Metformin Use May Reduce Risk of Sudden Hearing Loss in Diabetes Patients

Metformin, a commonly prescribed medication for Type 2 diabetes (T2D), has long been recognized for its glycemic control benefits. However, a recent study published in Diabetes, Obesity, and Metabolism highlights an exciting new dimension to its benefits: a reduced risk of sudden sensorineural hearing loss (SSNHL) in diabetes patients.

Understanding SSNHL and Its Link to Diabetes

Sudden sensorineural hearing loss (SSNHL) is an abrupt and often unexplained loss of hearing. For individuals with T2D, this risk is heightened due to vascular complications and oxidative stress—key contributors to hearing loss in metabolic disorders.

While SSNHL is a rare condition, its occurrence can significantly impact quality of life. Identifying ways to mitigate this risk in patients with T2D is crucial, and metformin may hold the key.

The Study: Metformin’s Role in Reducing SSNHL Risk

Led by Chun Huang and colleagues, the study utilized data from Taiwan’s National Health Insurance Research Database, focusing on T2D patients from 2008 onward. Researchers aimed to explore the link between metformin use and SSNHL, employing strict definitions of metformin exposure and robust comparator groups for accuracy.

Study Parameters:

Metformin Users: Patients with ≥80% medication possession ratio (MPR) and ≥28 cumulative defined daily doses (cDDD) within three months.
Comparator Group: Patients with ≥80% MPR of other antidiabetic medications.
Analytical Approach: Propensity score matching ensured covariate balance while competing risk models accounted for mortality.

Key Findings

1. Lower Incidence of SSNHL

Metformin Users: 11.48 cases per 10,000 person-years.
Non-Users: 15.66 cases per 10,000 person-years.
Incidence Rate Ratio (IRR): 0.73 (95% CI: 0.66–0.82; p < 0.0001).

Metformin users demonstrated a 27% reduced risk of developing SSNHL compared to non-users.

2. Dose-Dependent Effects

Higher Cumulative Doses (Q4): Associated with an HR of 0.36 (95% CI: 0.29–0.46), reflecting the greatest protective effect.
Daily Doses ≥1 Defined Daily Dose (DDD): HR of 0.78 (95% CI: 0.69–0.87).

These findings underline the importance of adherence to metformin therapy for optimal outcomes.

3. Overall Health Benefits

In addition to reducing SSNHL risk, metformin use correlated with a lower all-cause mortality rate, reinforcing its role in improving general health in T2D patients.

Implications for Clinical Practice

This study highlights metformin’s potential beyond glycemic control. Its anti-inflammatory and vascular protective properties may contribute significantly to reducing SSNHL risk in T2D patients.

For clinicians managing diabetes, emphasizing medication adherence and prescribing metformin where appropriate can provide both metabolic and broader health benefits, including protecting against hearing loss.

To register for our next masterclass please click here https://linktr.ee/docpreneur