Thomsen RW, et al. - Researchers examined the burden of hyperkalemia (HK) in patients with chronic kidney disease (CKD) in a real-world setting. The development of HK was noted in more than 1 in 4 CKD patients. The high risk patients were those with severe CKD, diabetes, heart failure or use of spironolactone. HK was correlated with severe clinical outcomes.

Methods

• The researchers assessed the incidence rate of HK [first blood test with an elevated blood potassium level level >5.0 mmol/L] in primary or hospital care in a population-based cohort of all newly diagnosed CKD patients [second estimated glomerular filtration rate (eGFR) measurement <60 mL/min/1.73 m² or hospital diagnosis] in northern Denmark.
• They compared risk factors and clinical outcomes for CKD patients with HK and matched CKD patients without HK.

Results

• Among the 157,766 patients with CKD, 28% experienced HK, for an overall HK incidence rate of 70/1000 person-years.
• It was noted that among patients with Stage 3A, 3B, 4 or 5 CKD, 9, 18, 31 and 42%, respectively, experienced HK within the first year.
• Diabetes {prevalence ratio [PR] 1.74 [95% confidence interval (CI) 1.69–1.79]}, heart failure [PR 2.31 (95% CI 2.23–2.40)] and use of angiotensin-converting enzyme inhibitors [PR 1.45 (95% CI 1.42–1.48)], potassium supplements [PR 1.59 (95% CI 1.55–1.62)] or spironolactone [PR 2.53 (95% CI 2.44–2.63)] were included as important HK risk factors.
• Thirty-four percent had any acute hospitalization 6 months before the HK event, increasing to 57% 6 months after HK [before–after risk ratio 1.72 (95% CI 1.69–1.74)], in CKD patients who developed HK.
• The 6-month mortality following HK was 26%, vs 6% in matched non-HK patients.
• Six-month hazard ratios for any acute hospitalization in HK patients were 2.11-fold higher compared with non-HK patients, including hazard ratios of 2.07 for cardiac diagnoses, 2.29 for ventricular arrhythmias, 3.26 for cardiac arrest, 4.77 for intensive care and 4.85 for death.