Birthweight implicated in age-related hearing loss

A U-shaped association exists between birthweight and hearing loss at old age, such that older people who were born with low or high birthweight are more likely to experience partial or total inability to hear, a study reports.

The study included 893 community-dwelling participants aged ≥50 years. They underwent pure-tone audiometry and were asked how much they weighed at birth either in pounds and ounces or in kilograms and grams.

Of the participants, 31.9 percent had self-reported low birthweight (<2.5 kg) and 50.0 percent had self-reported high birthweight (>4.5 kg) had hearing loss. Hearing loss was defined as pure-tone average of >25 dB HL at frequencies of 0.5, 1.0, 2.0, and 4.0 kHz (PTA0.5-4kHz) in the better ear.

On multivariate logistic regression analysis, the odds of experiencing any level of hearing loss were at least twofold greater among participants with high birthweight (odds ratio [OR], 2.43, 95 percent confidence interval [CI] 1.23–4.82) or low birthweight (odds ratio [OR], 2.00, 95 percent CI, 1.13–3.56) relative to those with self-reported normal birthweight (3.1–4.0 kg).

Moreover, participants with high birthweight had 2.4-fold higher likelihood of having mild hearing loss (25–40 dB HL), while those with low birthweight had 2.6-fold higher likelihood of moderate to severe hearing loss.

The findings contribute to the evidence base regarding the influence of foetal growth on the auditory system in later life.