The relationship between sleep-disordered breathing and high-sensitivity C-reactive protein in Japanese men

Sleep. 2006 May;29(5):661-5.


Study objectives: 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).

Design: Cross-sectional study.

Participants: 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.

Measurements and 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).

Conclusion: 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.

MeSH terms

  • Adult
  • Aged
  • Asian People*
  • Body Mass Index
  • C-Reactive Protein / metabolism*
  • Cholesterol, LDL / blood
  • Health Behavior
  • Humans
  • Hypersensitivity / metabolism*
  • Japan / epidemiology
  • Male
  • Middle Aged
  • Risk Factors
  • Sleep Apnea Syndromes / epidemiology*
  • Sleep Apnea Syndromes / metabolism*
  • Surveys and Questionnaires


  • Cholesterol, LDL
  • C-Reactive Protein