BOSTON—Black people have lower potassium levels on average than individuals of other races, according to data presented at the National Kidney Foundation’s 2016 Spring Clinical Meetings.

In a study of 2.7 million US veterans, Morgan Grams, MD, PhD, of Johns Hopkins University in Baltimore, and colleagues found that mean potassium levels at baseline were 4.1 mmol/L among blacks compared with 4.3 mmol/L among non-blacks, a significant difference between the groups. Hyperkalemia (potassium levels above 5 mmol/L) was significantly less prevalent among blacks than non-blacks (2.3% vs. 4.5%). Compared with non-blacks, blacks had a 34%, 48%, and 58% decreased risk of transient, intermittent, and persistent hyperkalemia, respectively.

The researchers defined transient hyperkalemia as a one-time potassium measurement above 5 mmol/L, intermittent hyperkalemia as a potassium value above 5 mmol/L in 50% or fewer potassium checks, and persistent hyperkalemia as a potassium value above 5 mmol/L in more than 50% of potassium checks.

The association between potassium levels and mortality was similar for blacks and non-blacks. Results also showed that blacks had a significantly higher prevalence of hypokalemia (potassium levels below 3.5 mmol/L) compared with non-blacks (5.4% vs. 2.2%).

The study population consisted of individuals with an estimated glomerular filtration rate of 60 mL/min/1.73 m2 or higher.