Association of metabolic syndrome with the incidence of hearing loss: A national population-based study

Background & aims

Sensorineural hearing loss (HL) is one of the most common public health problems, and its prevalence increases with increasing life expectancy. An association between HL and metabolic syndrome (MetS) is suspected. Although previous epidemiological studies have investigated the association between the two variables, there have been conflicting conclusions. Therefore, we aimed to evaluate the association between the presence of MetS—and individual components of MetS—and HL, using a longitudinal design and a large-scale population.

Methods

A total of 17,513,555 individuals who underwent national health screening between January 2009 and December 2010 were identified. Subject data from the Korean Health Insurance Review and Assessment Service were reviewed. A total of 11,457,931 subjects were ultimately included in the analysis. Baseline comorbidities were defined according to the ICD-10 code from the Korean Health Insurance Review and Assessment Service data. If the participants had an ICD-10 code for HL during the follow-up, they were defined as having incident HL. Criteria for MetS adhered to the revised National Cholesterol Education Program Adult Treatment Panel III.

Results

There were 7,574,432 subjects without MetS and 3,883,499 with MetS. The incidence of HL in subjects without MetS and with MetS was 1.3% and 1.8% at 1 year, 4.1% and 5.2% at 3 years, and 6.8% and 8.6% at 5 years, respectively (P < 0.001). However, multivariate analyses revealed a negative association. Analyses according to the components of MetS demonstrated a positive association for those associated with dyslipidemia; however, the others exhibited an inverse association with HL. We also performed analyses using 4 groups according to the presence of MetS and the components of dyslipidemia. Univariate analysis revealed a positive association between the presence of MetS and HL; however, multivariate analysis revealed a positive association between the presence of dyslipidemia components and HL, regardless of the presence of MetS.

Conclusion

Among the components of MetS, the association between low HDL or high TG levels and HL was most apparent. It is useful to evaluate each MetS component in isolation, such as the presence of low HDL or high TG levels, rather than the presence of MetS as a cluster of components.

A 4-Year Audit of Open Method Chemoport Insertions through Cephalic Vein Performed In Hospital Tengku Ampuan Afzan

Introduction: Many cancer patients in general require long term venous access such as chemoport for chemotherapy, as well as infusion of fluids and blood taking. However, chemoport insertions carry complications such as infection, blockage, pneumothorax and malposition. We received feedbacks regarding complications endured by patients after chemoport insertion from the respective teams managing the patients in our hospital. In view of that, we conducted a retrospective audit on the chemoport insertions which we have done. Materials and Methods: We conducted a retrospective audit on the chemoport insertions which was planned for open method insertion through cephalic vein performed over the last 4 years from 2014 to 2017. Results: A total of 102 chemoports were inserted. Majority of patient’s ages are 50-59 years old. 88 (86%) of the cases were done via open method whereas another 14 cases were converted to percutaneous route. Majority of patients (55%) of the patients have breast carcinoma followed by colorectal (28%), haematological (12%) and gynaecological malignancies (5%). Complications occurred in 10 patients (rate at 9.8%). Most common complications were catheter related infection (5 cases) followed by wound infection (3 cases) and malposition (2 cases). Malposition was detected on post-operative chest radiograph and revision was done. All catheter related infection occurred in patients with haematological malignancies. Our complication rate of 9.8% is lower than the accepted complication rate of 15-25% worldwide. Conclusion: Chemoport provides a robust vascular access especially for the purpose of chemotherapy infusion. We showed with adequate training and privileging, it can be performed with very limited complications.

