“…Moreover, variability in urine metabolite concentrations due to diet, lifestyle, volume status, medications, and other factors necessitates rigorous study design and data normalization strategies. Jeon et al [7] investigated the metabolomic profiles in the serum and urine of patients with IgAN to identify potential biomarkers for disease progression. The study included 20 IgAN patients, of whom a proportion exhibited disease progression, with higher urine protein/creatinine ratios than the non-progressor group.…”