LC-QTOF-MS Finds Blood Markers for Hearing Loss

Age-related hearing loss (ARHL) is a condition that gets worse over time as nerve function declines, but doctors do not yet have reliable tests to detect it early. To try to find blood markers that could help spot ARHL sooner and improve diagnosis, researchers analyzed blood samples from 300 people (125 with normal hearing and 175 with ARHL) from three different medical centers, using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) to look for chemical changes in the blood linked to the condition. A paper based on this work was published in the journal Biochemistry and Biophysics Reports.¹

What is ARHL, How Common Is It, and Why Is It Hard to Diagnose Early?

ARHL, also called presbycusis, is a complicated condition caused by the wear and tear that aging puts on the ears and hearing system over time.^2,3Hearing loss is the most common sensory problem among older adults. About half of people in their seventies experience some degree of hearing loss, making it the third most common health issue in older adults, right behind heart disease and arthritis.^4,5Right now, catching ARHL early is still difficult. For one thing, it usually affects high-pitched sounds first, while a person's ability to hear low and mid-range sounds stays normal, so early hearing loss can easily go unnoticed in everyday life. For another, ARHL is a complicated condition shaped by a mix of genetic, environmental, and other factors, many of which scientists still haven't fully figured out.^4,6,7

Which Blood Chemicals Were Found to Be Linked to Age-Related Hearing Loss?

The researchers used statistical modeling to see which blood chemicals were linked to hearing loss and then tested how well those chemicals could predict the condition. Out of an initial list of 10 possible markers, three stood out as being independently tied to ARHL, even after accounting for other factors like age, sex, weight, smoking, and blood fat levels: a molecule called d-glutamine, a type of fat called sphingomyelin, and a modified form of a genetic building block known as N6-methyladenosine. People with higher levels of these substances were more likely to have hearing loss. When the researchers tested this three-marker combination on a separate group of people, it did a strong job of correctly distinguishing those with ARHL from those without it.¹

“These findings,” write the authors of the paper,¹ “identify and validate a serum metabolomic signature for ARHL, providing new insight into early detection and clinical assessment of ARHL.”

The researchers admit to this study having a few limitations. First, it did not track people over time, so while the researchers found blood chemicals linked to hearing loss, they cannot say whether these changes appear before hearing loss starts, only that they are connected to hearing loss that has already happened. Second, since everyone in the hearing-loss group already had confirmed hearing problems at testing, it is unclear how useful these markers would be for real-world screening; proving they can flag at-risk people early would require future studies that follow people over time. Finally, while the results hint these chemicals may play a biological role in hearing loss, their causing it cannot be proven at this time; to do so would require further long-term, mechanistic research.¹

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References

1. Wang, H.; Shi, H.; Zhang, H. et al. Serum Metabolomic Profiling Identifies a Biomarker Panel Associated with Age-Related Hearing Loss. Biochem Biophys Rep. 2026, 47, 102725. DOI: 10.1016/j.bbrep.2026.102725
2. Qadir, M. I.; Gillani, M. Age-Related Hearing Loss: A Review of a Hot Topic in Audiology. Genetics 2025, 3, 100004. DOI: 10.70389/ PJG.100004
3. Tavanai, E.; Rahimi, V.; Khalili, M. E. et al. Age-Related Hearing Loss: An Updated and Comprehensive Review of the Interventions. Iran J Basic Med Sci. 2024, 27 (3), 256-269. DOI: 10.22038/IJBMS.2023.72863.15849
4. Hughes, S. E.; Brenner, C. R.; Pandian, A. T. et al. Age-Related Hearing Loss: Evidence-Based Strategies for Early Detection and Management. ORL Head Neck Nurs. 2025, 43 (2), 26-39.
5. Zheng, Q.; Xu, Z.; Li, N. et al. Age-Related Hearing Loss in Older Adults: Etiology and Rehabilitation Strategies. Front Neurosci. 2024, 18, 1428564. DOI: 10.3389/fnins.2024.1428564
6. Ferrán, S.; Manrique-Huarte, R.; Lima, J. P. et al. Early Detection of Hearing Loss among the Elderly. Life (Basel) 2024, 14 (4), 471. DOI: 10.3390/life14040471
7. Tsai Do, B. S.; Bush, M. L.; Weinreich, H. M. et al. Clinical Practice Guideline: Age-Related Hearing Loss. Otolaryngol Head Neck Surg. 2024, 170 (Suppl 2), S1-S54. DOI: 10.1002/ohn.750