Association between Sudden Sensorineural Hearing Loss and Preexisting Thyroid Diseases: A Nationwide Case-Control Study in Taiwan

Abstract

Background: Little evidence is available about the risk of sudden sensorineural hearing loss (SSNHL) in patients with thyroid diseases. We assessed whether a diagnosis of thyroid disease, particularly hyperthyroidism or hypothyroidism, is associated with SSNHL risk in an Asian population. Material and Methods: This case-control study was conducted with population-based data from Taiwan’s National Health Insurance Research Database from January 2000 to December 2013. The case group comprised 3331 adult patients with newly diagnosed SSNHL, and four controls without SSNHL for each case matched by sex, age, monthly income, and urbanization level of residence. Underlying Thyroid diseases were retrospectively evaluated in the case and control groups. Multivariate logistic regression analyses were used to explore relations between thyroid diseases and SSNHL. Results: Of the 3331 cases, 5.7% had preexisting thyroid diseases, whereas only 4.0% of the 13,324 controls had the same condition. After adjustment for sex, age, monthly income, urbanization level of residence, history of hypertension, diabetes mellitus, chronic otitis media, and hyperlipidemia, associations were identified between a history of either hypothyroidism (adjusted odds ratio [AOR], 1.54; 95% CI, 1.02–2.32; p = 0.042) or hyperthyroidism (AOR, 1.41; 95% CI, 1.07–1.85; p = 0.015) and an elevated risk of SSNHL. In subgroup analysis, the correlation between hypothyroidism and increased SSNHL risk remained significant only for patients aged over 50 years (AOR, 1.61; 95% CI, 1.01–2.57; p = 0.045), and that between hyperthyroidism and SSNHL was significant only for female patients (AOR, 1.48; 95% CI, 1.09–2.01; p = 0.012). Treatment for hypothyroidism and hyperthyroidism did not alter the association in subgroup analyses. Conclusion: Preexisting hypothyroidism and hyperthyroidism appear associated with SSNHL susceptibility in Taiwan. Physicians should be wary of this elevated risk of SSNHL among patients with previously diagnosed thyroid dysfunction, especially women and patients aged more than 50 years.

A Hospital based study on sudden sensorineural Hearing Loss: It’s audiological characteristics and prevalence

“… 13 Also a higher incidence (1.3 fold) of SSNHL has also been reported in cases with cardiac rhythm disorders, 14 Diabetes Mellitus, 15 and hypo and hyperthyroidism. 16 Here it must be kept in mind that identification of etiology is also related to the investigative facilities available and being used, which might result in difference in the frequency of different etiologies being reported from different centers.…”

Association between SSNHL and Thyroid Diseases

“…To our knowledge, it is the biggest cohort study investigating the association between thyroid diseases and SSNHL. Although there is a lack of pathophysiological study on the association of hypothyroidism with SSNHL, a few previous studies have suggested a positive association between thyroid disorders and SSNHL [ 12 , 15 , 23 ]. A cross-sectional study by Oiticica et al described a high prevalence of abnormal thyroid function in SSNHL patients (21.6%, 32/166) compared to the general population (21.6% (32/166) vs. 10%, p = 0.013) [ 12 ].…”

“…However, they did not discriminate between hyper or hypothyroidism. Both hyperthyroidism and hypothyroidism have been suggested to be associated with SSNHL [ 15 , 23 ]. Another cross-sectional study reported that 15.4% of SSNHL patients had low levels of Thyroid Stimulating Hormone (TSH) which was associated with poor prognosis [ 23 ].…”

“…Another cross-sectional study reported that 15.4% of SSNHL patients had low levels of Thyroid Stimulating Hormone (TSH) which was associated with poor prognosis [ 23 ]. A national health claim cohort study in Taiwan reported that hypothyroidism and hyperthyroidism were associated with a 1.54 fold (95% CI = 1.02–2.32, p = 0.042) and 1.41 fold (95% CI = 1.07–1.85, p = 0.045) higher odds for SSNHL, respectively [ 15 ]. However, they did not adjust for thyroid diseases and lifestyle factors such as obesity, smoking, and alcohol consumption.…”

“…Multiple causes, including autoimmunity [ 9 ], vascular compromise [ 10 ], viral infection [ 11 ], and metabolic disorders [ 12 ] have been suggested to be associated with SSNHL. As thyroid diseases encompass a wide spectrum of etiologies and are related to both autoimmunity [ 13 ] and vascular compromise [ 14 ], previous clinical studies have reported a positive association between thyroid diseases and hearing loss [ 12 , 15 ]. However, most of the previous studies were based on a small number of cases and focused on only one type of thyroid disease, such as Graves’ disease [ 5 ] or Hashimoto’s thyroiditis [ 16 ].…”