A metabolic syndrome in diffuse idiopathic skeletal hyperostosis. A controlled study.

OBJECTIVE

I addition to diabetes mellitus (DM), high incidence of common metabolic conditions such as dyslipidemia (DL) and hyperuricemia (HU) has been found in patients with diffuse idiopathic skeletal hyperostosis (DISH). Our objective was to confirm such observations comparing data from patients with DISH and appropriate controls.

METHODS

One hundred randomly identified inpatients with DISH were compared with 100 DISH-free inpatients with various rheumatic disorders matched for age, sex, body mass index, and excess body weight. The prevalence of metabolic disturbances was compared in the 2 groups. Data was analyzed statistically by chi-squared test and 4-fold table analysis.

RESULTS

In our DISH population, metabolic abnormalities were found in 70%, versus 45% in the control population (p < 0.0001). High prevalence of DL and/or HU associated with DM was observed among patients with DISH (p < 0.0001). Patients with uncomplicated diabetes (or DL or HU) were almost equally distributed between the 2 groups, with no significant differences (p > 0.1). Combined metabolic features of DM+DL, DM+HU, or DM+DL+HU were shown to be the main risk factor for DISH (K = 14). They may constitute a metabolic syndrome with high diagnostic specificity (u = 1.0) and nosologic sensitivity (g = 1.0), despite their lowest prevalence (0.07). Dyslipidemia occurred with the highest prevalence (p = 0.36), the highest positive predictive value (v = 0.44) and, together with HU and diabetes, the highest nosologic specificity (f = 0.55 in both cases).

CONCLUSION

We found metabolic disturbances confined to the group with DISH. Followup studies of the number of bridging ossifications in identically aged patients or bridging ossifications/year/patient could be a useful tool to determine their effect on the extent and progression rates of DISH.