To the Editor: Hearing and vision impairments are common in older age. Evidence suggests
that these sensory impairments are associated with incident cardiovascular disease
(CVD) (myocardial infarction (MI), stroke),1 but previous studies have been undertaken
mostly in specific subgroups of individuals with sudden sensorineural hearing loss
or with stroke and in middle‐aged populations rather than community‐dwelling older
adults.2, 3, 4, 5, 6, 7 Therefore, the association between self‐reported hearing and
vision impairment and incident CVD, MI, and stroke and CVD mortality was examined
in older men.
Methods
Community‐dwelling men aged 63 to 85 (N = 3,981, 82% of the British Regional Heart
Study cohort alive in 2003) were followed for 10 years, until 2013.8 Information on
lifestyle factors, comorbidities, hearing, and vision was obtained through postal
questionnaires. Self‐reported hearing aid use and ability to hear the television at
a volume others find acceptable allowed for four categories of hearing: could hear
(n = 2,851), could hear and used aid (n = 482), could not hear and no aid (n = 424),
and could not hear and used aid (n = 168). Vision impairment was defined as not being
able to recognize a friend across the street (n = 124). Dual sensory impairment (n = 57)
consisted of hearing impairment (could hear with aid, could not hear and no aid, could
not hear and used aid) and vision impairment. Follow‐up for CVD (nonfatal and fatal)
was through general practice records and mortality registers. Survival analysis was
used to examine the association between sensory impairments and incident CVD and mortality.
Cox proportional hazards regression was used to calculate hazard ratios (HRs) with
95% confidence intervals (CIs) using no hearing impairment and no vision impairment
(individually and combined) as reference groups. Prevalent CVD cases were excluded.
Results
During the 10‐year follow‐up, 1,463 deaths occurred, including 408 CVD deaths. In
3,466 men free of prevalent CVD, 489 CVD events, 288 MIs, and 216 strokes occurred
during follow‐up. In age‐adjusted analyses, men who could not hear and did not use
a hearing aid had greater risks of incident CVD, incident stroke, and CVD mortality
compared to men who could hear (Table 1). These associations remained statistically
significant after adjustment for social class, diabetes mellitus, hypertension, obesity,
smoking, and physical activity. The adjusted hazards ratio (95% CI) were 1.50 (1.14–1.98),
1.56 (1.04–2.34), and 1.39 (1.00–1.93) for incident CVD, stroke, and CVD mortality,
respectively. These associations remained statistically significant after adjustment
for social class, diabetes mellitus, hypertension, obesity, smoking, and physical
activity. Vision impairment and dual sensory impairment were not associated with CVD
incidence or CVD mortality.
Table 1
Risk of Outcome According to Sensory Impairment in Men Aged 63 to 85 in 2003 from
the British Regional Heart Study
Sensory Impairment
Incident CVD
Incident Myocardial Infarction
Incident Stroke
CVD Mortality
Rate/1,000 (n)
HR (95% CI)
Rate/1,000 (n)
HR (95% CI)
Rate/1,000 (n)
HR (95% CI)
Rate/1,000 (n)
HR (95% CI)
Hearing
Could hear
17 (330)
1.00
9 (191)
1.00
7 (149)
1.00
10 (257)
1.00
Could hear, used aid
20 (59)
0.91 (0.68–1.20)
13 (40)
1.09 (0.77–1.55)
7 (23)
0.76 (0.49–1.19)
17 (68)
1.15 (0.88–1.51)
Could not hear, no aid
25 (69)
1.42 (1.09–1.84)a
13 (38)
1.35 (0.95–1.91)
11 (32)
1.46 (1.00–2.14)a
15 (52)
1.37 (1.02–1.85)a
Could not hear, used aid
22 (22)
1.10 (0.71–1.70)
14 (14)
1.26 (0.73–2.17)
8 (8)
0.88 (0.43–1.80)
15 (20)
1.11 (0.71–1.76)
Vision
Could see
18 (467)
1.00
10 (273)
1.00
8 (209)
1.00
12 (383)
1.00
Poor vision
24 (16)
1.20 (0.73–1.97)
16 (11)
1.41 (0.77–2.57)
7 (5)
0.85 (0.35–2.06)
19 (17)
1.42 (0.87–2.30)
Dual
Could hear and could see
17 (326)
1.00
9 (185)
1.00
8 (151)
1.00
10 (254)
1.00
Dual impairment
26 (8)
1.40 (0.69–2.83)
13 (4)
1.23 (0.46–3.31)
13 (4)
1.52 (0.56–4.12)
22 (9)
1.73 (0.89–3.36)
a
Remained statistically significant after further adjustment for social class, obesity,
smoking, physical activity, hypertension, and diabetes mellitus.
CVD = cardiovascular disease; HR = hazard ratio; CI = confidence interval.
John Wiley & Sons, Ltd
Discussion
Men who could not hear and did not use a hearing aid had greater risks of incident
CVD, particularly incident stroke, and CVD mortality than men who could hear. Previous
research suggests that the associations between hearing impairment and CVD could be
attributed to smoking and atherosclerosis,9 but in the current study, the associations
remained significant after adjustment for smoking and CVD‐related comorbidities. Not
all hearing impairment groups were associated with CVD incidence, suggesting that
hearing per se may not underlie the observed associations. One possible mechanism
could be cognitive impairment, which is related to hearing impairment and stroke.10
Other possible explanations could be atherosclerotic or inflammatory changes, which
could not be taken into account in the analyses.9 Moreover, hearing impairment based
on self‐report could be subject to inaccurate reporting of hearing impairment because
of unawareness, denial of hearing problems, or use of hearing aid. Any inaccurate
reporting may have underestimated the influence of hearing impairment on CVD and may
also explain the inconsistent associations between the hearing impairment groups.
Although the findings are consistent with those of earlier studies that found objectively
measured hearing impairment to be associated with incident stroke,2, 3 and CVD mortality,1
another study found no association between objective hearing impairment and incident
stroke.5 These inconsistent findings could be due to different pathologies that underlie
different types of hearing impairment, such as sensorineural (sudden) or age‐related
(gradual) hearing loss.
The lack of association between vision impairment and incident CVD and CVD mortality
could be due to the definition of vision impairment used, which may have identified
severe vision impairment only, thus underestimating the true prevalence of vision
impairment. Similarly, dual sensory impairment was not associated with CVD incidence
or mortality, which could be due to the small number of men with dual sensory impairment.
Conclusions
Hearing impairment in older men was associated with greater risks of incident stroke
and CVD mortality. Early detection of hearing impairment in older adults could help
prevent CVD. Further research is warranted into the possible mechanisms underlying
these associations.