Olfactory function improves following hemodialysis

Abstract

Olfactory function has been shown to be affected in chronic kidney disease; however, studies are contradictory and little is known on the effects of dialysis. To resolve these issues we tested olfactory function in 24 healthy controls and in 28 patients with chronic kidney disease receiving hemodialysis (20 patients) or peritoneal dialysis (the other 8). As assays for olfactory function we measured smell identification, n-butanol and acetic acid thresholds, Kt/V urea, percentage reduced urea, and weights before and after dialysis. Olfactory function was also self-rated by the participants. Compared to healthy controls, predialysis olfactory function was moderately but significantly decreased in the two dialysis groups, with hemodialysis patients being more affected. Patients self-rated olfactory function similar to that of healthy controls, suggesting that patients are unaware of the olfactory decrease. Olfactory function was significantly improved by one hemodialysis session. Neither body mass index, total volume loss, nor any other dialysis parameter correlated with olfactory function or its restitution following hemodialysis. The observed pattern of improvement suggests underlying mixed peripheral and central mechanisms. Thus, olfactory dysfunction in patients with chronic kidney disease is readily reversible by hemodialysis.

‘Taste’ changes: A problem for patients and their dietitians

“…9 Taste problems in liver and renal disease: In liver and renal disease, taste and smell function is impaired. Alterations in perception have been identified for each of the five basic taste qualities, 14,15,17,40,47,48 as have disruption of olfactory (smell) function, 13,49,50 which greatly influences how flavour is perceived. Taste and smell disturbances may relate to issues presented with fluid imbalance, toxin accumulation and metabolic derangements characteristic of both liver and kidney disease.…”

Olfactory Thresholds of the U.S. Population of Home-Dwelling Older Adults: Development and Validation of a Short, Reliable Measure

“…Finally, it should be noted that we did not examine the reliability of model-based estimates using data collected with the staircase method, nor other areas in which the staircase method may have an advantage due to its dynamic presentation of dilutions. For example, the staircase method has successfully been employed using the Sniffin’ Sticks in a wide range of clinical research [33–35]. Thus, when possible, researchers may still wish to use this method, though ideally with model-based threshold estimates.…”

Neuronal Activation in the Central Nervous System of Rats in the Initial Stage of Chronic Kidney Disease-Modulatory Effects of Losartan and Moxonidine

“…In humans disturbances in taste and smell function are uncommon in mild CKD but may appear in moderate to severe CKD [75], [76], [77] and may contribute to appetite loss [77], [78], [79].…”