Analysis of the Ischemia-Modified Albumin as a Potential Biomarker for Cardiovascular Damage in Obstructive Sleep Apnea Patients with Acute Coronary Syndrome

Obstructive sleep apnea (OSA) has been identified as a cardiovascular (CV) risk factor. The potential of OSA promoting the synthesis of CV biomarkers in acute coronary syndrome (ACS) is unknown. Ischemia-modified albumin (IMA) has been identified as a specific CV biomarker. The aim of this study was to evaluate the role of IMA as a potential biomarker for determining the impact of OSA in ACS patients. A total of 925 patients (15.5% women, age: 59 years, body mass index: 28.8 kg/m²) from the ISAACC study (NCT01335087) were included. During hospitalization for ACS, a sleep study for OSA diagnosis was performed and blood samples extraction for IMA determination were obtained. IMA values were significantly higher in severe OSA (median (IQR), 33.7 (17.2-60.3) U/L) and moderate (32.8 (16.9-58.8) U/L) than in mild/no OSA (27.7 (11.8-48.6) U/L) (p = 0.002). IMA levels were very weakly related to apnea-hypopnea index (AHI) as well as hospital and intensive care unit stay, although they only maintained a significant relationship with days of hospital stay after adjusting for sex, age and BMI (ß = 0.410, p = 0.013). The results of the present study would suggest a potentially weaker role of OSA in the synthesis of the CV risk biomarker IMA in patients with ACS than in primary prevention.

Chronic obstructive pulmonary disease as a cardiovascular risk factor. Results of a case-control study (CONSISTE study)

Introduction

Chronic obstructive pulmonary disease (COPD) patients present a high prevalence of cardiovascular disease. This excess of comorbidity could be related to a common pathogenic mechanism, but it could also be explained by the existence of common risk factors. The objective of this study was to determine whether COPD patients present greater cardiovascular comorbidity than control subjects and whether COPD can be considered a risk factor per se.

Methods

1200 COPD patients and 300 control subjects were recruited for this multicenter, cross-sectional, case–control study.

Results

Compared with the control group, the COPD group showed a significantly higher prevalence of ischemic heart disease (12.5% versus 4.7%; P < 0.0001), cerebrovascular disease (10% versus 2%; P < 0.0001), and peripheral vascular disease (16.4% versus 4.1%; P < 0.001). In the univariate risk analysis, COPD, hypertension, diabetes, obesity, and dyslipidemia were risk factors for ischemic heart disease. In the multivariate analysis adjusted for the remaining factors, COPD was still an independent risk factor (odds ratio: 2.23; 95% confidence interval: 1.18–4.24; P = 0.014).

Conclusion

COPD patients show a high prevalence of cardiovascular disease, higher than expected given their age and the coexistence of classic cardiovascular risk factors.

Benefits at 1 year of nocturnal intermittent positive pressure ventilation in patients with obesity-hypoventi lation syndrome

BACKGROUND

Patients with the obesity-hypoventilation syndrome (OHS) benefit from non-invasive ventilatory support. We assessed the long-term physiopathological response to 12-months of nocturnal ventilatory assistance at home with bi-level positive airway pressure (BiPAP) via nasal mask in patients with this disease.

METHODS

A series of 13 non-consecutive patients diagnosed of OHS (5 men and 8 women) with a mean (SD) age of 61.9 (8) years, underwent the following studies before (baseline) and after 12 months of non-invasive domiciliary mechanical ventilation: arterial blood gases, nocturnal digital pulse oximetry, spirometry, body plethysmography, maximum muscular respiratory pressures and ventilatory pattern with measurement of occlusion pressure (P0.1) before and after hypercapnia. An overnight cardiorespiratory polygraphy was done at baseline.

