Evaluation of calcium, phosphorus and potassium in saliva and their relationship to blood biochemical factors in hemodialysis patients

Nowadays, chronic kidney disease (CKD) is known as an epidemic disease all around the world. Chronic kidney disease considered as a serious health problem with numerous side effects, including complications progressive in reducing glomerular filtration rate (GFR), imbalances in the homeostasis of the body and decreased quality of life and finally an increase in mortality due to cardiovascular problems. End-stage renal disease leads to hypocalcemia and hyperphosphatemia, that as a result of, parathyroid hormone (PTH) will increased that secondary hyperparathyroidism will occurred eventually. So it is essential to routine examination of electrolytes in these patients. The current study have been done to determine the electrolytes in saliva as a non-invasive sample in hemodialysis patients in order to the saliva to be presented as an appropriate samples for clinical laboratories.
In the present case-control study that has been performed at Imam Ali Hospital, Bojnord, North Khorasan Province, Iran, in the summer of 2016, 44 hemodialysis patients and 44 aged, gender and body mass index (BMI) matched healthy controls were selected and then their cell count, Hb, HCT, iron, ferritin, total iron binding capacity (TIBC), glucose, CRP, triglycerides, cholesterol, urea, creatinine, calcium, phosphorus, potassium and PTH were measured.
Calcium and phosphorus were higher in hemodialysis patients in comparison to the control group. Furthermore, there are not any significant relationship between levels of calcium, phosphorus and potassium in both serum and saliva samples. In addition, we observed the positive relationship between PTH in serum as well as phosphorus and potassium in the saliva.
The findings of current study have been shown that salivary levels of calcium and phosphorus in hemodialysis patients is higher than healthy people, therefor could be a non- invasive suitable marker for diagnosis. In addition, blood PTH levels in hemodialysis patients is associated with salivary levels of phosphorus and potassium, so, perhaps these parameters marked PTH's representative in the blood with further investigation of saliva’s electrolytes.