Higher serum magnesium concentration is associated with lower hearing thresholds and risk of hearing loss among a Chinese population.
Level 4 - case-series / case-control
Cross-sectional observational study
PubMed 31826373 · doi:10.6133/apjcn.201912_28(4).0012
What was done
A cross-sectional study was conducted in 3,267 adults aged 18 and older recruited from five hospitals in the Zhejiang region of China between October 2016 and May 2018. Pure-tone averages (PTAs) were measured via audiometric exam at speech frequencies (0.5, 1, 2, and 4 kHz) and high frequencies (3, 4, and 6 kHz). Magnesium concentrations were measured using inductively coupled plasma mass spectrometry. Associations were evaluated using linear and multivariable logistic regression models adjusted for potential confounders.
What was found
In fully adjusted linear regression, individuals in the highest magnesium quartile had lower speech-frequency PTA (-1.89%; 95% CI: -3.07 to -0.701; p=0.022) and lower high-frequency PTA (-3.05%; 95% CI: -4.64 to -1.46; p=0.005) compared with the lowest quartile. Logistic regression demonstrated a dose-dependent reduction in the odds of high-frequency hearing loss across quartiles; the highest quartile had a 54.0% reduction in odds of high-frequency hearing loss (OR: 0.460; 95% CI: 0.339-0.587).
Why it matters
This study provides large-sample epidemiological evidence linking higher magnesium status with preserved auditory thresholds and reduced odds of high-frequency hearing loss.
Limits
The cross-sectional design precludes establishing temporality or causality. Participants were recruited from hospitals in a single Chinese region, which may introduce selection bias and limit generalizability. Specific confounders adjusted for (e.g., occupational noise exposure, ototoxic medications) are not detailed in the abstract, and the abstract inconsistently refers to both serum and whole blood magnesium.