RESUMO
OBJECTIVE: To determine the prevalence and characteristics of problematic tinnitus in a representative United States (US) sample. DESIGN: Cross-sectional study of the NHANES database from 2011-2012 and 2015-2016. STUDY SAMPLE: 8029 records were included for analysis. RESULTS: The prevalence of any tinnitus was 16.32%. Only 1.38% reported tinnitus as a big problem or worse. Univariate analysis revealed a statistically significant relationship between tinnitus constancy and duration with severity, where more constant perception and longer duration was related to increased severity (p < 0.0001). Multivariable models showed a clear relationship of increased odds ratio (OR) of problematic tinnitus with constancy of tinnitus but not duration. Furthermore, multivariable models showed higher Body Mass Index (OR= 1.013, 95% CI: 0.99-1.03), sleep trouble (OR = 2.016, 95% CI: 1.52-2.66) and comorbidities (OR = 1.43, 95%CI: 1.06-1.94) were all associated with increased problematic tinnitus, but not non-problematic tinnitus. CONCLUSIONS: Our study demonstrated that the prevalence of problematic tinnitus is much lower than the prevalence of any tinnitus. There was also a relationship between BMI, sleep trouble, other comorbidities and increased odds of problematic tinnitus. Tinnitus severity was significantly related to constancy of perception but had a less clear relationship to duration.
RESUMO
Post-traumatic stress disorder (PTSD) is a debilitating psychiatric syndrome that occurs in individuals exposed to extremely threatening or traumatic events. In both animals and humans, dopamine (DA) function appears to be dysregulated in brain areas involved in the conditioned fear response(s) that underlie PTSD. In this study, we determined the effect of the selective DA D3 receptor antagonists YQA14A (6.25, 12.5 and 25 mg/kg i.p.) and SB-277011A (6 mg/kg i.p.) on tone-induced fear (assessed by measuring freeze time) in a modified version of the single-prolonged stress (SPS) model of PTSD in adult male Sprague-Dawley rats. Rats pretreated with vehicle and then subjected to restraint stress, forced swim and random foot shock (SPS) in the presence of a distinctive tone, displayed a significantly increased tone-induced contextual freeze time and fecal pellet mass following re-exposure to the tone. Rats pretreated with a single i.p. injection of 6.25 or 12.5 mg/kg of YQA14 or 6 mg/kg of SB-277011A showed significantly attenuated contextual freeze time in the presence of the tone when tested 14 days after exposure to SPS. Overall, our results indicate that selectively antagonizing DA D3 receptors significantly decreases freezing time caused by an environment previously associated with stress. If our findings can be extrapolated to humans with PTSD, they suggest that DA D3 receptors may play a role in the pathophysiology of PTSD, and may have therapeutic utility for the clinical management of PTSD.