Savica Vincenzo, Calò Lorenzo, Santoro Domenico, Monardo Paolo, Granata Antonio, Bellinghieri Guido
University of Messina, and Nephrology and Dialysis Unit, Papardo Hospital, Messina, Italy.
J Ren Nutr. 2008 Jan;18(1):87-90. doi: 10.1053/j.jrn.2007.10.018.
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.
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 hormone were measured.
Both HD and CRF patients had significantly higher salivary phosphate levels compared with healthy control subjects. In the latter group of patients, salivary phosphate correlated positively with serum creatinine (P < .0001) and the glomerular filtration rate (P < .0001).
These results suggest that the level of salivary phosphate may provide a better marker than serum phosphate for the initiation of treatment of hyperphosphatemia in CRF and HD patients. The results may also offer a new horizon in the therapy of hyperphosphatemia by establishing measures to bind salivary phosphate in the mouth, and before saliva is swallowed.
高磷血症是慢性肾衰竭（CRF）患者心血管钙化的重要促成因素。心血管钙化是接受血液透析（HD）患者高发病率和高死亡率的原因。尽管采取了减少饮食中磷摄入以及使用磷结合剂进行治疗，但根据K/DOQI指南的建议，只有50%的透析患者能达到血清磷水平。因此，有必要确定其他降低血清磷的治疗方法。磷可能会分泌到唾液中，然后被吞咽下去，这就提供了内源性磷的一个来源，从而导致CRF患者出现高磷血症。
本研究评估了68例HD患者和110例不同程度CRF患者的唾液磷水平，并与30例健康受试者进行了比较。萨克森氏试验证实所有受试者的唾液分泌量均正常。测量了唾液和血清中的磷、钙以及血清甲状旁腺激素水平。
与健康对照受试者相比，HD患者和CRF患者的唾液磷水平均显著更高。在后者这组患者中，唾液磷与血清肌酐呈正相关（P < .0001），与肾小球滤过率也呈正相关（P < .0001）。
这些结果表明，对于CRF和HD患者高磷血症治疗的起始阶段，唾液磷水平可能比血清磷水平提供更好的指标。这些结果还可能通过制定在口腔中、唾液被吞咽之前结合唾液磷的措施，为高磷血症的治疗开辟新的前景。
