RELATION BETWEEN NOISE ANNOYANCE, STRESS HORMONES AND THE RENAL HEMODYNAMIC

Abstract

Objective: Our previous studies showed that healthy men subjectively annoyed by every day noise showed lower renal plasma flow and higher renal vascular resistance compared to not annoyed men. We now further explored the pathophysiological mechanisms of this finding by analysing relations between noise annoyance and chronic stress hormones in healthy men. Design and method: We analysed the renal hemodynamic in 80 healthy men using steady state input clearance with infusion of paraaminohippuric acid and inulin, respectively. Intraglomerular pressure and resistances of the afferent (RA) and efferent (RE) arterioles were calculated according to the Gomez equation. Fasting morning cortisol and dehydroepiandrosterone sultate (DHEA-S) were also measured. All study participants ranked subjective annoyance due to noise in everyday life on a 7 grade likert scale. The median of all rankings was used as cut off point to divide the group into annoyed and non-annoyed subjects. Results: Even though annoyed subjects (n = 32) showed lower renal plasma flow (635 ± 96 vs 685 ± 116 ml/min, p = 0.039) and higher renal vascular resistance (77.4 ± 15 vs 70.0 ± 14 (mmHg/(ml/min)), p = 0.033) compared to not-annoyed subjects (n = 46) there was no difference in serum cortisol and DHEA-S between the groups (table 1). However, there was a correlation between serum cortisol and glomerular filtration rate (r = 0.345, p = 0.002) as well as renal plasma flow (r = 0.408, p < 0.001), and an inverse correlation between serum cortisol and renal vascular resistance (r = -0.420, p < 0.001), resistance of the vas afferens (r = -0.376, p = 0.001) and resistance of the vas efferens (r = -0.441, p < 0.001) in the total healthy study population. There was also an inverse correlation between DHEA-S and resistance of the vas efferens (r = -0.409, p < 0.001) in the total healthy study population. Conclusions: Annoyance due to noise in everyday life was not associated with an increased level of chronic stress hormones. However, our data suggests a relation between chronic stress hormones and impaired renal function. Chronic stress may trigger early renal vascular changes potentially leading to hypertension.