Silent brain infarction and platelet activation in obstructive sleep apnea.

RATIONALE: Silent brain infarction (SBI) and increased levels of soluble CD40 ligand (sCD40L) and soluble P-selectin (sP-selectin) are associated with an increased risk of cerebrovascular disease. OBJECTIVES: The aim of this study was to evaluate whether SBI and serum levels of sCD40L and sP-selectin are increased in patients with obstructive sleep apnea (OSA). METHODS: SBI was studied by brain magnetic resonance images in 50 male patients with OSA and 15 obese male control subjects who were free of comorbidities. In addition, the effects of 3 months of treatment with nasal continuous positive airway pressure (nCPAP) on serum parameters were studied in 24 patients with moderate to severe OSA. MEASUREMENTS AND MAIN RESULTS: The percentage of SBI in patients with moderate to severe OSA (25.0%) was higher than that of obese control subjects (6.7%) or patients with mild OSA (7.7%). Serum levels of sCD40L and sP-selectin were significantly higher in patients with moderate to severe OSA than in obese control subjects (p < 0.05) or patients with mild OSA (p < 0.05). In addition, nCPAP significantly decreased serum levels of sCD40L (p < 0.03) and sP-selectin (p < 0.01) in patients with moderate to severe OSA. CONCLUSIONS: These results suggest that serum levels of sCD40L and sP-selectin are elevated and SBI is more common in patients with moderate to severe OSA, leading to elevated cerebrovascular morbidity. Moreover, nCPAP may be useful for decreasing risk in patients with moderate to severe OSA.

Increased carotid intima-media thickness and serum inflammatory markers in obstructive sleep apnea.

Increased carotid intima-media thickness (IMT) and increased serum levels of inflammatory markers, such as C-reactive protein (CRP), interleukin (IL)-6, and IL-18, are associated with an increased risk of cardiovascular and cerebrovascular diseases. The aim of this study was to evaluate whether carotid IMT, a useful marker for early atherosclerosis, is associated with these inflammatory markers in patients with obstructive sleep apnea (OSA). Carotid IMT was investigated with ultrasonography in 36 patients with OSA and 16 obese control subjects. Serum levels of CRP, IL-6, and IL-18 were measured at 5:00 A.M. Carotid IMT (p < 0.001) and serum levels of CRP (p < 0.003), IL-6 (p < 0.005), and IL-18 (p < 0.03) of patients with OSA were significantly higher than those of obese control subjects. Carotid IMT was significantly correlated with serum levels of CRP (r = 0.61, p = 0.0001), IL-6 (r = 0.41, p = 0.01), and IL-18 (r = 0.45, p = 0.005), duration of OSA-related hypoxia (r = 0.60, p = 0.0001), and severity of OSA (r = 0.50, p = 0.002). In addition, the primary factor influencing carotid IMT was duration of hypoxia during total sleep time (p = 0.036). These results suggest that OSA-related hypoxia and systemic inflammation might be associated with the progression of atherosclerosis and thus might increase the risks of cardiovascular and cerebrovascular morbidity in patients with OSA.

Elevated production of tumor necrosis factor-alpha by monocytes in patients with obstructive sleep apnea syndrome.

STUDY OBJECTIVES: Tumor necrosis factor (TNF)-alpha is involved in the pathogenesis of atherosclerosis. In the present study, we examined TNF-alpha production by monocytes, serum levels of TNF-alpha, and the effects of nasal continuous positive airway pressure (nCPAP) in patients with obstructive sleep apnea syndrome (OSAS). DESIGN: Prospective observational study. SETTING: University hospital. SUBJECTS: Twenty-four patients with OSAS, 15 obese control subjects, and 12 healthy subjects. MEASUREMENTS AND RESULTS: After polysomnography, venous blood was collected at 5 am. Spontaneous production of TNF-alpha by monocytes for 24 h and serum levels of TNF-alpha were investigated. In addition, patients with moderate-to-severe OSAS were treated with nCPAP for 1 month, and spontaneous production of TNF-alpha by monocytes and serum levels of TNF-alpha were also measured. Spontaneous production of TNF-alpha by monocytes was significantly higher in patients with moderate-to-severe OSAS than in patients with mild OSAS (p < 0.0001), obese control subjects (p < 0.0001), or healthy subjects (p < 0.0001). Serum levels of TNF-alpha were also significantly higher in patients with moderate-to-severe OSAS than in patients with mild OSAS (p < 0.03), obese control subjects (p < 0.0005), or healthy subjects (p < 0.0001). Duration of hypoxia during total sleep time was independently associated with spontaneous production of TNF-alpha by monocytes in patients with OSAS and healthy and obese control subjects. nCPAP significantly decreased spontaneous production of TNF-alpha by monocytes (p < 0.03) and serum levels of TNF-alpha (p < 0.05) in patients with moderate-to-severe OSAS. CONCLUSIONS: Spontaneous production of TNF-alpha by monocytes and serum levels of TNF-alpha are elevated in patients with moderate-to-severe OSAS but are decreased by nCPAP.

