[[alternative]]The relationship between duration of type II diabetes and characteristics of hearing loss

[[abstract]] 本研究目的為探討第二型糖尿病的罹病時長與聽力損失特徵的關係。將第二型糖尿病的罹患時長以四年為一個時期，比較不同罹病時長之糖尿病患者與無糖尿病者，在純音聽閾、變頻耳聲傳射波幅以及聽性腦幹反應I-V波波間潛時值是否有顯著差異。 研究對象共58位受試者，年齡介於36歲至68歲之間。實驗組依第二型糖尿病罹患時長分成三組：1) 未滿4年、2) 滿4年至未滿8年、及 3) 滿8年至未滿12年；控制組為年齡相當之無糖尿病者。第二型糖尿病患者之罹病時長的起始點以診斷時間為依據，糖化血色素值皆小於等於8%。受試者之純音聽力閾值、變頻耳聲傳射絕對波幅以及聽性腦幹反應I-V波波間潛時值，利用單尾變異數分析法進行分析。 研究結果顯示，無糖尿病組與三組不同第二型糖尿病罹患時長組，在1000Hz的純音聽力閾值，以及 f2 為1000Hz 與 2000Hz 所獲得之耳聲傳射絕對波幅有顯著差異，在聽性腦幹反應I-V波波間潛時值則未呈現顯著差異。 本研究觀察到隨著第二型糖尿病罹患時長的增加，純音聽力閾值以及耳聲傳射絕對波幅有變小的趨勢，且在罹病長於8年之後的改變較為明顯。第二型糖尿病相關的聽力損失對中頻率 (1000Hz 及 2000Hz) 的聽力閾值及外毛細胞受損關聯性較高頻率 (4000Hz) 為大。由聽性腦幹反應的波間潛時的觀察，推測對於罹病短於12年的第二型糖尿病患者，若能夠控制血糖，可能與糖尿病相關耳蝸後病變較低的盛行率有關。[[abstract]]Objective: The relationship between diabetes and characteristics of hearing has been debated by previous studies. Hyperglycemia appears to have negative effect on hearing and auditory systems. The objective of this study was to evaluate the characteristics of hearing between the type II diabetes with different durations and pure tone audiometry, distorsion product otoacoustic emission (DPOAE), as well as auditory brainstem evoked response (ABR).Methods: Forty-four type II diabetes subjects and 14 age- and gender-matched nondiabetic subjects aged 36-68 years were recruited. Subjects were divided into four groups according to the duration of diabetes: 1) nondiabetic, 2) less than 4 years, 3) 4years to less than 8years, and 4) 8 years to less than 12 years. Duration of diabetes were determined according to the date of diagnosis from medical records. HbA1c of all type II diabetes subjects did not exceed 8%. Pure tone thresholds, DP-amplitudes, and ABR I-V inter-peak latencies from each subjects of different groups were measured and analyzed by one way analysis of variance ( one way ANOVA).Results: There were statistically significant differences in the pure tone threshold at 1000Hz, and DP amplitudes at 1000Hz and 2000Hz between nondiabetic and three of type II diabetes groups. No statistically significant difference in the ABR I-V inter-peak latencies was observed between nondiabetic group and three groups of type II diabetes in this study.Discussion: The result of this study showed a trend that the auditory threshold and the DP-amplitude deteriorated with prolonged duration of type II diabetes. The significant changes at the auditory threshold and the DP-amplitude were observed in type II diabetes patients for longer than 8 years. Type II diabetes related hearing impairment was found more in the middle frequencies than in the high frequencies in this study. ABR finding suggested that type II diabetes patients shorter than 12 years may be associated with lower prevalence of retrocochlear pathology with glycemic control