Modified U1 snRNA and antisense oligonucleotides rescue splice mutations in SLC26A4 that cause hereditary hearing loss

One of most important factors for messenger RNA (mRNA) transcription is the spliceosomal component U1 small nuclear RNA (snRNA), which recognizes 5' splicing donor sites at specific regions in pre-mRNA. Mutations in these sites disrupt U1 snRNA binding and cause abnormal splicing. In this study, we investigated mutations at splice sites in SLC26A4 (HGNC 8818), one of the major causative genes of hearing loss, which may result in the synthesis of abnormal pendrin, the channel protein encoded by the gene. Seventeen SLC26A4 variants with mutations in the U1 snRNA binding sites were assessed by minigene splicing assays, and 11 were found to result in abnormal splicing. Interestingly, eight of the 11 pathogenic mutations were intronic, suggesting the importance of conserved sequences at the intronic splice site. The application of modified U1 snRNA effectively rescued the abnormal splicing for most of these mutations. Although three were cryptic mutations, they were rescued by cotransfection of modified U1 snRNA and modified antisense oligonucleotides. Our results demonstrate the important role of snRNA in SLC26A4 mutations, suggesting the therapeutic potential of modified U1 snRNA and antisense oligonucleotides for neutralizing the pathogenic effect of the splice-site mutations that may result in hearing loss.

Design of a dual-coil type electromagnetic actuator for implantable bone conduction hearing devices

BACKGROUND

This paper describes the design and implementation of a dual-coil type electromagnetic actuator for implantable bone conduction hearing devices.

OBJECTIVE

The structure of the proposed actuator was designed to generate maximum Lorentz force via the dual-coil method with a closed magnetic circuit. To satisfy the indications required by implantable bone conduction hearing devices, high output was generated within a specific frequency range using a vibrational membrane with a cantilever.

METHODS

The structure of the membrane consists of a fixed ring, a circular plate, and two cantilevers connected symmetrically. Variable elements of the vibrational membrane affecting the actuator frequency characteristics were analyzed through mathematical modeling and finite element analysis, based on the analysis used to derive the optimum structure of the vibrational membrane. The components of the actuator were fabricated through chemical etching and computer numerical control process, and the bone conduction actuator was fabricated through the precision assembly process.

RESULTS

The output characteristics of the implemented actuator were measured using a laser Doppler vibrometer. As a result of measurement, the proposed actuator generated mechanical resonance at 1.2 kHz.

CONCLUSIONS

By comparing the measured results with the finite element analysis results, we confirmed the validity of the proposed actuator design.

CRISPR/Cas9-mediated genome editing of splicing mutation causing congenital hearing loss

Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system has ushered in a new era of gene therapy. In this study, we aimed to demonstrate precise CRISPR/Cas9-mediated genome editing of the splicing mutation c.919-2A > G in intron 7 of the SLC26A4 gene, which is the second most common causative gene of congenital hearing loss. We designed candidate single-guide RNAs (sgRNAs) aimed to direct the targeting of Staphylococcus aureus Cas9 to either exon 7 or exon 8 of SLC26A4. Several of the designed sgRNAs showed targeting activity, with average indel efficiencies ranging from approximately 14% to 25%. The usage of dual sgRNAs delivered both into Neuro2a cells and primary mouse embryonic fibroblasts resulted in the successful removal of large genomic fragments within the target locus. We subsequently evaluated genome editing in the presence of artificial donor templates to induce precise target modification via homology-directed repair. Using this approach, two different donor plasmids successfully introduced silent mutations within the c.919-2A region of Slc26a4 without evident off-target activities. Overall, these results indicate that CRISPR/Cas9-mediated correction of mutations in the Slc26a4 gene is a feasible therapeutic option for restoration of hearing loss.

Correction to: Exocyst Complex Member EXOC5 Is Required for Survival of Hair Cells and Spiral Ganglion Neurons and Maintenance of Hearing

The original article contains an error for a grant number in the Acknowledgements section.

Evaluation of the blend of organic acids and medium-chain fatty acids in matrix coating as antibiotic growth promoter alternative on growth performance, nutrient digestibility, blood profiles, excreta microflora, and carcass quality in broilers

