Hearing screening outcomes in infants of pregestational diabetic mothers

Exploring predisposing factors of hearing loss in prematurely born children: A nationwide case-control study

BACKGROUND

We conducted a nationwide population-based case-control study to analyse potential predisposing factors for hearing loss (HL) that present during the fetal, perinatal, and postnatal periods in prematurely born children.

METHODS

This study enrolled 21,576 children born at < 37 weeks of gestation; 3,596 with HL and 17,980 with normal hearing born between 2002 and 2015, matched for sex, age at diagnosis, and enrollment time. Data were abstracted from the concatenation of three nationwide databases for overall risk factors till the diagnosis of HL.

RESULTS

Maternal HL, maternal diabetes, particularly type 1 diabetes mellitus, and at or before 32 weeks of gestation were the major obstetric risk factors for HL. Prematurely born children who were born via cesarean section and received a combination of antenatal steroids and magnesium sulfate exhibited a significantly reduced risk of developing HL. Ear malformation was a critical predictor for HL. The major postnatal risk factors included seizure and ototoxic drugs use. Premature infants diagnosed with more than 1 diagnosis of bronchopulmonary dysplasia, necrotizing enterocolitis, and intracerebral hemorrhage were at an increased risk of developing HL. Congenital CMV infection and recurrent acute otitis were also independent postnatal factors for HL in prematurely born children.

CONCLUSION

To reduce the incidence of childhood HL in prematurely born children, aggressive management of premature birth-related consequences and treatable causes and longitudinal audiological follow-up with early detection and adequate intervention are crucial.

The effect of maternal diabetes on the expression of gamma-aminobutyric acid and metabotropic glutamate receptors in male newborn rats' inferior colliculi

OBJECTIVES

Few studies have examined the molecular alterations in the auditory pathway of infants of diabetic mothers, notwithstanding the fact that maternal diabetes may have an impact on the development of the neonatal peripheral and central nervous systems. Male newborn rats were studied to determine how maternal diabetes affected the expression of gamma-aminobutyric acid (GABAAα1 and GABAB1) and metabotropic glutamate (mGlu2) receptors in the inferior colliculus (IC) in this research.

METHODS

Female rats were given a single intraperitoneal injection of streptozotocin (STZ) at a 65 mg/kg dose to develop a model of diabetic mothers. The study population was split into sham, diabetes without treatment, and diabetes with insulin groups. Their male neonatal rats were anesthetized on P0, P7, and P14 after mating and delivery. The receptors' distribution pattern was studied using immunohistochemistry (IHC).

RESULTS

Pairwise comparison in the groups revealed that the GABA receptors (Aα1 and B1) were significantly downregulated in the diabetes without treatment group (p<0.001). Furthermore, pairwise comparison in the groups indicated significant mGlu2 upregulation in the diabetes without treatment group (p<0.001). Regarding the concentration of all receptors, there was no discernible distinction between the diabetes with insulin and sham groups.

CONCLUSIONS

This investigation showed that the concentration of GABAAα1 and GABAB1 receptors decreased significantly over time, whereas the concentration of mGlu2 receptors increased significantly over time in male neonatal rats born to streptozotocin-induced diabetic mothers.

Effect of Preeclampsia and Gestational diabetes mellitus on Neonatal Distortion Product Otoacoustic Emissions: A Tertiary Care Center Study

PURPOSE

To determine whether preeclampsia and gestational diabetes mellitus is a risk factor for cochlear damage and sensorineural hearing impairment in infants.

MATERIALS AND METHODS

Longitudinal study was conducted in 2 tertiary referral centers. 1068 neonates were included, who were born to preeclampsia, gestational diabetes mellitus, and healthy mothers. The hearing evaluation was done using DPOAE on day 2 and for those who failed the initial DPOAE on day 2, underwent repeat DPOAE on day 15, ABR was done on day 30 if repeat DPOAE was Refer. The results were compared between the groups and analyzed.

