title: Arterial indices and serum cystatin C level in individuals with occupational wide band noise exposure.
abstract: BACKGROUND
  Chronic exposure to noise is known to cause a wide range of health problems including extracellular matrix (ECM) proliferation and involvement of cardiovascular system. There are a few studies to investigate noise-induced vascular changes using noninvasive methods. In this study we used carotid artery intima-media thickness (CIMT) and aortic augmentation as indices of arterial properties and cystatin C as a serum biomarker relating to ECM metabolism.
  
  
  METHODS
  Ninety-three male participants were included in this study from aeronautic technicians: 39 with and 54 without a history of wide band noise (WBN) exposure. For better discrimination, the participants were divided into the two age groups: <40 and >40 years old. Adjusted aortic augmentation index (AI) for a heart rate equal to 75 beats per minute (AIx@HR75) were calculated using pulse wave analysis (PWA). CIMT was measured in 54 participants who accepted to undergo Doppler ultrasonography. Serum cystatin C was also measured.
  
  
  RESULTS
  Among younger individuals the mean CIMT was 0.85 ± 0.09 mm and 0.75 ± 0.22 mm in the in the exposed and the control groups respectively. Among older individuals CIMT had a mean of 1.04 ± 0.22 mm vs. 1.00 ± 0.25 mm for the exposed vs. the control group. However, in both age groups the difference was not significant at the 0.05 level. A comparison of AIx@HR75 between exposure group and control group both in younger age group (5.46 ± 11.22 vs. 8.56 ± 8.66) and older age group (17.55 ± 10.07 vs. 16.61 ± 5.77) revealed no significant difference. We did not find any significant correlation between CIMT and AIx@HR75 in exposed group (r = 0.314, P value = 0.145) but the correlation was significant in control group (r = 0.455, P value = 0.019). Serum cystatin C level was significantly lower in individuals with WBN exposure compared to controls (441.10 ± 104.70 ng/L vs. 616.89 ± 136.14, P value < 0.001) both in younger and older groups.
  
  
  CONCLUSIONS
  We could not find any evidence for the association of WBN exposure with arterial properties, but cystatin C was significantly lower in the exposed group.
authors.affiliation: Department of Epidemiology, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran.
authors.forename: Ali R
authors.initials: AR
authors.lastname: Khoshdel
authors.affiliation: Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Benyamin
authors.initials: B
authors.lastname: Mousavi-Asl
authors.affiliation: Department of Radiology, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Shekarchi
authors.affiliation: Department of Aerospace Medicine, School of Aerospace Medicine, AJA University of Medical Sciences, Tehran, Iran.
authors.forename: Kazem
authors.initials: K
authors.lastname: Amini
authors.affiliation: Department of Physiology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran.
authors.forename: Iraj
authors.initials: I
authors.lastname: Mirzaii-Dizgah
mesh_terms: D000328:Adult; D000367:Age Factors; D001011:Aorta / Q000503:physiopathology*; D001359:Aviation; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D059168:Carotid Intima-Media Thickness; D016022:Case-Control Studies; D055316:Cystatin C / Q000097:blood*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects*; D063177:Pulse Wave Analysis; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D055316:Cystatin C