This study was conducted to evaluate the effects of the blend of organic acids (OAs) and medium-chain fatty acids (MCFAs) in broiler chickens. A total of 816 1-d-old male Ross 308 broiler chickens (35 ± 0.44 g) were randomly allocated into 1 of the following 6 dietary treatments (17 broilers per pen with 8 pens per treatment): dietary treatments consisted of corn-soybean meal-based basal diet and the basal diet supplemented with 0.02, 0.03, 0.04, 0.05, and 0.06% blend of OAs and MCFAs. The study lasted 5 wk during which growth performance was determined. In the current study, the inclusion of 0.02, 0.03, 0.04, 0.05, and 0.06% blend of OAs and MCFAs in the basal diet linearly increased (P < 0.05) body weight gain and improved feed conversion ratio (P < 0.0001) on day 7 to 14, day 14 to 35, as well as overall. Increasing inclusion of the blend of OAs and MCFAs levels in the diets also linearly increased (P = 0.001) the digestibility of dry matter on day 35. Broilers fed with different levels of the blend of OAs and MCFAs showed a linear increment (P = 0.042) in Lactobacillus concentration and decrease (P = 0.002) in Escherichia coli concentration. With regard to relative organ weight, a trend of linear reduction (P = 0.052) in bursa of Fabricius weight of broilers fed the blend of OAs and MCFAs was observed. There was a significant linear improvement (P = 0.011) in the IgG concentration associated with the inclusion of the blend of OAs and MCFAs levels in the diets. In conclusion, the blend of OAs and MCFAs supplementation positively influenced growth performance, nutrient digestibility, and excreta microflora in broiler chickens.

Therapeutic potential of the mitochondria-targeted antioxidant MitoQ in mitochondrial-ROS induced sensorineural hearing loss caused by Idh2 deficiency

Mitochondrial NADP⁺-dependent isocitrate dehydrogenase 2 (IDH2) is a major NADPH-producing enzyme which is essential for maintaining the mitochondrial redox balance in cells. We sought to determine whether IDH2 deficiency induces mitochondrial dysfunction and modulates auditory function, and investigated the protective potential of an antioxidant agent against reactive oxygen species (ROS)-induced cochlear damage in Idh2 knockout (Idh2^−/−) mice. Idh2 deficiency leads to damages to hair cells and spiral ganglion neurons (SGNs) in the cochlea and ultimately to apoptotic cell death and progressive sensorineural hearing loss in Idh2^−/− mice. Loss of IDH2 activity led to decreased levels of NADPH and glutathione causing abnormal ROS accumulation and oxidative damage, which might trigger apoptosis signal in hair cells and SGNs in Idh2^−/− mice. We performed ex vivo experiments to determine whether administration of mitochondria-targeted antioxidants might protect or induce recovery of cells from ROS-induced apoptosis in Idh2-deficient mouse cochlea. MitoQ almost completely neutralized the H₂O₂-induced ototoxicity, as the survival rate of Idh2^−/− hair cells were restored to normal levels. In addition, the lack of IDH2 led to the accumulation of mitochondrial ROS and the depolarization of ΔΨ_m, resulting in hair cell loss. In the present study, we identified that IDH2 is indispensable for the functional maintenance and survival of hair cells and SGNs. Moreover, the hair cell degeneration caused by IDH2 deficiency can be prevented by MitoQ, which suggests that Idh2^−/− mice could be a valuable animal model for evaluating the therapeutic effects of various antioxidant candidates to overcome ROS-induced hearing loss.

Evaluating protective and therapeutic effects of alpha-lipoic acid on cisplatin-induced ototoxicity

Cisplatin, a small platinum-containing molecule, is a widely used, highly effective anticancer drug. However, severe side effects have been found in cancer patients treated with cisplatin, including nephrotoxicity, neurotoxicity, and ototoxicity. These cisplatin-induced side effects can have a major impact on patient quality of life, including social development problems in pediatric patients that develop hearing loss. Previous studies have suggested that the major cause of cisplatin-induced ototoxicity is abnormal accumulation of reactive oxygen species (ROS) and oxidative stress. Alpha-lipoic acid (ALA), one of the most effective antioxidants, is known to be involved in the cellular antioxidant system and may have a protective effect on cisplatin-induced ototoxicity. However, the therapeutic effect of ALA on damaged hearing function and its detailed mechanism of action are not fully understood. This study focused on determining whether ALA has a potential as a protective and/or therapeutic agent for cisplatin-induced ototoxicity. Histological and physiological analyses were performed using cisplatin-treated mouse cochlea and HEI-OC1 culture cells in pre- and post-treatment with ALA in vitro and in vivo. We found that ALA contributes to protecting mitochondrial function by preventing ROS accumulation and inhibiting apoptotic cell death. Importantly, post-treatment with ALA consistently showed an almost equal restorative effect to pretreatment, in vitro and in vivo, supporting the possible use of ALA as a therapeutic agent for cisplatin-induced ototoxicity. This study is the first report on a strong therapeutic potential of ALA to rescue ototoxic hearing loss caused by cisplatin, and our data provide key evidence that ALA may act as a reducing agent for glutathione disulfide to increase glutathione levels on behalf of glutathione reductase. This result was consistent in both cultured cells and the mouse model, which improves the clinical value of ALA for therapy of cisplatin-induced ototoxicity.

