Salivary Stress-Related Responses in Tinnitus: A Preliminary Study in Young Male Subjects with Tinnitus

Abstract

Objective: This preliminary study examined if baseline measures of stress-related biomarkers as measured by salivary secretions of specific autonomic [measured by salivary α-amylase (sAA)], endocrine (measured by salivary cortisol), and immune (measured by salivary neopterin) responses are greater in male subjects with tinnitus in response to an induced-stress task.

Method: Twenty male subjects with no significant hearing loss, 10 with tinnitus, and 10 without tinnitus were enrolled in this study.Salivary secretions were collected before and after the induced stress task at four different time intervals.

Results: sAA levels were lower in the tinnitus group in comparison to subjects without tinnitus, suggesting impaired sympathetic activity in the subjects with tinnitus although these levels remained stable throughout the stress experiment.While no significant effects could be obtained for salivary cortisol or neopterin, salivary neopterin levels were trending toward significance over all measurements. Behavioral measures of stress were found to correlate negatively with measures of sAA and salivary neopterin.

Conclusion: The results of this study suggest impaired stress-related sAA mechanisms in male subjects with tinnitus, as evidenced by the different stress reactions induced in the endocrine system (as measured by salivary cortisol) and the immune system (as measured by salivary neopterin).

Keywords: salivary alpha amylase; salivary cortisol; salivary neopterin; stress-related responses; tinnitus.

Figure 1

Experimental effect of group differences at baseline vs.post-test for (A) salivary α amylase, (B) salivary cortisol, and (C) salivary neopterin. (A) Subjects with tinnitus (M = 42.84, Sd = 24.38) had lessened salivary α amylase scores than those without tinnitus (M = 98.60, Sd = 61.51). (A) *Indicates significant differences. (B) Salivary cortisol, and (C) salivary neopterin yielded no statistical significant differences between baseline and post-test measure.

Figure 2

Correlation between the perceived stress scale (PSS) and stress-related markers. (A) A significant negative correlation (r_s = −0.49 p = 0.02) between PSS and baseline measures of salivary α amylase, indicating the higher the stress the lower salivary α amylase concentrations. (B) No correlation between PSS scores and baseline measures of salivary cortisol was obtained (r_s = −0.05 p = 0.81). Similarly, (C) PSS with baseline measures of salivary neopterin (r_s = 0.34 p = 0.14), yielded no statistical significance.

Figure 3

Follow-up effect of group differences at 5, 30, and 60 min post-test measures. (A) Salivary α amylase yielded no statistical significant difference for 30 min post-test, however a significant difference was obtained for 60 min post-test Specifically, subjects with tinnitus (M = 40.21, Sd = 30.06) had lower measures of salivary α-amylase than subjects without tinnitus (M = 87.81, Sd = 48.04). (B) Salivary cortisol and (C) salivary neopterin yielded no statistical significant difference for the effect of time. *Indicates significant difference.

Figure 4

Experimental validation using a numeric rating scale. Subjects had increases stress scores post-test in comparison to baseline; this was characterized by subjects with tinnitus (M = 4.40, Sd = 2.50) exhibiting higher stress scores than subjects without tinnitus (M = 2.80, Sd = 2.39). *Indicates significant difference.

Figure 5

(A) Significant correlations was obtained between AUC of salivary α-amylase, but not with (B) AUC salivary cortisol, or (C) AUC neopterin.Spearman's Rho were significant for (D) AOC, (E) COA, (F) AON, (G) NOA, and (H) CON, but not for (I) NOC. This suggests that the higher the scores of the PSS the lower the individual scores of AUC for salivary α-amylase, salivary cortisol, and salivary neopterin, and the higher the likelihood that subjects has chronic stress.