Exploration of the early auditory effects of hyperlipoproteinemia and diabetes mellitus using otoacoustic emissions

Abstract

Although the relationship between hearing loss and hyperlipoproteinemia (HLP) or diabetes mellitus (DM) has been shown in many clinical investigations, this concept is still controversial. A prospective study was designed to search for the existence of subclinical auditory dysfunction related to HLP and DM by transient-evoked (TEOAEs) and distortion-product otoacoustic emissions (DPOAEs) in patients with hearing levels better than 30 dB. Evoked otoacoustic emissions were utilized to investigate subclinical auditory dysfunction. Fifteen hypercholesterolemic patients (28 ears), 21 hypertriglyceridemic patients (42 ears) and 21 DM patients (40 ears) were eligible for investigation. The results of the DPOAEs and TEOAEs of the study groups were compared with the control group composed of individuals with similar ages and with normal blood lipids and glycemia. This group consisted of 22 people (44 ears). There was no difference in the existence of TEOAEs at all frequencies among the groups (P>0.05). No differences were found in the amplitudes of the DPOAES between the groups except at 4 kHz (P>0.05). The difference was caused by the hypertriglyceridemia group (P=0.014) and the non-insulin-dependent diabetes mellitus (NIDDM) group (P=0.012) when compared with the control group. The mean DPOAE amplitudes of the hypertriglyceridemic and NIDDM groups at 4 kHz were higher than those of the control group. The decreased DPOAE amplitudes at 4 kHz in hypertriglyceridemic and diabetic patients without clinical findings are compatible with the sensorineural hearing loss observed with hyperviscosity and increased noise susceptibility, as was shown before in these patients. Longitudinal investigations should be performed with otoacoustic emissions to help with the early prediction of the prospective effects of HLP and DM on the auditory system.

Pterostilbene Protects Cochlea from Ototoxicity in Streptozotocin-Induced Diabetic Rats by Inhibiting the Apoptosis

“…Cochlear deterioration may be caused by metabolic diseases, such as hyperlipoproteinemia, and DM has been reported to cause changes in DPOAE amplitudes. 25,46 In our study, the mean DPOAE amplitudes were low in the diabetic rats and increased in a dose-dependent manner with PTS treatment. These data indicate that PTS may protect the outer hair cells, a finding that is consistent with our histopathological, immunohistochemical, and molecular findings, which all demonstrated decreased cochlear damage related to DM.…”

Pure tone audiometry and otoacoustic emissions in hypertensive subjects

“…It is clinically beneficial in revealing early cochlear damage even in patients with normal hearing. Using DPOAE and TEOAE, Erdem T et al showed that hyperlipoproteinemia and diabetes mellitus result in cochlear pathology affecting outer hair cells in patients with normal hearing (7). In this paper, we evaluated the pathological effects of HT on the cochlea by pure tone audiometry and DPOAE in patients without any clinical hearing loss.…”

Characteristics of Hearing in Elderly People

“…A close interrelation between hearing loss and high serum cholesterol levels is shown in several studies, and the dependence of hearing function on some other atherogenic lipid levels in the blood is found. Inverse correlation of high significance between high-density lipoproteins (HDL) level of the peripheral blood and hearing acuity at the frequency of 4 kHz was revealed [22]. Morphological and functional damages of the cochlea and their correlations with hyperlipidemia, atherosclerosis, and endothelial dysfunction in mice are described in studies of Guo et al [23].…”