Performance, egg quality, nutrient digestibility, and excreta microbiota shedding in laying hens fed corn-soybean-meal-wheat-based diets supplemented with xylanase

The aim of this study was to evaluate the effects of dietary levels of xylanase on production performance, egg quality, nutrient digestibility, and excreta microbiota shedding of laying hens in a 12-week trial. Two-hundred-forty Hy-Line brown laying hens (44 wk old) were distributed according to a randomized block experimental design into one of 4 dietary treatments with 10 replicates of 6 birds each. The 4 dietary treatments were corn-soybean-meal-wheat-based diets supplemented with 0, 225, 450, or 900 U/kg xylanase. Daily feed intake, egg production, egg weight, egg mass, feed conversion ratio, and damaged egg rate showed no significant response to increasing xylanase supplementation during any phase (P > 0.05). No significant responses were observed for apparent total tract digestibility of dry matter, nitrogen, or gross energy (P > 0.05). A significant linear increase to increasing xylanase supplementation was seen for lactic acid bacteria numbers, although coliforms and Salmonella counts were not affected. Increasing the dietary xylanase resulted in a significant linear increase in eggshell thickness in wk 3, 6, 9, and 12 (P < 0.05). In addition, a significant linear increase occurred for Haugh unit and albumen height in wk 12 (P < 0.05). In summary, the inclusion of xylanase in corn-soybean-meal-wheat-based diets increased eggshell thickness, Haugh unit, albumen height, and excreta lactic acid bacteria count but had no effect on production performance or nutrient digestibility.

Diagnostic role of cone beam computed tomography for the position of straight array

OBJECTIVE

To assess the usefulness of cone beam computed tomography (CBCT) for characterizing electrode insertion and evaluate the influence of electrode insertion status on post-cochlear implantation (CI) outcomes.

DESIGN

Twenty-six ears with post-CI CBCT scans were included. The devices were MED-EL Flex28 (n = 21) and Nucleus slim straight (n = 5). The parameters including cochlear duct length (CDL), insertion depth angle (IDA), insertion length of electrode (IL), and cochlear coverage (CC) were analyzed and compared with aided pure-tone threshold (PTA) with implant in free field, and open-set sentence score.

RESULTS

The mean CDL was 36.8 ± 1.4 mm. Electrode array was dislocated into scala tympani in two ears. The mean IL and IDA were 26.5 ± 1.9 mm and 541.4 ± 70.2°. The mean linear CC (IL/CDL, 0.73 ± 0.06) was larger than the mean angular CC (IDA/900, 0.60 ± 0.08). The CBCT parameters showed correlation one another. While the aided pure-tone threshold was correlated with IL and IDA, there were no significant correlations in the open-set sentence score. For the postlingually deaf patients with single electrode (Flex 28), the sentence score had no significant correlation and the aided PTA was positively correlated with IL (R = 0.517, p = .028).

CONCLUSIONS

This study validated the CBCT evaluating the electrode array position. The CBCT could be helpful for the preoperative selection of the optimal array and prediction of the CC.

