Weight Loss Improves Renal Hemodynamics
Condition: Obesity; Metabolic Syndrome; Chronic Kidney Disease
MeSH terms: Kidney Diseases; Renal Insufficiency, Chronic; Metabolic Syndrome; Syndrome; Weight Loss
Study type: Interventional
Phase: Phase 4

Summary: 
      Metabolic syndrome (MS) is a clustering of risk factors for cardiovascular disease (CVD) such
      as hypertension, hypertriglyceridemia, low HDL-cholesterol levels, disorders of glucose
      metabolism, and insulin resistance. A number of associated conditions are included in the MS
      spectrum such as abdominal obesity, systemic inflammatory activation, endothelial
      dysfunction, non-alcoholic fatty liver disease, hyperuricemia, polycystic ovarian syndrome,
      and microalbuminuria. As a consequence, the diagnosis of MS identifies patients who are at
      increased risk for type 2 diabetes mellitus and CVD. In the last few years, the potential for
      MS to trigger renal damage and accelerate the progression of pre-existing nephropathy has
      become a focus of research. Some studies have suggested that MS can influence the development
      of CKD, although the underlying mechanisms are not well understood. In this study, the
      investigators hypothesized that modifying a key component of the MS, namely obesity, could
      attenuate renal damage. The investigators examined the impact of weight loss on creatinine
      clearance and urinary albumin excretion in non-diabetic obese patients with MS.
    

Detailed description: 
      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.
    

Intervention name(s): dietary intervention
Intervention type(s): Other
Intervention description(s): 12-week calorie-restricted diet consisting of 50% carbohydrate, 20-25% protein, and 25-30% fat
Other intervention name(s): calorie-restricted diet
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Supportive Care
Keywords: Obesity; Metabolic Syndrome; Microalbuminuria; Chronic Kidney Disease