An electrocardiogram-based analysis evaluating sleep quality in patients with obstructive sleep apnea

Objective

The study compares polysomnography (PSG) and cardiopulmonary coupling (CPC) sleep quality variables in patients with (1) obstructive sleep apnea (OSA) and (2) successful and unsuccessful continuous positive airway pressure (CPAP) response.

Patients/methods

PSGs from 50 subjects (32 F/18 M; mean age 48.4?±?12.29 years; BMI 34.28?±?9.33) were evaluated. OSA patients were grouped by no (n?=?16), mild (n?=?13), and moderate to severe (n?=?20) OSA (apnea–hypopnea index (AHI)?≤?5, >5–15, >15 events/h, respectively). Outcome sleep quality variables were sleep stages in non-rapid eye movement, rapid eye movement sleep, and high (HFC), low (LFC), very low-frequency coupling (VLFC), and elevated LFC broad band (e-LFC_BB). An AHI?≤?5 events/h and HFC?≥?50 % indicated a successful CPAP response. CPC analysis extracts heart rate variability and QRS amplitude change that corresponds to respiration. CPC-generated spectrograms represent sleep dynamics from calculated coherence product and cross-power of both time series datasets.

Results

T tests differentiated no and moderate to severe OSA groups by REM % (p?=?0.003), HFC (p?=?0.007), VLFC (p?=?0.007), and LFC/HFC ratio (p?=?0.038) variables. The successful CPAP therapy group (n?=?16) had more HFC (p?=?0.003), less LFC (p?=?0.003), and e-LFC_BB (p?=?0.029) compared to the unsuccessful CPAP therapy group (n?=?8). PSG sleep quality measures, except the higher arousal index (p?=?0.038) in the unsuccessful CPAP group, did not differ between the successful and unsuccessful CPAP groups. HFC?≥?50 % showed high sensitivity (77.8 %) and specificity (88.9 %) in identifying successful CPAP therapy.

Conclusions

PSG and CPC measures differentiated no from moderate to severe OSA groups and HFC?≥?50 % discriminated successful from unsuccessful CPAP therapy. The HFC?≥?50 % cutoff showed clinical value in identifying sleep quality disturbance among CPAP users.     

The effect of continuous positive airway pressure on total cerebral blood flow in healthy awake volunteers

Purpose

Continuous positive airway pressure (CPAP) is the gold standard treatment for obstructive sleep apnea. However, the physiologic impact of CPAP on cerebral blood flow (CBF) is not well established. Ultrasound can be used to estimate CBF, but there is no widespread accepted protocol. We studied the physiologic influence of CPAP on CBF using a method integrating arterial diameter and flow velocity (FV) measurements obtained for each vessel supplying blood to the brain.

Methods

FV and lumen diameter of the left and right internal carotid, vertebral, and middle cerebral arteries were measured using duplex Doppler ultrasound with and without CPAP at 15 cm H₂O, applied in a random order. Transcutaneous carbon dioxide (PtcCO₂), heart rate (HR), blood pressure (BP), and oxygen saturation were monitored. Results were compared with a theoretical prediction of CBF change based on the effect of partial pressure of carbon dioxide on CBF.

Results

Data were obtained from 23 healthy volunteers (mean?±?SD; 12 male, age 25.1?±?2.6 years, body mass index 21.8?±?2.0 kg/m²). The mean experimental and theoretical CBF decrease under CPAP was 12.5 % (p?<?0.001) and 11.9 % (p?<?0.001), respectively. The difference between experimental and theoretical CBF reduction was not statistically significant (3.84?±?79 ml/min, p?=?0.40). There was a significant reduction in PtcCO₂ with CPAP (p?=?<0.001) and a significant increase in mean BP (p?=?0.0017). No significant change was observed in SaO₂ (p?=?0.21) and HR (p?=?0.62).

Conclusion

Duplex Doppler ultrasound measurements of arterial diameter and FV allow for a noninvasive bedside estimation of CBF. CPAP at 15 cm H₂O significantly decreased CBF in healthy awake volunteers. This effect appeared to be mediated predominately through the hypocapnic vasoconstriction coinciding with PCO₂ level reduction. The results suggest that CPAP should be used cautiously in patients with unstable cerebral hemodynamics.     

Willingness score obtained after a short CPAP trial predicts CPAP use at 1 year

Purpose

To predict continuous positive airway pressure (CPAP) adherence at 1 year.

Methods

We followed consecutive OSA patients scheduled for CPAP initiation for 1 year. Patients completed a self-efficacy questionnaire (5 = low, 25 = high score) before CPAP initiation. After CPAP initiation, we enquired about patients’ satisfaction in CPAP trial and their eagerness and willingness to continue CPAP therapy (0 = unsatisfied, uneager, or refused CPAP; 100 = satisfied, eager, or willing to continue CPAP treatment).

Results

Of the 580 patients we followed, 377 continued CPAP therapy beyond 1 year. A low willingness score (<50) was expressed by 77 patients but only 7 of them used CPAP >4 h daily at 1 year, yielding a specificity of 97 % in predicting CPAP failure. At 1 year, patients with a self-efficacy score >20, expressed prior to CPAP initiation, used CPAP more often than the patients with a score <20 (average use 4.4?±?2.2 h vs. 3.7?±?2.3 h, p?<?0.001).

Conclusions

A low score of willingness to continue CPAP therapy after a short trial predicts CPAP failure and poor CPAP adherence at 1 year.     

The effect of continuous positive airway pressure therapy on blood pressure and arterial stiffness in hypertensive patients with obstructive sleep apnea

Aim

We aimed to evaluate the effect of continuous positive airway pressure (CPAP) therapy on blood pressure (BP) and arterial stiffness in hypertensive patients with obstructive sleep apnea (OSA).

Patients and methods

We studied 38 hypertensive patients who suffered from severe OSA. Ambulatory BP measurement was performed at baseline and after at least 3 months of uninterrupted CPAP therapy. In 19 of these patients, we also measured pulse wave velocity (PWV) at baseline, after the first night of CPAP therapy and at 3 months. Fifteen normotensive subjects without OSA comprised the control group.

Results

CPAP therapy reduced systolic BP from 141.5?±?12.1 to 133.5?±?9.7 mmHg (p?=?0.007) and diastolic BP from 87.8?±?6.8 to 83?±?5.4 mmHg (p?=?0.004). CPAP also reduced the PWV from 8.81?±?1.4 to 8.18?±?1 m/s after the first night of CPAP therapy (p?=?0.003) and to 7.37?±?1 m/s at 3 months (p?=?0.007).

Conclusions

To the best of our knowledge, this is the first study demonstrating that CPAP therapy in hypertensive patients with OSA improves arterial stiffness from the first night and that this favorable effect is maintained for at least 3 months of CPAP use. A reduction in BP was also observed, even though BP control was not always achieved.     

CPAP therapy prevents increase in blood pressure after upper airway surgery for obstructive sleep apnoea

Objective

The aim of this study was to investigate the efficacy of continuous positive airway pressure (CPAP) therapy following uvulopalatopharyngoplasty (UPPP) to prevent blood pressure (BP) elevation during sleep.

Methods

Sixteen normotensive patients with OSA were subjected to UPPP with or without septoplasty. These patients were instrumented for 24 h of ambulatory BP recording, polysomnography, nocturnal urinary catecholamine and pain evaluation using a visual analogue scale in the day prior to surgery (D?1), following the surgery (D+1) and 30 days later (D+30). For the D+1, the patients were divided into two groups: the without CPAP therapy group and the with CPAP therapy group.

Results

The apnoea–hypopnoea index (AHI) significantly increased in the patients without CPAP therapy compared with the D?1 (74?±?23 vs. 35?±?6 times/h, p?<?0.05), and in the CPAP group, there was a significant reduction in the average AHI value to 14?±?6 times/h, p?<?0.01. During D+1, we observed an increase in the nocturnal systolic BP (10 %), diastolic BP (12 %) and heart rate (14 %) in the group without CPAP. These metrics were re-established in the CPAP group to values that were similar to those that were observed on the D?1. The absence of nocturnal dipping in the group without CPAP was followed by a significant increase in nocturnal norepinephrine (42?±?12 μg/l/12 h) and epinephrine (8?±?2 μg/l/12 h) levels compared with the D?1 (norepinephrine 17?±?3; epinephrine 2?±?0.3 μg/l/12 h, p?<?0.001). In the patients who used the CPAP treatment, the nocturnal catecholamine levels were similar to D?1. The effectiveness of intravenous analgesic therapy was verified by a significant decrease in the pain scores in patients both with and without CPAP therapy.

Conclusion

These data confirm an increase in the AHI on the night following UPPP with or without septoplasty. This increase promotes an absence of nocturnal dipping and a significant increase in urinary catecholamine levels. CPAP therapy was effective to prevent the transitory increase in BP.     

Oronasal masks require higher levels of positive airway pressure than nasal masks to treat obstructive sleep apnea

Purpose

The purpose of this study was to compare the therapeutic pressure determined by an automated CPAP device (AutoCPAP) during the titration period, between nasal and oronasal mask and the residual apnea-hypopnea index (AHI) on a subsequent poligraphy performed with the established therapeutic CPAP.

Methods

As a retrospective study, 109 subjects with moderate and severe obstructive sleep apnea-hypopnea (apnea-hypopnea index?≥?15 events/h) were studied. CPAP titration was performed using an auto-titrating device.

Results

There was significant difference in the mean pressure delivered with autoCPAP between the group of patients using the nasal mask (mean 10.0 cmH₂O?±?2.0 SD) and the group which used the oronasal mask (mean 11.2 cmH₂O?±?2.1) (p?p?r?=?0.245, p 0.008).

Conclusions

Therapeutic CPAP level for OSAH is higher when administered via oronasal mask, leaving more residual events. These findings suggest that nasal mask should be the first choice for OSAH treatment.     

Effects of calcium–vitamin D co-supplementation on glycaemic control,inflammation and oxidative stress in gestational diabetes: a randomised placebo-controlled trial

Aims/hypothesis

This study was designed to assess the effects of calcium and vitamin D supplementation on the metabolic status of pregnant women with gestational diabetes mellitus (GDM).

Methods

This randomised placebo-controlled trial was performed at maternity clinics affiliated to Kashan University of Medical Sciences, Kashan, Iran. Participants were 56 women with GDM at 24–28 weeks’ gestation (18 to 40 years of age). Subjects were randomly assigned to receive calcium plus vitamin D supplements or placebo. All study participants were blinded to group assignment. Individuals in the calcium–vitamin D group (n?=?28) received 1,000 mg calcium per day and a 50,000 U vitamin D₃ pearl twice during the study (at study baseline and on day 21 of the intervention), and those in the placebo group (n?=?28) received two placebos at the mentioned times. Fasting blood samples were taken at study baseline and after 6 weeks of intervention.

Results

The study was completed by 51 participants (calcium–vitamin D n?=?25, placebo n?=?26). However, as the analysis was based on an intention-to-treat approach, all 56 women with GDM (28 in each group) were included in the final analysis. After the administration of calcium plus vitamin D supplements, we observed a significant reduction in fasting plasma glucose (?0.89?±?0.69 vs +0.26?±?0.92 mmol/l, p?p?=?0.02) and HOMA-IR (?0.91?±?1.18 vs +0.63?±?2.01, p?=?0.001) and a significant increase in QUICKI (+0.02?±?0.03 vs ?0.002?±?0.02, p?=?0.003) compared with placebo. In addition, a significant reduction in serum LDL-cholesterol (?0.23?±?0.79 vs +0.26?±?0.74 mmol/l, p?=?0.02) and total cholesterol: HDL-cholesterol ratio (?0.49?±?1.09 vs +0.18?±?0.37, p?=?0.003) and a significant elevation in HDL-cholesterol levels (+0.15?±?0.25 vs ?0.02?±?0.24 mmol/l, p?=?0.01) was seen after intervention in the calcium–vitamin D group compared with placebo. In addition, calcium plus vitamin D supplementation resulted in a significant increase in GSH (+51.14?±?131.64 vs ?47.27?±?203.63 μmol/l, p?=?0.03) and prevented a rise in MDA levels (+0.06?±?0.66 vs +0.93?±?2.00 μmol/l, p?=?0.03) compared with placebo.

Conclusions/interpretation

Calcium plus vitamin D supplementation in women with GDM had beneficial effects on their metabolic profile.

Trial registration

www.irct.ir IRCT201311205623N11

Funding

The study was supported by a grant (no. 92110) from Kashan University of Medical Sciences.     

CPAP therapy in patients with idiopathic pulmonary fibrosis and obstructive sleep apnea: does it offer a better quality of life and sleep?

Background

The recent literature shows an increased incidence of obstructive sleep apnea (OSA) in patients with idiopathic pulmonary fibrosis (IPF). On the other hand, there are no published studies related to continuous positive airway pressure (CPAP) treatment in this patient group. Our aim was to assess the effect of CPAP on sleep and overall life quality parameters in IPF patients with OSA and to recognize and overcome possible difficulties in CPAP initiation and acceptance by these patients.

