Type 2 Diabetes: The Impact of Vision and Hearing Impairments on CV Risk Outcomes and Mortality

A comprehensive study reveals the importance of ophthalmologic and otologic care in patients with T2DM due to the association of increased risks for cardiovascular events in those with a decline in vision and hearing abilities.

It is known that patients with type 2 diabetes mellitus (T2DM) have an increased risk of cardiovascular diseases and mortality. In addition, diabetes can lead to vascular and neuropathic complications that can lead to various issues, including vision and hearing impairments. Nearly 5–17% and 21%, respectively, of patients with T2DM, have been reported. While diabetic retinopathy has been associated with high cardiovascular diseases and mortality have been reported in previous studies, the data there is limited data available on the role of vision impairment on these previously mentioned outcomes, and currently, no studies exist that explore the role of hearing loss for these same complications.

This study severed to just that by assessing the association between vision and hearing loss in patients with type two diabetes with increased risks for cardiovascular events and mortality. This was a nationwide cohort study that utilized the Korean National Health Information Database (KNHID) and included 771,128 subjects with T2DM who had undergone a National Health Screening Program (NHSP) through the Korean National Health Insurance Service (KNHIS) in 2009. These patients were followed for nine years, and the study concluded in December of 2018. The primary outcome was newly diagnosed myocardial infarction (MI), stroke, or all-cause mortality. Basel-line characteristics were compared using ANOVA for continuous variables and Chi-squared test for categorical variables. In addition, the study data were analyzed using Cox proportional hazards regression models to assess the association of vision and hearing loss to the primary outcome.

The results demonstrated an increased risk of MI, stroke, and all-cause mortality in those with diabetes who had either vision or hearing impairment and was in those with both vision and hearing impairments had an even higher risk of MI (adjusted HR (aHR) 1.362, 95% CI 1.252–1.481) and mortality (aHR 1.591, 95% CI 1.532–1.651. When comparing those with only vision and not hearing impairments, those with vision impairments showed an increased risk for all three outcomes, MI (aHR 1.324, 95% CI 1.275–1.375 and aHR 1.117, 95 CI 1.066–1.170), stroke (aHR 1.318, 95% CI 1.276–1.362 and aHR 1.134 95% CI 1.089–1.180) and mortality (aHR 1.417, 95% CI 1.390–1.446 and aHR 1.163, 95 %CI 1.135–1.191). Additionally, those who were under the age of 65 also showed and an increased risk of MI and all-cause mortality, but also stoke as well, and was even higher in those in those with only vision impairments and not with both vision and hearing impairments (p-value <0.0001 for both).

This study was essential to assess for the potential increased risk of cardiovascular complication and mortality in patients with diabetes that also have vision or hearing impairments or both. The results demonstrate a statistical significance for the primary endpoints. They should serve as a tool to guide clinicians to focus on the importance of routine ophthalmologic and otologic care in this patient population. This study used objective tools to measure the patient’s hearing and vision functions and included an extensive age range (>40 years old), which increased generalizability by reducing selection bias. With that said, the authors did note some limitations that included that the severity of both diabetes and the vision/hearing impairments were not stratified or included in the overall assessment. Another limitation was the way that T2DM was defined in the utilized database; it was done by using ICD-10 codes or one measurement of FBG (fasting blood glucose), this made it possible that there were patients who did not have T2DM but could have had either pre-diabetes or type-1 diabetes mellitus. In future studies, it could be essential to look at a more diverse patient population that includes other races since this study mainly consisted of individuals from Korea who were of Asian descent to help increase generalizability. Also, a future study could be warranted to assess why those with vision impairments alone had a higher HR for CV events, but those with vision and hearing impairments had a higher HR for death. Nevertheless, this study utilized a large population of patients and assessed them over an extended period and should serve as a clear indicator of the risk present with T2DM and with vision and or hearing impairments.

Practice Pearls:

• Patients with type-two diabetes mellitus who also have vision or hearing impairments should be closely monitored and assessed for other cardiovascular risk factors as they are at an increased risk for events and other co-morbidities.
• Since vision and hearing impairments can cause patients to have difficulty managing their diabetes, modifications must be introduced to these patients to allow them to access the care they need to help sustain baseline health.
• Regular ophthalmologic and otologic care should be given and overseen by practitioners for patients with type-two diabetes to prevent the development or progression of vision and hearing loss.

Jung, Younhea et al. “Impact of vision and hearing impairments on risk of cardiovascular outcomes and mortality in patients with type 2 diabetes: A nationwide cohort study.” Journal of diabetes investigation, 10.1111/jdi.13689. 8 Oct. 2021, doi:10.1111/jdi.13689

Alexa Rodriguez, PharmD Candidate 2022, University of South Florida, Taneja College of Pharmacy