ANNOYANCE DUE TO NOISE TRIGGERS VASCULAR CHANGES IN THE RENAL HEMODYNAMIC

Abstract

Objective: There is evidence from epidemiological and animal studies that noise exposure is associated with an increased incidence of arterial hypertension and cardiovascular disease. We recently investigated the influence of annoyance due to noise on the renal hemodynamic and found a lower renal plasma flow in patients subjectively annoyed in every-day life compared to not-annoyed patients. We now further explored the pathophysiological mechanisms of this finding. Design and method: We analysed the influence of annoyance due to noise on the renal and systemic hemodynamic in 110 subjects, who were either healthy or presented with drug-naive hypertension (HT) without evidence of end-organ damage. Renal hemodynamic was measured 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. The systemic hemodynamic was recorded by the SphygmoCor System (AtCor Medical). All subjects 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: Annoyed subjects (n = 55) showed lower renal plasma flow (596 ± 108 vs 646 ± 130 ml/min, p = 0.030), higher filtraction fraction (22.9 ± 3.3 vs 21.6 ± 3.2, p = 0.036), higher renal vascular resistance (93.4 ± 27.5 vs 81.0 ± 25.7 mmHg/(ml/min), p = 0.021), higher RA (4565 ± 1744 vs 3792 ± 1676, p = 0.024) and a trend to higher RE (2442 ± 480 vs 2288 ± 411, p = 0.076) compared to not-annoyed subjects (n = 55). There was no difference in glomerular filtration rate (133 ± 12 vs 136 ± 15 ml/min, p = 0.307) and intraglomerular pressure (37.1 ± 2.5 vs 37.6 ± 3.1 mmHg, p = 0.325) between annoyed and not-annoyed subjects. There was also no difference in office blood pressure (133 ± 13/79 ± 10 vs 131 ± 13/78 ± 11 mmHg, p = 0.429/p = 0.527), central blood pressure (115 ± 13/79 ± 11 vs 112 ± 12.8/75 ± 12 mmHg, p = 0.317/p = 0.092), central pulse pressure (36.3 ± 6.9 vs 37.6 ± 6.3 mmHg, p = 0.304) and heart rate (66 ± 8.4 vs 65 ± 10 bpm, p = 0.680) between annoyed and not-annoyed subjects. Conclusions: Annoyance due to noise in everyday life was associated with a vasoconstrictive response in the renal hemodynamic. Our data suggest the hypothesis that annoyance due to noise may trigger early renal vascular changes potentially leading to hypertension.