Limited Link of Common Blood Parameters with Tinnitus.

Background: Tinnitus severity is generally assessed by psychometric and audiological instruments. However, no objective measure exists to evaluate the subjective discomfort and suffering caused by this hearing phenomenon. The objective of this work was to determine the possible blood parameters for diagnostics and therapy. Methods: We measured tinnitus distress by using the Tinnitus Questionnaire (TQ) and collected tinnitus-related audiological measures, namely the hearing threshold (HT), tinnitus loudness (TL), and sensation level (SL, i.e., the tinnitus loudness/hearing threshold at a tinnitus frequency). Blood samples were taken from 200 outpatients of the Tinnitus Centre of the Charité, and 46 routine blood count parameters were examined. The possible interactions were determined by (robust) linear models. Results: Tinnitus distress and audiological measurements were largely uncorrelated but could partly be predicted by selected blood parameters. First, the erythrocyte counts predicted tinnitus distress to a small extent. Second, the levels of vitamin D3 explained about 6% of tinnitus loudness and, age-dependently, the hearing threshold variability. Last, the levels of uric acid explained about 5% of the sensation level variability. Conclusions: Tinnitus is a multidimensional phenomenon. The marginal influences of blood markers suggest the possible roles of inflammation and oxidative stress produced by psychological or somatic burdens. Clinically, a vitamin D substitution (in older patients) might have a hearing-protective effect.

Hearing Aid Use Time Is Causally Influenced by Psychological Parameters in Mildly Distressed Patients with Chronic Tinnitus and Mild-to-Moderate Hearing Loss.

BACKGROUND: Hearing aids (HAs) can improve tinnitus-related distress (TRD) and speech-comprehension (SC) in silence or at 55 dB noise-interference (SC_55 dB) in patients with chronic tinnitus and mild-to-moderate hearing loss. However, the role of HA use time in relation to psychological, audiological, or self-reported tinnitus characteristics is under-investigated. METHODS: We examine 177 gender-stratified patients before (t1) and after an intervention comprising binaural DSLchild algorithm-based HA fitting and auditory training (t2) and at a 70-day follow up [t3]. HA use time was retrospectively retrieved (at t2) for the pre-post- and (at t3) post-follow up periods. General linear models investigated HA use time in relation to (1) general audiological, (2) tinnitus-related audiological, (3) tinnitus-related self-report, and (4) distress-related self-report indices before and after treatment, where applicable. Receiver operator characteristic analyses identified optimal HA use time for hereby-mediated treatment changes. RESULTS: At t1 and t2, psychological, but not audiological indices causally influenced prospective HA use time-except for SC_55 dB at t1, which, however, correlated with patients' anxiety, depressivity, and psychological distress levels. Correlations did not differ between patient subgroups defined by categorical tinnitus-related audiological or self-report indices. HA use time partly mediated treatment-related improvement in TRD, but not SC. Optimal use amounted to 9.5-10.5 h/day. CONCLUSIONS: An awareness of psychological influences may help clinicians facilitate HA use and, thereby, TRD improvement with hearing amplification.

DSLchild-Algorithm-Based Hearing Aid Fitting Can Improve Speech Comprehension in Mildly Distressed Patients with Chronic Tinnitus and Mild-to-Moderate Hearing Loss.

BACKGROUND: Patients with chronic tinnitus and mild-to-moderate hearing loss (HL) can experience difficulties with speech comprehension (SC). The present study investigated SC benefits of a two-component hearing therapy. METHODS: One-hundred-seventy-seven gender-stratified patients underwent binaural DSLchild-algorithm-based hearing aid (HA) fitting and conducted auditory training exercises. SC was measured at four timepoints under three noise interference conditions each (0, 55, and 65 dB): after screening (t0; without HAs), HA- fitting (t1), additional auditory training (t2), and at 70-day follow-up (t3). Repeated-measure analyses of covariance investigated the effects of HAs (t0-t1), auditory training (t1-t2), and the stability of the combined effect (t2-t3) on SC per noise interference level and HL subgroup. Correlational analyses examined associations between SC, age, and psychological indices. RESULTS: Patients showed mildly elevated tinnitus-related distress, which was negatively associated with SC in patients with mild but not moderate HL. At 0 dB, the intervention lastingly improved SC for patients with mild and moderate HL; at 55 dB, for patients with mild HL only. These effects were mainly driven by HAs. CONCLUSIONS: The here-investigated treatment demonstrates some SC-benefit under conditions of no or little noise interference. The auditory training component warrants further investigation regarding non-audiological treatment outcomes.

Vascular-Metabolic Risk Factors and Psychological Stress in Patients with Chronic Tinnitus.

