospective cohort study included 201 adults with subacute thyroiditis (SAT), Graves’ disease, toxic multinodular goiter (TMNG), or toxic adenoma. Laboratory measurements were evaluated at baseline and at 1, 3, 6, and 12 months. Primary longitudinal analyses included SAT, Graves’ disease, and TMNG (n = 195); toxic adenoma (n = 6) was retained for descriptive analyses only. Age- and sex-adjusted linear mixed-effects models assessed disease-by-time interactions. NLR and PLR were natural-log transformed, MLR was cube-root transformed, and MPV was analyzed on its original scale. All available repeated observations were included without imputation of missing follow-up values. Disease-by-time interactions were significant for NLR (F(8, 292.433) = 8.080, p < 0.001), MLR (F(8, 263.220) = 3.298, p = 0.001), PLR (F(8, 320.648) = 11.496, p < 0.001), and MPV (F(8, 329.878) = 2.616, p = 0.009). In SAT, NLR and PLR declined markedly and remained lower throughout follow-up, while MLR also decreased significantly. Graves’ disease showed more limited longitudinal changes, whereas TMNG showed no clear overall temporal change in these inflammatory ratios. MPV increased modestly in SAT, particularly at 6 and 12 months, but remained stable in Graves’ disease and TMNG. Hemogram-derived inflammatory indices show distinct longitudinal patterns according to thyrotoxicosis etiology, with the most pronounced changes occurring in SAT. These findings support their biological responsiveness to inflammatory activity but do not establish incremental clinical utility over established inflammatory markers such as C-reactive protein or erythrocyte sedimentation rate. Prospective studies are needed to clarify their independent diagnostic, prognostic, and monitoring value. Longitudinal changes in NLR, MLR, PLR, and MPV differed significantly according to thyrotoxicosis etiology. The most pronounced reductions in NLR, MLR, and PLR were observed in patients with subacute thyroiditis, whereas changes were more limited in Graves’ disease and minimal in toxic multinodular goiter. MPV showed a modest longitudinal increase in subacute thyroiditis, particularly at 6 and 12 months, while remaining stable in Graves’ disease and toxic multinodular goiter. Hemogram-derived inflammatory indices appear to reflect inflammatory activity, but their incremental clinical value beyond established markers such as CRP and erythrocyte sedimentation rate remains uncertain.