Elderly patients with gout were more likely to develop hearing impairment over a 6-year period compared with those without gout, according to a report published in BMJ Open.
Given that hearing impairment and gout are suspected of sharing some pathogenicity, investigators sought to establish whether there is a correlation between both conditions, stating, “We hypothesize that hyperuricemia-related inflammation and oxidative stress pathways potentially link gout to the risk of hearing loss in the older adults.”
The retrospective cohort study included a 5% random sample of all United States Medicare claims (adults ≥65 years) between 2006 and 2012 and examined records from a total of 1,716,438 patients (mean age, 75.3 years; 42.4% men; 86.1% white). The primary end point was incident hearing loss, validated by ≥2 claims separated by at least 4 weeks without similar claims during a 1-year baseline period. Incidence rates (IRs) and hazard ratios (HRs) were calculated to determine association and risk.
In this cohort, 89,409 individuals were found to have new-onset hearing impairment, resulting in a crude IR of 16.9 per 1000 person-years for those with gout, compared with 8.7 per 1000 person-years for participants without gout. Multivariate adjustment using regression analysis to account for potential confounders such as comorbidities, gout and cardiovascular medications, and various demographic factors determined that gout was still independently linked to incident hearing impairment (HR, 1.44; 95% CI, 1.40-1.49; P <.0001). Further subgroup sensitivity analyses found only mild HR attenuation upon data manipulation, which confirmed the findings.
Study strengths include a large sample size, adequate event occurrences, multiple adjustments, and robustness in sensitivity models. Study limitations include limited generalizability to older adults, potential misclassification bias, observational design prone to possible residual confounding by unmeasured variables, and lack of laboratory markers for inflammation or oxidative stress that might aid in the identification of pathogenetic mechanisms.
This was one of the first descriptions in the literature of an association between gout and hearing loss in an older population. The authors noted that, “An early recognition of hearing loss related to the presence of gout may have a meaningful clinical implication.” They recommended that future research examine possible common disease mechanisms, evaluate risk factors, and explore therapies to reduce hearing loss in the elderly.
Please see original article for a full list of author disclosures.
Singh JA, Cleveland JD. Gout and hearing impairment in the elderly: a retrospective cohort study using the US Medicare claims data. BMJ Open. 2018;8:e022854..