The association between diet, other lifestyle behaviors, physical function and hearing loss

Resumen

Hearing loss is increasing rapidly worldwide. Hearing loss is the fourth most important cause of years lived with disability, which produces great economic and health costs for society. Hearing loss in adults is associated with impaired quality of life and social isolation. Currently there is no treatment that restores hearing, so prevention is essential. It is known that exposure to high levels of sound pressure, the consumption of ototoxic drugs or suffering from certain diseases are important risk factors of hearing loss. However, the role of diet and other modifiable lifestyles such as never smoking, higher level of physical activity, moderate alcohol intake, and optimal sleep on hearing loss is not entirely clear. It is also important to know the role that hearing loss plays in other unfavorable conditions in older adults. For example, hearing loss has been related to cognitive impairment and some types of dementia; however, its association with other common conditions like impaired physical function, the frailty syndrome and disability, is unknown. Knowing the impact that diet and other lifestyle behaviors have on the auditory system and adequately characterizing the associations between hearing loss and common health conditions among older adults, will provide us with tools for the development of prevention-oriented policies. This doctoral thesis tries to understand the role of diet and lifestyles on hearing loss. We defined different diet quality indexes: healthy diet patterns that share certain characteristics, including high consumption of fruits and vegetables, consumption of fish, and low consumption of processed foods. We also examined the effect of the intake of different types of fatty acids on this endpoint. In addition, we estimated the impact of the adherence to five healthy lifestyles (including never smoking, high level of physical activity, high diet quality, moderate alcohol intake and optimal sleep) on hearing. Lastly, we characterized the relation between hearing loss, and impaired lower extremity function, the frailty syndrome and disability in instrumental activities of daily living. The definition of hearing loss used included objective methods (functional auditory capacity and audiometry), as well as self-reported information on hearing loss, which is still the standard measurement in large population studies.