Increased levels and activity of matrix metalloproteinase-9 in obstructive sleep apnea syndrome.

Matrix metalloproteinases (MMPs) are involved in the pathogenesis of cardiovascular diseases. We examined serum levels of MMP-9 and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), activity of MMP-9, and the effect of nasal continuous positive airway pressure (nCPAP) in patients with obstructive sleep apnea syndrome (OSAS). After polysomnography, venous blood was collected at 5:00 A.M. from 44 patients with OSAS and 18 control subjects who were obese, and serum levels of MMP-9, TIMP-1, and enzymatic activity of MMP-9 were measured. In addition, the effects of 1 month of treatment with nCPAP were studied in patients with moderate to severe OSAS. Although serum levels of MMP-9 (p < 0.03) and MMP-9 activity (p < 0.01) were higher in patients with OSAS than in control subjects who were obese, TIMP-1 levels did not differ significantly. In patients with OSAS, the severity of OSAS was the primary factor influencing levels (p < 0.01) and activity (p < 0.01) of MMP-9. nCPAP significantly decreased serum levels (p < 0.01) and activity (p < 0.001) of MMP-9 but did not affect TIMP-1 levels. Therefore, OSAS may increase risks of cardiovascular morbidity, and nCPAP might be useful for decreasing these risks.

Elevated levels of C-reactive protein and interleukin-6 in patients with obstructive sleep apnea syndrome are decreased by nasal continuous positive airway pressure.

BACKGROUND: C-reactive protein (CRP) and interleukin (IL)-6 are important risk factors for atherosclerosis and coronary heart disease. In the present study, we examined serum levels of CRP and IL-6, IL-6 production by monocytes, and the effect of nasal continuous positive airway pressure (nCPAP) in patients with obstructive sleep apnea syndrome (OSAS). METHODS AND RESULTS: After polysomnography, venous blood was collected at 5 AM from 30 patients with OSAS and 14 obese control subjects. Serum levels of CRP and IL-6 and spontaneous production of IL-6 by monocytes were investigated. In addition, the effects of 1 month of nCPAP were studied in patients with moderate to severe OSAS. Levels of CRP and IL-6 were significantly higher in patients with OSAS than in obese control subjects (CRP P<0.001, IL-6 P<0.05). IL-6 production by monocytes was also higher in patients with OSAS than in obese control subjects (P<0.01). In patients with OSAS, the primary factors influencing levels of CRP were severity of OSAS and body mass index and those influencing levels of IL-6 were body mass index and nocturnal hypoxia. nCPAP significantly decreased levels of both CRP (P<0.0001) and IL-6 (P<0.001) and spontaneous IL-6 production by monocytes (P<0.01). CONCLUSIONS: Levels of CRP and IL-6 and spontaneous production of IL-6 by monocytes are elevated in patients with OSAS but are decreased by nCPAP. Therefore, OSAS is associated with increased risks for cardiovascular morbidity and mortality, and nCPAP may be useful for decreasing these risks.

Cross-over comparison between respiratory muscle stretch gymnastics and inspiratory muscle training.

