Metabolic syndrome loses its predictive power in late-stage chronic kidney disease progression - A paradoxical phenomenon

Background: Metabolic syndrome (MS) is a significant determinant of CKD. The aim of this study was to determine the possible impact of MS on CKD progression. Methods: 746 CKD subjects were included. The presence of MS was determined according to the modified criteria proposed by the Adult Treatment Panel (ATP) III. The study endpoints were stage-to-stage CKD progression or starting renal replacement therapy during the study period. CKD Stages 1, 2 and 3 were defined as early-stage CKD, while CKD Stages 4 and 5 were defined as late-stage CKD. Results: Early-stage CKD patients with MS had a higher risk of CKD progression than those without MS. Cox regression analysis showed that MS was a significant determinant of CKD progression in early-stage (HR: 1.60, p = 0.041) but not late-stage CKD patients (HR: 1.00, p = 0.975). The results of subgroup analysis in non-diabetic subjects also showed that only early-stage CKD subjects with MS had significant risks of CKD progression (HR: 2.21, p = 0.010). In diabetic patients, the association between MS and CKD progression was not significant in both early- and late-stage CKD. Conclusions: Our findings suggested that the impact of MS on CKD progression might be prominent in non-diabetic early-stage CKD subjects, and became non-significant in diabetic late-stage CKD and diabetic CKD patients.