Higher Phosphate, PTH Predict Worse Outcomes
SAN DIEGO—Hyperparathyroidism develops prior to significant hyperphosphatemia in patients with chronic kidney disease (CKD) but not on dialysis, according to study findings presented at Kidney Week 2012.
The findings confirm the presence of a state of phosphorus retention in early in the course of CKD, researchers concluded.
In a study of 446 predialysis CKD patients, investigators in Bangkok, Thailand, examined abnormalities of mineral metabolism in relation to the development of end-stage renal disease (ESRD) and mortality. Hyperparathyroidism and 25-hydroxyvitamin D deficiency developed as early as CKD stage 2, whereas significant hyperphosphatemia only developed in CKD stage 4 or later. Higher serum phosphate (greater than 3.7 mg/dL) and Higher parathyroid hormone (PTH) levels (greater than 42 pg/mL), despite being in the normal ranges were associated with an increased likelihood of ESRD and the composite outcomes of ESRD and mortality after adjusting for cardiovascular risk factors and other mineral parameters. In addition, the study showed that 25-hydroxyvitamin D deficiency (less than 15 ng/mL) is associated with worse outcomes.
The association between higher levels of serum phosphate and PTH—even if those levels are within normal limits—and worse renal and patient outcomes emphasize the need for early intervention in the care of CKD patients, the researchers concluded.