Little is known about molecular correlates of chronic tinnitus. We examined interrelationships between vascular−metabolic risk factors, perceived stress, and other routine blood values in patients with chronic tinnitus. Two-hundred patients (51% female) were screened for 49 blood parameters pertaining to vascular−metabolic risk, immune function, and redox processes. They further completed perceived stress- and tinnitus-related distress questionnaires. Following descriptive analyses, gender-specific sets of age- and tinnitus-severity-adjusted regression models investigated associations between perceived stress and blood parameters. Patients reported mildly elevated levels of perceived stress. Elevated levels of total cholesterol (65% and 61% of female and male patients, respectively), non-HDL-c (43/50%), LDL-c (56/59%), and lipoprotein_a (28/14%) were accompanied by high rates of overweight (99/100%) and smoking (28/31%). A low-level inflammatory state was accompanied by reduced reactive oxygen species (ROS)-neutralizing capacity (reduced co-enzyme Q10 and SOD1 levels). Most vascular risk factors were not correlated with perceived stress, except for fibrinogen (ß = −0.34) as well as C-reactive protein (ß = −0.31, p < 0.05) in men, and MCV (ß = −0.26, p < 0.05) in women. Interrelations between blood parameters and stress levels need to be investigated within psychobehavioural frameworks across varying distress levels. Alongside psychological interventions, a low-level inflammatory state may be a route for pharmacological therapeutics.

Hearing Therapy Improves Tinnitus-Related Distress in Mildly Distressed Patients with Chronic Tinnitus and Mild-to-Moderate Hearing Loss: A Randomized-Controlled Cross-Over Design.

BACKGROUND: The psychological effects of hearing aids and auditory training are underinvestigated. OBJECTIVE: To assess the short- and long-term effects of an industry-developed auditory training on tinnitus-related distress, perceived stress, and psychological epiphenomena in patients with chronic tinnitus and mild-to-moderate hearing loss. METHOD: One-hundred-seventy-seven gender-stratified patients were randomized to an immediate [IIG] or delayed [DIG] intervention group. Following binaural hearing aid fitting, participants completed a CD-enhanced 14-days self-study program. Applying a randomized-controlled cross-over design, psychological measures were obtained at four times: pre-treatment/wait [IIG: t1; DIG: wait], post-treatment/pre-treatment [IIG: t2; DIG: t1], follow-up/post-treatment [IIG: t3; DIG: t2], and follow-up [DIG: t3]. Between- and within-group analyses investigated treatment-related effects and their stability at a 70-day follow-up. RESULTS: Overall, distress symptom severity was mild. Unlike the DIG, the IIG showed significant improvements in tinnitus-related distress. Some psychological epiphenomena, notably anxiety, slightly improved in both groups. Within-group analyses demonstrated the stability of the tinnitus-distress-related effects, alongside uncontrolled improvements of perceived stress and mood-related symptoms at follow-up. CONCLUSIONS: The investigated hearing therapy lastingly improves tinnitus-related distress in mildly distressed patients with chronic tinnitus and mild-to-moderate hearing loss. Beneficial psychological knock-on effects deserve further investigation.

Recombinant human erythropoietin prevents ischemia-induced apoptosis and necrosis in explant cultures of the rat organ of Corti.

This study was designed to evaluate the effect of recombinant human erythropoietin (rhEPO), insulin-like growth factor-1 (rhIGF-1) and epidermal growth factor (rhEGF) on ischemia-induced hair cell loss in an organotypic cochlea culture. The apical, middle and basal parts of the organs of Corti (newborn rat, postnatal days 3-5) were exposed to ischemia (3.5 h) in glucose-free artificial perilymph (pO2 10-20 mmHg) with or without growth factors. Controls were exposed to normoxia. Twenty-four hours after the onset of ischemia, the cultures were stained using tetramethyl rhodamine isothiocyanate (TRITC) phalloidin (hair cells), propidium iodide (membrane integrity) and apoptosis detection kit (DNA-fragmentation). Ischemia (3.5 h) induced a hair cell loss of 20 and 40% in the middle and basal cochlear parts, respectively, and an increase of the numbers of PI-stained and DNA-fragmented nuclei (controls 0-1, ischemia 4-7 nuclei/100 microm). The basal part was more affected than the apical one. rhEPO and rhIGF-1 significantly attenuated the ischemia-induced hair cell loss by reducing processes involved in apoptosis and necrosis. rhEPO has been in clinical use for more than a decade and found to be well tolerated. Therefore, rhEPO could be an effective drug for the prevention of hearing loss via a hair cell protective mechanism.