A cross-sectional study of the association between the lymphocyte to high-density lipoprotein ratio and pain in parkinson's disease.

To explore the association between lymphocyte to high-density lipoprotein ratio (LHR) and pain in Parkinson's disease (PD). In this cross-sectional study, 133 inpatients with PD (84 with pain, 49 without pain) were consecutively recruited. Demographic, clinical, and peripheral immune-inflammatory markers were compared between PD patients with and without pain. Risk factors were identified through binary logistic regression. The independent association of the LHR with pain was assessed using multivariable logistic regression, with progressive adjustment for demographic, clinical, and comorbidity factors. Subgroup analyses were conducted to assess the consistency of the association across different clinical subgroups. Compared with patients without pain, those with pain had higher levodopa equivalent daily dose, more severe motor symptoms, greater levels of anxiety, depression, and sleep disturbances, along with elevated LHR. Binary logistic regression identified LHR (odds ratio [OR] = 3.64, 95% confidence interval [CI] 1.56-8.49, P = 0.003) as independent risk factors for pain. In the multivariable model, adjusted for key covariates including age, sex, disease duration, and major comorbidities, LHR remained a significant and independent risk factor (adjusted OR = 4.50, 95% CI 1.77-11.47, P = 0.002). Subgroup analyses confirmed the stability of this association across age, sex, body mass index, hypertension, diabetes, disease duration, and age at onset, with no significant interactions observed (P > 0.05). In this observational study, a higher LHR was positively associated with pain in PD. Future studies should validate these findings and explore LHR-based interventions.