Diffuse idiopathic skeletal hyperostosis: diagnosis in a palaeopathological context.

Clinically, the presence of diffuse idiopathic skeletal hyperostosis (DISH) has been linked to a disturbance of glucose and insulin metabolism, hypertension, dyslipidemia and obesity associated with a rich diet. The prevalence of DISH in archaeological skeletal samples may therefore be a valuable indicator of their socio-economic status when compared to other contemporary groups. However, various methods are currently being used to diagnose DISH. The purpose of this study was therefore to assess the comparability of results obtained using four different diagnostic methods to estimate the prevalence of DISH in a skeletal sample, and to discuss the implications of the results in relation to palaeopathological health assessments. Four different diagnostic criteria were applied to 127 male and 113 female skeletons to diagnose DISH. Skeletal remains were obtained from two 16th century samples from Delft and one modern sample from the anatomy dissection hall of the Leiden University Medical Centre. The estimated prevalences were statistically compared. Special attention was also given to the distribution of extra-spinal enthesophytes described in diagnostic criteria, in order to assess their diagnostic value. The prevalence of DISH observed in the skeletal samples varied significantly depending on the criteria used for diagnosis. Furthermore, extra-spinal enthesophytes, suggested as being indicative of DISH, proved to be variable and unreliable. It was concluded that it is of great importance to explicitly state and adhere to criteria employed for diagnosing DISH in both palaeopathological and clinical investigations in order to ensure reliable comparisons between studies. Also, DISH cannot be positively diagnosed solely based on the presence of extra-spinal enthesophytes.