Detection of unsaturated disaccharides, pyridinoline, and hydroxyproline in urine of patients with Kashin-Beck disease: comparison with controls in an endemic area.

OBJECTIVE To investigate the pathologic status of adult patients with Kashin-Beck disease (KBD) in an endemic area of China through detection of 5 biochemical markers in their urine, and to study the correlations between these markers and KBD. METHODS A total of 55 patients with KBD over age 40 years were recruited and divided into groups, Grade 1 and Grade 2, according to clinical diagnosis criteria for KBD and our inclusion criteria; 25 healthy persons were enrolled into a control group. The first-time urine of the 80 participants was collected in the morning. Three unsaturated disaccharides, pyridinoline (PYD), and hydroxyproline (HYP) were detected in urine samples with high performance liquid chromatography, ELISA, and a chemical kit. Mean levels of these markers were compared in the 3 groups. RESULTS The mean concentrations of 3 unsaturated disaccharides and PYD in the Grade 2 group were significantly higher than levels in the Grade 1 group and controls (p<0.05). There was no significant difference between findings in the Grade 1 group and controls. Levels of 3 unsaturated disaccharides correlated with each other (p<0.01). The correlation coefficient between PYD and HYP was 0.470 (p<0.01). Except for HYP, the other markers all correlated with grade of KBD, rather than age or sex of subjects. CONCLUSION The cartilage degradation of patients with Grade 2 KBD was more severe than that of Grade 1 patients and controls. The pathologic condition of Grade 1 patients was mild. Except for HYP, the markers we investigated specifically reflected the pathologic bone metabolism of adult patients with KBD. Trial registration number ChiCTR-TRC-00000140.