UMOD and diabetic kidney disease: Subgroup analysis showed that uromodulin level was significantly decreased in DKD regardless of the region of study, in America (SMD: -0.34; 95% CI: -0.51 to -0.17; p < 0.0001), Europe (SMD: -0.54; 95% CI: -1.06 to -0.02; p = 0.04), and Asia (SMD: -0.63; 95% CI: -1.15 to -0.11; p = 0.02), with stronger predictive value in America and Asia than in Europe.