OBJECTIVES: To compare the effect of respiratory muscle stretch gymnastics (RMSG), proposed as a possible additional form of rehabilitation for patients with chronic obstructive pulmonary disease (COPD), with that of inspiratory muscle training (IMT). PATIENTS: Twelve naive outpatients with COPD at a university hospital. METHOD: The patients performed IMT (2 sessions of 10 minutes of training at 30% of PImax, daily) for 4 weeks and RMSG (3 sessions of 5 RMSG patterns 4 times each, daily) for 4 weeks, in randomized order, with a 4-week washout period between the two interventions. MEASUREMENTS AND RESULTS: PImax increased with IMT (mean 66.1 to 79.1 cmH2O), but not with RMSG (mean 66.0 to 69.4 cmH2O). RMSG and IMT similarly increased maximum chest wall expansion. FRC was significantly decreased by 158 ml with RMSG, but not with IMT. There were no significant changes in VC, FEV1, or PEF nor in arterial blood gases with either form of rehabilitation. Six-minute walking distance was more significantly increased with RMSG (mean 383 to 430 m), than with IMT (mean 386 to 412 m). CONCLUSIONS: RMSG may have clinically significant benefits, which may be somewhat different from the benefits of IMT, in patients with COPD.

[Japanese cedar pollinosis is a risk factor for bronchial asthma in Japanese adult asthmatics].

It is well known that allergic rhinitis and asthma often coexist in the same patients. Here, we investigated the influence of Japanese cedar pollinosis on the exacerbation of asthma investigated by questionnaire, daily asthma diary, and peak expiratory flow (PEF) monitoring. Furthermore, airway responsiveness to histamine before pollen season was also investigated in some patients. 333 adult patients with asthma were enrolled into the study and 116 patients (34.8%) were suffering from Japanese cedar pollinosis diagnosed by the presence of nasal allergic symptoms during pollen season and high titer of Japanese cedar-specific IgE antibody. Exacerbation of asthma symptoms, including wheezing, dyspnea, cough, and sputum, was detected in 41 of 116 patients (35.3%) during pollen season. Decrease in morning PEF more than 10% compared with the baseline values before pollen season was observed in 13 of 41 patients (11.2% of total asthmatic patients who complicated with Japanese cedar pollinosis). No significant differences in airway responsiveness to histamine and the titer of Japanese cedar-specific IgE antibodies before pollen season were observed between the patients whose asthma exacerbated and the patients whose asthma was not exacerbated. These results suggest that Japanese cedar pollinosis is one of risk factors for asthma in Japanese adult patients with asthma.

Reduction of eosinophilic inflammation in the airways of patients with asthma using montelukast.

OBJECTIVE: Leukotrienes (LTs) are involved in airway eosinophilic inflammation in patients with asthma. We examined the effects of a cysteinyl LT 1-receptor antagonist, montelukast, on sputum eosinophil levels, and the correlation between sputum eosinophils and bronchodilatation in patients with asthma. DESIGN: Double-blind, randomized, crossover study. SETTING: University hospital and private hospital. PATIENTS: Twenty-nine patients with mild-to-moderate asthma. INTERVENTIONS: Montelukast, 10 mg, and placebo tablet, once daily, each for 4 weeks. MEASUREMENTS: Sputum eosinophils analyzed using hypertonic saline solution-induced sputum and airway hyperresponsiveness to histamine were evaluated before and after treatment. In addition, morning and evening peak expiratory flow (PEF), asthma symptoms, and peripheral blood eosinophil levels were assessed. RESULTS: The percentage of eosinophils in sputum decreased from 24.6 +/- 12.3% at baseline to 15.1 +/- 11.8% after montelukast treatment, for a change of - 9.5 +/- 12.7% (n = 20). During placebo administration, the percentage of eosinophils fell from 21.3 +/- 12.1% to 21.0 +/- 11.5%, resulting in a decrease of - 0.3 +/- 10.8% (n = 20). There was a statistically significant difference in the change in sputum eosinophil levels between these two periods (p < 0.005). The number of peripheral blood eosinophils also significantly decreased after montelukast treatment (314.1 +/- 237.6/mL) compared with placebo (413.1 +/- 232.1/mL; p < 0.005, n = 21). Although morning and evening PEF values were significantly improved from baseline after montelukast treatment (p < 0.01, n = 20), asthma symptoms and airway responsiveness to histamine were not significantly altered. Furthermore, there was no significant correlation between the decrease in sputum eosinophils and the increase in PEF. CONCLUSION: These results suggest that montelukast has anti-inflammatory effects on the airway in patients with asthma, and that its bronchodilatory effect is not solely dependent on a decrease in airway eosinophilia.