Department of Environmental and Occupational Health, Toho University Graduate School of Medicine, Tokyo, Japan.
Division of Occupational Health and Promotion, All Japan Labor Welfare Foundation, Tokyo, Japan.
BMJ Open. 2018 Sep 17;8(9):e023220. doi: 10.1136/bmjopen-2018-023220.
The aim of this study was to determine whether haemoglobin A1c (HbA1c) level is associated with the incidence of hearing impairment accounting for smoking status and diabetic condition at baseline.
Participants were 131 689 men and 71 286 women aged 30-65 years and free of hearing impairment at baseline (2008) who attended Japanese occupational annual health check-ups from 2008 to 2015. We defined low-frequency hearing impairment at a hearing threshold >30 dB at 1 kHz and high frequency at >40 dB at 4 kHz in the better ear in pure-tone audiometric tests. HbA1c was categorised into seven categories. The association between HbA1c and hearing impairment was assessed using the Cox proportional hazards model.
On 5 years mean follow-up, high HbA1c was associated with high-frequency hearing impairment. In non-smokers, HbA1c≥8.0% was associated with high-frequency hearing impairment, with a multivariable HR (95% CI) compared with HbA1c 5.0%-5.4% of 1.46 (1.10 to 1.94) in men and 2.15 (1.13 to 4.10) in women. There was no significant association between HbA1c and hearing impairment in smokers. A J-shaped association between HbA1c and high-frequency hearing impairment was observed for participants with diabetes at baseline. HbA1c was not associated with low-frequency hearing impairment among any participants.
HbA1c ≥8.0% of non-smokers and ≥7.3% of participants with diabetes was associated with high-frequency hearing impairment. These findings indicate that appropriate glycaemic control may prevent diabetic-related hearing impairment.
本研究旨在确定血红蛋白 A1c（HbA1c）水平是否与听力损伤的发生率相关，同时考虑到基线时的吸烟状况和糖尿病状况。
参与者为 131689 名男性和 71286 名年龄在 30-65 岁之间且基线（2008 年）时无听力损伤的日本职业年度健康检查受检者，他们参加了 2008 年至 2015 年的日本职业年度健康检查。我们在纯音测听试验中定义低频听力损伤为较好耳在 1 kHz 时的听力阈值>30 dB，高频听力损伤为 4 kHz 时的听力阈值>40 dB。将 HbA1c 分为七个类别。使用 Cox 比例风险模型评估 HbA1c 与听力损伤之间的关联。
在 5 年的平均随访期间，高 HbA1c 与高频听力损伤相关。在不吸烟者中，与 HbA1c 5.0%-5.4%相比，HbA1c≥8.0%与高频听力损伤相关的多变量 HR（95%CI）分别为男性 1.46（1.10 至 1.94）和女性 2.15（1.13 至 4.10）。在吸烟者中，HbA1c 与听力损伤之间无显著关联。在基线患有糖尿病的参与者中，HbA1c 与高频听力损伤之间存在 J 形关联。HbA1c 与任何参与者的低频听力损伤均无关联。
非吸烟者的 HbA1c≥8.0%和糖尿病患者的 HbA1c≥7.3%与高频听力损伤相关。这些发现表明，适当的血糖控制可能预防糖尿病相关的听力损伤。
