Potassium Can Help Lower Blood Pressure, Reduce CVD Risk in Women

Liffert Vogt, MD, PhD

Results of a recent study have investigators calling for an increased emphasis on potassium intake among women for prevention of cardiovascular disease.

An analysis of the EPIC-Norfolk study, results demonstrate a potassium-rich dietwas associated with reductions in systolic blood pressure among women and a reduction in cardiovascular disease events among both men and women, but investigators pointed out this reduction in risk was more pronounced in women.

“The results suggest that potassium helps preserve heart health, but that women benefit more than men,” said lead investigator Liffert Vogt, MD, PhD, professor of clinical nephrology and renal physiology at Amsterdam University Medical Centers, in a statement. “The relationship between potassium and cardiovascular events was the same regardless of salt intake, suggesting that potassium has other ways of protecting the heart on top of increasing sodium excretion.”

Although salt restriction remains a staple of prevention strategies for men and women, less research been dedicated to how increased levels of potassium, which can lead to increased sodium secretion in urine, might influence cardiovascular risk and blood pressure. The current study was designed by Vogt and colleagues in the Netherlands to provide further insight into potential associations between potassium intake and cardiovascular health and whether these associations were modified by patient sex. A prospective, population-based cohort study, the European Prospective Investigation into Cancer (EPIC-Norfolk) study enrolled 25,639 participants aged 40-79 years recruited from general practices in the UK from 1993-1997 with the most recent follow-up occurring from 2016-2018.

After exclusion of patients with missing data for sex, age, height, weight, spot urine sodium, potassium, or creatinine concentration, investigators identified 24,963 participants for inclusion in the present study. This cohort included 11,267 men and 13,696 women. The cohort of men had a mean age of 59±9 years, an estimated potassium intake of 71±16 mmol/day (2.8±0.6 g/day), an estimated sodium intake of 214±62 mmol/day (4.9±1.4 g/day), and 18.5% were using antihypertensive medications. The cohort of women had a mean age of 58±9 years, an estimated potassium intake of 66±16 mmol/day (2.6±0.6 g/day), an estimated sodium intake of 183±61 mmol/day (4.2±1.4 g/day), and 18.6% were using antihypertensive medications.

For the purpose of analysis, patients were divided into turtles based on their daily potassium intake. Investigators pointed out linear and Cox regression were used to estimate associations between potassium intake, systolic blood pressure, and cardiovascular events. Cardiovascular events of interest were defined as hospitalization or death due to cardiovascular disease.

In adjusted analyses, results pointed to an interaction by sex for the association between potassium intake and systolic blood pressure (P <.001), with the inverse slope between potassium intake and systolic blood pressure being steeper in those within the highest tertile of sodium intake compared with those within the lowest tertile of sodium intake (P <.001 for interaction by sodium intake), which was only observed in women and not among men. When assessing risk of cardiovascular disease events, results indicated both men and women in the tertile with the greatest levels of potassium intake had a lower risk of events, but this was more pronounced in women (HR, 0.89 [95% CI, 0.83-0.94]) than among men (HR, 0.93 [95% CI, 0.87-1.00]) (P <.033).

“It is well known that high salt consumption is associated with elevated blood pressure and a raised risk of heart attacks and strokes,” Vogt added. “Health advice has focused on limiting salt intake, but this is difficult to achieve when our diets include processed foods. Potassium helps the body excrete more sodium in the urine. In our study, dietary potassium was linked with the greatest health gains in women.”

This study, “Sex-specific associations between potassium intake, blood pressure, and cardiovascular outcomes: the EPIC-Norfolk study,” was published in the European Heart Journal.