Early stages of diffuse idiopathic skeletal hyperostosis (DISH) and chronic inflammation: the Camargo Cohort Study.

INTRODUCTION/OBJECTIVES: DISH has traditionally been considered a non-inflammatory rheumatic disorder. Currently, an inflammatory component has been theorized in the early phases of this condition (EDISH). The study is aimed at investigating a possible relationship between EDISH and chronic inflammation. METHOD: Analytical-observational study: participants from the Camargo Cohort Study were enrolled. We collected clinical, radiological, and laboratory data. C-reactive protein (CRP), albumin-to-globulin ratio (AGR), and triglyceride-glucose (TyG) index were assessed. EDISH was defined by Schlapbach's scale grades I or II. A fuzzy matching with tolerance factor = 0.2 was performed. Subjects without ossification (NDISH), sex- and age-matched with cases (1:4), acted as controls. Definite DISH was an exclusion criterion. Multivariable analyses were performed. RESULTS: We evaluated 987 persons (mean age 64 ± 8 years; 191 cases with 63.9% women). EDISH subjects presented more frequently obesity, T2DM, MetS, and the lipid pattern [↑TG ↓TC]. TyG index and alkaline phosphatase (ALP) were higher. Trabecular bone score (TBS) was significantly lower (1.310 [0.2] vs. 1.342 [0.1]; p = 0.025). CRP and ALP showed the highest correlation (r = 0.510; p = 0.0001) at lowest TBS level. AGR was lower, and its correlations with ALP (r = - 0.219; p = 0.0001) and CTX (r = - 0.153; p = 0.022), were weaker or non-significant in NDISH. After adjustment for potential confounders, estimated CRP means for EDISH and NDISH were 0.52 (95% CI: 0.43-0.62) and 0.41 (95% CI: 0.36-0.46), respectively (p = 0.038). CONCLUSIONS: EDISH was associated with chronic inflammation. Findings revealed an interplay between inflammation, trabecular impairment, and the onset of ossification. Lipid alterations were similar to those observed in chronic-inflammatory diseases. Key Points • An inflammatory component has been theorized in early stages of DISH (EDISH) • In EDISH group compared to non-DISH, we observed significantly higher correlations between biomarkers and some relevant variables. In particular, with alkaline phosphatase (ALP) and with trabecular bone score (TBS) • EDISH has shown to be associated with chronic inflammation • The lipid alterations observed in the EDISH group were similar to those observed in chronic-inflammatory diseases.