REN and chronic kidney disease: Likewise, a J-shaped association of both the SBP and DBP with mortality has been reported for 651,749 U.S. veterans with CKD, and 53.7%, 49.7%, and 34.2% of them were taking renin–angiotensin–aldosterone system (RAS) inhibitors, beta-blockers, and calcium-channel blockers, respectively8.