Platelet-related thromboinflammatory indices and coronary artery calcium burden in fibromyalgia patients undergoing coronary CT

Abstract Background Fibromyalgia is traditionally considered a disorder of central pain processing; however, systemic inflammatory, autonomic, and vascular alterations have also been described. Objective imaging-based data evaluating coronary artery calcium (CAC) burden in fibromyalgia remain limited. The association between CAC burden and platelet-related thromboinflammatory indices has not been well established. Methods This retrospective cross-sectional study included 139 patients with fibromyalgia and 62 non-fibromyalgia individuals who underwent coronary computed tomography for clinical indications. Fibromyalgia patients were stratified according to CAC score (< 100 and ≥ 100), with additional exploratory analyses using a CAC threshold of ≥ 400. Platelet-based and composite thromboinflammatory indices, including the mean platelet volume-to-platelet ratio (MPV/PLT), were evaluated. Associations with CAC burden were assessed using correlation analyses, receiver operating characteristic (ROC) curve analysis, and multivariable logistic regression models. Results MPV/PLT showed a statistically significant but small-magnitude correlation with CAC score that remained significant after FDR adjustment ( r = 0.275, nominal p = 0.001, q = 0.008). In ROC analysis, MPV/PLT showed limited discriminatory performance for identifying CAC ≥ 100 (AUC 0.65) and CAC ≥ 400 (AUC 0.68), while other composite indices showed poor discriminatory performance. In the primary multivariable model, MPV/PLT was associated with CAC ≥ 100 after adjustment for selected cardiovascular risk factors; however, this association was attenuated and no longer reached conventional statistical significance after additional adjustment for medication use. Analyses using the CAC ≥ 400 threshold were considered exploratory because of the limited number of events. VAS pain and VAFS scores showed positive correlations with CAC, whereas FIQR was not significantly associated with CAC. Conclusions In selected fibromyalgia patients undergoing coronary computed tomography, MPV/PLT showed a statistically significant but small-magnitude correlation with CAC score and a graded increase across CAC categories. However, the association was no longer statistically significant after adjustment for medication exposure, and its discriminatory performance was limited. These findings support further investigation of MPV/PLT in an exploratory research context but do not establish an independent biomarker relationship or clinical utility.