Study on Laxative Use and Dyskalemia in Advanced CKD

Patients with advanced CKD experience increased intestinal potassium excretion. This compensatory mechanism may be enhanced by laxative use; however, little is known about the association of laxative use with risk of dyskalemia in advanced CKD.

Laxative use was independently associated with lower risk of hyperkalemia during the last 1-year pre-ESKD period, finds a recent study. The research is published in the Journal of American Society of Nephrology.

Keiichi Sumida and colleagues from the Division of Nephrology, Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee included a study population encompassing 36,116 United States veterans transitioning to ESKD with greater than or equal to one plasma potassium measurement during the last 1-year period before ESKD transition.

Using generalized estimating equations with adjustment for potential confounders, the authors examined the association of time-varying laxative use with risk of dyskalemia (i.e., hypokalemia [potassium <3.5 mEq/L] or hyperkalemia [>5.5 mEq/L]) versus normokalemia (3.5–5.5 mEq/L) over the 1-year pre-ESKD period.

To avoid potential overestimation of dyskalemia risk, potassium measurements within 7 days following a dyskalemia event were disregarded in the analyses.

It was observed that over the last 1-year pre-ESKD period, there were 319,219 repeated potassium measurements in the cohort. Out of these, 12,787 (4.0%) represented hypokalemia, and 15,842 (5.0%) represented hyperkalemia; the time-averaged potassium measurement was 4.5 mEq/L.

After multivariable adjustment, time-varying laxative use (compared with nonuse) was significantly associated with lower risk of hyperkalemia but was not associated with risk of hypokalemia. The results were robust to several sensitivity analyses.

As a result, the authors concluded that "laxative use was independently associated with lower risk of hyperkalemia during the last 1-year pre-ESKD period."

Our findings support a putative role of constipation in potassium disarrays and also support (with a careful consideration for the risk-benefit profiles) the therapeutic potential of laxatives in hyperkalemia management in advanced CKD, the authors further inferred.

For more details, visit the study at: https://doi.org/10.1681/ASN.2020081120