Correction: Continuous Positive Airway Pressure Treatment Reduces Mortality in Elderly Patients with Moderate to Severe Obstructive Severe Sleep Apnea: A Cohort Study.

[This corrects the article DOI: 10.1371/journal.pone.0127775.].

Continuous Positive Airway Pressure Treatment Reduces Mortality in Elderly Patients with Moderate to Severe Obstructive Severe Sleep Apnea: A Cohort Study.

Obstructive sleep apnea (OSA) is much more prevalent in older people than in middle-aged or young populations, and has been associated with cardiovascular disease. Continuous positive airway pressure (CPAP) is the first-line therapy for OSA, but its long-term clinical benefit in the elderly is unclear. Here, we carried out a prospective cohort study to explore the survival rate and incidence of cardiovascular events in elderly patients with moderate to severe OSA who did or did not receive CPAP treatment. The study included 130 patients (104 male, 26 female; mean age: 77.8 ± 6.2 years) who were followed up for a mean of 5 ± 2.54 years (range, 1-8 years). Thirty-six patients received CPAP and 88 had no CPAP. The results showed that mortality in the untreated group (21.6%) was significantly higher than in the CPAP group (5.6%). Kaplan-Meier survival analysis showed that the survival rate in the CPAP group was 94.4%, which was markedly higher than the rate of 78.4% in the untreated group. The incidence of cardiovascular events was 13.9% in the CPAP group and 55.7% in the untreated group. The present study provides evidence that CPAP can reduce mortality in older patients with moderate to severe OSA, and lead to a good long-term prognosis. The study also indicates that death in older OSA patients is associated with cardiovascular disease and diabetes.

[Investigation on long-term efficacy of CPAP treatment for the elderly with obstructive sleep apnea syndrome].

OBJECTIVE: To investigate the long-term efficacy of continuous positive airway pressure (CPAP) treatment for the elderly with obstructive sleep apnea syndrome (OSAS). METHODS: Case control study was performed among 106 elderly with obstructive sleep apnea syndrome (OSAS). They were divided into treatment group (n=34) and control group (n=72), based on whether they underwent long-term CPAP treatment or not. The long-term efficacy of CPAP treatment was evaluated by long-term clinical observation. RESULTS: The incidence of cardiovascular events was 12% (4/34) in treatment group and 47% (34/72) in control group (P<0.01). Kaplan-Meier survival analysis showed that after controlling the factors of age, sex, body mass index, apnea hypopnea index and previous diseases, failing to receive CPAP treatment was the independent risk factor for cardiovascular events (chi2=17.0, P<0.01). CONCLUSIONS: CPAP treatment for moderate-severe OSAS could reduce cardiovascular and neurovascular events risk for elderly patients with OSAS.

[Effects of acute cerebral ischemia on cerebral perfusion: quantitative evaluation by contrast-enhanced ultrasound in dogs].

OBJECTIVE: To evaluate the changes of cerebral blood flow (CBF) with real-time contrast-enhanced ultrasound (CEU) in a canine model of acute cerebral ischemia. METHODS: Cerebral perfusion was assessed in 6 dogs subjected to craniotomy with CEU at the time of 0, 30, 60, 90 and 120 min after occlusion of the left common carotid artery (LCCA). The microvascular volume (A) and blood flow velocity (beta) in the brain were measured from the time-versus-acoustic intensity plots, and the value of Axbeta were calculated. 99mTc-ECD brain single photon emission computed tomography (SPECT) was performed on the day before the experiment and at 120 min after LCCA occlusion. The radioactive counts on both sides of the cerebral cortex were calculated. RESULTS: A significant correlation was found between Axbeta from CEU and volume of the blood flow of the CCA from Doppler flowmetry. A, beta and Axbeta values varied significantly between the different time points (P>0.001). The ipsilateral hemisphere showed a low-perfusion state while the contralateral hemisphere showed a high-perfusion state immediately after the occlusion. CONCLUSIONS: The changes of beta is the main regulation mechanism during acute cerebral ischemia in dogs.

[Effect of obstructive sleep apnea syndrome on blood lipid and blood glucose in elderly hypertensive patients].

OBJECTIVE: To investigate the effect of obstructive sleep apnea syndrome (OSAS) on blood lipid and blood glucose in elderly hypertensive patients. METHOD: a One hundred and seven elderly hypertensive patients received examinations by polysomnography and according to the apnea-hypopnea index (AHI), the patients were divided into four groups, namely uncomplicated hypertension group (n=23) and 3 hypertension groups with mild (n=31), moderate (n=29) and severe (n=24) OSAS. The fasting and 2-hour postprandial plasma glucose, glycosylated hemoglobin (HbA1c), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), Apo-A, and Apo-B of these patients were measured. RESULTS: aCompared with the non-OSAS patients, all the OSAS patients showed increased fasting and 2-hour postprandial plasma glucose, HbA1c, TC, TG, LDL and TC/HDL, and the increments were statistically significant in severe OSAS patients (P<0.05). The level of HDL was lowered in the OSAS groups, showing significant difference between severe OSAS group and the non-OSAS group (P<0.05). Apo-A level was lowered and Apo-B increased in the OSAS groups, but the differences were not statistically significant (P>0.05). CONCLUSIONS: OSAS may produce harmful affect on the blood glucose and blood lipids in elderly hypertensive patients.

[Relationship between chronic congestive heart failure and sleep-disordered breathing in elderly patients].

OBJECTIVE: To determine the prevalence of sleep disordered breathing (SDB) in elderly patients with chronic congestive heart failure (CHF) and explore the relations between SDB and left ventricular function. METHODS: By means of polysomnography, 56 elderly patients with CHF were divided into non-SDB, mild SDB, moderate SDB, and severe SDB groups, and the left ventricular ejection fraction (LVEF) was measure by (99)Tc equilibrium radionuclide angiography. RESULTS: In the 56 elderly patients with CHF, 38 (67.9%) had SDB, including 12 (21.4%) mild SDB, 14 (25.0%) moderate SDB, and 12 (21.4%) severe SDB patients. Thirty (53.6%) of the 56 patients with CHF had obstructive sleep apnea (OSA), 4 (7.1%) had central sleep apnea and 22 (39.2%) had mixed sleep apnea. The moderate and severe SDB groups had lower minimum arterial oxyhemoglobin saturation during sleep than the non-SDB groups, and the apnea-hyponea index was closely related to LVEF (r=-0.74, P<0.01). CONCLUSION: The prevalence of SDB, predominantly OSA, is high in elderly patients with CHF. Moderate and severe SDB might affect the left ventricular function in these patients, who require polysomnography monitoring.