Statin therapy does not appear to reduce progression to kidney failure, according to a new review and meta-analysis. Treatment may mildly reduce proteinuria and decline in estimated glomerular filtration rate (eGFR) in chronic kidney disease (CKD) patients, however.
Since previous studies yielded conflicting results on renal protection, Xiaole Su, MD, and colleagues from Peking University in Beijing, pooled data from 57 randomized controlled trials involving 143,888 adult patients with and without non-dialysis CKD. Most trials compared statins with placebo or usual care; 6 compared statins of various types; and 3 compared doses of the same statin. Patients took statin medication for at least 6 months.
According to findings published in the American Journal of Kidney Diseases, statin treatment did not cut kidney failure events, including a 25%-50% decrease in eGFR, doubling of serum creatinine level, or end-stage renal disease (ESRD). In statin users, eGFR declined more slowly by 0.41 mL/min/1.73m2 per year and proteinuria or albuminuria by -0.65 units. No adverse effects on the kidney were seen from statin use.
Consistent with previous research, statin therapy did reduce cardiovascular events, such as myocardial infarction, stroke, cardiovascular death, and heart failure, in CKD patients by 31%.
The findings align with the Study of Heart and Renal Protection (SHARP), a large trial of 6,245 patients with advanced CKD that found statins did not reduce kidney failure risk or rate of eGFR decline. Other notable research failed to examine clinically relevant renal outcomes.
Dr. Su and colleagues acknowledged that their review might not be the “final answer” as to whether lowering low-density lipoprotein cholesterol levels with statins would slow progression of kidney disease. Evidence supports dyslipidemia as a risk factor for CKD development or progression. Intensive lipid lowering might reduce the risk for kidney failure compared with the usual dose of statins, they noted. Individual statin medications also may differ in the degree of kidney protection they offer. Atorvastatin showed the greatest renal benefit in the trials examined by the researchers, and atorvastatin, pravastatin, and simvastatin showed a trend toward benefit.
“Statin administration for kidney protection remains to be debated,” Dr. Su and colleagues stated. “Regardless, statins also should be used for patients with kidney disease and high-risk cardiovascular disease…”
The researchers noted that most trials in their review were designed to evaluate cardiovascular rather than renal outcomes. The analysis of proteinuria was based on a relatively small number of patients. The possibility that statins increase creatinine generation or secretion could not be excluded.
Large prospective randomized trials using measured (not estimated) GFR are still needed to prove a protective, clinically relevant effect of statins on kidney function, the investigators emphasized.