Hyperphosphatemia Linked to Diuretic Use
PARIS—Diuretics may raise phosphate levels and increase the likelihood of hyperphosphatemia in patients with chronic kidney disease (CKD), researchers reported at the 49th Congress of the European Renal Association-European Dialysis and Transplant Association.
Rocio Martinez-Gallardo, MD, and colleagues at Hospital Infanta Cristina in Badajoz, Spain, studied 922 Caucasian patients with an estimated glomerular filtration rate (GFR) below 40 mL/min/1.73 m2 who were not receiving treatment with phosphate binders or vitamin D. Sixty-three percent of subjects were on diuretics.
The study population had a mean serum phosphate level of 4.79 mg/dL; 512 (55%) had hyperphosphatemia (serum phosphate levels above 4.5). Compared with patients not on diuretics, those taking the drugs had significantly higher serum phosphate levels (4.88 vs. 4.65). Diuretic users had a significant 72% increased likelihood of hyperphosphatemia compared with nonusers, after adjusting for age, gender, GFR, and other potential confounders.
In a separate study of 343 CKD patients, researchers in Germany found that the use of loop diuretics, but not thiazide diuretics, is significantly associated with elevated levels of fibroblast growth factor 23 (FGF-23) as well as higher levels of intact parathyroid hormone.