Prevalence and characteristics of diffuse idiopathic skeletal hyperostosis (DISH) in Italy

Diffuse idiopathic skeletal hyperostosis: Imaging findings with special focus on extraspinal involvement

Diffuse Idiopathic Skeletal Hyperostosis (IDHS) is a multifactorial disease with a high prevalence and that is frequently detected incidentally in imaging tests. Most of its diagnostic criteria are focused on axial involvement and more specifically the spine. However, peripheral involvement in DISH is less well known despite its non insignificant frequency. DISH can be associated with serious complications, the most severe being vertebral fractures in low energy trauma and dysphagia or airway obstruction in cervical involvement. Knowing how to identify the patterns of peripheral involvement of DISH and its complications helps in the radiological and clinical management of patients with this disease.

Association between serum interleukin-17 levels and ectopic bone formation in OPLL patients with DISH

OBJECTIVE

To investigate the relationship between the severity and morphology of heterotopic ossification in the spinal ligaments including sacroiliac (SI) joints, and serum interleukin-17 (IL-17) levels in patients with ossification of the posterior longitudinal ligament (OPLL) with or without diffuse idiopathic skeletal hyperostosis (DISH), as well as a non-OPLL group.

METHODS

A total of 103 patients with OPLL [DISH (-), n = 50; DISH (+), n = 53] and 53 age- and gender-matched controls were included. The serum levels of IL-17 were analysed, and the severity of ectopic ossification and the morphology of ectopic bone formation were evaluated. The SI joint morphological variations were categorized into four types.

RESULTS

No significant differences were found in serum IL-17 levels between the OPLL and control groups. However, the DISH (+) group showed higher IL-17 levels than the DISH (-) group, especially in female patients (P = 0.003). Additionally, IL-17 levels were positively correlated with the number of flat vertebral units, this being one of the characteristic DISH ossification types (R2 = 0.199, P = 0.012). IL-17 levels in the type showing bridging osteophyte and bone fusion were significantly higher in the DISH (+) group than in the DISH (-) group.

CONCLUSION

The morphological characteristics of paravertebral bone formation in the entire spine, including the SI joint, are likely associated with serum IL-17 levels in OPLL. These findings provide pathological and serological evidence of local inflammation contributing to paravertebral ossification of OPLL patients.

High prevalence of diffuse idiopathic skeletal hyperostosis (DISH) among obese young patients - A retrospective observational study

OBJECTIVE

Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by ossification of ligaments and entheses, and most commonly affects the spinal column. The prevalence of DISH is increasing with age and is considered uncommon before the age of 50 years, with an estimated prevalence of less than 5 %. DISH is known to be highly associated with metabolic syndrome and obesity. We aim to assess the prevalence of DISH among young (≤50 yr.) patients suffering from severe obesity (BMI of 35 kg/m2 or higher).

METHODS

A retrospective analysis assessing chest and spine radiographs (including Computed Tomography, CT) of patients with BMI≥35 visiting the bariatric ambulatory clinic in an academic medical center from 2013 to 2022. Patients included in the analysis were 31-50 years old. Diagnosis of DISH was made according to the Resnick criteria. The prevalence of DISH was calculated. Demographic, clinical and laboratory data were collected and compared between the DISH and non-DISH groups.

RESULTS

183 young (mean age: 40.4; 118 females, 64.2 %) obese (BMI median: 40.6; range 35-73) patients were included in the radiographic review. DISH was diagnosed in 33 patients (18.0 %; 95 % CI: 13.1-24.2 %) which was significantly higher than the expected 10 % (Z = 3.62, p<.001); another 8 patients (4.4 %; 95 % CI: 2.2-8.4 %) were considered as "near DISH" (not fulfilling yet the Resnick criteria) as it represents a pre-disease state. Patients diagnosed with DISH were significantly older than patients without DISH (t = 4.54, p<.001), as the prevalence of DISH increased by age (linear association=14.95, p<.001). There was a statistically significantly higher prevalence of hypertension (χ2 = 8.30, p<.004), smoking (χ2 = 4.69, p<.03) and OSA (χ2 = 6.16, p<.013) in the DISH group as compared to their non-DISH counterparts.

CONCLUSION

The prevalence of DISH among obese young patients was 18 %, which is much higher than in the general population. Early-onset DISH should be regarded as a musculoskeletal obesity-related complication.

The prevalence and characteristics of diffuse idiopathic skeletal hyperostosis in the community-living middle-aged and elderly population: The Yakumo study

BACKGROUND

The incidence of diffuse idiopathic skeletal hyperostosis (DISH) is increasing with the aging of the population. Asymptomatic DISH can decrease the spinal range of motion (ROM) and cause fractures. However, the prevalence or physical function of patients with DISH before experiencing fractures and other serious conditions is unclear. This study aimed to investigate the prevalence of DISH in the community residents on the basis of age and sex and characterize their physical function, ROM, and bone fragility.

METHODS

The subjects were community volunteers who attended a health checkup in 2018 and 2019. Overall, 455 subjects (mean age, 64.2 ± 9.7 years; 177 men) were included for analysis. We performed whole-spine lateral radiography for detecting DISH according to the criteria reported by Resnick. We compared the age, sex, body mass index (BMI), results of muscle strength and walking tests, ROM measured by SpinalMouse®, and quantitative ultrasound (QUS) of calcaneus with and without DISH.

RESULTS

DISH was detected in 83 (18.2%) cases. The DISH group was older (69.8 y.o. vs. 63.0 y.o.; p < 0.05) and comprised more men (prevalence: men, 27.7%; women, 12.2%; p < 0.001). BMI was high in the DISH group (24.8 vs. 23.3 kg/m2, p < 0.05). SpinalMouse measurements showed the DISH group had a significantly decreased ROM in the lumbar spine (43.2°, 57.2°, p < 0.05). The DISH group had a significantly lower T-score on the QUS measurement in the calcaneus (-2.0, -1.5, p < 0.05). There were, however, no significant differences between groups in both muscle strength test and walking test.

CONCLUSION

Subjects with DISH had decreased ROM in the lumbar spine and bone mineral density in calcaneal QUS. However, physical functions such as muscle strength and walking ability were similar among subjects with and without DISH without subjective symptoms.