Microbiological Results From Middle Ear Effusion in Pediatric Patients Receiving Ventilation Tube Insertion: Multicenter Registry Study on the Effectiveness of Ventilation Tube Insertion in Pediatric Patients With Chronic Otitis Media With Effusion: Part I

Objectives

The aim of this multicenter registry study was to investigate the effectiveness of ventilation tube insertion and the microbiology of otitis media with effusion (OME) in children. This part I study was conducted to evaluate the microbiological profile of children with OME who needed ventilation tube insertion.

Methods

Patients <15 years old who were diagnosed as having OME and received ventilation tube insertion were prospectively enrolled in 16 tertiary hospitals from June 2014 to December 2016. After excluding patients with missing data, the data of 397 patients were analyzed among a total of 433 enrolled patients. The clinical symptoms, findings of the tympanic membrane, hearing level, and microbiological findings were collected.

Results

In 103 patients (25.9%), antibiotics were used within 3 weeks before surgery. Ventilation tube insertion was performed in a total of 710 ears (626 in both ears in 313 patients, 55 in the left ear only, and 29 in the right ear only). Culture of middle ear effusion was done in at least one ear in 221 patients (55.7%), and in a total of 346 ears. Only 46 ears (13.3%) showed positive results in middle ear effusion culture. Haemophilus influenzae (17.3%, followed by coagulase-negative Staphylococcus and Staphylococcus auricularis) was the most common bacteria detected.

Conclusion

H. influenzae was the most commonly found bacteria in middle ear effusion. Relatively low rates of culture positivity were noted in middle ear effusion of patients with OME in Korea.

High resolution Thomson scattering system for steady-state linear plasma sources

The high resolution Thomson scattering system with 63 points along a 25 mm line measures the radial electron temperature (T_e) and its density (n_e) in an argon plasma. By using a DC arc source with lanthanum hexaboride (LaB₆) electrode, plasmas with electron temperature of over 5 eV and densities of 1.5 × 10¹⁹ m^-3 have been measured. The system uses a frequency doubled (532 nm) Nd:YAG laser with 0.25 J/pulse at 20 Hz. The scattered light is collected and sent to a triple-grating spectrometer via optical-fibers, where images are recorded by an intensified charge coupled device (ICCD) camera. Although excellent in stray-light reduction, a disadvantage comes with its relatively low optical transmission and in sampling a tiny scattering volume. Thus requires accumulating multitude of images. In order to improve photon statistics, pixel binning in the ICCD camera as well as enlarging the intermediate slit-width inside the triple-grating spectrometer has been exploited. In addition, the ICCD camera capture images at 40 Hz while the laser is at 20 Hz. This operation mode allows us to alternate between background and scattering shot images. By image subtraction, influences from the plasma background are effectively taken out. Maximum likelihood estimation that uses a parameter sweep finds best fitting parameters T_e and n_e with the incoherent scattering spectrum.

Metronome vs. Popular Song: A Comparison of Long-Term Retention of Chest Compression Skills after Layperson Training for Cardiopulmonary Resuscitation

Introduction

Long-term retention of cardiopulmonary resuscitation (CPR) skill is challenging for layperson trainees. This study compared the long-term retention of chest compression skills after either metronome-guided (MG) or popular song-guided (PG) CPR training.

Methods

This was a prospective randomised simulation trial. Untrained laypersons were randomly allocated to MG (n=61) or PG (n=68) groups at CPR training sessions. After CPR training, each participant performed 5-cycle CPR using a manikin with a Skill-Reporter™ immediately and six months afterwards.

Results

Immediately after training, the mean compression rate (MCR) was slightly higher in the PG than the MG group (107.4 vs. 102.2/min; p<0.0001), but there was no significant difference in the proportions of participants with an appropriate chest compression rate (100-120/min) (PSACCR) between the MG and PG (53/61 (86.9%) vs. 65/68 (95.6%); p=0.114). Six months later, MCR was faster in the MG than the PG (124.8 vs. 110.0/min; p<0.0001), and PSACCR in the PG was higher than that in the MG (62/68 (91.2%) vs. 25/61 (41.0%); p<0.0001). In both tests, there were no significant differences in other chest compression parameters of between the two groups, except for a minimal difference in incomplete chest release.

