Avaliação do paratormônio na saliva de pacientes com insuficiência renal crônica submetidos a hemodiálise: comparação com nível plasmático e com índice cortical falangeal

Abstract

Previous studies have described the presence of parathyroid hormone (PTH) in the saliva of menopausal women, as well as increased salivary concentration of this hormone in those with evidence of xerostomia. Chronic kidney disease (CKD) is a frequent and serious disease, which sometimes causes, among other consequences, hyperparathyroidism. The quantification of salivary PTH in patients with CKD could contribute to the monitoring and even to the early diagnosis of hyperparathyroidism, in a clinically relevant way since the saliva of biological material collected in a simpler and less invasive way than the blood is treated, favoring a more frequent study of the hormonal condition of each patient. However, no studies on the quantification of this hormone in patients with CKD have been identified in the literature. For these reasons, this study investigated a possible correlation between salivary and serum levels of PTH, as well as the association of these levels with changes in the phalangeal radiographic pattern, in patients with CKD and in hemodialysis treatment. Unstimulated saliva samples were collected from 30 patients with CKD and evaluated by ELISA for quantification of PTH. Patients were still submitted to x-rays of the index, middle and annular fingers to determine phalangeal cortical index (CSF), and authorized the collection of the available quantification of serum PTH in their medical records. The patients studied were between 25 and 80 years of age, equally distributed among men and women. Diabetes and hypertension were the main causes of CKD, and they underwent hemodialysis for 44 months (± 42 months), on average. Only four patients had serum PTH levels within normal range (<65pg / ml), with all others presenting hyperparathyroidism (mean blood PTH of 528.5pg / ml, ± 508.4pg / ml). There was a positive and significant correlation between serum PTH and IFC. Minimally detectable amount of PTH was not identified in the salivary samples. In conclusion, the results of the present study cast doubt on the presence of salivary PTH, but corroborate phalangeal radiographic analysis as a useful method for the monitoring of bone alterations in patients with CKD on hemodialysis.