Low serum potassium levels correlate with mortality risk in patients on hemodialysis
Click Here to Manage Email Alerts
In adult patients on hemodialysis, a low serum potassium level was associated with a 1.4-fold higher risk of death compared with the optimal level of 5.1 mmol/L.
“Both high and low serum potassium levels can cause fatal heart arrhythmias. In patients receiving hemodialysis, the mortality risk of low serum potassium levels, in particular, may have been underestimated,” Esther N.M. de Rooij, MD, from the department of nephrology at Leiden University Medical Center in The Netherlands, and colleagues wrote. They added, “Therefore, we studied the relationship between serum potassium levels and death in a prospective cohort of incident hemodialysis patients and investigated whether there is an optimum level to pursue.”
In a prospective multicenter cohort study, researchers evaluated 1,117 patients on hemodialysis with incident end-stage renal disease (median age was 63 years; 58% were men; baseline mean serum potassium level was 5 mmol/L) from the Netherlands Cooperative Study on the Adequacy of Dialysis-2 study from their first hemodialysis treatment until death, transplantation, switch to peritoneal dialysis or 10 years.
Three-months after patients started hemodialysis, researchers collected baseline demographics, then conducted follow-ups at 6-month intervals to measure pre-dialysis serum potassium levels. Measurements were divided into six categories (4 mmol/L, >4 mmol/L to 4.5 mmol/L, >4.5 mmol/L to 5 mmol/L, >5 mmol/ L to 5.5 mmol/L (reference), >5.5 mmol/L to 6 mmol/L, and >6 mmol/L).
Using Cox proportional hazards and restricted cubic spline analyses with time-dependent pre-dialysis serum potassium levels, researchers determined the adjusted hazard ratios for death.
By the 10-year follow-up, 555 patients died. Analyses revealed multivariable adjusted hazard ratios for deaths respective to the six categories as 1.42, 1.09, 1.21, 1, 0.95 and 1.32. Researchers identified a U-shaped relationship between serum potassium level and mortality in patients on incident hemodialysis.
“Our results indicate an optimum pre-dialysis serum potassium level of approximately 5.1 mmol/L. Low and high pre-dialysis serum potassium levels resulted in 1.4- and 1.3-fold stronger risk factors for death, respectively, compared with the optimum level. If proven causal, the clinical implication of these results is that potassium-lowering therapy should be used with caution in patients receiving hemodialysis with normal or low serum potassium levels before the dialysis session,” de Rooij and colleagues wrote. “Furthermore, as low pre-dialysis serum potassium level could result from malnourishment, the associated mortality risk emphasizes the importance of preventing nutritional disorders in patients receiving hemodialysis.”
Collapse
Read more about
Click Here to Manage Email Alerts