Metabolic syndrome in severe chronic kidney disease: Prevalence, predictors, prognostic significance and effects of risk factor modification

Background: Metabolic syndrome (MS) is a significant risk factor for cardiovascular disease, mortality and chronic kidney disease (CKD) in the general population. However, the prevalence, predictors, prognostic value and treatment of MS in the CKD population have not been rigorously studied. Methods: The study involved 200 stages 4 and 5 CKD patients enrolled in a randomized controlled trial of intensive multiple risk factor modification (targeting hypercholesterolaemia, hyperhomocysteinaemia, anaemia and disordered bone mineral metabolism) versus usual care. Participants were followed for a median period of 22 months. Results: The overall prevalence of MS was 30.5%. MS was independently predicted by older age, peritoneal dialysis and Maori/Pacific Islander origin. When laboratory parameters were included as covariates, the only significant predictors of MS were higher serum malondialdehyde and lower serum adiponectin concentrations. MS was an independent predictor of time to composite end-point of cardiovascular death, acute coronary syndrome, revascularization, non-fatal stroke and amputation (adjusted hazard ratio 2.46, 95% Cl 1.17-5.18). No significant difference in cardiovascular event-free survival was observed in those allocated to intensive risk factor modification compared with usual care. Conclusion: Metabolic syndrome occurs in 30.5% of stages 4 and 5 CKD patients and is associated with older age, peritoneal dialysis, ethnicity, increased oxidative stress, lower serum adiponectin concentrations and a significantly increased risk of future cardiovascular events. Intervention strategies targeting hypercholesterolaemia, hyperhomocysteinaemia, anaemia and disordered bone mineral metabolism may not be effective in ameliorating the heightened cardiovascular risk of CKD patients with MS.