Methods

Twelve patients (ten males and two females, age 67.1?±?7.2 years) with newly diagnosed IPF and moderate to severe OSA, confirmed by overnight attended polysomnography, were included. Therapy with CPAP was initiated after a formal in-lab CPAP titration study. The patients completed the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index (PSQI), the Functional Outcomes in Sleep Questionnaire (FOSQ), the Fatigue Severity Scale (FSS), the SF-36 quality of life questionnaire, and the Beck Depression Inventory (BDI) at CPAP initiation and after 1, 3, and 6 months of effective CPAP therapy.

Results

A statistically significant improvement was observed in the FOSQ at 1, 3, and 6 months after CPAP initiation (baseline 12.9?±?2.9 vs. 14.7?±?2.6 vs. 15.8?±?2.1 vs. 16.9?±?1.9, respectively, p?=?0.02). Improvement, although not statistically significant, was noted in ESS score (9.2?±?5.6 vs. 7.6?±?4.9 vs. 7.5?±?5.3 vs. 7.7?±?5.2, p?=?0.84), PSQI (10.7?±?4.4 vs. 10.1?±?4.3 vs. 9.4?±?4.7 vs. 8.6?±?5.2, p?=?0.66), FSS (39.5?±?10.2 vs. 34.8?±?8.5 vs. 33.6?±?10.7 vs. 33.4?±?10.9, p?=?0.44), SF-36 (63.2?±?13.9 vs. 68.9?±?13.5 vs. 72.1?±?12.9 vs. 74.4?±?11.3, p?=?0.27), and BDI (12.9?±?5.5 vs. 10.7?±?4.3 vs. 9.4?±?4.8 vs. 9.6?±?4.5, p?=?0.40). Two patients had difficulty complying with CPAP for a variety of reasons (nocturnal cough, claustrophobia, insomnia) and stopped CPAP use after the first month, despite intense follow-up by the CPAP clinic staff. Heated humidification was added for all patients in order to improve the common complaint of disabling nocturnal cough.

Conclusion

Effective CPAP treatment in IPF patients with OSA results in a significant improvement in daily living activities based on the FOSQ, namely an OSA-specific follow-up instrument. Improvement was also noted in other questionnaires assessing quality of life, though not to a statistically significant degree, probably because of the multifactorial influences of IPF on physical and mental health. The probability of poor CPAP compliance was high and could only be eliminated with intense follow-up by the CPAP clinic staff.     

Assessment of the impact on compliance of a new CPAP system in obstructive sleep apnea

Background

Despite the efficacy of continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea (OSA), compliance with therapy remains suboptimal. The aim of this study was to determine whether the use of S9^TM increased compliance in established CPAP users.

Methods

Subjects with OSA (50) were recruited into the study. When subjects entered the study, 28 days of respective compliance data were downloaded from the patient's usual CPAP device. Subjects trialled the S9 CPAP for 28 days. Subjects then resumed use of their usual CPAP for 28 days. Compliance data from the patient's usual CPAP pre- and post-trialling S9 were compared with data from the S9 CPAP.

Results

Patients were significantly more compliant when using the S9 than their usual CPAP device both pre- and post-S9 based on average daily usage. CPAP pre-S9?=?6.58?±?1.95 (mean hours?±?SD), S9?=?7.08?±?1.18 h and CPAP post-S9?=?6.71?±?1.72 h. The difference between CPAP pre-S9 and S9 was 0.5 h (p?=?0.003). The difference between S9 and CPAP post-S9 was 0.35 h (p?=?0.01). There was no significant difference between CPAP pre-S9 and CPAP post-S9 (p?=?0.34). Patients also completed questionnaires comparing the S9 system to their usual device. Subjective feedback showed a strong preference for the S9.

Conclusions

Participants were significantly more compliant when using the S9 than their usual CPAP device both pre- and post-S9 use.     

Reverse atrial electrical remodelling induced by continuous positive airway pressure in patients with severe obstructive sleep apnoea

Background

Obstructive sleep apnoea (OSA) is associated with cardiovascular morbidity and mortality, including atrial arrhythmias. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA; its impact on atrial electrical remodelling has not been fully investigated. Signal-averaged p-wave (SAPW) duration is an accepted marker for atrial electrical remodelling.

Objective

The objective of this study is to determine whether CPAP induces reverse atrial electrical remodelling in patients with severe OSA.

