High PTH and FGF-23 Predict Vascular Calcification
PHILADELPHIA—Elevated levels of serum parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF-23) are associated with an increased likelihood of progression of vascular calcification (VC) in hemodialysis patients, French researchers reported at Kidney Week 2011.
In a study of 85 patients still alive after three years, 38 (44.7%) had experienced radiographic progression of vascular calcification and 47 (55.3%) did not (non-progressors).
The study, led by Guillaume Jean, MD, a nephrologist at NEPHROCARE Tassin-Charcot in Saint Foy-les-Lyon, revealed that median PTH levels and FGF-23 levels were significantly higher in progressors compared with non-progressors (244.3 vs. 179.6 pg/mL and 4204 vs. 2640 RU/mL, respectively).
Subjects with serum PTH values above 190 pg/mL and FGF-23 values above 3,000 RU/mL had a 5.8 times increased likelihood of vascular calcification progression compared with patients with lower values, according to investigators.
With regard to specificity and sensitivity in predicting CV progression, the optimal cut-off values were 191 pg/mL for PTH and 3,025 RU/mL for FGF-23. Using values above these thresholds, the specificity and sensitivity in predicting CV progression were 58.9% and 62%, respectively, for PTH, and 59% and 61% for FGF-23, the researchers found.
The researchers observed few hyperphosphatemia cases (10% or less), only one case of hypercalcemia, and no severe cases of hyperparathyroidism.