Chronic kidney disease a risk factor for tinnitus
Chronic kidney disease (CKD) is correlated with the risk of tinnitus, with CKD patients undergoing dialysis particularly at a greater risk, a new study has found.
“This nationwide, population-based study is the first research to investigate the association between tinnitus and CKD. We confirm CKD is a significant risk factor for tinnitus. The CKD population is at a 3.02 times higher risk of tinnitus compared to the general population,” said researchers.
In the study sample of 185,430 CKD patients (54.32 percent male), the 10-year cumulative incidence rate of developing tinnitus was 0.18 percent (n=325), yielding an overall incidence rate of 97.25 per 100,000 person-years. [PLoS One 2017;doi:10.1371/journal.pone.0183192]
In 556,290 controls (54.32 percent male), the cumulative incidence rate was 0.15 percent (n=848), corresponding to a 72.56 per 100,000 person-years overall incidence rate. The odds of developing tinnitus were significantly higher in CKD patients than in controls, according to Kaplan-Meier analysis (p<0.001).
Cox regression analysis showed that the risk of tinnitus was significantly higher in CKD patients even after adjusting for age, gender, drug intake and other comorbidities (adjusted hazard ratio [HR], 3.02; 95 percent CI, 2.655 to 3.456; p<0.001).
“CKD is associated with an increased inflammatory status. Inflammation is proposed as an etiopathogenic mechanism of hearing loss in chronic nephropathy because of the induction of cochlear microcirculation dysfunction,” explained researchers. [Clin J Am Soc Nephrol 2012;7:1938-1946]
“[T]he CKD-related cochlear dysfunction or auditory deafferentation can be attributed to the development of tinnitus,” they continued.
From the subgroup analyses, other risk factors that increased the risk of tinnitus in CKD patients included diabetes mellitus (adjusted HR, 3.712; 2.856 to 5.007), heart failure (adjusted HR, 9.975; 5.001 to 18.751) and hypertension (adjusted HR, 3.714; 2.511 to 4.065).
CKD patients on dialysis (n=87,361; 47.11 percent; adjusted HR, 4.586; 2.399 to 6.700; p<0.05) and those not on dialysis (n=98,069; 52.89 percent; adjusted HR, 2.461; 1.033 to 3.454; p<0.001) had significantly higher risk of tinnitus than controls.
“[This finding] indicates that the patients with end-stage renal disease carry a more increased risk of developing tinnitus. It also suggests the risk of developing tinnitus is positively correlated to the severity of the loss of kidney function,” noted researchers.
Data used in the study were retrieved from the National Health Insurance Research Database of Taiwan. CKD patients were excluded if they had baseline tinnitus, a history of kidney transplant or sensorineural hearing loss before tracking. Age-, sex- and index year-matched controls were enrolled at a 1:3 ratio.
“This study presented that CKD is a significant and independent risk factor for tinnitus. The patients with CKD have a 3.02 times higher risk of developing tinnitus,” said researchers, adding that those receiving dialysis for end-stage renal disease are at an even greater risk.
“The underlying mechanism of this association and the effect of disease progression on the development of tinnitus need clarifying in future studies.”