| Objective:A number of recent studies suggest that obstructive sleep apnea (OSA) may have a tight relationship with cardiovascular diseases. The epidemiological studies overboard have suggested that patients with OSA have an increased risk for coronary artery disease (CAD). However, the data in China is rare. The objective of the current study is to determine the incidence of CAD in patients with OSA, and to evaluate the clinical relationship between CAD and OSA, using coronary angiography (CAG) and polysomnography (PSG).Methods:Consecutive patients who underwent CAG from January 2009 to June 2010 in our department were enrolled into the current study. The patients who have heart failure, chronic pulmonary diseases were excluded. After overnight PSG, patients with central sleep apnea were excluded. The clinical characteristics were collected including height, weight, smoke habit, alcohol consumption, and medical history, et al. In the next morning, fasting blood samples was drawn from an antecubital vein for determination of insulin, blood glucose, lipid profiles, et al. All patients were divided into four groups according to the severity of OSA. (1) no OSA group:apnea hypopnea index (AHI)<5; (2) mild OSA group:5≤AHI<15; (3) moderate OSA group:15≤AHI<30; (3) severe OSA group:30≤AHI。Results:257 patients were included and divided into four groups according to the severity of OSA. There were 56 patients in no OSA group,79 patients in mild OSA group,61 patients in moderate OSA group, and 61 patients in severe OSA group. In the analysis of variance, AHI, Oxygen desaturation index (ODI), average oxygen saturation, minimal oxygen saturation, and oxygen saturation below 90%(TST) were all significantly different between the four groups (P<0.001). In Pearson correlation, ODI was the most significantly correlated with AHI (r=0.978). The other factors correlated with AHI included minimal oxygen saturation (r=-0.561), TST (r=0.392), average oxygen saturation (r=-0.355).The incidence of CAD were 44.6%:60.0%:70.5%:72.1% (P<0.01) in no OSA group, mild OSA group, moderate OSA group, and severe OSA group, respectively. In logistic regression analysis, minimal oxygen saturation was significantly correlated with CAD (P=0.024).Conclusions:OSA is tightly related with the development of CAD. Among all the PSG variables, ODI was the most significantly correlated with AHI even after adjustment for confounders. Among all the variables for oxygen saturation, minimal oxygen saturation was the most significantly correlated with AHI. The incidence of CAD was significantly higher in OSA patients than no OSA patients, and had an increased trend with the severity of OSA. OSA is the independent risk factors. Objective:Obstructive sleep apnea (OSA) has high prevalence and wide spectrum in adults. OSA patients are in high risk of cardiovascular diseases, and also have high risk factors for metabolic syndrome. However, the mechanism of OSA is not very clear. The independent relationship between OSA and metabolic disorders might be one pathway contributing to cardiovascular diseases. Insulin resistance is an important linkage between cardiovascular diseases and metabolic syndrome. The aim of the current study is to determine the relationship between OSA and insulin resistance by polysomnography (PSG) and homeostatic model assessment of insulin resistance (HOMA-IR).Methods:Consecutive snoring patients were enrolled from the Sleep Center of Fuwai Hospital from October 2009 to June 2010. All patients underwent overnight PSG using an Embletta recording device in the current study. The patients who have diabetes, heart failure, and other endocrine diseases were excluded. The clinical characteristics were collected including height, weight, smoke habit, alcohol consumption, and medical history. In the morning at 6:00, fasting blood samples were drawn from an antecubital vein for determination of insulin, blood glucose, lipid profiles, high sensitivity C-reactive protein, et al at the local clinical testing center. Insulin resistance was evaluated by HOMA2-IR. HOMA2-IR was calculated by software HOMA Calculator V2.2.2 where fasting blood glucose and fasting insulin levels were enrolled.Results:218 patients after matched with the Inclusion and Exclusion criteria were enrolled.176 patients were males while 42 were females. The average age is (57.1±10.1) years. All patients were divided into four groups according to the severity of OSA. There were 50 patients in no OSA group,64 patients in mild OSA group,61 patients in moderate OSA group, and 43 patients in severe OSA group. There were no significant differences in sex, smoker, and alcohol consumption between the four groups. The age of mild OSA group is significantly lower than the other three groups. Body mass index (BMI) is also significantly different between the four groups. In the analysis of variance, apnea hypopnea index (AHI), Oxygen desaturation index (ODI), average oxygen saturation, minimal oxygen saturation, and oxygen saturation below 90%(TST) were all significantly different between the four groups. Fasting insulin levels and HOMA-IR indexes were also significantly different between the four groups. Fasting insulin levels were significantly higher in severe OSA group than the other three groups. HOMA-IR