RESULTS

After 12 months of non-invasive mechanical ventilation, there were significant (P < 0.05) reductions of arterial carbon dioxide tension (PaCO2) and increases in arterial oxygen tension, forced vital capacity and ventilatory response to hypercapnia, as measured by the relationship between changes of P0.1 and PaCO2 (deltaP0.1 / deltaPaCO2) as well as respiratory minute volume (V(E)) and PaCO2 (deltaV(E) / deltaPaCO2). Changes of the PaCO2 correlated significantly with those in the (deltaP0.1 / deltaPaCO2) slope (r = 0.576, P < 0.05).

CONCLUSIONS

The present results confirm that non-invasive home mechanical ventilation is an effective approach for long-term treatment of OHS.

Utility of transfer factor to detect different bronchodilator responses in patients with chronic obstructive pulmonary disease

Previous studies have described that there are different types of disease in patients with established chronic obstructive pulmonary disease (COPD) with different clinical course and functional responses. The aim of this study was to evaluate if the presence of low transfer factor (LTF) values can predict the effectiveness of bronchodilator therapy, and to assess whether this group has different risk factors that may be related with the responses. Eighty patients with COPD were evaluated on three occasions. Initial assessment included a standard respiratory questionnaire, blood analysis, skin prick test and baseline lung function, all performed on the first visit. Bronchodilator response was evaluated after low (0.2 mg) and high (1 mg) doses of salbutamol, and after 2 weeks of oral prednisone. In patients with normal TLCO/VA % (NTF), a higher proportion of subjects with previous history of atopy was the only statistically significant difference compared to those with LTF (odds ratio 4.33; 95% confidence interval 1.06-25.15). Although the mean response in forced expiratory volume in 1 s (FEV1) to treatment was analogous in both groups, when bronchodilation was expressed as percent of predicted, there was a clear trend to a lower response in patients with LTF (0.2 mg salbutamol: 6.99 +/- 5.64 vs. 8.94 +/- 6. 61, p = 0.15; 1 mg salbutamol: 10.18 +/- 6.37 vs. 13.45 +/- 7.90, p < 0.05; oral prednisone: 5.51 +/- 6.94 vs. 8.74 +/- 10.81, p = 0.06). The percentage of patients who had >12% improvement from that predicted in FEV1 was also lower in this group (42 vs. 72%; p < 0. 05). Moreover, TLCO/VA% was significantly lower in those subjects with a negative bronchodilator trial with salbutamol (68 +/- 25 vs. 81 +/- 26; p < 0.05) and prednisone (69 +/- 26 vs. 90 +/- 22; p < 0. 01). In patients with LTF and NTF, airway responsiveness was only significantly related with basal airflow limitation (LTF, r = 0.44; NTF, r = 0.38). All other interaction terms were not statistically significant. These results indicate that in patiens with similar serverity of COPD, the presence of LTF indicates a decreased probability of a positive bronchodilator response, probably reflecting different pathological lesions. We suggest that transfer factor should be taken into consideration when bronchial response is evaluated in large clinical trials.

Utility of complete dead space washout by real-time gas analysis in the measurement of transfer factor in patients with chronic airflow limitation

Chronic obstructive pulmonary disease (COPD) is associated with impaired gas mixing and increased dead space, but little is known about the effect of improving alveolar gas sample by complete correction of dead space in an attempt to significantly improve the final result of transfer factor compared with standard guidelines of the European Respiratory Society (ERS) and American Thoracic Society (ATS). By using a rapid infrared analyzer, TLCO was measured by the single breath method in 152 COPD patients at different stages of severity (FEV1:57% predicted; CI 95%:24-91). Standard washout volume of 0.75 liter was insufficient to clear phases I and II in 36 patients (23.7%). In 19 subjects (12.5%), a washout volume larger than 1 liter was necessary for complete dead space clearance, although in these patients, correction visually adequate to complete clear phases I and II resulted in higher TLCO values. Only in 5 patients (3.3%) did the final result change by more than 5% from the previous value. A vital capacity higher than 3 liters, rather than the degree of airflow limitation was a better predictor for larger washout volume requirements. We conclude that in the measurement of TLCO by the breathholding method, ERS and ATS recommendations for washout volume can be safely used for clinical purposes in a wide range of patients with mild to severe obstruction.