Conclusion

CPR training using a popular song is more effective than metronome-guided training in helping laypersons to maintain recommended compression rates after 6 months. (Hong Kong j.emerg.med. 2016;23:145-152)

Genome-wide loss-of-function genetic screening identifies opioid receptor μ1 as a key regulator of L-asparaginase resistance in pediatric acute lymphoblastic leukemia

L-asparaginase is a critical chemotherapeutic agent for acute lymphoblastic leukemia (ALL). It hydrolyzes plasma asparagine into aspartate and NH₃, causing asparagine deficit and inhibition of protein synthesis and eventually, leukemic cell death. However, patient relapse often occurs due to development of resistance. The molecular mechanism by which ALL cells acquire resistance to L-asparaginase is unknown. Therefore, we sought to identify genes that are involved in L-asparaginase resistance in primary leukemic cells. By unbiased genome-wide RNAi screening, we found that among 10 resistant ALL clones, six hits were for opioid receptor mu 1 (oprm1), two hits were for carbonic anhydrase 1 (ca1) and another two hits were for ubiquitin-conjugating enzyme E2C (ube2c). We also found that OPRM1 is expressed in all leukemic cells tested. Specific knockdown of OPRM1 confers L-asparaginase resistance, validating our genome-wide retroviral shRNA library screening data. Methadone, an agonist of OPRM1, enhances the sensitivity of parental leukemic cells, but not OPRM1-depleted cells, to L-asparaginase treatment, indicating that OPRM1 is required for the synergistic action of L-asparaginase and methadone, and that OPRM1 loss promotes leukemic cell survival likely through downregulation of the OPRM1-mediated apoptotic pathway. Consistent with this premise, patient leukemic cells with relatively high levels of OPRM1 are more sensitive to L-asparaginase treatment compared to OPRM1-depleted leukemic cells, further indicating that OPRM1 loss has a crucial role in L-asparaginase resistance in leukemic patients. Thus, our study demonstrates for the first time, a novel OPRM1-mediated mechanism for L-asparaginase resistance in ALL, and identifies OPRM1 as a functional biomarker for defining high-risk subpopulations and for the detection of evolving resistant clones. Oprm1 may also be utilized for effective treatment of L-asparaginase-resistant ALL.

Identification of a novel splicing mutation within SLC17A8 in a Korean family with hearing loss by whole-exome sequencing

Hereditary hearing loss (HHL) is a common genetically heterogeneous disorder, which follows Mendelian inheritance in humans. Because of this heterogeneity, the identification of the causative gene of HHL by linkage analysis or Sanger sequencing have shown economic and temporal limitations. With recent advances in next-generation sequencing (NGS) techniques, rapid identification of a causative gene via massively parallel sequencing is now possible. We recruited a Korean family with three generations exhibiting autosomal dominant inheritance of hearing loss (HL), and the clinical information about this family revealed that there are no other symptoms accompanied with HL. To identify a causative mutation of HL in this family, we performed whole-exome sequencing of 4 family members, 3 affected and an unaffected. As the result, A novel splicing mutation, c.763+1G>T, in the solute carrier family 17, member 8 (SLC17A8) gene was identified in the patients, and the genotypes of the mutation were co-segregated with the phenotype of HL. Additionally, this mutation was not detected in 100 Koreans with normal hearing. Via NGS, we detected a novel splicing mutation that might influence the hearing ability within the patients with autosomal dominant non-syndromic HL. Our data suggests that this technique is a powerful tool to discover causative genetic factors of HL and facilitate diagnoses of the primary cause of HHL.

