Screening based on title and abstract identified 56 citations for full-text review (Fig. 1). Additional five studies[25-27, 39, 53] were identified from reference lists of the identified articles and from other databases. Of the 56 potentially relevant articles,

32 were excluded for reasons given in Figure 1, leaving a total of 24 studies[24-47] that met the inclusion criteria. Twenty one studies[24-30, 32, 34-38, 40-47] reported associations Palbociclib in vitro between use of statins and AKI, and 14 studies[28, 31-35, 37, 39-41, 43-46] reported associations between use of statins and AKI requiring RRT. Five studies[24-28] used RCT design, and the rest applied a cohort design.[29-47] Only one RCT[28] defined AKI as the primary endpoint. The other four RCTs defined postoperative thrombocytosis,[24] postoperative inflammatory responses,[25]

postoperative myocardial injury,[26] and the number of postoperative endothelial progenitor cells[27] as primary endpoints. Among the cohort studies, only three used prospective design; the remaining studies were retrospective in design. As for the study population, two studies involved nation-wide populations, while most of the other studies were conducted at one single centre. Among the two population-based studies, one was conducted in Canada,[43] and the other in the USA.[47] We assessed the quality Protein Tyrosine Kinase inhibitor of included studies with the Jadad scale.[54] The study conducted by Prowle JR and colleagues[28]

had the highest score on the Jadad scale. The results were summarized in the Appendix 1 (Table App1). The studies varied in their types of surgery, mean age, and case definition (Table 1). The types of surgery were restricted to cardiac or vascular surgery in most studies. Specific type, dosage, and duration of preoperative statin therapy Farnesyltransferase were not available in most studies. In contrast to AKI defined by database codes, AKI defined by a pre-specified increase of serum creatinine level was regarded as ‘AKI defined by laboratory criteria’. Among these, there were seven studies[28, 37, 38, 41, 44-46] using AKIN or RIFLE criteria[48, 49] as the definition for AKI. In all studies, the definition of AKI requiring RRT was based on clinical judgment without additional objective laboratory criteria. Specific statin type available i Dosage and duration not available Increase of sCr level > 30% (AKIN stage 1) Atorvastatin 20 mg/day or simvastatin 20 mg/day for at least 6 months Started before surgery Type, dosage and duration not available At least one dose of statin between admission and surgery In the 21 studies reporting the association of statin use and AKI, the incidence of AKI ranged from 1.88%[43] to 52.17%[44] (Table 1). The pooled incidence of AKI for all 21 studies was 4.89%. The pooled incidence of AKI among statin user and nonstatin user were 6.13% and 4.28%, respectively (Table 2).