Supervisors info:
Αθανάσιος Μπίμπας, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ, Επιβλέπων
Δημήτριος Κικίδης, Επιμελητής Β, Α’ Πανεπιστημιακή ΩΡΛ κλινική, ΓΝΑ "Ιπποκράτειο"
Αναστασία Δερβεντζή, ΕΔΙΠ, Ιατρική Σχολή, ΕΚΠΑ
Summary:
Introduction: This pilot cross-sectional observational study is the second part of a larger pilot
cross-sectional observational study that investigates the relationship between major β-thalassemia
and sensorineural hearing loss and focuses on investigating speech-in-noise discrimination
disorders in the respective patients. An attempt is made to investigate the risk factors, identifying
the role of age, sex, type of chelating agent, average annual value of ferritin and hemoglobin,
average number of transfusions per year received by the patient, but also of the disease per se.
The purpose of this study is to investigate the effect of these factors on the hearing threshold and
on the speech in noise discrimination ability of patients with TDT. Our aim is to highlight the
need for a wider investigation of the factors that affect the hearing and discrimination ability of
this vulnerable population, in order to ensure their early diagnosis and rehabilitation.
Method: Τhis study involved 20 patients with TDT who underwent a complete audiological
examination with tympanogram, PTA and WIB in the Greek language. The SNR value of 50%
SRT (SRT50n) (dB) and WRS% was calculated. The secondary hypothesis of a negative
correlation of the SNR value of 50% SRT (SRT50n) with a) the need and volume of transfusions
(average number of units per year) b) the average annual hemoglobin level c) the use and type of
chelating factor and d) the mean annual ferritin levels. Descriptive statistical analysis was
performed both to extract the demographic data of the sample and to analyze the quantitative
characteristics of the study while at the same time regression models were developed with the aim
of studying the effect and predicting values of WRS and SRT50n from possible predictive factors
such as age, gender, presence of thalassemia and SNR. Descriptive statistics were extracted using
the SPSS V.23.0 statistical package while regression models were developed using the R
language. Participants provided written consent after being fully informed about the research's
purpose.
Results: Our study included 20 TDT patients with a mean age of 49.1 years, mean annual ferritin
levels of 839ng/ml, and mean number of transfusions per year of 23.1. All were receiving
iron-deprivation therapy and chelating agents systemically. The audiological test with PTA
showed SNHL in 40% in the right ear and 45% in the left respectively. In the WIB test at 5 SNR
levels (-3,0,+3,+6,+9) the patients' WRS% and SNR50n were calculated. In the statistical
investigation, a strong statistical correlation of the value of WRS% only from the value of SNR
and the value of SNR50n from the number of transfusions and male gender, was observed.
Compared to the healthy population, an 8.029% lower WRS% was observed in the patients’ group
with a strong statistical correlation with SNR. Accordingly, the SNR50n of the healthy population is on average 0.99 units lower than that of TDT patients and is statistically strongly associated
with both disease and increasing age (increase in SRT50n by approximately 0.024 units with each
additional year of life).
Discussion: The prevalence of SNHL in our sample is compared with the international literature
data and the utility of the WIB test in investigating the speech in noise discrimination disorders of
patients with TDT, is analyzed. The effect of age and disease per se on the WRS% and SNR50n
of our patients is established, while at the same time, the relationship between auditory function
disorder, auditory processing disorder and cognitive decline with the final outcome of dementia is
analyzed. Particular emphasis is placed on the importance of a wider application of the SIN test in
clinical practice as well as on the need to design programs for early diagnosis and rehabilitation of
our patients' auditory function problems, with the aim of preserving their quality of life in the long
term.
Conclusions: The results of this pilot study are in agreement with the international literature for
an increased prevalence of SNHL among patients with TDT. At the same time, from the
investigation of their speech in noise discrimination, a decrease in the WRS% and an increase in
the SRT50n were observed, compared to the healthy population. As important risk factors were
identified the increasing age and thalassemia per se. The interdependence between auditory
function, central auditory processing and cognitive processing, in relation to the extension of the
patients' life time, is of particular interest and raises the need to design and implement wider
research to assess the extent of the problem, understand the pathogenic mechanisms and develop
prevention strategies and rehabilitation. The application in clinical practice of systematic
audiological tests by using valuable tools, such as the WIB test in the Greek language, opens up
new optimistic horizons for the scientific community to improve health services for this
vulnerable population.
Keywords:
B-thalassemia, Thalassemia, Hearing loss, Sensorineural hearing loss, Speech audiometry in noise using sentences (SIN test) and words (WIB test or WIN test), Auditory processing disorder, Cognitive impairment, Chelating agents, Ferritin, Transfusions, Word recognition, Pure tone audiogram, Risk factors
