• Environmental lead exposure and otoacoustic emissions in Andean children

      Buchanan, Leo H.; Counter, S. Allen; Ortega, Fernando (2011-04-15)
      Studies relating sensory hearing impairment to lead (Pb) exposure in children have presented inconsistent results. The objective of this study was to measure distortion product otoacoustic emissions (DPOAE), sounds emanating from the outer hair cells of the inner ear, in Pb-exposed children to determine the effects of Pb poisoning on the inner ear. DPOAE were recorded for 9 f(2) frequencies from 1187 to 7625 Hz on 102 ears of 53 Pb-exposed children (aged 6-16 yr) residing in Pb-contaminated environments in the Andes Mountains of Ecuador where Pb glazing of ceramics is the primary livelihood. Blood lead (PbB) levels ranged from 4.2 to 94.3 mug/dl (mean: 37.7; SD: 25.7; median: 36.4). The median PbB level was markedly higher than the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) 10-mug/dl action level. Spearman rho correlation analyses of the relation between PbB level and DPOAE amplitude and between PbB level and DPOAE signal-to-noise ratio revealed no significant associations at any of the f(2) frequencies tested. In addition, no significant correlation (Spearman rho) between PbB level and hearing sensitivity for 6 pure-tone test frequencies from 1000 to 8000 Hz was found. Although the study group was found to have abnormally elevated PbB levels, in contrast to some earlier reports, the results of the current study showed no consistent Pb-induced sensory effects on the cochlea of Pb-intoxicated children.
    • Hearing loss and cognitive decline among older adults with atrial fibrillation: the SAGE-AF study

      Wang, Weijia; Lessard, Darleen M.; Abu, Hawa Ozien; McManus, David D.; Mailhot, Tanya; Gurwitz, Jerry H.; Goldberg, Robert; Saczynski, Jane (2020-04-28)
      Objective: To examine the association between hearing loss and cognitive function cross-sectionally and prospectively among older adults with atrial fibrillation (AF). Methods: Patients with AF > /= 65-year-old (n = 1244) in the SAGE (Systematic Assessment of Geriatric Elements)-AF study were recruited from five internal medicine or cardiology clinics in Massachusetts and Georgia. Hearing was assessed by a structured questionnaire at baseline. Cognitive function was assessed by Montreal Cognitive Assessment (MoCA) at baseline and one year. Cognitive impairment was defined as score < /= 23 on the MoCA. The associations between hearing loss and cognitive function were examined by multivariable adjusted logistic regression. Results: Participants with hearing loss (n = 451, 36%) were older, more likely to be male, and have depressive symptoms than patients without hearing loss. At baseline, 528 (42%) participants were cognitively impaired. Individuals with hearing loss were significantly more likely to have cognitive impairment at baseline [adjusted odds ratio (OR) = 1.37, 95% confidence interval (CI): 1.05-1.81]. Among the 662 participants who did not have cognitive impairment at baseline and attended the one-year follow-up visit, 106 (16%) developed incident cognitive impairment. Individuals with, versus those without, hearing loss were significantly more likely to develop incident cognitive impairment at one year (adjusted OR = 1.68, 95% CI: 1.07-2.64). Conclusions: Hearing loss is a prevalent but under-recognized factor associated with cognitive impairment in patients with AF. Assessment for hearing loss may be indicated among these patients to identify individuals at high-risk for adverse outcomes.