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

Article (PDF Available)inChest 135(4):950-6 · February 2009with95 Reads
DOI: 10.1378/chest.08-1798 · Source: PubMed
Abstract
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.
    • "Third, our results from separately controlling for each of obesity-related factors such as BMI, WHR, and FM in regression model may not sufficient to exclude the influence of obesity on the association between OSA and elevated CRP levels. A previous study from the Asian patients demonstrated an independent associations of AHI and CRP levels, adjusting for BMI and visceral fat measured by MRI [45]. However, MRI measurement of visceral fat mass is an expensive and laborious technique, so we did not use this technique to estimate visceral obesity in the present study population. "
    [Show abstract] [Hide abstract] ABSTRACT: Obstructive sleep apnea syndrome (OSA) has been recognized as a common health problem, and increasing obesity rates have led to further remarkable increases in the prevalence of OSA, along with more prominent cardiovascular morbidities. Though previous studies have reported an independent relationship between elevated high sensitivity C-reactive protein (hsCRP) levels and OSA, the issue remains controversial owing to inadequate consideration of obesity and various confounding factors. So far, few population based studies of association between OSA and hsCRP levels have been published. Therefore, the purpose of the present study was to investigate whether OSA is associated with increased hsCRP levels independent of obesity in a large population-based study. A total of 1,835 subjects (968 men and 867 women) were selected from a larger cohort of the ongoing Korean Genome and Epidemiology Study (KoGES). Overnight polysomnography was performed on each participant. All participants underwent anthropometric measurements and biochemical analyses, including analysis of lipid profiles and hsCRP levels. Based on anthropometric data, body mass index (BMI) and waist hip ratio (WHR) were calculated and fat mass (FM) were measured by means of multi-frequency bioelectrical impedance analysis (BIA). Mild OSA and moderate to severe OSA were defined by an AHI >5 and ≥15, respectively. The population was sub-divided into 3 groups based on the tertile cut-points for the distribution of hsCRP levels. The percentage of participants in the highest tertile of hsCRP increased dose-dependently according to the severity of OSA. After adjustment for potential confounders and obesity-related variables (BMI, WHR, and body fat) in a multiple logistic model, participants with moderate to severe OSA had 1.73-, 2.01-, and 1.61-fold greater risks of being in the highest tertile of hsCRP levels than participants with non-OSA, respectively. Interaction between obesity (BMI ≥25kg/m²) and the presence of moderate-to-severe OSA was significant on the middle tertile levels of hsCRP (OR = 2.4), but not on the highest tertile, compared to the lowest tertile. OSA is independently associated with elevated hsCRP levels and may reflect an increased risk for cardiovascular morbidity. However, we found that OSA and obesity interactively contribute to individuals with general levels of hsCRP (<1.01 mg/dl). The short-term and long-term effects of elevated hsCRP levels on cardiovascular risk in the context of OSA remain to be defined in future studies.
    Full-text · Article · Sep 2016
    Jinkwan KimJinkwan KimSeok Jun LeeSeok Jun LeeKyung-Mee Choi+3 more authors ...Chol ShinChol Shin
    • "Compared to otherwise healthy obese men with and without OSA, it has been found that OSA is associated with increased CRP levels after controlling for BMI in both types of adults [14, 29, 30]. Although previous studies have suggested that obesity rather than OSA per se is the best predictor of CRP [31], this study's result obviously show that an independent relationship in hs-CRP was identified with OSA and MetS. "
    [Show abstract] [Hide abstract] ABSTRACT: It is unclear whether obstructive sleep apnea (OSA) is independently associated with increased levels of the acute-phase reactant C-reactive protein (CRP). The purpose of this study was to evaluate the relationship between OSA and high-sensitivity CRP (hs-CRP) levels according to the presence or absence of metabolic syndrome (MetS). This study recruited 245 male bus drivers from one transportation company in Taiwan. Each participant was evaluated by a polysomnography (PSG) test, blood lipids examination, and hs-CRP. Severity of OSA was categorized according to the apnea-hypopnea index (AHI). Subjects were categorized into severe OSA group (n = 44; 17.9 %), moderate and mild OSA group (n = 117; 47.8 %), and non-OSA group (n = 84; 34.3 %). AHI had a significant association with hs-CRP (β = 0.125, p = 0.009) adjusting for age, smoking, drinking, and MetS status. Hs-CRP was elevated with severe OSA (β = 0.533, p = 0.005) even adjusting for BMI and MetS. Moreover, there was an independent effect for adjusted odds ratios (AORs) between the stratification of the severity for OSA and MetS. Elevated hs-CRP level is associated with severe OSA, independent of known confounders. The effect of OSA in CRP is independent of MetS was identified.
    Full-text · Article · Apr 2015
    • "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. "
    [Show abstract] [Hide abstract] 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.
    Full-text · Article · May 2014
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