Injection of L-glutamate into the insular cortex produces sleep apnea and serotonin reduction in rats.

PURPOSE: Obstructive sleep apnea (OSA) is primarily characterized by repetitive episodes of complete or partial obstruction of airflow during sleep. The neuronal and cellular mechanisms underlying this process are not fully understood, although the focus of some studies is on putative serotonin (5-HT) mechanisms, and serotonergic therapy may be beneficial to OSA patients. This study aimed to demonstrate possible changes in 5-HT associated with induction of OSA in a rat model. METHODS: Apnea was induced in rats by injection of L-glutamate (L-Glu) into the insular cortex. We examined changes in: (1) simultaneous genioglossus and diaphragm EMG activity; and (2) peripheral and cerebral levels of 5-HT, by histology. RESULTS: Injection of L-glutamate (L-Glu) into the insular cortex induced apnea in the rats. L-Glu stimulation of the insular cortex also produced significant reductions in plasma 5-HT levels and the expression of 5-HT in the brainstem. In addition, lower activity was observed in the GG and a higher activity was observed in the diaphragm, as compared to controls. CONCLUSION: Data indicate that L-Glu stimulation of the insular cortex simulates the electrical activity of the genioglossus muscle and diaphragm in sleep apnea, and contributes to reduced peripheral and cerebral 5-HT levels in rats. The results of our study suggest that 5-HT may play a role in the pathogenesis of OSA.

Mal-effects of obstructive sleep apnea on the heart.

OBJECTIVE: This study aims to examine the impact of chronic intermittent hypoxia on hearts in patients with obstructive sleep apnea (OSA). METHODS: Two hundred twenty patients were divided into groups based on (1) severity of the disease, (2) years of disease history, and (3) with or without secondary hypertension. All subjects underwent blood pressure measurements, polysomnogram monitoring, and cardiac Doppler ultrasound examinations. RESULTS: The left ventricular ejection fraction (LVEF), fractional shortening (FS), and the ratio of early to late diastolic filling (E/A) in patients with severe OSA were lower than in those with moderate OSA and in healthy controls. The inner diameters of the main pulmonary artery (inD of MPA), the inner diameters of the right cardiac ventricle (inD of RV), and the thickness of anterior wall of the right ventricle (TAW of RV) were increased in patients with severe OSA compared to those with moderate disease and worsened as a function of time with disease. The tissue Doppler imaging-derived Tei index and pulmonary artery systolic pressure were also increased along with the severity of OSA. LVEF and FS in patients who had suffered from OSA for >10 years were decreased compared with those suffering from OSA for a shorter time. LVEF and FS in patients with secondary hypertension were decreased significantly relative to non-hypertensive OSA patients and healthy controls. E/A was decreased in OSA patients whether they had secondary hypertension or not. CONCLUSION: OSA affected the left ventricular diastolic function in the early stage of the disease. Extended exposure to OSA resulted in left ventricular dysfunction with increased hypertension. Right ventricle dysfunction and abnormalities became more severe as the disease progressed.

[The observation of the influence about blood pressure and cardiovascular B ultrasonic wave by chronic intermittent hypoxia].

OBJECTIVE: To investigate the influence of left heart function in obstructive sleep apnea by CIH, and explore left heart function and blood pressures before or after CPAP. METHODS: 75 OSA were divided into two groups: 40 patients blood pressures were coincident with diagnostic standard of hypertension recording; 35 patients blood pressures were non-hypertension recording. The control group included 30. healthy adults. The blood pressures before and also after sleep, left ventricular ejection fraction (LVEF), shortening fraction (FS), E, A and E/A were compared with those of normal control subjects. Analyzed BP, LVEF and E/A after CPAP. RESULTS: (1) The blood pressure soon after getting up in the morning (150.80+/-20.73/108.0+/-15.34) mm Hg (1 mm Hg=0.133 kPa) was significantly higher than that before sleep (134.16+/-18.33/90.09+/-11.24) mm Hg (P<0.001). (2) Multiple parameters including LVEF, FS and E/A, were impaired in OSA patients relative to the control subjects (P<0.05 or P<0.01), OSA affected cardiovascular function directly; E/A was significantly decreased in obstructive sleep apnea unallied hypertension than that in normal control subjects; E/A was conspicuously decreased in obstructive sleep apnea associated hypertension comparing with that in obstructive sleep apnea unallied hypertension. These showed OSA affected cardiovascular function directly, hypertension aggravated the drop in cardiovascular function. 3. After CPAP in 6 months, it (142.59+/-15.34/96.52+/-9.81) mm Hg was significantly decreased than that before treatment (150.80+/-20.73/108.0+/-15.34) (P<0.001); LVEF (59.70+/-11.1)% was increased than that before treatment (56.40+/-9.74)% (P<0.05) and E/A 1.16+/-0.25 was increased. Than that before treatment 0.87+/-0.17 (P<0.01). CONCLUSION: (1) CIH may affect left heart structure and function; these changes were aggravated with hypertension. (2) CPAP treatment had important sense in the treatment of hypertension and cardiovascular function, and improved the life quality.

Correction of nonvertex presentation with moxibustion: a systematic review and metaanalysis.

