REN and acute kidney injury: What is also noteworthy is that a random-effects meta-analysis of 14 studies with 17,876 patients showed that renin–angiotensin–aldosterone system (RAAS) blockade significantly increased the risk of AKI in hospitalized COVID-19 patients (OR: 1.68; 95% CI: 1.19–2.36); an association that remained significant after stratifying by drug class and AKI severity [48].