Virtaniemi J, Laakso M, Nuutinen J, Karjalainen S, Vartiainen E
Department of Otolaryngology, University of Kuopio, Finland.
Am J Otolaryngol. 1994 Mar-Apr;15(2):109-13. doi: 10.1016/0196-0709(94)90059-0.
Patients with insulin-dependent diabetes mellitus (IDDM) are especially susceptible to microangiopathic complications such as nephropathy, retinopathy, and neuropathy. Microangiopathic changes are also the most important findings in histopathologic studies of the inner ear and central nervous systems in diabetic subjects. No previous studies have measured acoustic-reflex latencies (ARL) or amplitudes (ARA) in patients with IDDM. ARL and ARA reflect the function of the acoustic-reflex arch. Furthermore, possible changes in the tympanic membrane, ossicular chain, and stapedius muscle may affect the shape of acoustic-reflex.
Acoustic-reflex thresholds, latencies, and amplitudes were studied in 53 patients with IDDM and 42 randomly selected nondiabetic control subjects, aged between 20 and 40 years, using the Madsen Model ZO 73 Impedance Bridge (Madsen Electronics, Copenhagen, Denmark). Subjects with an abnormal tympanic membrane, conductive hearing loss, and known cause for hearing impairment eg, noise damage, were excluded from the study.
There were no differences between control and diabetic subjects in the contralateral acoustic-reflex thresholds. In contrast, patients with IDDM had longer ARLs and decreased ARAs compared with those of control subjects. ARA amplitude had linear correlation with the amplitude of tympanogram, whereas ARL had no linear correlation with auditory brainstem latencies in the same study subjects. Acoustic-reflex responses in insulin-dependent diabetic patients were not associated with the duration of diabetes, metabolic control, microangiopathy, or neuropathy.
Prolonged ARLs and decreased ARAs in patients with insulin-dependent diabetes are probably caused more by the stiff middle ear system than disturbances in the brainstem.
胰岛素依赖型糖尿病（IDDM）患者特别易患微血管并发症，如肾病、视网膜病变和神经病变。微血管病变也是糖尿病患者内耳和中枢神经系统组织病理学研究中最重要的发现。此前尚无研究测量IDDM患者的声反射潜伏期（ARL）或幅度（ARA）。ARL和ARA反映声反射弧的功能。此外，鼓膜、听骨链和镫骨肌的可能变化可能会影响声反射的形态。
使用Madsen Model ZO 73阻抗桥（丹麦哥本哈根的Madsen Electronics公司），对53例IDDM患者和42例年龄在20至40岁之间随机选取的非糖尿病对照者进行声反射阈值、潜伏期和幅度的研究。鼓膜异常、传导性听力损失以及已知听力损害原因（如噪声损伤）的受试者被排除在研究之外。
对照者和糖尿病患者的对侧声反射阈值无差异。相比之下，IDDM患者的ARL更长，ARA低于对照者。在同一研究对象中，ARA幅度与鼓室图幅度呈线性相关，而ARL与听觉脑干潜伏期无线性相关。胰岛素依赖型糖尿病患者的声反射反应与糖尿病病程、代谢控制、微血管病变或神经病变无关。
胰岛素依赖型糖尿病患者ARL延长和ARA降低可能更多是由中耳系统僵硬而非脑干功能紊乱所致。
