EP242 - ECE_2607 - “Serum inflammation-based scores (SIBs) in primary hyperparathyroidism: association with biochemical severity and postoperative outcomes”

Abstract

Primary hyperparathyroidism (PHPT) is a chronic endocrine disorder increasingly associated with low-grade inflammation, partly caused by persistently elevated parathyroid hormone (PTH) levels. Serum inflammation-based scores (SIBS), obtained from routine blood tests, are widely used as markers of inflammation in various clinical settings; however, their role in primary hyperparathyroidism remains poorly defined. The aim of this study was to assess the association between SIBS and the biochemical severity of primary hyperparathyroidism, to evaluate gender differences in these markers, and to analyze their changes after parathyroidectomy. This retrospective single-center study included patients with primary hyperparathyroidism treated between 2020 and 2025 in our clinic. Of the 279 initially identified patients, 153 with complete preoperative laboratory data were included in the analysis. The analyzed inflammation-based scores included the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and the systemic immune-inflammation index (SII: platelets × neutrophils/lymphocytes). Associations between serum calcium, PTH, and SIBS were assessed using correlation analyses and multivariable linear regression models. Postoperative follow-up data were available for 19 patients, allowing for paired pre-post comparisons using Student's t-test or the Wilcoxon signed-rank test, as appropriate. P value < .05 was considered statistically significant. The final cohort consisted of 153 patients (127 females, 26 males). Due to the non-normal distribution of the data, nonparametric analyses were used. Male patients demonstrated significantly higher MLR and NLR values ​​compared to females (P = .0014 and P = .024, respectively). Significant associations were observed between SIBS and biochemical markers of PHPT. Serum calcium levels showed positive correlations with NLR (P < .001), MLR (P = .002), and SII (P < .001). Similarly, PTH levels positively correlated with NLR (P < .001), MLR (P < .001), and SII (P < .001). In multivariate analysis, MLR was independently associated with PTH, age, and male sex. All inflammation-based scores showed a numerical decrease after parathyroidectomy; however, a statistically significant reduction was observed only for PLR (mean change −34.2, P = .046). Changes in MLR, NLR, and SII did not differ significantly, most likely due to the limited number of patients with available postoperative complete blood count with differential. Serum inflammation-based scores are associated with the biochemical severity of primary hyperparathyroidism. Sex-related differences were observed, with higher MLR and NLR values in male patients. Although SIBS tended to decrease after parathyroidectomy, larger studies with bigger follow-up are needed to confirm postoperative changes and clarify their clinical relevance.