This study evaluates the safety of increasing dietary potassium intake in a hypertensive population that may be at risk for hyperkalemia.

The blood pressure lowering benefits of increasing dietary potassium (K⁺) are well known. As such dietary recommendations for hypertension focus on a diet rich in high K⁺ food sources such as fruits and vegetables. An important theme to be addressed is the safety of achieving high dietary K⁺ intake in hypertensive individuals who are also receiving medical therapy that might predispose to elevated serum K⁺ levels (hyperkalemia).

The purpose of this study was to assess the impact of aggressively increasing dietary K⁺ on serum K⁺ concentrations in hypertensive individuals with intact renal function medicated with RAAS blocking drugs. The investigators hypothesized that dietary K⁺ supplementation would not provoke hyperkalemia despite treatment with either an angiotensin converting enzyme (ACEi) or an angiotensin receptor blocker (ARB).

The investigators conducted an open controlled clinical trial in 20 hypertensive subjects with normal renal function who were randomized to a usual diet group (UD n=10), or a high potassium diet group (HKD, n= 10). Fruits and vegetables were used to increase potassium intake. All participants were on an ACEi or and ARB. Serum potassium concentration, 3- day food records and 24 Hour urine collections were completed at baseline and at the end of the 4-week study.

Inclusion Criteria:

• Medically treated hypertension as diagnosed Hypertension was established by the participant's cardiologist or if recruited from the online community hypertension was self-reported and confirmed by study investigators based on participant's medical prescription.
• Treatment with an beta blocker, ACE inhibitor, or angiotensin receptor blocker without any adjustment over the previous 3 months
• K+ intake at baseline of less than 80 mmol/day (food diary of 24 hour food recall).

Exclusion Criteria:

• Patients with an episode of acute coronary syndrome, or revascularization within the previous 3 months will not be included.
• Serum K+ concentration 5.0 mmol/L
• Serum creatinine > 130 mmol/L.
• Inability to provide informed consent.

Treating physicians and participants were not blinded to randomization. Investigators performing randomization and analysis of dietary intake were blinded.