Prevalence of Hyperkalemia in Patients With CKD

There is an independent association between hyperkalemia and poor outcomes among individuals with chronic kidney disease (CKD). According to Ajay K. Singh and colleagues, there are few data available on the prevalence, risk factors, and severity of hyperkalemia in the United States stratified by demographic groups, Kidney Disease: Improving Global Outcomes (KDIGO) risk categories, categories of estimated glomerular filtration rate (eGFR), and levels of albuminuria.

The researchers conducted an analysis of data from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2018 to examine hyperkalemia prevalence and risk. Results were reported during a poster session at the American Society of Nephrology Kidney Week 2023 in a poster titled Prevalence of Elevated Serum Potassium in CKD Population by KDIGO Risk and eGFR Categories in a Representative US Population: NHANES 1999-2018.

The analysis cohort included 101,316 NHANES participants. To account for the complex survey design and the oversampling of certain age and minority groups, 20-year weights were calculated. Hyperkalemia was defined and assessed based on levels of elevated serum potassium: >5.0 mmol/L (mild hyperkalemia), >5.5 mmol/L (moderate hyperkalemia), and >6 mmol/L (severe hyperkalemia).

Independent predictors for hyperkalemia were identified using univariate and multivariate regression analysis. Each model was adjusted for age, sex, race/ethnicity, diastolic blood pressure, hypertension, diabetes, hemoglobin A1c, hemoglobin, triglyceride, and history of cardiovascular disease. In the model with eGFR as exposure, urine albumin-creatinine-ratio (UACR) was additionally adjusted, and in the model with UACR as exposure, eGFR was additionally adjusted.

In the nationally representative sample of adults in the United States with CKD, the prevalence of mild hyperkalemia was 2.46%, moderate hyperkalemia prevalence was 0.43%, and prevalence of severe hyperkalemia was rare at 0.76%. Mild hyperkalemia was common among patients in the KDIGO high and very high risk categories (9.72%) and in those with eGFR <15 to 20 mL/min/1.73 m² (15.67%). Severe hyperkalemia was rare in those two groups (0.54% and 1.45%, respectively). Both KDIGO risk category and eGFR category were independent predictors of mild and moderate hyperkalemia.

In summary, the researchers said, “Mild hyperkalemia is relatively common in patients with advanced CKD, although not as high as previously reported in unweighted samples of CKD patients. Severe hyperkalemia is rare. The most important predictors of hyperkalemia are high and very high KDIGO risk categories as well as eGFR of <15-29 mL/min/1.73 m².”

Source: Singh AK, Zheng Z, Farag YM. Prevalence of elevated potassium in CKD population by KDIGO risk and eGFR categories in a representative US population: NHANES 1999-2018. TH-PO1030. Abstract of a poster presented at the American Society of Nephrology Kidney Week 2023; November 2, 2023; Philadelphia, Pennsylvania.