Examining the Association Between the Extent of Anterior Longitudinal Ligament Ossification Progression and Comorbidities in Diffuse Idiopathic Skeletal Hyperostosis.

Background:  It has been documented that diffuse idiopathic skeletal hyperostosis (DISH) exhibits a higher prevalence among elderly, male, and obese individuals. Additionally, diabetes mellitus and other comorbidities are more frequently observed in this patient population. However, there is a lack of reports exploring the correlation between the extent of ossification and these demographic and clinical characteristics.

Objective: To examine the correlation between comorbidities and the severity of ossification of the anterior longitudinal ligament in patients with DISH.

Materials And Methods: The study included 468 patients who visited our hospital in 2018-2022. They were divided into DISH and non-DISH groups based on computed tomography image evaluation according to the Resnick criteria. The patients in the two groups were matched for age and sex. We compared comorbidity-related factors including body mass index (BMI), serum markers for metabolic syndrome and renal function, and hemoglobin A1c (HbA1c) levels between the matched groups. Moreover, we examined the correlation between the number of fused vertebral bodies and comorbidity-related factors, age, and sex within the DISH group.

Results: The DISH group included significantly more men and elderly patients than the non-DISH group. Furthermore, the average BMI and HbA1c levels were significantly higher in the matched-DISH group than in the matched-non-DISH group, whereas no differences were observed in other markers. In the DISH group, the number of fused vertebral bodies did not correlate with age, sex, BMI, or HbA1c levels.

Discussion: BMI and HbA1c levels were significantly higher in patients with DISH than those without; however, the number of fused vertebral bodies and the possibility of having coexisting obesity or diabetes mellitus showed no correlation with the age or sex of the patient. Therefore, each patient should be carefully assessed for ossification severity regardless of age, sex, and the comorbidities they possess.