Methods

Consecutive patients attending the Sleep Disorder Clinic at Kingston General Hospital underwent full polysomnography. OSA-negative controls and severe OSA were defined as apnoea–hypopnea index (AHI)?<?5 events/hour and AHI?≥?30 events/hour, respectively. SAPW duration was determined at baseline and after 4–6 weeks of CPAP in severe OSA patients or without intervention controls.

Results

Nineteen severe OSA patients and 10 controls were included in the analysis. Mean AHI and minimum oxygen saturation were 41.4?±?10.1 events/hour and 80.5?±?6.5 % in severe OSA patients and 2.8?±?1.2 events/hour and 91.4?±?2.1 % in controls. At baseline, severe OSA patients had a greater SAPW duration than controls (131.9?±?10.4 vs 122.8?±?10.5 ms; p?=?0.02). After CPAP, there was a significant reduction of SAPW duration in severe OSA patients (131.9?±?10.4 to 126.2?±?8.8 ms; p?<?0.001), while SAPW duration did not change after 4–6 weeks in controls.

Conclusion

CPAP induced reverse atrial electrical remodelling in patients with severe OSA as represented by a significant reduction in SAPW duration.     

Electrocardiographic P wave changes after thoracoscopic pulmonary vein isolation for atrial fibrillation

Background

Changes in P wave duration (PWD) and P wave area (PWA) have been described following catheter ablation for atrial fibrillation (AF). We hypothesize that video-assisted thoracoscopic pulmonary vein isolation (VATS-PVI) for AF results in decrease of PWD, PWA and P wave dispersion, which may resemble reverse electrical remodeling of the atrium after restoration of sinus rhythm.

Methods

VATS-PVI consisted of PVI and ganglionic plexus ablation in 29 patients (mean age, 59?±?7 years; 23 males; 17 paroxysmal AF) and additional left atrial lesions in patients with persistent AF. PWD and PWA were measured in ECG lead II, aVF and V2 of ECGs during sinus rhythm before, directly after, and 6 months postprocedure. P wave dispersion was derived from the 12 lead ECG.

Results

Prior to VATS-PVI, PWD did not correlate with left atrial size and no difference in left atrial size was found between patients with paroxysmal or persistent AF (p?=?0.27). Following VATS-PVI, PWD initially prolonged in all patients from 115?±?4.6 ms to 131?±?3.6 ms (p?<?0.01) but shortened to 99?±?3.2 ms after 6 months (p?<?0.01). PWA was 5.60?±?0.32 mV*ms at baseline, 6.44?±?0.32 mV*ms post-VATS-PVI (P?=?NS), and 5.40?±?0.28 mV*ms after 6 months (p?=?NS vs. baseline, p?<?0.05 vs. post-VATS-PVI). P wave dispersion decreased in the persistent AF group from baseline 67?±?3.3 to 64?±?2.5 ms post-VATS-PVI (p?=?0.30) and to 61?±?3.4 ms after 6 months (p?<?0.05).

Conclusions

PWD increases significantly directly after successful VATS-PVI in both groups. There was significant decrease in PWD after 6 months. Similarly, P wave dispersion decreased in the persistent group. These changes suggest an immediate procedure related effect, but the later changes may represent reverse electrical atrial remodeling following cessation of AF.     

Incidence,predictors, and clinical course of atrial tachyarrhythmias in patients with pulmonary hypertension

Background

The prevalence and predictors of atrial tachyarrhythmias (ATa) in patients with pulmonary hypertension (PH) is less well understood.

Methods

We performed a retrospective study including 311 patients with PH, confirmed by right heart catheterization in our center between 2007 and 2011. Baseline characteristics, clinical, echocardiographic, and hemodynamic data were collected and compared between patients with and without ATa.

Results

The mean age was 61?±?13 years with 64 % females. The mean pulmonary artery pressure (mPAP) was 46?±?20 mmHg, mean left ventricular ejection fraction (LVEF) was 55?±?13 %, and mean pulmonary capillary wedge pressure (PCWP) was 19?±?9 mmHg. Of the 311 patients with PH, 121 (39 %) patients had ATa. Patients with ATa were older (p?p?=?0.03), diabetes (p?=?0.015), coronary artery disease (p?p?p?=?0.001), impaired LVEF (p?=?0.02), and left atrial enlargement (p?p?=?0.022). In multivariate analysis using Cox-proportional hazard model, the independent predictors of mortality were age (HR 1.05; p?=?0.003), coronary artery disease (HR 2.34; p?=?0.047), LVEF (HR 0.793; p?=?0.023), and mPAP (HR 1.023; p?=?0.003).