indexes were significantly higher in severe OSA group than no OSA group, and moderate OSA group.In Pearson correlation, TST was the most significantly correlated with HOMA index (r= 0.305, P<0.001). The other factors correlated with HOMA index included BMI index (r= 0.247, P<0.001),AHI/ODI(r= 0.20, P<0.01),average oxygen saturation (r=-0.151, P<0.05). Meanwhile, TST was also the most significantly correlated with fasting insulin levels (r= 0.331,P<0.001). The other factors correlated with fasting insulin levels included BMI index (r= 0.227,P=0.001),AHI/ODI(r= 0.19, P<0.01),average oxygen saturation (r=-0.170, P<0.05). In partial correlation adjusted for age, sex, and BMI index, TST was still the most significantly correlated with HOMA index (r=0.302, P<0.001), and the other factor significantly correlated HOMA index was AHI(r= 0.142, P<0.05); moreover, TST was still the most significantly correlated with fasting insulin levels (r= 0.328, P<0.001), and the other two factors significantly correlated fasting insulin levels were average oxygen saturation (r=-0.150, P<0.05) and ODI (r=0.136, P<0.05).In multiple logistic regression analysis, TST, average oxygen saturation, and BMI were significantly correlated with HOMA-IR (P<0.001).Conclusions:Fasting insulin levels and HOMA-IR index were significantly higher in severe OSA group than no OSA groups. In Pearson correlation, TST was the most significantly correlated with both HOMA index and fasting insulin levels, even after adjustment for age, sex, and BMI. In multiple logistic regression analysis, insulin resistance was independently correlated with the variables of hypoxemia and obesity. Insulin resistance increased with the severity of hypoxemia. OSA is independently related with insulin resistance. Background:Obstructive sleep apnea (OSA) is prevalent in adult and is an independent risk factor for the development of coronary artery disease (CAD). Lots of data suggest that metabolic syndrome is also an independent risk factor for CAD. More and more clinical studies reveal that OSA is tightly related with metabolic syndrome. However, due to many confounding factors, the mechanism between OSA and metabolic syndrome is very complicated. Continuous positive airway pressure (CPAP) is an effective therapy for OSA. However, for patients who already have OSA and CAD with optimal medications, whether CPAP can improve metabolic disorders and quality of life is not clear. This is a prospective randomized controlled study to evaluate the effects of CPAP on metabolic disorders in Chinese cohorts with CAD under optimal medications.Methods:Patients with CAD and moderate to severe OSA were enrolled from the Sleep Center of Fuwai Hospital from May 2009 to September 2010. These CAD patients were optimal treated for CAD and hypertension. The patients who have heart failure, chronic pulmonary diseases, and central sleep apnea were excluded.56 patients were enrolled; however,6 patients were excluded in sham-CPAP phase. Thus 50 patients were randomized into two groups:CPAP group and control group. Patients in CPAP group accept CPAP treatment and standard care; control group only accept standard care. Before randomization, the clinical characteristics were collected and blood biochemical profiles were measured, as well as assessment of Epworth sleepiness score (ESS) and quality of life. The patients of the two patients were followed up at 1 month,3 months and 6 months after randomization. Clinical characteristics, blood biochemical profiles and quality of life were re-assessed and compared with the data of baseline.Results:At baseline, all the data were matched between the two groups except HbAlc. After 6 months, compared with control group, CPAP treatment significantly reduced the levels of fasting insulin (P=0.026). At the same time, HOMA2 indexes in CPAP group were also significantly reduced by CPAP treatment (P=0.021). However, the other blood biochemical measurements remained unchanged between the CPAP group and control group. Compared with control group, CPAP treatment markedly reduced the morning diastolic BP (P=0.023) at 1 month,3 months, and 6 months follow-up. In contrast, there were no significant changes in systolic BP and heart rate. After 1 month CPAP treatment, ESS scores were significantly improved in CPAP group compared with control group (Δ-5.2±3.1 vsΔ-0.5±3.2, respectively, P<0.001).And this significant deference remained until the sixth month. The depression score was significantly increased in control group compared with CPAP group after 6 months (P=0.002). On the other hand, the anxiety score had no deference between the two groups. The quality of life also had no significant changes in CPAP group compared with control group.Conclusions:In the current study, CPAP treatment for 6 month was associated with significant improvement in insulin resistance, reduction in diastolic BP and improvement in ESS score of patients with both moderate-to-severe OS A and CAD on optimal medication. This study suggested that OSA might cause a series of metabolic disorders, especially insulin resistance, which could further promote the development of CAD. This provides a new target for the second prevention of CAD. So CPAP treatment for OSA has great benefits for CAD patients.
|
PDF Full Text Request