Acute effects of noise exposure on 24-h ambulatory blood pressure in hypertensive adults.
OBJECTIVE
Noise exposure is associated with elevated blood pressure, but the effects on susceptible workers have not been reported. This repeated-measure study investigated the effects of noise exposure on 24-h ambulatory blood pressure among hypertensive, pre-hypertensive, and normotensive adults.


METHODS
We enrolled 113 volunteers in an occupational cohort in 2009. Individual noise exposure and personal blood pressure were measured simultaneously over 24 h on working and non-working days. Linear mixed-effects regressions were used to estimate the effects on SBP and DBP by controlling for potential confounders.


RESULTS
Each A-weighted decibel (dBA) increase in a 30-min time-lagged exposure was associated with transient elevations of work-time SBP [0.30 (95% confidence interval: 0.06, 0.54) mmHg] on working days as well as sleep-time SBP [0.39 (0.12, 0.66) mmHg] and DBP [0.33 (0.14, 0.51) mmHg] on non-working days among 19 hypertensive adults. In contrast, 46 normotensive workers had transient increases in work-time SBP [0.16 (0.03, 0.29) mmHg] and DBP [0.25 (0.15, 0.34) mmHg] on working days as well as sleep-time SBP [0.17 (0.06, 0.29) mmHg] and DBP [0.21 (0.14, 0.29) mmHg] on non-working days caused by a 1-dBA increase in the current exposure. All groups had sustained increases in 24-h average ambulatory SBP and DBP induced by noise exposure on 2 days, but the hypertensive workers had the most pronounced increase in SBP.


CONCLUSIONS
Hypertensive adults are more susceptible to noise exposure with a greater effect on ambulatory SBP. These results suggest a need for more protection for this subpopulation.
aDepartment of Occupational Safety and Health, College of Public Health, China Medical University bDepartment of Family Medicine, China Medical University Hospital cSchool of Medicine, College of Medicine, China Medical University dDepartment of Pharmacy, College of Pharmacy, China Medical University, Taichung eInstitute of Labor, Occupational Safety and Health, Ministry of Labor, Executive Yuan, Taipei, Taiwan, ROC.
Ta-Yuan
TY
Chang
Chiu-Shong
CS
Liu
Bing-Fang
BF
Hwang
Hsiu-Hui
HH
Hsieh
Bo-Ying
BY
Bao
Chiou-Jong
CJ
Chen
Ven-Shing
VS
Wang
Jim-Shoung
JS
Lai
D000328:Adult; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects*