Correlation between the olfactory test results and mucociliary activity in chronic renal failure patients

ABSTRACT Objective: It has been shown that olfactory functions in chronic renal failure (CRF) patients deteriorate and these seem to be connected to effects of uraemia over both peripheral olfactory system and central olfactory pathways. It has also been demonstrated that all body secretion are reduced in CFR due to glandular degenerations, thus, it is assumed that olfactory disturbances in CFR at least partly caused by changes in nasal mucus secretion. In this study, we aimed to investigate olfactory functions and mucoliliary activity in CFR patients and seek a correlation between the changes in these parameters and degree of CFR. Method: Our study groups were consisted of 35 CRF and 35 predialysis patients, managed by Dumlupınar University Evliya Çelebi Research and Training Hospital Nephrology Department who were non-smoker and without any nasal pathology and systemic disease which potentially cause olfactory disturbances between 01 August 2016 and 20th December 2016; and 35 healthy non-smoking volunteer without any known olfactory problems served as the control group. All study and control group patients have been subjected to "Sniffin Sticks" olfactory test and nasal mucociliary clearance time assessment. Olfactory tests: consisted of three modules and validated normal score for each module. These modules are olfactory threshold, discrimination and identification tests. Scores of these tests indicate olfactory functions of patients. Assessments of nasal mucociliary clearance were carried out through measurement of time between the placement of saccharine over anterior aspect of the inferior concha and sensation of its taste in the palate. Results: It has been shown that in both study group patients olfactory functions were deteriorated in comparison with control group subjects. It has also been found that in study groups' mucociliary clearance time was prolonged, although there were no statistical differences between both groups in this respect. Also, there were statistically significant correlations between prolongations of clearance times and changes in olfactory test scores. Conclusions: In both dialysis and predialysis patients olfactory functions have been found diminished and mucociliary clearance times have been prolonged. However, the tendency of improvements in olfactory discrimination and identification in dialysis group with respect to predialysis group indicates reversibility of these parameters in CRF. Correlation between olfactory disturbances and nasal mucociliary clearance as well as irreversibility of olfactory threshold values in contrast to identification and discrimination values suggest that one of the important reasons of olfactory function losses in CRF is related to amount and physico-chemical features of nasal mucus.