We searched systematically for randomized controlled trials, comparing moxibustion with a nonmoxibustion control group or other methods such as external cephalic version, postural methods, and acupuncture in databases, both Western and Chinese, up to June 2007. Six studies, with 1087 subjects and a high degree of heterogeneity, compared moxibustion vs observation or postural methods and reported a rate of cephalic version among the moxibustion group of 72.5% vs 53.2% in the control group (relative risk, 1.36; 95% confidence interval, 1.17-1.58); the number needed to treat was 5 (95% confidence interval, 4-7). In terms of safety, no significant differences were found in the comparison of moxibustion with other techniques. Moxibustion at acupuncture point BL67 has been shown to produce a positive effect, whether used alone or in combination with acupuncture or postural measures, in comparison with observation or postural methods alone, for the correction of nonvertex presentation, although these results should be viewed with caution, given the considerable heterogeneity found among studies.

[Effects of obstructive sleep apnea-hypopnea syndrome upon cardiac structure and function].

OBJECTIVE: To investigate the effects of obstructive sleep apnea-hypopnea syndrome (OSAHS) upon cardiac structure and function of patients. METHODS: According to apnea hypopnea index, 75 OSAHS patients were divided into three groups: mild (n = 25), moderate (n = 25) and serious (n = 25); according to the course of disease, < 5 years (n = 22), 5-10 years (n = 26) and > 10 years (n = 27). The control group included 25 healthy adults. All subjects received polysomnogram and echocardiography. The following parameters were recorded: aortic dimension, pulmonary artery inner diameter, chambers heart size, interventricular septal thickness, anterior wall thickness and movement extent of end-diastole right ventricle, left ventricular ejection fraction (LVEF), shortening fraction (FS) and E/A ratio, etc. RESULTS: Pulmonary artery inner diameter of mild, moderate, serious and control groups were (21.4 +/- 2.5), (24.7 +/- 2.0), (26.7 +/- 2.1), (21.2 +/- 2.7) mm, right ventricle internal diameter (19.0 +/- 1.8), (22.0 +/- 2.1), (23.9 +/- 2.1), (18.9 +/- 1.8) mm, and anterior wall thickness of right ventricle (4.7 +/- 1.2), (6.5 +/- 1.3), (7.5 +/- 1.4), (4.1 +/- 1.0) mm. The moderate and serious groups were all higher than control and mild groups obviously (P < 0.01). The serious group was higher than the moderate group (P < 0.01). LVEF of four groups: (63.1 +/- 8.1)%, (60.0 +/- 10.2)%, (54.5 +/- 9.1)%, (63.6 +/- 7.7)%, FS: (38.1 +/- 4.3)%, (37.0 +/- 6.4)%, (33.6 +/- 5.4)%, (39.5 +/- 4.9)%, and E/A: (1.13 +/- 0.13), (0.96 +/- 0.16), (0.85 +/- 0.12), (1.28 +/- 0.15). LVEF and FS of the serious group were lower than those of the control, mild and moderate groups (P < 0.05). E/A ratio of the mild, moderate and serious groups were lower than the control group (P < 0.01). The interclass comparison of mild, moderate and serious groups had significant differences (P < 0.01). Right ventricle internal diameter, pulmonary artery inner diameter, anterior wall thickness of right ventricle of > 10 years group were higher than 5-10 years group obviously (P < 0.05, P < 0.01). The 5-10 years group was higher than the < 5 years and control groups obviously (P < 0.05, P < 0.01). LVEF, FS, and E/A ratio of > 10 years group were lower than 5-10 years, < 5 years and control groups obviously (P < 0.05, P < 0.01). CONCLUSION: OSAHS causes structural and functional cardiac changes worsening with disease aggravation and course extension.

[The prevalence of obstructive sleep apnea-hypopnea syndrome in adults aged over 20 years in Changchun city].

OBJECTIVE: To investigate the prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in adults aged over 20 years in Changchun city, providing epidemiological data for treatment and prevention of the disease. METHODS: 3,960 subjects were derived from a stratified cluster and random sampling of the population in two districts of Changchun city. They were asked to answer the questions from a questionnaire in their houses. According to the degree of snoring, 200 subjects with a snoring score >or= 2 degree were selected to undergo polysomnography for a whole night and the prevalence of the disease was estimated. RESULTS: A total of 3,648 (97.64%) validated questionnaires was collected. Of them 31.00% had a snoring score >or= 2 degree, the prevalence was higher in males (40.07%) than in females (21.76%). The prevalence of snoring was higher in drivers (42.47%) than in other occupations. The estimated prevalence of OSAHS defined by apnea-hypopnea index (AHI) >or= 5, Epworth sleepiness scale (ESS) >or= 9 and arterial oxygen saturation (SaO(2)) < 90% was 4.81%. CONCLUSIONS: The estimated prevalence of OSAHS in adults aged over 20 years in Changchun city was 4.81%. Doctors should pay more attention to the disease and the ordinary people should be informed of the health impact of snoring and OSAHS.

A case-control study on children with Guillain-Barre syndrome in North China.

OBJECTIVE: To explore the risk factors for Guillain-Barre syndrome. METHODS: Case-control study design was used in 51 cases of Guillain-Barre syndrome, and 51 matched controls. All of the 51 cases in this study had been examined by electrophysiology. Serum IgG antibodies specific for C. jejuni were determined in all the subjects by ELISA. Each case and control were interviewed using an ad hoc questionnaire, including his/her demographic information, onset of the illness, their personal hygiene and so on. RESULTS: The study showed that Guillain-Barre syndrome was associated with a few factors, such as polio vaccine immunization before onset of illness (OR=7.27), no hand washing after defecation and before meals (OR=6.15). Infection of C. jejuni was strongly associated with the illness (OR=9.5, P<0.001). CONCLUSION: It is suggested that occurrence of Guillain-Barre syndrome may correlate to infection of C. jejuni and poor personal hygiene in children.