Effects of atorvastatin on renal function in patients with dyslipidemia and chronic kidney disease: rationale and design of the ASsessment of clinical Usefulness in CKD patients with Atorvastatin (ASUCA) trial.

BACKGROUND: Since dyslipidemia has been shown to be an independent risk factor for the progression of chronic kidney disease (CKD), low-density lipoprotein cholesterol (LDL-C)-lowering therapy can be potentially associated with inhibition of CKD progression. The ASsessment of clinical Usefulness in CKD patients with Atorvastatin (ASUCA) trial was designed to determine whether atorvastatin has protective effects on renal function in patients with dyslipidemia and CKD.

METHODS: We decided to carry out a prospective multi-center, open-labeled, randomized trial to compare the reno-protective effects between diet therapy alone and atorvastatin plus diet therapy in patients with dyslipidemia (LDL-C ≥ 140 mg/dL if not treated or LDL-C ≥ 100 mg/dL if treated with lipid-lowering drugs in subjects taking dyslipidemia-treating agents other than statins) and CKD [estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2)]. The primary endpoint is the change in eGFR (mL/min/1.73 m(2)) as calculated by the modified MDRD equation for Japanese after 2 years of treatment.

RESULTS: Enrollment began in April 2009 and was completed in March 2011. A total of 334 patients (213 male and 121 female) were randomly assigned to either diet therapy alone or atorvastatin plus diet therapy and included in an intent-to-treat population. In the atorvastatin and control groups, the mean ages were 63.2 and 63.1 years, mean eGFRs were 55.9 and 54.0 mL/min/1.73 m(2), and median urinary albumin/creatinine ratios were 24.9 and 29.1 mg/g, respectively.

CONCLUSIONS: This study distinguishes itself from similar studies by increasing statistical accuracy derived from its significantly larger sample size and longitudinal magnitude. The results of this study will help to determine whether atorvastatin has reno-protective effects in patients with dyslipidemia and CKD.