No evidence for statin-induced proteinuria in healthy volunteers as assessed by proteomic analysis

Technological advances and proteomic applications in drug discovery and target deconvolution: identification of the pleiotropic effects of statins

Proteomic-based techniques provide a powerful tool for identifying the full spectrum of protein targets of a drug, elucidating its mechanism(s) of action, and identifying biomarkers of its efficacy and safety. Herein, we outline the technological advancements in the field, and illustrate the contribution of proteomics to the definition of the pharmacological profile of statins, which represent the cornerstone of the prevention and treatment of cardiovascular diseases (CVDs). Statins act by inhibiting 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, thus reducing cholesterol biosynthesis and consequently enhancing the clearance of low-density lipoproteins from the blood; however, HMG-CoA reductase inhibition can result in a multitude of additional effects beyond lipid lowering, known as 'pleiotropic effects'. The case of statins highlights the unique contribution of proteomics to the target profiling of a drug molecule.

A novel therapeutic effect of statins on nephrogenic diabetes insipidus

Statins competitively inhibit hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase, resulting in reduced plasma total and low-density lipoprotein cholesterol levels. Recently, it has been shown that statins exert additional 'pleiotropic' effects by increasing expression levels of the membrane water channels aquaporin 2 (AQP2). AQP2 is localized mainly in the kidney and plays a critical role in determining cellular water content. This additional effect is independent of cholesterol homoeostasis, and depends on depletion of mevalonate-derived intermediates of sterol synthetic pathways, i.e. farnesylpyrophosphate and geranylgeranylpyrophosphate. By up-regulating the expression levels of AQP2, statins increase water reabsorption by the kidney, thus opening up a new avenue in treating patients with nephrogenic diabetes insipidus (NDI), a hereditary disease that yet lacks high-powered and limited side effects therapy. Aspects related to water balance determined by AQP2 in the kidney, as well as standard and novel therapeutic strategies of NDI are discussed.

Statins of high versus low cholesterol-lowering efficacy and the development of severe renal failure

BACKGROUND

The objective of this nationwide retrospective cohort study was to examine the renal outcomes of HMG-CoA reductase inhibitor (statin) initiators.

METHODS

The patients who started to take statins with high cholesterol-lowering efficacy (atorvastatin and rosuvastatin) and low efficacy (lovastatin, simvastatin, pravastatin, and fluvastatin) between 1 January 2001 and 31 December 2008 were identified from the Taiwan National Health Insurance claims database. The outcome of interest was severe renal failure, defined as the composite endpoint of hemodialysis, peritoneal dialysis, and kidney transplantation. A proportional hazard regression model was applied to estimate the incidence ratio between the two groups, adjusted for the propensity scores based upon baseline characteristics.

RESULTS

Among of the 26,007 and 42,249 statin initiators, the crude incidence rate for developing severe renal failure was 0.65 and 0.46 per 100 person-years for the high-efficacy and low-efficacy groups, respectively. Despite that these two groups had comparable risk for myocardial infarction (hazard ratio: 1.06, 95%CI: 0.92–1.21), there was a 13% increased hazard for developing severe renal failure in the rosuvastatin and atorvastatin initiators (hazard ratio: 1.13, 95%CI: 1.02–1.26). The increased risk associated with these two statins was consistent across different risk groups (diabetes, chronic kidney disease, and ischemic heart disease).

CONCLUSIONS

Statins with high cholesterol-lowering efficacy might increase the risk for developing severe renal failure. An alternative explanation is that the renal risk cannot be ameliorated as much as cardiovascular risk. Further follow-up studies or meta-analyses are needed to solve the controversy.