Research through a so-called Genome-Wide Association Study (GWAS) shows a common genetic component between tinnitus (symptoms) and psychiatric features. The researchers found an association with bipolar disorder, brooding, anxiety, stress and sensation-seeking behavior. An association was also found with the genetic signature of cardiovascular and metabolic diseases.
Tinnitus, hearing sounds that are not present in the environment, can lead to insomnia, difficulty concentrating, difficulty relaxing, anxiety and depression. It can also coexist with hyperacusis. Tinnitus often accompanies hearing impairment and can be caused by exposure to loud noise. About 15% of workers exposed to noise at work experience problems due to perceived tinnitus. Scientists assume that tinnitus takes place in the brain because changes occur there. Not only parts of the brain responsible for hearing play a role in this, but also other parts such as the amygdala and hippocampus.
Diseases such as diabetes and high blood pressure can affect tinnitus. A link has also been found between tinnitus and cardiovascular problems. Psychological factors such as stress, anxiety and depression can and often do affect tinnitus. Smoking and substances and medications toxic to the ear increase the risk of getting tinnitus.
Twin studies suggest a genetic component to susceptibility to tinnitus.
A so-called Genome-Wide Association Study (GWAS) is genetic research that compares the genomes of individuals in a population. With this, researchers try to discover genetic variations associated with a specific trait or disease. This study looked at links to tinnitus. Based on links found, scientists can better understand biological mechanisms associated with them. These types of studies may in turn lead to new diagnostic tests, therapies or preventive strategies. GWAS studies are being used to study complex features in diseases such as cancer, diabetes, cardiovascular disease and recently in tinnitus. This involves both genetic and environmental factors.
The U.S. researchers used the UK Biobank database (N=132,438) for their GWAS study. With the study, the researchers looked for so-called SNPs associated with tinnitus and the symptoms associated with it. SNP stands for “Single Nucleotide Polymorphism. These are variations in the DNA sequence in which one nucleotide in the genome has changed. Such a found variation may (but need not) lead to a disease or symptom. SNPs are used in research to identify the genetic basis of diseases and other traits. They are also used in medicine to personalize treatments and predict the risk of certain conditions.
The goal of the U.S. study was to identify specific genetic variations common in people with tinnitus.
The study revealed a common genetic component between tinnitus (symptoms) and psychiatric features. For example, the researchers found a genetic link to bipolar disorder, brooding, anxiety, stress and sensation-seeking behavior. An association was also found with the genetic signature of cardiovascular and metabolic diseases.
[Source : Bhatt, I.S., Wilson, N., Dias, R. et al. A genome-wide association study of tinnitus reveals shared genetic links to neuropsychiatric disorders. Sci Rep 12, 22511 (2022)]