Protective effects of 1,2,3-triazole derivative KPR-A020 against cisplatin-induced ototoxicity in murine cochlear cultures

Cisplatin (cis-diaminedichloridoplatinum(II), cis-[PtCl₂(NH₃)₂]) is an effective chemotherapeutic agent in the treatment of several types of malignant solid tumors but its clinical use is associated with ototoxicity. Several studies have investigated the effect of antioxidants on cisplatin-induced ototoxicity in mice. The triazole KPR-A020 has been shown to play a protective role against mitochondrial dysfunction by reducing the production of mitochondrial reactive oxygen species (ROS). The effect of KPR-A020 on cisplatin-induced ototoxicity was examined using cultures of cochlear explants. Healthy mice were randomly divided into 4 groups: control, treated with cisplatin alone (CP), treated with cisplatin and KPR-A020 (CP + KPR-A020), and treated with KPR-A020 alone (KPR-A020). The cochlear explants were harvested for histological and immunohistochemical examinations. Biochemical analyses of the explants revealed that pre-treatment with KPR-A020 prevented an increase in mitochondrial ROS levels. Moreover, the CP + KPR-A020 group showed better hair cell survival than the CP group. Immunohistochemical examinations of cochlear explants stained with anti-caspase-3 revealed greater immunopositivity in the CP group. The CP + KPR-A020 group showed significantly less immunopositivity than the CP group (P < 0.05). Thus, it appears that KPR-A020 protects hair cells in the organ of Corti from cisplatin-induced toxicity by decreasing the production of mitochondrial ROS. The results of this study suggest that KPR-A020 can be used as an antioxidant and antiapoptotic agent to prevent hearing loss caused by cisplatin induced-oxidative stress.

Association between sarcopenia and hearing thresholds in postmenopausal women

Background: Given the association between metabolic disturbance and sarcopenia, sarcopenia may be intrinsically associated with the prevalence of HL. However, few studies describe the association between sarcopenia and HL. The aim of this study was to evaluate the clinical association between sarcopenia and HL in postmenopausal Korean women. Patients and Methods: A total of 4,038 women were ultimately included in this study. All participants were postmenopausal. Participants were divided into two groups based on criteria from the Foundation for the National Institute of Health Sarcopenia Project: a normal group (sarcopenia index ≥ 0.512) and a sarcopenia group (sarcopenia index < 0.512). Low-frequency (Low-Freq), mid-frequency (Mid-Freq), and high-frequency (High-Freq) values were obtained. The average hearing threshold (AHT) was calculated as the pure tone average at the 4 frequencies of 0.5 kHz, 1 kHz, 2 kHz, and 3 kHz. Mild HL was as an AHT of 24 to 40 dB; moderate-to-profound HL was defined as an AHT of 40 dB or greater. Results: Of the 4,038 participants, 272 (6.7%) were allocated to the sarcopenia group, leaving 3,766 (93.3%) in the normal group. The groups differed significantly in terms of having hypertension (775 [20.6%] vs. 108 [39.7%]; P < 0.001) or metabolic syndrome (817 [21.7%] vs. 110 [40.4%]; P < 0.001) in the normal and sarcopenia groups, respectively. Visceral fat area (cm³) in the normal and sarcopenia groups was 99.0 ± 21.9 cm³ and 117.0 ± 21.8 cm³ , respectively (P < 0.001). The hsCRP level was higher in the sarcopenia group than in the normal group. For univariate and multivariate analyses, all 4 hearing thresholds were higher in the sarcopenia group than in the normal group. In addition, linear regression analyses showed Low-Freq, Mid-Freq, and High-Freq to be inversely correlated with the sarcopenia index. The unadjusted OR for mild HL was 2.692 (95% CI, 1.963-3.692; P < 0.001) in the sarcopenia group relative to the normal group, with an adjusted OR of 1.584 (95% CI, 1.131-2.217; P = 0.007). The unadjusted OR for moderate-to-profound HL in the sarcopenia group relative to the normal group was 6.246 (95% CI, 4.530-8.612; P < 0.001); the adjusted OR was 2.667 (95% CI, 1.866-3.812; P < 0.001). Conclusion: Sarcopenia may be associated with HL. It may be beneficial to perform screening audiometry in patients with sarcopenia.

Association Between Hearing Impairment and Albuminuria With or Without Diabetes Mellitus

Objectives

Few studies have evaluated the accurate association between hearing loss (HL) and albuminuria in patients with or without diabetes mellitus (DM). The aim of our study was to identify the clinical effects of albuminuria on HL with or without DM.

