February 22, 2013
According to researcher Yung-Song Lin, MD of Taipei Medical University in Taiwan and colleagues, individuals aged 35 or younger with HIV infection had twice the risk of sudden hearing loss compared to HIV-negative controls. The researchers noted that up to 44 percent of persons with HIV infection have a chronic hearing impairment. In this retrospective study, they reviewed records from Taiwan's national health insurance system on a cohort of 8,760 HIV-infected persons diagnosed between January 1, 2001 and December 31, 2006, and those of 43,800 persons not infected with HIV. The subjects were divided by age into groups 18 through 35 years and those older than 35.
Sudden sensorineural hearing loss was defined as a loss of 30 decibels or more in at least three contiguous audiometric frequencies that develops over a period of a few hours to 3 days. The researchers found that among the younger HIV-infected individuals, there were 11 cases of sudden hearing loss in 25,439 person-years of follow-up, and among the controls there were 26 cases in 130,722 person-years of follow-up. These numbers meant incidence rates of 4.32 and 1.99 cases per 10,000 person-years, respectively. Also, the incidence rate ratio for sudden hearing loss was significantly elevated only in men and did not reach significance among the women. The hazard ratio in the younger group when adjusted for age, sex, geographic region, and annual income was 2.17 using a cox proportional hazards regression model with propensity score matching. Among older participants, there were five cases in 15,506 person-years of follow-up among individuals with HIV infection, and 38 cases in 87,570 person-years of follow-up and an incidence rate ratio of 0.72 for an incidence rate of 3.22 and 4.45 cases per 10,000 person-years, respectively, and a nonsignificant incidence rate ratio of 0.72.
The researchers were not clear why the effect was only among individuals 35 years or younger. They noted that possible risk factors, such as smoking history and noise exposure, were not included in the study. Also the study did not include information about severity of hearing loss.
The full report, "Increased Risk of Sudden Sensorineural Hearing Loss in Patients with Human Immunodeficiency Virus Aged 18 to 35 Years: A Population-Based Cohort Study," was published online in JAMA Otolaryngology -- Head & Neck Surgery (2013;():1-5. doi:10.1001/jamaoto.2013.1709).