Department of Otolaryngology, University of Miami, Miller School of Medicine, Miami, Florida 33136, USA.
Laryngoscope. 2012 Nov;122(11):2539-42. doi: 10.1002/lary.23577. Epub 2012 Sep 10.
OBJECTIVES/HYPOTHESIS: Audiometric patterns have been shown to indirectly provide information regarding the pathophysiology of presbycusis and be useful in the phenotyping of hereditary deafness.
Hospital-based cohort study of adults with presbycusis, comparing the association of audiometric patterns and polymorphisms of antioxidant enzymes that have been linked to presbycusis: GSTT1, GSTM1 and NAT2. All subjects underwent a clinical evaluation and completed questionnaires regarding ototoxicity and noise exposure. Pure-tone threshold audiometry was obtained and subjects' audiograms were classified into specific patterns. DNA was extracted from blood and the polymorphisms of GSTT1, GSTM1, and the NAT2 variants (NAT2* 5A; NAT2* 6A,B) were analyzed by PCR.
The audiometric patterns that were more prevalent in our cohort were "High-Frequency Steeply Sloping" or HFSS (33%), "High-Frequency Gently Sloping" or HFGS (31%), and "Flat" (27%), with other patterns being rare. We did not find a statistical significant effect of gender, age, hearing level, and ear side on the audiometric pattern. Subjects with mutant alleles for GSTT1 were more likely to have a HFSS audiogram than subjects with the wild type genotype.
In this cohort, there was a similar prevalence for the three audiometric configurations HFSS, HFGS, and Flat, with other configurations being rare. Subjects with mutant alleles for GSTT1 were more likely to have a HFSS audiogram than subjects with the wild type genotype, suggesting that the basal turn of the cochlea is susceptible to GSTT1 regulated oxidative stress. However, further studies of audioprofiles with larger sample sizes may be needed to establish phenotype-genotype correlations in presbycusis.
目的/假设：听力模式已被证明可间接提供关于 presbycusis 病理生理学的信息，并有助于遗传性耳聋的表型分析。
这是一项基于医院的 presbycusis 成人队列研究，比较了听力模式与已与 presbycusis 相关的抗氧化酶多态性（GSTT1、GSTM1 和 NAT2）之间的关联。所有受试者均接受了临床评估，并完成了有关耳毒性和噪声暴露的问卷。进行纯音阈值听力测试，并将受试者的听力图分类为特定模式。从血液中提取 DNA，并通过 PCR 分析 GSTT1、GSTM1 和 NAT2 变体（NAT25A；NAT26A、B）的多态性。
在我们的队列中更常见的听力模式是“高频陡峭下降”或 HFSS（33%）、“高频缓慢下降”或 HFGS（31%）和“平坦”（27%），其他模式则很少见。我们没有发现性别、年龄、听力水平和耳侧对听力模式有统计学显著影响。与野生型基因型相比，携带 GSTT1 突变等位基因的受试者更有可能出现 HFSS 听力图。
在该队列中，HFSS、HFGS 和平坦这三种听力配置的患病率相似，其他配置则很少见。与野生型基因型相比，携带 GSTT1 突变等位基因的受试者更有可能出现 HFSS 听力图，这表明耳蜗的基底转更容易受到 GSTT1 调节的氧化应激影响。然而，可能需要进行更大样本量的听力图研究，以建立 presbycusis 中的表型-基因型相关性。