RESULTS

On initial DPOAE, bilateral ear absent DPOAE rates were 19.5%, 15.8%, and 3.5% among preeclampsia, Gestational Diabetes Mellitus (GDM), control groups respectively. The difference was statistically significant (P < .001). Also it was noted that absent DPOAE was significantly high at low and mid frequencies (1000, 2000, 3000, and 4000 Hz) in bilateral ear. However the difference in repeat DPOAE among the groups were not significant (Right ear P = .17, Left ear P = .31). Infants who failed repeat DPOAE test underwent ABR test in which 3 of GDM group, 2 infants of preeclampsia group and 1 infant of control group had absent ABR test.

CONCLUSION

This study reveals that GDM and preeclampsia showed remarkable association of hearing loss at lower and mid frequencies which was transient. The prevalence of absent DPOAE was corresponding to the severity of the maternal conditions under the study.

Prevalence of Hearing Impairment in Neonates of Mothers with Diabetes Mellitus: A Cross Sectional Study

This study aims to find out the prevalence of hearing impairment in neonates of mothers with diabetes mellitus. The objective is to assess any correlation between the glycemic control and the development of neonatal hearing impairment. A total of 120 neonates of diabetic mothers were included in the study. Data was collected from hospital medical records, direct interview of parent or care taker and clinical examination of child done whenever possible. 120 Neonates were evaluated by OAE soon after birth. Those who failed the test are evaluated with BERA and results were statistically analysed. In our study prevalence of deafness in neonates of mothers with diabetes mellitus was 4.16%. Prevalence of hearing impairment was higher in neonates of mothers with pre gestational diabetes (9.09%) than gestational diabetes mellitus (3.06%). Mean of HbA1c was higher in mothers of neonates with hearing impairment than those without hearing impairment. Prevalence of deafness in neonates of mothers with diabetes mellitus was 4.16%, which is about sevena times higher than the prevalence of deafness in neonates without any risk factors. Prevalence was higher in neonates of mothers with pre gestational diabetes than neonates of mothers with gestational diabetes mellitus.

The distribution pattern of M2 and Adrenergicα2 receptors on inferior colliculi in male newborns of diabetic rats

AIMS

Despite the high prevalence of diabetes in the world, its possible effects throughut pregnancy on neonatal auditory nervous system development are still unknown. In the present research, maternal diabetes' impact on the M2 and Adrenergic_α2 receptors expression in the inferior colliculus (IC) of male newborn rats was investigated. Main methods Female rats were grouped into three: sham, insulin-treated diabetic, and diabetic. Diabetes was induced through streptozotocin (STZ) injection as one dose intraperitoneally (65 mg/kg). After mating and delivery, male rats were euthanized on P0, P7, and P14. Immunohistochemistry (IHC) was used to study the distribution pattern of receptors. Key findings The present study indicated that the expression of M2 receptors in the diabetic group was significantly increased in pairwise comparisons in the sham and diabetic treated with insulin groups (P<0.001, each). The highest M2 expression was for the diabetic group on P14 and the lowest one was for the sham group on P0. The Adrenergic_α2a receptors expression in the diabetic group was significantly reduced in pairwise comparisons in the sham and diabetic treated with insulin groups (P <0.001, each). The highest Adrenergic_α2a expression was for the sham group on P14 and the lowest one was for the diabetic group on P0. There was no significant difference between the sham and insulin groups regarding all receptors expression.

SIGNIFICANCE

This study demonstrated a time-dependent significant decrease in Adrenergic_α2a but a time-dependent significant increase in M2 receptors expression.

