Introduction: Contrast-induced acute kidney injury (CI-AKI) is a major acute renal failure that can be prevented by atorvastatin administration. This study aims to evaluate the association between atorvastatin use and CI-AKI incidence using a systematic review and meta-analysis approach. Materials and Methods: Several international databases, including Cochrane, Web of Science, Scopus, ProQuest, PubMed, and the Google Scholar search engine, were queried in this study. STATA 14 software was conducted to analyze the data. In this study, standardized mean difference (SMD) index was conducted to investigate the relationship between atorvastatin and serum creatinine level. Results: Twelve clinical trials with a total sample size of 3299 were retrieved. The effect of atorvastatin on serum creatinine levels indicated a SMD of -2.26 (95% CI: -2.53, -1.98) at a dose of 20 mg/kg, -0.76 (95% CI: -1.47, -0.05) at a dose of 40 mg/kg, -2.69 (95% CI: -2.96, -2.42) at a dose of 60 mg/ kg, and -0.03 (95% CI: -0.14, 0.09) at a dose of 80 mg/kg. The effect of atorvastatin use on serum creatinine levels achieved a SMD of -2.72 (95% CI: -3.02, -2.43) in the 40-49 years age group and a SMD of -0.96 (95% CI: -1.73, -0.19) in the 50-59 years age group. The effect of high-dose atorvastatin therapy in reducing the serum creatinine levels, compared to low-dose therapy, was a SMD of -0.54 (95% CI: -1.03, -0.04). However, estimates for the effect of atorvastatin compared to rosuvastatin and placebo showed a SMD of -0.26 (95% CI: -0.76, 0.24) and -1.23 (95% CI: -2.22, -0.25), respectively. The effect of atorvastatin on blood urea nitrogen (BUN) and high-sensitivity C-reactive protein (hs-CRP) levels relative to the comparison group was a SMD of -1.10 (95% CI: -1.61, -0.58) and -1.36 (95% CI: -2.30, -0.42) respectively. Conclusion: Pre-treatment with atorvastatin is effective in CI-AKI prevention. High-dose atorvastatin administration at younger ages provides the best outcome for preventing CI-AKI. Meta-analysis Registration: This study has been compiled based on the PRISMA checklist, and its protocol was registered on the PROSPERO website (ID: CRD42023397276, available at https:// www.crd.york.ac.uk/prospero/#recordDetails).

Introduction: Sodium-glucose cotransporter-2 (SGLT2) inhibitors are the most recent pharmaceutical group for type 2 diabetes (T2D) treatment. Evidence indicates contradictory relationships between sodium-glucose cotransporter-2 inhibitors and bladder cancer (BC). Hence, this study aims to investigate the relationship between SGLT2 inhibitors and BC in patients with T2D. Materials and Methods: This study is a systematic review and meta-analysis based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). International databases including Cochrane, Web of Science, Scopus, PubMed, and Google Scholar were conducted for searching with keywords and without time and language limitations. The reference searching stage continued upgrading until November, 2022. Data analysis was performed with STATA 14 software. The tests with P values lower than 0.05 were considered statistically significant. Results: The four reviewed studies with a sample size comprising 497 755 individuals indicated the impact of SGLT2 inhibitors on BC of patients with T2D (OR: 0.68; 95% CI: 0.37, 1.2). The effect of dapagliflozin, canagliflozin and empagliflozin administration on the incidence of BC among the T2D patients were (OR: 0.72; 95% CI: 0.39, 1.30), (OR: 0.53; 95% CI: 0.23, 1.20), and (OR: 0.51; 95% CI: 0.20, 1.28), respectively. Conclusion: The general conclusion of this study revealed that SGLT2 inhibitors did not increase the risk of BC in T2D patients. The analysis of subgroups also indicated that the administration of dapagliflozin, canagliflozin, and empagliflozin also did not increase the risk of BC in T2D patients. Registration: This study has been compiled based on the PRISMA checklist, and its protocol was registered on the PROSPERO website (ID=CRD42023389014).