[Dysfunction of the upper respiratory airways in patients with essential tremor]

OBJECTIVES

To investigate pulmonary function abnormalities in essential tremor.

METHODS

We obtained maximal inspiratory and expiratory flow-volume curves in 41 unselected patients with essential tremor (14 males, 27 females, age 61.7 +/- 2.14 years). Severity of essential tremor was evaluated using the Fahn, Tolosa and Marin clinical scale.

RESULTS

Sixteen patients (39.0%) had flow oscillations on the flow-volume curves (8 only during inspiration, 7 during inspiration and expiration, and 1 with flow oscillations during inspiration and obstructive pattern). The duration and severity of the essential tremor did not influence the pattern of the curve, but abnormal curves were more frequent in patients with voice tremor. Although there were a number of significant correlations between essential tremor scales and spirographic parameters, they were of very low range. Four patients (9.8%) fulfilled criteria for physiological upper airway obstruction: 2 had smooth flow-volume loop contour and 2 had flow oscillations in inspiration and expiration.

CONCLUSION

Abnormalities in flow-volume loop contour are a usual finding in essential tremor. This probably reflects involvement of the upper airway musculature, that in some patients can produce clinical upper airway obstruction.

Severe upper airway obstruction in essential tremor presenting as asthma

A 57 year old man with essential tremor (ET) presented with a 2 year history of paroxysmal attacks of dyspnoea and wheezing. He had been diagnosed as having bronchial asthma, and propanolol was excluded from his treatment. Flow-volume loops showed abrupt changes in maximum flows, with poor reproducibility. A diagnosis of functional upper airway obstruction was confirmed by fibreoptic bronchoscopy. The importance of establishing the precise diagnosis, in order to provide appropriate treatment, is emphasized.

Severe upper airway obstruction in essential tremor presenting as asthma

A 57 year old man with essential tremor (ET) presented with a 2 year history of paroxysmal attacks of dyspnoea and wheezing. He had been diagnosed as having bronchial asthma, and propanolol was excluded from his treatment. Flow-volume loops showed abrupt changes in maximum flows, with poor reproducibility. A diagnosis of functional upper airway obstruction was confirmed by fibreoptic bronchoscopy. The importance of establishing the precise diagnosis, in order to provide appropriate treatment, is emphasized.

Airway dysfunction in patients with Parkinson's disease

To investigate pulmonary function abnormalities in Parkinson's disease (PD), we obtained maximal inspiratory and expiratory flow-volume curves in 63 patients (59 under treatment) with different stages of the disease, not filtered for respiratory symptoms. PD severity was evaluated by the Unified PD Rating Scale, the Webster's scale, and Hoehn and Yahr staging. Patients with more severe PD had lower percentage forced vital capacity (FVC%), and peak inspiratory and expiratory flows. Those with fluctuations and/or dyskinesias had lower FVC% and percentage forced expiratory flow volume in 1 sec (FEV1%). There were a number of weak but significant correlations between PD scales and spirographic parameters. Thirty one patients (49.2%) had pathological flow-volume curves. The clinical profile and the duration of the disease did not influence the pattern of the curve. Physiologic evidence of upper airway obstruction was observed in 3 cases. A spirometric restrictive ventilatory defect (FEV1/FVC higher than or equal to 80%) was observed in 54 patients (85%), while generalized airway obstruction was present only in one nonsmoker. We conclude that abnormal flow-volume loop contour is a frequent finding in PD. This probably reflects involvement of the upper airway musculature, that in some patients can produce upper airway obstruction. Generalized airflow limitation is not an important characteristic of PD. By contrast, a restrictive spirometric defect, probably due to incoordinated expiratory effort or abnormally low chest wall compliance, is the main spirometric finding in these patients.