Hearing loss increases all-cause and cardiovascular mortality in middle-aged and older Chinese adults: the Dongfeng-Tongji Cohort Study

We aimed to investigate the association between hearing loss and all-cause and cardiovascular disease (CVD) mortality, and whether the relationship could be modified by chronic conditions in middle-aged and older Chinese adults. We selected 18,625 participants who underwent audiometry in 2013 from the Dongfeng-Tongji Cohort conducted in China, and followed them until December 2018. Hearing loss was grouped as normal, mild, and moderate or severe by pure-tone hearing threshold at speech (0.5, 1, and 2 kHz) and high frequency (4 and 8 kHz). We applied Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and CVD mortality. Among the 18,625 participants, the mean age was 64.6 (range: 36.7–93.0) years, and 56.2% were women. A total of 1185 died, with 420 CVD deaths during a mean follow-up period of 5.5 years. The adjusted HR for all-cause and CVD mortality increased gradually with the increasing hearing threshold (All p for trend < 0.05). Compared to participants with normal hearing at speech frequency, the adjusted HRs (95% CIs) of moderate or severe hearing loss were 1.42 (1.21–1.67), 1.44 (1.10–1.89), and 1.92 (1.21–3.04) for all-cause, CVD, and stroke mortality, respectively. While moderate or severe hearing loss at high frequency was only related to an increased risk of all-cause mortality (HR, 1.60; 95% CI, 1.18–2.17). The associations were generally consistent across subgroups (All p for interaction > 0.05). Additionally, individuals with a combination of moderate or severe hearing loss and occupational noise exposure, diabetes, or hypertension had higher risk of all-cause or CVD mortality, ranging from 1.45 to 2.78. In conclusion, hearing loss was independently associated with an increased risk of all-cause and CVD mortality, in a dose–response manner. Meanwhile, hearing loss and diabetes or hypertension could jointly increase the risk of all-cause and CVD mortality.