Weight Loss Improves Renal Hemodynamics in Patients With Metabolic Syndrome

Non-diabetic patients with MS were recruited from an outpatient clinic at the Division of Nephrology of the Federal University of Juiz de Fora, Brazil. MS was defined according to the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII). The study was divided into two phases: phase 1 (baseline) and phase 2 (intervention). At the first study visit, a full medical history was taken and a clinical examination was performed. Blood samples were taken to determine plasma glucose levels, both after fasting and 2 h after a 75-g oral glucose overload (oral glucose tolerance test; OGTT), as well as levels of plasma insulin, creatinine, total cholesterol, HDL-cholesterol, triglycerides, and uric acid. At visit 2, the preliminary results were evaluated and urine samples were collected in duplicate for measurement of microalbuminuria. Creatinine clearance was estimated using the Cockcroft-Gault formula, corrected for body surface area. The subjects were kept free of any medication (statins, antihypertensive, and anti-inflammatory drugs) over the entire study period. The only medications allowed during the study were analgesics such as dipyrone and hioscin. At visit 3, each patient was evaluated by a registered dietitian with expertise in medical nutrition therapy with the aim of achieving a weight loss of at least 5% from baseline. Patients were commenced on a 12-week calorie-restricted diet consisting of 50% carbohydrate, 20-25% protein, and 25-30% fat. The patients were evaluated by the dietitian every 2 weeks. At the final visit all laboratory tests were repeated. At the end of phase 2, patients were divided into two groups: responders, who had achieved at least a 5% reduction in body weight and non-responders, who had not achieved the target weight reduction.