Potassium Disorders Linked to Early Death in CKD Patients
Researchers discovered a U-shaped relationship between patients’ serum potassium levels and mortality.
Serum potassium levels below 4.0 mmol/L or above 5.0 mmol/L in patients with stage 3 or 4 chronic kidney disease (CKD) are linked with greater odds of early death, according to a new study. Researchers did not find an association with progression to end-stage renal disease (ESRD).
For the study, Georges N. Nakhoul, MD, of Glickman Urological and Kidney Institute at Cleveland Clinic in Ohio, and colleagues examined medical records from 36,359 CKD patients (treated from 2005–2009) with an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m2.
Hypokalemia (serum potassium less than 3.5 mmol/L) was observed in 3% of patients and hyperkalemia (greater than 5.0 mmol/L) in 11%, according to results published in the American Journal of Nephrology (2015;41:456-463).The following factors were associated with hyperkalemia: lower eGFR, diabetes, and use of ACE inhibitors or angiotensin-receptor blockers (ARBs). Heart failure and African American ethnicity were associated with hypokalemia.
After adjusting for patients' kidney function, the researchers found that serum potassium levels below 4.0 and above 5.0 mmol/L were significantly associated with increased mortality risk. Despite the concern, they found no greater risk of progression to ESRD.