Diffuse idiopathic skeletal hyperostosis (DISH) is a poorly understood, systemic condition characterized by progressive calcification and ossification of ligaments and entheses with marked predilection for the axial skeleton [1-2]. DISH is associated with metabolic syndrome (MS) and its risk factors, especially obesity and type 2 diabetes mellitus [3-4]. These were also reported in patients with ankylosing spondylitis (AS), the inflammatory counterpart of DISH also known to involve entheses of the axial and peripheral sites [5]. Obesity can be measured, in addition to traditional measurement methods...

Abdominal CT examinations of 43 DISH (diagnosed by Resnick radiographic criteria), 31 AS (diagnosed by Modified New-York Criteria [11]) and 42 age-and gender matched (to DISH) control subjects (Males: 29/29/27; mean age: 71.74/56.1/72.71 years, respectively) were evaluated retrospectively and compared for VAT and SAT adipose tissue surface areas on axial mid-L3, L4, L5 levels. Visceral and subcutaneous fat boundaries were registered manually by a single reader on each mid-vertebral level in which adipose tissue volume was then computed as shown in Figure 1. Adipose tissue...

Gender distribution was similar in all 3 groups but AS subjects were significantly younger compared to the DISH and controls. ICC values for VAT and SAT measurements on all evaluated levels reached almost perfect agreement (ICC>0.95, p<0.0001). Results of average VAT, SAT areas and VAT/SAT ratio at L3 level are shown on Figures 2a-c. No significant difference was seen between average VAT or SAT surface areas of DISH and AS subjects (also after correction for age using multivariate analysis). Average VAT area was significantly larger...

The higher VAT surface area in DISH and the VAT/SAT ratio in both DISH and AS complement well with the known association of both diseases with MS and cardiovascular risks. Though DISH and AS are different in their age distribution and disease manifestations, it is becoming more and more apparent that some shared pathogenic mechanisms exist between the two diseases [12-13]. A potential pathogenic link between the two diseases may be visceral fat accumulation and adipokines unbalanced secretion, potentially leading to both entheseal bone proliferation...

Dan Lantsman C, MD Department of Diagnostic Imaging, Sheba Medical Center, Sackler school of medicine , Tel Aviv University, Israel Emek HaEla st1, Ramat Gan phone: +97235302530 email: [email protected]

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