Prevalence, recurrence and seasonal variation of hyperkalemia among patients on hemodialysis

Observational studies have shown that among patients on hemodialysis, hyperkalemia is strongly associated with excess risk for cardiovascular-related hospitalizations and sudden cardiac death. However, the actual burden of hyperkalemia, the rates of its recurrence and seasonality in its variation still remain unclear.

Between June 2020 and May 2021, 1786 mid-week pre-dialysis serum potassium (sK) measurements were retrospectively recorded from 149 patients receiving thrice-weekly hemodialysis in a single-center in Thessaloniki, Greece. The prevalence, recurrence and seasonal variation of hyperkalemia were assessed using three pre-specified sK thresholds (≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L).

At baseline, 60.4%, 42.2% and 13.4% of patients had sK levels ≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L, respectively. At any time-point during follow-up, 85.2%, 69.8% and 38.9% of patients experienced at least one hyperkalemic event ≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L, respectively. Of the 104 patients experiencing an initial sK elevation ≥ 5.5 mmol/L, hyperkalemia at the same threshold reoccurred in 60.6% at month 1, in 47.1% at month 2 and in 46.1% at month 3 of follow-up. Seasonal variation was also observed, with the prevalence of hyperkalemia to be significantly higher in summer. Shorter delivered hemodialysis < 4 h/session (OR: 2.568; 95% CI 1.045-6.313) and the use of a high dialysate K concentration (OR: 14.646; 95% CI 2.727-78.647) were the 2 factors that were independently associated with hyperkalemia.

The present study shows that among hemodialysis patients, the rates of hyperkalemia prevalence and recurrence are very high, reflecting the large unmet need to identify more effective potassium-lowering therapeutic interventions in this high-risk population.