C-Reactive Protein Is Associated With Obstructive Sleep Apnea Independent of Visceral Obesity

Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong SAR, People's Republic of China.
Chest (Impact Factor: 7.48). 02/2009; 135(4):950-6. DOI: 10.1378/chest.08-1798
Source: PubMed


Obstructive sleep apnea (OSA) is associated with adverse cardiovascular outcomes. C-reactive protein (CRP) predicts atherosclerotic complications. Our study evaluates whether OSA is associated with an elevated CRP level, after elimination of known confounders including visceral obesity.
Men without significant chronic medical illness, regular medications, or illness in the preceding 4 weeks were enrolled. Subjects with morbid obesity, newly detected high BP, or fasting glucose were excluded. They underwent polysomnography and MRI of abdomen to quantify visceral fat volume. High-sensitivity CRP levels were measured.
111 men with mean body mass index (BMI) 26.3 +/- 3.8 kg/m(2) were evaluated. After adjustment for age, smoking, BMI, waist circumference, and sleep efficiency, CRP correlated positively with the apnea-hypopnea index (AHI) [r = 0.35, p < 0.001], duration of O(2) saturation < 90% (r = 0.29, p = 0.002), and arousal index (r = 0.32, p = 0.001), and it correlated negatively with minimal O(2) saturation (r = -0.29, p = 0.002). These correlations were consistent when adjustment was made for MRI visceral fat volume instead of waist circumference. In the regression model, significant predictors of CRP included AHI, waist circumference, and triglycerides (adjusted R(2), 0.33, p = 0.001, p = 0.002, p = 0.018, respectively). Among the 111 subjects, 32 subjects with no or mild OSA (AHI < 15 events/h) were matched with 32 subjects with moderate-to-severe OSA (AHI > or = 15 events/h) in MRI visceral fat volume. CRP was higher in subjects with moderate-to-severe OSA (median, 1.32; 0.45 to 2.34 mg/L) when compared to subjects with no or mild OSA (median, 0.54; 0.25 to 0.89 mg/L; p = 0.001).
In healthy middle-aged men, elevated CRP level is associated with OSA independent of visceral obesity.

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Available from: Henry Mak, Oct 04, 2015
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    • "Higher blood viscosity can lead to stasis and promote thrombus formation. OSAS also promotes an inflammatory state and, as a result, the level of acute-phase proteins is increased [9, 10]. In our patient, chronic high serum levels of fibrinogen and CRP were reported. "
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    ABSTRACT: Purpose To describe a case of bilateral and simultaneous central retinal vein occlusion (RVO) in a young patient diagnosed with obstructive sleep apnea syndrome (OSAS). Case Report A 38-year-old man with morbid obesity and daytime sleepiness presented with a history of bilateral vision loss. His visual acuity (VA) was hand movements, and fundus examination (FE) revealed bilateral central RVO. General medical examination revealed untreated hypertension and type II respiratory failure. Laboratory tests for thrombophilia showed increased hematocrit (59%) and high levels of fibrinogen and C-reactive protein. Other causes of congenital and acquired hypercoagulability were ruled out. Pathologic polysomnography led to the diagnosis of OSAS. The patient was treated with antihypertensive drugs and continuous positive air pressure. In addition, he received intravitreal ranibizumab. At 10 months after presentation, his VA was no light perception in the right eye and hand movements in the left eye. FE revealed bilateral retinal and optic nerve atrophy, and the occurrence of a nonarteritic anterior ischemic neuropathy in the right eye was considered.
    Case Reports in Ophthalmology 05/2014; 5(2):150-6. DOI:10.1159/000363132
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    • "It is a sensitive marker of inflammation and an important marker of future cardiovascular risk [12,13]. Elevated CRP levels have been reported by several researchers in OSAS patients [14–16]. "
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    ABSTRACT: Background: Continuous positive airway pressure (CPAP) is the most effective method for treating obstructive sleep apnea syndrome (OSAS) and alleviating symptoms. Improved sleep quality with effective CPAP therapy might also contribute to attenuated systemic inflammation and improved endothelial function, with subsequent reduction of cardiovascular risk. The aim of this study was to assess the effect of 3-month CPAP therapy on brachial artery flow-mediated dilation (FMD) and plasma C-reactive protein (CRP) levels in patients with OSAS. Material/methods: Our study group consisted of 38 male patients with no prior history of cardiovascular disease. Twenty patients with an Apnea-Hypopnea Index (AHI) ≥15 were assigned to receive CPAP treatment and 18 subjects with an AHI<5 were included in the control group. Six patients failed to comply with the CPAP treatment. Measurement of FMD and blood analysis was performed at baseline and 3 months after CPAP therapy. Results: Baseline FMD values were negatively correlated with age, BMI, AHI, DSI,% of time <90% Sa02, and CRP (p<0.05). Plasma CRP values were positively correlated with BMI, AHI, DSI and% of time <90% Sa02 (p<0.05). In the group of patients who complied with the CPAP treatment, there was a significant increase in the FMD values (9.18 ± 0.55 vs. 6.27 ± 0.50) and a decrease in the levels of CRP (0.67 ± 0.15 vs. 0.84 ± 0.18) (p<0.05). Conclusions: Appropriate CPAP therapy improved both CRP and FMD values, suggesting its potentially beneficial role in reducing cardiovascular risk in OSAS patients.
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    ABSTRACT: Die obstruktive Schlafapnoe (OSA) ist in der westlichen Gesellschaft weit verbreitet und hat eine Prävalenz von 20 % für die milde OSA und von 6–7 % für die mittelschwere bis schwere OSA (1). Die Prävalenz steigt bis zu einem Alter von 65 Jahren an (2). Einer aktuellen Arbeit zufolge haben weibliche Schlafapnoiker im Vergleich zu Männern einen höheren Body-Mass-Index (BMI), eine geringer ausgeprägte Tagesschläfrigkeit, weniger Atempausen und benötigen einen geringeren effektiven Beatmungsdruck (3).
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