Salivary phosphate secretion in chronic kidney disease.

Background: Hyperphosphatemia is an important contributor to cardiovascular calcification in chronic renal failure (CRF) patients. Cardiovascular calcifications are responsible for the high morbidity and mortality in patients undergoing hemodialysis (HD). Despite dietary phosphate reduction and treatment with phosphate binders, serum phosphorus level, as recommended by K/DOQI guidelines, is achieved only by 50% of dialysis patients. Thus it is necessary to identify other therapeutic approaches to reducing serum phosphate. Phosphate may be secreted in the saliva, which is then swallowed, and this provides a source of endogenous phosphate and thus contributes to the hyperphosphatemia in CRF. Patients and Intervention: This study evaluated salivary phosphate in 68 HD patients and 110 subjects with various degrees of CRF, compared with 30 healthy subjects. Saxon's test confirmed normal salivary secretion volume in all subjects. Salivary and serum phosphate and calcium and serum parathyroid...