Association of Race, Ethnicity With Hyperkalemia Recurrence

Although previous studies have examined associations between race, ethnicity, and other demographic factors in patients with hyperkalemia (elevated serum potassium [K+] of >5.0 mmol/L), information remains limited on how such factors might be associated with the risk of recurrent hyperkalemia. Additional insight could help guide decisions about the frequency of serum K+ monitoring and aid in identifying patients who need more frequent screening to avoid hyperkalemia-associated complications.

 A group of researchers led by Rebecca S. Ahdoot examined a possible relationship between racial or ethnic groups and recurrent hyperkalemia in a population of US veterans. The goal was to determine whether these factors are independently associated and to spark a discussion about the underlying socioecological causes related to race and ethnicity that may explain these associations. The study results were published by Cureus.

The retrospective study utilized data from the US Veterans Affairs database. Patients were aged ≥18 years and had ≥1 serum K+ measurement of >5.0 mmol/L between January 2004 and December 2018. They were followed for up to 1 year after the index hyperkalemia event. Hyperkalemia recurrence was the primary outcome, and all-cause mortality was the competing event. Hyperkalemia recurrence was defined as having a serum K+ lab value level of >5.0 mmol/L that was measured ≥7 days after the index event and following ≥1 serum K+ lab value level of ≤5.0 mmol/L postindex (ie, there was at least one serum K+ lab value of ≤5.0 mmol/L between the index hyperkalemia event and the hyperkalemia recurrence).

Out of 9,894,683 US veterans with at least one serum K+ measurement between 0.5 mmol/L and 8.0 mmol/L during the study period, there were 1,493,539 veterans who experienced an index hyperkalemia event and therefore were included in the study. The median age of the overall population was 61 years. Most patients in the study were White (79.3%; n=1,184,008); 14.3% were Black (n=213,725). There were 77,069 patients with Hispanic or Latino ethnicity. The percentage of patients receiving renin-angiotensin-aldosterone system (RAAS) inhibitors, which increase the risk of hyperkalemia, was similar among different races and ethnicities.

Hyperkalemia recurrence within 1 year after the index hyperkalemia event occurred in 234,807 (15.7%) patients. When analyzed by race, Black patients (19.1%; n=40,879) had the highest rate of hyperkalemia recurrence, while Asian patients had the lowest rate (13.1%; n=1026). When analyzed by ethnicity, recurrent hyperkalemia was more common among individuals with Hispanic or Latino ethnicity (18.1%; n=13,961) than those with non-Hispanic or Latino ethnicity (15.6%; n=212,734). A competing risk regression analysis found that the risk of recurrent hyperkalemia within 1 year after the index hyperkalemia event was significantly higher in Black versus White patients (by 17%; subhazard ratio [sHR], 1.17; 95% CI, 1.16-1.19; P<.0001) and in patients with Hispanic or Latino ethnicity versus those without Hispanic or Latino ethnicity (by 30%; sHR, 1.30; 95% CI, 1.28-1.33; P<.0001). Racial and ethnic differences in hyperkalemia recurrence were independent of medications typically associated with hyperkalemia, including RAAS inhibitors.

There were a few limitations to the study. The retrospective, observational design could have resulted in confounding variables. Because the study was observational, no causal associations may be concluded. The results may be appropriate for group-level awareness, education, and messaging, but the authors do not support using race or ethnicity in formulas for individualized medical decision-making or clinical algorithms. Lastly, the veteran population studied primarily comprised older White males with several comorbidities, so the results may not be generalizable.

In conclusion, the authors wrote, “In this study, the risk of recurrent hyperkalemia was highest in Black and Hispanic patients. This information may be useful for population-level and health system-level screening. It also warrants further studies on the underlying socioecological reasons for racial and ethnic differences in hyperkalemia recurrence and the possible implications for clinical practice, including the frequency of serum K+ monitoring and the prescription of concomitant medications in patients at high risk.”

Source: Cureus