Laboratory evaluation of blood and saliva of patients with chronic kidney disease and oral manifestations: a systematic review

Abstract

The oral cavity has been affected by the multisystemic nature of the consequences of Chronic Kidney Disease (CKD) and it is estimated that about 90% of patients with CKD have oral symptoms. In this context, different blood and salivary laboratory alterations can be observed and, therefore, investigations on clinical-laboratory correlations are fundamental for the management and treatment of affected individuals. In this study, a systematic review was carried out to identify and evaluate the main laboratory alterations in the blood and saliva of patients with CKD who present oral manifestations. The bibliographic search included the electronic databases MEDLINE via PubMed, Scopus, Virtual Health Library, Web of Science, Embase and gray literature. Case-control, cross-sectional and cohort studies published in any language and without date restrictions were included. After evaluating the inclusion criteria, the extracted data were analyzed for methodological quality and risk of bias assessment, according to the QUADAS-2 approach. The main laboratory alterations found were the increase in blood and salivary concentrations of urea, creatinine and phosphate, in addition to the decrease in the respective concentrations of calcium, and in the salivary flow rate. In addition, it was observed that the concentrations of these substances in the blood and saliva are directly correlated with the GFR, as well as the existence of a correlation between the appearance of oral manifestations and laboratory alterations. The main oral manifestations observed were: xerostomia, dysgeusia and uremic breath. The systematic review was registered in the PROSPERO database CRD42022250533.

Keywords: CKD, laboratory alterations, blood, saliva and oral manifestations.