Analysis of the Referral Rates of Newborn Hearing Screening Test According to Childbirth Delivery Methods in Neonatal Care Units

It is known that neonates born by cesarean delivery (CD) may have higher referral rates than those born by vaginal delivery (VD) for newborn hearing screening (NHS). False-positive NHS results can increase costs and parental anxiety. This study analyzed the differences in NHS referral rates according to delivery methods in Level I, II, and III neonatal care units. A retrospective chart review was done for 2322 infants (4644 ears) with delivery records who underwent NHS between 2004 and 2017. The first NHS was performed immediately before discharge when the infant was in good condition via the automated auditory brainstem response (AABR) or automated otoacoustic emissions (AOAE). There were 98 neonates (196 ears) who underwent both AABR and AOAE simultaneously as the first NHS, 30 of which failed. We used a total of 4810 ears in this analysis. Of all enrolled ears, 2075 ears were of neonates born by CD, and 2735 ears were of neonates born by VD. A total of 2460 ears were from patients in Level III neonatal intensive care units (NICU) and 2350 ears were from Level I and II neonatal care units. The overall referral rate was higher in infants born via CD (4.5%) than VD (3.2%). In Level I and II neonatal intensive care units, the referral rate was significantly higher in those born via CD (3.0%) than via VD (1.4%). Further, based on the screening method, AABR (75.8%) was more frequently used than AOAE (24.2%), thereby revealing AABR’s higher referral rate in CD (2.9%) than in VD (1.2%). The referral rate of infants who underwent the NHS within three days of birth was higher in the CD group (3.0%) than in the VD group (1.3%). There was no significant difference in the referral rate depending on the delivery method when infants were hospitalized for more than four days or hospitalized in the NICU. The referral rate according to the delivery methods was significantly higher when the NHS test was performed for healthy newborns in the Level I and II neonatal care units born by CD within 72 h using AABR. Therefore, we recommend that the hearing screening test for newborns delivered by cesarean section be performed after 72 h of age. The results of this study may reduce the false-positive NHS results, unnecessary further tests, and parental anxiety.

Hearing outcomes in children of diabetic pregnancies

OBJECTIVE

Children of diabetic pregnancies (CDPs) face numerous risk factors for hearing loss (HL). The objective of this study was to investigate the hearing outcomes of CDPs on a population scale.

METHODS

Using the Audiological and Genetic Database, the prevalence, severity, and progression of HL in CDPs was compared against children of non-diabetic pregnancies (CNDPs) who served as controls.

RESULTS

Among 311 CDPs, 71.1% demonstrated evidence of HL compared to 45.5% in CNDPs (p < 0.001). The mean age at which CDPs received audiograms was 3.6 years compared to 5.4 years for CNDPs (p < 0.001). Compared to CNDPs, CDPs were similarly affected by common otologic conditions such as acute otitis media (25.7%), chronic otitis media (38.3%), and Eustachian tube dysfunction (41.8%) (all p > 0.05). CDPs were more likely to have bilateral HL (81%) and sensorineural hearing loss (SNHL) (8%) relative to CNDPs (p < 0.001 and p = 0.004, respectively). Rates of conductive HL and mixed HL were not significantly different between groups (p = 0.952 and p = 0.058, respectively). CDPs were at significant risk for the development of HL (aOR 1.66 [1.28-2.17], SNHL (aOR 1.63 [1.01-2.52], and high-frequency HL (aOR 1.32 [1.03-1.68]). Of the comorbidities evaluated, CDPs with hyperbilirubinemia (aOR 1.85 [1.18-2.84]), perinatal asphyxia (aOR 1.90 [1.06-3.16]), or congenital heart disease (aOR 1.21 [1.07-1.37]) demonstrated higher risk of SNHL.

CONCLUSION

Children of diabetic pregnancies face increased risks of developing HL, particularly bilateral and sensorineural hearing loss. Given these findings, we recommend close audiologic follow-up for these children, especially those with complicated birth histories or additional medical problems.

