Vitamin D dynamics predict treatment response to intravenous glucocorticoids in thyroid-associated ophthalmopathy: a retrospective cohort study

BackgroundIntravenous glucocorticoids (IVGC) represent first-line therapy for active moderate-to-severe thyroid-associated ophthalmopathy (TAO). The relationship between vitamin D (VitD) and IVGC efficacy in TAO remains undefined.MethodsThis retrospective study grouped TAO patients completing IVGC therapy with standardized VitD/calcium supplementation at First Affiliated Hospital of Xi’an Jiaotong University (2015–2019).

Serum 25-hydroxyvitamin D (25(OH)D) and bone markers were measured pre/post-treatment. Multivariate regression and ROC analysis identified predictors.ResultsIn total, 52 TAO patients were enrolled, including 33 responders and 19 non-responders.

Non-responders had significantly higher baseline triglycerides, thyroxine and longer duration of ophthalmopathy. Responders exhibited higher baseline β-CTX and N-MID OC.

Notably, 73.08% of patients had baseline 25(OH)D deficiency (<20 ng/mL), with a significant 25(OH)D increase observed only in responders (P = 0.02). Between-group comparison showed that the treatment-induced change in 25(OH)D (Δ25(OH)D) was significantly greater in responders (P = 0.008), who also demonstrated larger improvements in clinical activity score (CAS), NOSPECS score, and diplopia.

Multivariate analysis confirmed Δ25(OH)D as an independent predictor after adjustment for confounders (adjusted OR = 1.205, 95% CI:1.033–1.405; P = 0.017).