Objectives: This study aimed to analyse blood glucose and lipid levels in subjective
tinnitus compared to healthy controls. Method: A total of 414 patients with subjective
tinnitus and 274 healthy participants were enrolled. All participants underwent comprehensive
laboratory testing, which included measurements of fasting blood glucose, HbA1c, and
blood lipids. Results: The tinnitus group had significantly higher glucose levels
than the control group (p = 0.024). Additionally, the HbA1c levels were higher in
the tinnitus group (p = 0.006). Tinnitus patients exhibited elevated levels of total
cholesterol (p < 0.001), triglycerides (p < 0.001), and LDL (p < 0.001). However,
HDL levels showed no significant difference (p = 0.984). Although the triglyceride–glucose
index tends to show higher values in the tinnitus group, this difference is statistically
insignificant (p = 0.688). ROC indicated that LDL had the highest sensitivity for
predicting tinnitus (AUC = 0.620; p < 0.001, 95% CI: 0.573–0.668). Other parameters
showed significant results, excluding the triglyceride–glucose index (AUC = 0.514;
p = 0.688, 95% CI: 0.443–0.585), which was not a significant predictor. Glucose levels
significantly correlate with age (rho = 0.338, p < 0.001) and tinnitus onset (rho
= 0.107, p = 0.034). Additionally, age showed a significant correlation with total
cholesterol levels (rho = 0.156, p = 0.002) and triglycerides (rho = 0.121, p = 0.020)
and tinnitus onset (rho = 0.344, p < 0.001). Logistic regression analysis revealed
that the presence of tinnitus was significantly associated with elevated HbA1c levels
(p = 0.007) and TG levels (p = 0.001). Furthermore, the occurrence of chronic tinnitus
was significantly influenced by elevated glucose levels (p = 0.026). Conclusions:
The results showed increased glucose and blood lipid levels in tinnitus. LDL levels
exhibited the highest sensitivity in predicting tinnitus. However, the TyG index was
not a significant predictor. Given the cross-sectional design of the study, which
may limit the results, further longitudinal studies are necessary.
