Effect of uvulopalatopharyngoplasty on work of breathing during wakefulness in obstructive sleep apnea syndrome

OBJECTIVES: We evaluated the effects of uvulopalatopharyngoplasty (UPPP) on the work of breathing (WOB) in obstructive sleep apnea syndrome (OSAS). METHODS: Fifteen healthy subjects and 30 subjects with OSAS who desired UPPP were prospectively enrolled. All underwent measurement of WOB while awake as well as in a sleep study. These studies were repeated 3 months after UPPP in the patients with OSAS. RESULTS: In OSAS before UPPP, the WOB while supine was increased above that of normal subjects. After UPPP, the WOB while supine remained elevated in those whose OSAS did not respond to surgery, and it returned to normal levels in patients whose OSAS improved after UPPP. CONCLUSIONS: Abnormal WOB in patients with OSAS returns to normal if UPPP results in amelioration of OSAS.     

Imbalanced plasma ACE and ACE2 level in the uremic patients with cardiovascular diseases and its change during a single hemodialysis session

Background: The renin-angiotensin system (RAS) has significant influences on heart and renal disease progression. Angiotensin converting enzyme (ACE) and angiotensin converting enzyme II (ACE2) are major peptidases of RAS components and play counteracting functions through angiotensin II (Ang II)/ATIR and angiotensin-(1–7) (Ang-(1–7))/Mas axis, respectively.

Methods: There were 360 uremic patients on regular hemodialysis (HD) treatment (inclusive of 119?HD patients with cardiovascular diseases (CVD) and 241?HD patients without CVD and 50 healthy subjects were enrolled in this study. Plasma ACE, ACE2, Ang II and Ang-(1–7) levels of the HD patients were determined.

Results: We compared pre-HD levels of plasma ACE, ACE2, Ang II and Ang-(1–7) in the HD patients with and without CVD to those of the controls. The HD patients, particularly those with CVD, showed a significant increase in the levels of ACE and Ang II, whereas ACE2 and Ang-(1–7) levels were lower than those in the healthy controls. Therefore, imbalanced ACE/ACE2 was observed in the HD patients with CVD. In the course of a single HD session, the plasma ACE, ACE/ACE2 and Ang II levels in the HD patients with CVD were increased from pre-HD to post-HD. On the contrary, ACE2 levels were decreased after the HD session. These changes were not detected in the HD patients without CVD.

Conclusions: Pathogenically imbalanced circulating ACE/ACE2 was detected in the HD patients, particularly those with CVD. HD session could increase ACE/Ang II/AT1R axis and decrease ACE2/Ang-(1–7)/Mas axis activity in the circulation of HD patients with CVD.     

A novel intermittent negative air pressure device ameliorates obstructive sleep apnea syndrome in adults

Purpose

Patients with obstructive sleep apnea syndrome (OSAS) have difficulties in compliance with continuous positive airway pressure (CPAP) and the treatment outcome is heterogeneous. We proposed a proof-of-concept study of a novel intermittent negative air pressure (iNAP®) device for physicians to apply on patients who have failed or refused to use CPAP.

Methods

The iNAP® device retains the tongue and the soft palate in a forward position to decrease airway obstruction. A full nightly usage with the device was evaluated with polysomnography. Subgrouping by baseline apnea–hypopnea index (AHI) and body mass index (BMI) with different treatment response criteria was applied to characterize the responder group of this novel device.

Results

Thirty-five patients were enrolled: age 41.9?±?12.2 years (mean?±?standard deviation), BMI 26.6?±?4.3 kg/m², AHI 41.4?±?24.3 events/h, and oxygen desaturation index (ODI) 40.9?±?24.4 events/h at baseline. AHI and ODI were significantly decreased (p?<?0.001) by the device. Patients with moderate OSAS, with baseline AHI between 15 to 30 events/h, achieved 64% response rate; and non-obese patients, with BMI below 25 kg/m², achieved 57% response rate, with response rate defined as 50% reduction in AHI from baseline and treated AHI lower than 20. There were minimal side effects reported.

Conclusions

In a proof-of-concept study, the device attained response to treatment as defined, in more than half of the moderate and non-obese OSAS patients, with minimal side effects.

     

Triggering receptor expressed on myeloid cells-1 in pleural effusions: a marker of inflammatory disease

BACKGROUND: Triggering receptor expressed on myeloid cells (TREM)-1 is a recently described molecule that plays an important role in myeloid cell-activated inflammatory responses. The aim of this study was to investigate the expression of TREM-1 in pleural effusions of various causes. METHODS: For this cross-sectional, observational study conducted between February and August 2005 in Taiwan, 74 patients with pleural effusions of varying etiology were investigated. Soluble TREM-1 (sTREM-1) was measured in pleural fluid samples, and cells in the fluid were assessed for surface expression of TREM-1. RESULTS: Concentrations of sTREM-1 were significantly higher in infectious and neoplastic pleural effusions (189.1+/-36.7 and 69.9+/-22.8ng/ml, mean+/-sem) than in transudates (10.1+/-5.3ng/ml; P<0.001). Among infectious effusions, the sTREM-1 levels were significantly higher in parapneumonic than in tuberculous effusions (301.8+/-49.8 vs. 38.9+/-17.3ng/ml; P<0.001). TREM-1 was expressed on a portion of the myeloid (CD11b positive) cells in each type of effusion, without significant differences among them (transudative, 34.7%; neoplastic, 36.0%; parapneumonic, 27.7%; tuberculous, 21.2%; P=0.861). Non-myeloid cells expressed very little TREM-1 (transudative, 6.3%; neoplastic, 0.5%; parapneumonic, 1.0%; tuberculous, 0.7%; P=0.192). CONCLUSIONS: sTREM-1 expression in pleural fluids is highest in parapneumonic and neoplastic effusions but low in transudates. In infectious effusions, a high concentration of sTREM-1 may exclude tuberculous pleurisy.     

Cardiopulmonary exercise testing in obstructive sleep apnea syndrome

To investigate whether cardiac dysfunction or abnormal measurements on cardiopulmonary exercise testing (CPET) are present in patients with obstructive sleep apnea syndrome (OSAS) and what factors are responsible for exercise limitation in these patients. We enrolled 20 patients with moderate or severe OSAS in the OSA group and 20 subjects without OSAS in the control group. All subjects underwent a sleep study and cardiac evaluation by radionuclide scanning and CPET. There was no difference in left ventricular ejection fraction (VEF) between the two groups, but the OSA group had a lower right VEF. Patients in the OSA group had a lower VO2(peak), VO2(peak/kg) and workpeak than the control group. The OSA group had a higher breathing reserve and a greater decrease in anaerobic threshold (AT) and oxygen pulse. In conclusion, patients with moderate to severe OSAS had abnormal CPET results. These abnormalities may be due to cardiac disease, pulmonary vascular disease, or possible lack of fitness.