The alteration of urinary metabolomics profiles in Kashin-Beck disease in a three consecutive year study

Kashin-Beck disease (KBD) is a serious, endemic chronic osteochondral disease characterized by symmetrical enlargement of the phalanges, brachydactyly, joint deformity, and even dwarfism. To investigate the urinary metabolomic profiles of KBD patients, we performed an untargeted metabolomics approach using liquid chromatography coupled with mass spectrometry (LC-MS). Adult urinary specimens were collected from 39 patients with KBD and 19 healthy subjects; the children's urinary specimens were collected from 5 patients with KBD, 25 suspected KBD cases and 123 healthy subjects in the KBD endemic area during a three consecutive year study. We identified 10 upregulated and 28 downregulated secondary level metabolites highly associated with aetiology and pathogenesis of KBD between adult KBD and adult controls. A total of 163, 967 and 795 metabolites were significantly different in the urine among children with KBD, suspected children with KBD cases and healthy child controls, respectively, for each year in three consecutive years. HT-2 toxin, Se-adenosylselenomethionine (AdoSeMet), the toxin T2 tetrol, and many kinds of amino acids were identified as differential metabolites in this study. Amino sugar and nucleotide sugar metabolism, fructose and mannose metabolism, arachidonic acid metabolism, D-glutamine and D-glutamate metabolism, ubiquinone and other terpenoid-quinone biosynthesis, and D-glutamine and D-glutamate metabolism were perturbed pathways in adult and child KBD patients. Our study provides new insight into the underlying mechanisms of KBD, and suggests that we should pay more attention to these differences in small-molecule metabolites and metabolic pathways in the environmental aetiology and pathogenesis of KBD.