The relationship between sleep-disordered breathing and high-sensitivity C-reactive protein in Japanese men.
OBJECTIVE
Elevated C-reactive protein (CRP), an inflammatory marker and emerging risk factor for atherosclerosis and coronary heart disease, has been reported in overweight patients with sleep-disordered breathing (SDB). However, the contribution of C-reactive protein to this disease among non-overweight individuals is uncertain. We thus examined the relationship between serum C-reactive protein levels and nocturnal arterial oxygen desaturation, stratified by category of body mass index (BMI).


METHODS
Cross-sectional study.


METHODS
Subjects were 316 men with a mean BMI of 25.4 kg/m2, aged 20-79 years, who attended a sleep clinic at Osaka, Japan.


RESULTS
SDB was assessed by oxygen desaturation index (ODI) measured by pulse oximetry during sleep. We used 3% oxygen desaturations per hour (3% ODI), as the indicator of SDB. We also measured serum levels of C-reactive protein (CRP). After adjustment for age, BMI, hypertension, diabetes mellitus, hypercholesterolemia, smoking status, alcohol consumption, and daily sleep duration, mean high-sensitivity CRP levels were 0.63, 0.65, and 0.96 mg/L for SDB severity levels of 3%ODI<5, 5 to 19.9, and >=20, respectively (p for trend=0.015). This association with SDB tended to be stronger in non-overweight men (BMI<25 kg/m2) (0.47, 0.48 and 1.02 mg/L, p for trend=0.017) than in overweight men (BMI > or = 25 kg/m2) (0.92, 0.87 and 1.21 mg/L, p for trend=0.11).


CONCLUSIONS
SDB is associated with increased levels of CRP, especially in non-overweight men. Our results suggest the importance of follow-up and control of SDB in the prevention of cardiovascular disease even in non-overweight SDB patients.
Yao
Masayuki
M
Department of Public Health Medicine, Doctoral Program in Social and Environmental Medicine, Graduate School of Comprehensive Human Sciences and Institute of Community Medicine, University of Tsukuba, Tsukuba, Japan.
Tachibana
Naoko
N
Okura
Mutsumi
M
Ikeda
Ai
A
Tanigawa
Takeshi
T
Yamagishi
Kazumasa
K
Sato
Shinichi
S
Shimamoto
Takashi
T
Iso
Hiroyasu
H
D000328:Adult; D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism*; D008078:Cholesterol, LDL / Q000097:blood; D015438:Health Behavior; D006801:Humans; D006967:Hypersensitivity / Q000378:metabolism*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000453:epidemiology* / Q000378:metabolism*; D011795:Surveys and Questionnaires
D008078:Cholesterol, LDL; D002097:C-Reactive Protein