Sleep-disordered breathing and blood pressure levels among shift and day workers.
BACKGROUND
Sleep-disordered breathing (SDB) can be one of the major determinants of high blood pressure (BP), but there has been no study on SDB with an emphasis on shift workers. The objective of this study was to examine whether a relationship between SDB and blood pressure/hypertension is more evident among shift workers than among day workers.


METHODS
In this cross-sectional study, we measured BP levels and oxygen desaturation index (by nocturnal pulse oximetry) among 253 male shift workers and 206 male day workers aged 30 to 62 years at nuclear power plants in Japan.


RESULTS
The prevalence of SDB (3% oxygen desaturation index >or=10 and >or=15 per hour) in all subjects was 11.3% (95% confidence interval [95% CI] 8.4-14.2) and 6.1% (95% CI 3.9-8.3), respectively, with no statistical difference between shift and day workers. Systolic and diastolic BP levels were correlated with 3% oxygen desaturation index in all subjects after adjustment for potential confounding variables. This association was primarily observed among workers aged >or=40 years, more specifically older shift workers.


CONCLUSIONS
A correlation between SDB severity and diastolic BP levels among shift workers aged >or=40 years suggests the importance of screening for SDB among shift workers for BP control.
Department of Public Health Medicine, Doctorial Program in Social and Environmental Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan. tt9178@aol.com
Takeshi
T
Tanigawa
Isao
I
Muraki
Mitsumasa
M
Umesawa
Naoko
N
Tachibana
Hiroyuki
H
Noda
Masaya
M
Takahashi
Keiko
K
Mutou
Yoshiko
Y
Kage
Lawrence
L
Smith
Hiroyasu
H
Iso
D000328:Adult; D000367:Age Factors; D001794:Blood Pressure / Q000502:physiology*; D015992:Body Mass Index; D002940:Circadian Rhythm / Q000502:physiology*; D003430:Cross-Sectional Studies; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012119:Respiration; D012720:Severity of Illness Index; D020178:Sleep Disorders, Circadian Rhythm / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D014940:Work Schedule Tolerance / Q000502:physiology*