Methods

This study included 9,762 patients from the Korean National Health and Nutrition Examination Survey between 2011 and 2013. Participants were divided into 4 groups based on DM and urine albumin/creatinine ratio levels: group 1 included participants with neither DM nor albuminuria, group 2 included participants without DM and with albuminuria, group 3 included patients with DM and without albuminuria, and group 4 included patients with both DM and albuminuria. The low- or mid-frequency and high-frequency, and average hearing threshold values were obtained.

Results

There were 7,508, 545, 1,325, and 384 participants in groups 1, 2, 3, and 4, respectively. Univariate and multivariate analyses showed that the 3 hearing thresholds in group 1 were the lowest and those in group 4 were the highest among the 4 groups. No significant differences were observed in those thresholds between groups 2 and 3. Group 4 was associated with HL compared with the other groups, but moderate to severe HL was not associated with DM or albuminuria.

Conclusion

The presence of albuminuria was associated with a modest effect on hearing thresholds regardless of presence of DM.

Clinical Aspects and Surgical Outcomes of Congenital Cholesteatoma in 93 Children: Increasing Trends of Congenital Cholesteatoma from 1997 through 2012

BACKGROUND AND OBJECTIVES

The recent increase in the reported incidence of congenital cholesteatoma (CC) may be secondary to the widespread use of otoendoscopy as well as an increased awareness of these lesions among primary care physicians. However, little research about CC has been conducted in a large group of patients. This study aimed to analyze the clinical characteristics of CC including the annual number of patients, symptoms, age at diagnosis, stage and type of disease, surgical techniques, recurrence, and postoperative complications.

SUBJECTS AND METHODS

Retrospective chart review was performed for patients who met the inclusion criteria between January 1997 and June 2012.

RESULTS

Ninety-three patients underwent surgery for CC. The age at operation ranged from 12 months to 17 years (mean age, 6.1 years). The number of patients was less than 4 per year until 2005, but increased to more than 10 per year since 2008. CC was most commonly reported as an incidental finding (58.1%). The operative procedures included the transcanal myringotomy approach (46.2%), canal wall up mastoidectomy (37.6%), tympanoplasty (8.6%), and canal wall down mastoidectomy (7.5%). The recurrence rate was 20.4% and the complication rate was 12.9%. No patients with stage I CC had complications.

CONCLUSIONS

This study showed that the incidence of CC has recently increased notably. Most patients with stage I and II CC were completely cured by transtympanic surgery, and complication and recurrence rates increased according to the extent of disease. Early detection of CC is important to facilitate minimally invasive surgery and to reduce complication and recurrence rates.

A tri-coil bellows-type round window transducer with improved frequency characteristics for middle-ear implants

A number of methods to drive the round window (RW) using a floating mass transducer (FMT) have been reported. This method has attracted attention because the FMT is relatively easy to implant in the RW niche. However, the use of an FMT to drive the RW has been proven to produce low outputs at frequencies below approximately 1 kHz. In this study, a new tri-coil bellows-type transducer (TCBT), which has excellent low frequency output and is easy to implant, is proposed. To design the frequency characteristics of the TCBT, mechanical and electrical simulations were performed, and then a comparative analysis was conducted between a floating mass type transducer (like the FMT) and a fixed type transducer (like the TCBT). The features of the proposed TCBT are as follows. First, the TCBT's housing is fixed to the RW niche so that it does not vibrate. Second, the internal end of a tiny bellows is connected to a vibrating three-pole permanent magnet located within three field coils. Finally, the rim of the bellows bottom is attached to the end of the housing that hermetically encloses the three field coils. In this design, the only vibrating element is the bellows itself, which efficiently drives the RW membrane. To evaluate the characteristics of this newly developed TCBT, the transducer was installed in the RW niche of temporal bones and the velocity of the stapes was measured using a laser Doppler vibrometer. The experimental results indicate that the TCBT can produce 100, 111, and 129 dB SPL equivalent pressure outputs at below 1 kHz, 1-3 kHz, and above 3 kHz, respectively. Thus, the TCBT with one side coupled to the RW via a bellows will be easy to implant and offer better performance than an FMT.