The association of neutrophils with the development of thyroid nodules: a cross-sectional study

The prevalence of thyroid nodules (TN) is increasing, necessitating urgent investigation of preventive measures. Evidence has linked the neutrophil-to-lymphocyte ratio to the development of TN. However, the specific role of neutrophils(NEUT) in TN development remains unclear. This study aimed to investigate the association between NEUT levels and TN presence.

This study included 2,792 participants. Data collected included demographic characteristics (age and gender) and relevant clinical indicators. The association between NEUT levels and TN was analyzed using logistic regression, Restricted Cubic Spline (RCS) models, subgroups and multiplicative interaction analysis.

Univariate logistic regression analysis revealed a significant negative association between NEUT levels and the presence of TN (OR = 0.9149, 95% CI: 0.8598-0.9726). After further adjusting for potential covariates (age, sex, white blood cell count, alanine aminotransferase, serum uric acid, triglycerides, high-density lipoprotein cholesterol, monocyte count, and systolic blood pressure), this inverse association remained statistically significant (OR = 0.8237, 95% CI:0.7116-0.9527). Furthermore, RCS regression analysis indicated a significant linear relationship between NEUT levels and TN risk (P-overall = 0.0267). Subgroup and interaction analyses consistently showed an inverse association between NEUT and TN risk across most strata, with significant heterogeneity in the ALT subgroup (I² = 84.6%, P = 0.011) but no multiplicative interaction (P interaction > 0.05).

Elevated NEUT levels were independently associated with lower odds of TN. This inverse association suggests a potential role of NEUT in the immunological processes related to TN, offering novel insights for further investigation. However, given the cross-sectional design, causality cannot be inferred, and whether modulating NEUT levels may have preventive value remains to be explored in prospective studies.