The effect of electrolyte balance on the voice in hemodialysis patients.

OBJECTIVE: The aim of the study was to demonstrate the effect of blood electrolytes on the voice in chronic hemodialysis patients.

METHODS: The study included a total of 59 hemodialysis patients. Pre- and post-dialysis voice recordings were performed. In the analysis of vocal acoustic parameters, fundamental frequency (F0), jitter, shimmer, the noise-to-harmonics ratio (NHR), and F0 minimum and F0 maximum were measured. The Voice Handicap Index-10 (VHI-10), and maximum phonation time (MPT) were evaluated. For perceptual evaluation, the GRBAS scale was used. The duration of dialysis (years) and changes in weight during dialysis were recorded for each patient. From venous blood samples, measurements were taken of hemoglobin (Hb), albumin, Na+, K+, creatinine, uric acid, phosphorus, Ca++, and parathormone.

RESULTS: The difference in the pre and post-dialysis values of F0, shimmer, NHR and MPT were found to be statistically significant (p = 0.001). The only variable determined to have an effect on the change in F0 values was uric acid, and the change in the F0 values was statistically significant (p = 0.009). The only variable determined to have an effect on the change in shimmer values was sodium, and the change was statistically significant (p = 0.034). The only variable determined to have an effect on the change in NHR values was creatinine, and the change in the NHR values was statistically significant (p = 0.028). Hb and the duration of dialysis were determined to have a statistically significant effect on the change in MPT values (p = 0.001).

CONCLUSIONS: The results showed that uric acid was the agent creating a reduction in vocal cord vibration, the agent increasing the difference between vibration waves was Na+, and creatinine increased the NHR rate. The effect of these variables can be considered important in the understanding of vocal cord physiology.