Association between hypertension and hearing impairment in health check-ups among Japanese workers: a cross-sectional study

Objectives Prevention of hearing impairment (HI) is important because recovery of hearing is typically difficult. Epidemiological studies have examined the risk factors for HI. However, the association between hypertension and HI remains unclear. We aimed to clarify the association between hypertension and HI. Design Cross-sectional study. Setting Japanese workers in an information and communication technologies company. Participants Of 24 823 employees of the same company, we recruited 13 475 participants who underwent hearing testing by audiometry in annual health check-ups and did not have missing data regarding body measurement, blood test results and drinking/smoking status (mean age: 49.4 years; males: 86.4%). Primary outcomes Hearing tests were performed at two frequencies (1 kHz, 4 kHz). We defined the inability of participants to respond to 30 dB at 1 kHz and/or 40 dB at 4 kHz as overall moderate HI. We also defined moderate HI at 1 or 4 kHz as an abnormal finding at 1 or 4 kHz. We defined hypertension as >= 140 mm Hg systolic blood pressure and/or >= 90 mm Hg diastolic blood pressure and/or taking medication for hypertension. We examined the association between hypertension and HI after adjusting for age, sex, body mass index, smoking/drinking status, diabetes mellitus, hyperlipidaemia and proteinuria. Results Moderate HI was identified in 980 participants (7.3%). Of these, 441 participants (3.3%) exhibited moderate HI at 1 kHz, and 787 participants (5.8%) exhibited moderate HI at 4 kHz. Subjects with hypertension showed a higher prevalence of any HI. The prevalence of overall moderate HI, moderate HI at 1 kHz and moderate HI at 4 kHz among subjects with hypertension was 8.7%, 4.3% and 6.8%, while those among subjects without hypertension was 6.9%, 3.0% and 5.6% (p<0.01, p<0.01 and p=0.01, respectively). Conclusions Hypertension was associated with moderate HI in Japanese workers.