Research design
SECONDARY
This study was a single-center randomized controlled trial which lasted 14 days and consisted of two stages (run-in period and intervention period), each one comprising 7 days without potassium supplementation. If participants met the enrollment criteria at the end of the run-in period, they were randomly assigned (random number method) 1:1 to the low sodium group (50 mmol/d sodium) or the normal sodium group (100 mmol/d sodium) until the end of the intervention period. We took into account both the sodium contained in the food and the sodium in the salt. The primary outcome was the change in BP and serum potassium, and their corresponding control rates. The secondary outcome was the change in RAAS activity.