Risk Factors of Persistent Tinnitus: Longitudinal Analyses in the Nurses’ Health Study I and II

Abstract

Persistent tinnitus, derived from the Latin verb tinnire (“to ring”) and historically described in terms ranging from “storming ears” in Ancient Egypt to “singing ears” in Ancient Babylon, is characterized by phantom auditory perception with no external source of sound. The disease can be distressing, costly, and associated with anxiety, depression, suicide attempts, sleep impairments, social isolation, and workdays missed. However, most cases of persistent tinnitus have no identified cause. A more nuanced understanding of the risk factors leading to development of persistent tinnitus is needed to better characterize pathophysiology and improve prevention and treatment strategies. We leveraged data from two large prospective cohort studies, the Nurses’ Health Study I and II, to explore potential risk factors including inflammatory biomarkers, alcohol intake, and statin use, in relation to development of persistent tinnitus. In Chapter 1, we evaluated the association between plasma levels of three inflammatory biomarkers (CRP, IL-6, and TNFR-2) and risk of developing tinnitus. We did not observe significant associations between these biomarkers and increased risk of incident persistent tinnitus or daily tinnitus. In Chapter 2, we studied the association between alcohol intake and risk of developing tinnitus. Alcohol intake was longitudinally associated with lower risk of developing persistent tinnitus; the magnitude of the reduced risk increased with increasing alcohol intake. White wine was associated with lower risk, while regular beer was associated with higher risk. These findings suggest that consumption of certain alcoholic beverages, but not regular beer, may help protect against tinnitus. In Chapter 3, we evaluated the association between statin use and risk of developing tinnitus. Elevated cholesterol was associated with higher risk of developing persistent tinnitus, while current statin use was associated with lower risk. Our findings suggest that elevated cholesterol may represent a modifiable risk factor for persistent tinnitus, and statin use may help mitigate that elevated risk. Further studies are warranted to determine whether statins may represent a viable clinical strategy for preventing tinnitus.