ILLUSTRATIVE CASE
A 47-year-old man in generally good health presents to a family medicine clinic for a well visit. He does not use tobacco products and had a benign colonoscopy last year. He reports walking for 30 minutes 3 to 4 times per week for exercise, althoug h he has gained 3 lbs over the past 2 years. He has no family history of early coronary artery disease, but his father and older brother have hypertension. His mother has a history of diabetes and hyperlipidemia.
The patient’s physical exam is unremarkable except for an elevated BP reading of 151/82 mm Hg. A review of his chart indicates he has had multiple elevated readings in the past that have ranged from 132/72 mm Hg to 139/89 mm Hg. The patient is interested in antihypertensive treatment but wants to know if modifying his diet and replacing his regular table salt with a salt substitute will lower his high BP. What can you recommend?
Hypertension is a leading cause of CV morbidity and mortality worldwide and is linked to increased dietary sodium intake. An estimated 1.28 billion people worldwide have hypertension; however, more than half of cases are undiagnosed.2 The US Preventive Services Task Force recommends screening for hypertension in adults older than 18 years and confirming elevated measurements conducted in a nonclinical setting before starting medication (grade “A”).3
Cut-points for the diagnosis of hypertension vary. The American Academy of Family Physicians, 4 the Eighth Joint National Committee (JNC 8), 5 the International Society of Hypertension, 6 and the European Society of Cardiology 7 use ≥ 140 mm Hg systolic BP (SBP) or ≥ 90 mm Hg diastolic BP (DBP) to define hypertension. The American College of Cardiology/American Heart Association guidelines use ≥ 130/80 mm Hg. 8
When treating patients with hypertension, primary care physicians often recommend lifestyle modifications such as the Dietary Approaches to Stop Hypertension (DASH) diet. Other lifestyle modifications include weight loss, tobacco cessation, reduced daily alcohol intake, and increased physical activity. 9
Systematic reviews have shown a measurable improvement in BP with sodium reduction and potassium substitution. 10-12 More importantly, high-quality evidence demonstrates a decreased risk for CV disease, kidney disease, and all-cause mortality with lower dietary sodium intake. 13 Previous studies have shown that potassium-enriched salt substitutes lower BP, but their impact on CV morbidity and mortality is not well defined. Although lowering BP is associated with improved clinical impact, there is a lack of patient-oriented evidence that demonstrates improvement in CV disease and mortality.
The Salt Substitute and Stroke Study (SSaSS), published in 2021, demonstrated the protective effect of salt substitution against stroke, other CV events, and death. 14 Furthermore, this 5-year, cluster-randomized controlled trial of 20,995 participants across 600 villages in China demonstrated reduced CV mortality and BP reduction similar to standard pharmacologic treatment. Prior to SSaSS, 17 randomized controlled trials demonstrated a BP-lowering effect of salt substitutes but did not directly study the impact on clinical outcomes. 13
Continue to: In this 2022 systematic review...
