Impact of treating the metabolic syndrome on chronic kidney disease.

The metabolic syndrome is defined by the concurrent presence of at least three metabolic disorders that are associated with an increased risk of cardiovascular disease and diabetes. Results from prospective and cross-sectional studies also point to an association between the metabolic syndrome and chronic kidney disease. Visceral obesity and insulin resistance are two important features of the metabolic syndrome that might explain renal injury. We reviewed the literature to examine whether treatment of the metabolic syndrome can favorably influence renal outcomes. Weight loss, regular exercise, and a low-calorie, low-fat diet are first-line treatments of the metabolic syndrome, yet few data are available to indicate that such lifestyle interventions can prevent or reverse renal damage. Similarly, results from few studies show little or no beneficial effect of blood pressure control, use of statins, fibrates, thiazolidinediones or metformin on renal parameters in patients with metabolic syndrome. The reasons for the lack of trials in this research field are also discussed. This Review identifies the need to improve understanding of the role of metabolic syndrome in chronic kidney disease, define consistent criteria for metabolic syndrome and perform clinical trials that analyze renal outcomes as primary end points.