Epidemiology of Diabetes and Hearing Loss

Hearing loss is a highly prevalent chronic condition. In addition to age, sex, noise exposure, and genetic predisposition, cardiovascular disease and its antecedents may precipitate hearing loss. Of emerging interest is the connection between diabetes and auditory dysfunction. Cross-sectional studies consistently suggest that prevalence of hearing loss is higher in persons with diabetes compared with those without diabetes, especially among younger persons. Furthermore, longitudinal studies have demonstrated higher incidence of hearing loss in persons with diabetes compared to those without diabetes. These findings seem to hold for both type 1 and type 2 diabetes, although considerably more population-based evidence is available for type 2 diabetes. Data on gestational diabetes and hearing outcomes are limited, as are data relating diabetes to otologic sequelae such as fungal infection. Here, we examine evidence from epidemiologic studies of diabetes and hearing loss and consider clinical and laboratory data where population-based data are lacking.

Neonatal hearing screening of newborns of mothers with Diabetic Mellitus and/or hypertension in pregnancy: a systematic literature review

ABSTRACT Purpose: to investigate the results of the Neonatal Hearing Screening (NHS) in neonates whose mothers presented hypertension and/or diabetes mellitus in their pregnancy. Methods: a systematic review of the literature, without restriction of year and language, guided by the PRISMA protocol, that was carried out through a search in the MEDLINE (PUBMED), LILACS (BVS), SCOPUS, WEB OF SCIENCE and EMBASE databases, using neonatal screening AND hearing AND (hypertension OR diabetes mellitus) as descriptors. Studies that were duplicated or were unavailable were excluded. Results: 64 records were found, 5 being included for analysis. These articles had been published in the last 13 years, originated from different countries, and using a retrospective (cross-sectional, n=1, case-control, n=1) or prospective design (cross-sectional, n=1, case-control, n=1; cohort, n=1). The findings of the articles demonstrated differences regarding the presence of changes in the NHS outcomes of newborns whose mothers presented hypertension and/or diabetes during pregnancy. Conclusion: since the review showed contradictory results regarding changes in the NHS outcomes in the presence of mothers’ hypertension and/or diabetes during pregnancy, prospective cohort studies are needed, in different contexts, in order to isolate confounding factors for hearing loss and minimize measurement bias and selection.

Inner Hair Cell Loss Disrupts Hearing and Cochlear Function Leading to Sensory Deprivation and Enhanced Central Auditory Gain

There are three times as many outer hair cells (OHC) as inner hair cells (IHC), yet IHC transmit virtually all acoustic information to the brain as they synapse with 90–95% of type I auditory nerve fibers. Here we review a comprehensive series of experiments aimed at determining how loss of the IHC/type I system affects hearing by selectively destroying these cells in chinchillas using the ototoxic anti-cancer agent carboplatin. Eliminating IHC/type I neurons has no effect on distortion product otoacoustic emission or the cochlear microphonic potential generated by OHC; however, it greatly reduces the summating potential produced by IHC and the compound action potential (CAP) generated by type I neurons. Remarkably, responses from remaining auditory nerve fibers maintain sharp tuning and low thresholds despite innervating regions of the cochlea with ~80% IHC loss. Moreover, chinchillas with large IHC lesions have surprisingly normal thresholds in quiet until IHC losses exceeded 80%, suggesting that only a few IHC are needed to detect sounds in quiet. However, behavioral thresholds in broadband noise are elevated significantly and tone-in-narrow band noise masking patterns exhibit greater remote masking. These results suggest the auditory system is able to compensate for considerable loss of IHC/type I neurons in quiet but not in difficult listening conditions. How does the auditory brain deal with the drastic loss of cochlear input? Recordings from the inferior colliculus found a relatively small decline in sound-evoked activity despite a large decrease in CAP amplitude after IHC lesion. Paradoxically, sound-evoked responses are generally larger than normal in the auditory cortex, indicative of increased central gain. This gain enhancement in the auditory cortex is associated with decreased GABA-mediated inhibition. These results suggest that when the neural output of the cochlea is reduced, the central auditory system compensates by turning up its gain so that weak signals once again become comfortably loud. While this gain enhancement is able to restore normal hearing under quiet conditions, it may not adequately compensate for peripheral dysfunction in more complex sound environments. In addition, excessive gain increases may convert recruitment into the debilitating condition known as hyperacusis.