REN and chronic kidney disease: Since this feedback mechanism is incomplete in CKD patients, they often have high BP with normal or elevated renin levels.[15] Literature suggests that renin levels may be twice as high in hypertensive HD patients compared to normal, with a study reporting plasma renin activity increasing from 2.3 ± 0.5 ng/mL/h just before the initiation of HD to 6.5 ± 1.3 ng/mL/h over an 8- to 10-year period among hypertensive HD patients.[15,16] This finding suggests that renin secretion continues even after complete decline of kidney function.