Sleep Study
In the sleep laboratory of the Institutes of Respiratory Diseases of the
University of Bari, all patients were evaluated for sleep disordered
breathing during one night. They were monitored continuously for about 8
h using a portable cardiorespiratory monitoring (POLYMESAM®, MAP,
Martinsried, Germany). The POLYMESAM® (PM) device consists of a
recorder, to which multiple sensors are linked for the detection of the
following signals: oxy-hemoglobin saturation (by a finger sensor), heart
rate (derived from three electrocardiogram (ECG) electrodes placed on
the chest), snoring sound (by a microphone placed on the thyroid
cartilage), body posture oro-nasal airflow (by a threefold thermocouple
sensor for both nostrils and mouth), and thoracic and abdominal
movements (by stretch belts). Apnea was identified if the airflow was
absent or nearly absent for at least 10 s. Hypopnea, was considered when
there was a decrease of airflow for at least 10 seconds in respirations,
a 30-percent reduction in ventilation, and a decrease in oxygen
saturation.
Statistics
Data are presented as mean ± standard error (SEM) or as percentages.
One-way analysis of variance (ANOVA) assessed inter-group differences.
Differences between two groups were tested by Student’s t-test for
unpaired data. The Chi-square test was used to compare proportions. The
Pearson correlation coefficient was used for correlations. Results were
considered significant at the 5% critical level (P<0.05).
Statistical analyses were performed with NCSS10 Statistical Software
(NCSS, LLC. Kaysville, Utah, USA).
Study Approval
Since the study was retrospective, the patients did not sign any
informed consent, while the Local Ethic Committee approved the study
number 1089, July the31st 2009, with note prot n.
24961/DS 03/26/2009, and approved the study number prot. N. 44696/DS
06-03-2009 n.527/DG/2004modified by the protocol n. 828/DG/2007.
Table 1