Metformin Use may Reduce Risk of Sudden Hearing Loss in Diabetes Patients: Study
Researchers have observed that the antidiabetic agent, metformin widely used for Type 2 diabetes, reduced the risk for developing sudden sensorineural hearing loss (SSNHL) in a dose-dependent manner. A recent study was conducted by Chun Huang and colleagues which was published in the journal Diabetes,Obesity and Metabolism.
SSNHL represents an abrupt and, very often, unexplained hearing loss; it has commonly been noted in individuals suffering from metabolic disorders, especially T2D. SSNHL may increase the risk in T2D patients because of various vascular complications and oxidative stress. In the treatment of T2D, metformin primarily provides glycemic control but is believed to exert other potential benefits related to its anti-inflammatory and vascular protective actions. This study aimed to investigate the association between metformin use and the risk of SSNHL, with an emphasis on strict definitions of metformin exposure and a well-matched comparator group.
This cohort study used data from Taiwan's National Health Insurance Research Database, focusing on T2D patients from 2008 onwards.
• Metformin Use: Achieved ≥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.
Covariate balance was achieved by conducting propensity score matching. Models with competing risks accounted for mortality. Hrs, IRs and IRRs were calculated
Key findings
Incidence Rate:
• Metformin users 11.48 per 10,000 person-years.
• Non-users 15.66 per 10,000 person-years.
• IRR : 0.73 (95% CI: 0.66–0.82; p < 0.0001).
Percentage Reduction in Risk
• Adjusted hazard ratio (HR): 0.73 (95% CI: 0.66–0.82), meaning a 27% reduced risk of SSNHL in users of metformin.
Dose-Dependent Effects:
• Higher cumulative doses (Q4): HR 0.36 (95% CI: 0.29–0.46).
• Daily doses ≥1 DDD: HR 0.78 (95% CI: 0.69–0.87).
Mortality:
• Metformin was also associated with a lower all-cause mortality rate, pointing out that it was beneficial in general for the health.
This study showed that metformin significantly reduces the risk of sudden sensorineural hearing loss in patients with Type 2 diabetes. The dose-dependent reduction in SSNHL risk and associated survival benefits underscore the importance of metformin adherence. These findings highlight the potential of metformin to prevent SSNHL and improve overall health outcomes in T2D patients.
Reference:
Huang CC, Hsu RF, Chen WM, Shia BC, Wu SY, Huang CC. Metformin lowers risk of hearing loss and mortality in type 2 diabetes. Diabetes Obes Metab. 2024 Dec 17. doi: 10.1111/dom.16128. Epub ahead of print. PMID: 39690329.