Conclusion

ATa are common in patients with PH. Left heart disease, left atrial enlargement, and elevated PCWP but not right atrial enlargement or mPAP predict the occurrence of ATa in patients with PH.     

Genetics correlates with lung function and nocturnal ventilation in myotonic dystrophy

Background

Dystrophia myotonica (DM) is the most frequent adult-onset muscular dystrophy. Type 1 is caused by the cytosine–thymine–guanine (CTG) repeat expansion in the DM protein kinase gene. Respiratory muscle weakness and altered central ventilatory control lead to hypercapnia and lung volume restriction.

Purpose

This study aims to review the respiratory involvement in DM patients and study its relation with genetics.

Methods

Retrospective study of patients with DM referred for respiratory assessment was made. Noninvasive ventilation (NIV) was considered to daytime hypercapnia or symptoms of nocturnal hypoventilation.

Results

Forty-two consecutive patients (37.9?±?13.6 years) were evaluated. Mean CTG length was 642.8?±?439.2 repeats. In the first evaluation, mean forced vital capacity (FVC) was 74.4?±?20.2 %, maximal expiratory pressure (MEP) 35?±?16 %, maximal inspiratory pressure 52?±?23 %, peak cough flow (PCF) 327.3?±?97.7 L/min, arterial pressure of oxygen 79.7?±?11.3 mmHg, arterial pressure of carbon dioxide 45.5?±?6.2 mmHg, overnight minimal peripheral oxygen saturation (SpO₂) 79.6?±?11.6 %, and apnea–hypopnea index 13.9?±?9.9. CTG length was found to be related with MEP (r?=??0.67; p?=?0.001) and SpO₂ (r?=??0.37; p?=?0.039). NIV was started in 25 patients. Ventilated patients had lower FVC (2.19 to 3.21 L; p?<?0.001) and PCF (285.3 to 388.5 L/min; p?=?0.003) and more CTG repeats (826.6 to 388.5 repeats; p?=?0.02). NIV compliance was poor in seven patients (28 %) and related with hypercapnia (r?=?0.87; p?=?0.002) and inspiratory positive airway pressure setting (r?=?0.65; p?=?0.009). Ventilation improved symptoms and nocturnal hypoventilation. Comparing the first and last evaluations, only PCF was significantly lower (275.0 to 310.8 L/min; p?=?0.019).

Conclusions

Ventilatory insufficiency is very common in patients with DM and CTG length may be useful to predict it. Prolonged NIV improves symptoms, nocturnal hypoventilation and maintains daily blood gases. Routine evaluation of PCF should not be forgotten and assisted coughing training provided.     

Insomnia symptoms influence CPAP compliance

Purpose

The aim of this study is to determine parameters which influence 6-month compliance of continuous positive airway pressure therapy (CPAP) in patients with obstructive sleep apnea syndrome (OSAS).

Methods

This prospective study investigated 73 patients (24 females) with OSAS and medical indication for CPAP therapy: age 55.1?±?11.5 years, body mass index (BMI) 30.8?±?5.0 kg/m2, Apnea–Hypopnea Index (AHI) 39.2?±?26.7/h, Oxygen Desaturation Index (ODI) 33.2?±?25.4/h, minimum O₂ saturation 78.9?±?7.6%. The influence of baseline parameters (demographic and polysomnographic data, sleeping medication intakes, BMI, psychometrics [Epworth Sleepiness Scale, Regensburg Insomnia Scale, Vigilance test and Beck Depression Inventory]) on 6-month compliance was evaluated with a correlation and a linear regression analysis.

Results

The baseline value of the Regensburg Insomnia Scale (RIS) predicts 6-month CPAP compliance (r?=??0.376, R ²?=?0.14, p?<?0.001), although no other baseline parameter correlates. Patients with a compliance of <4 h/night show higher RIS scores, i.e., more insomnia symptoms (17.6?±?8.8) compared to those with ≥4 h/night (12.6?±?6.9; p?<?0.05).

Conclusions

Insomnia symptoms prior to the beginning of CPAP treatment show a negative influence on CPAP compliance. Further studies should clarify, if a treatment of insomnia symptoms leads to a benefit in compliance.     

Early cardiovascular remodelling in Fabry disease

Aims

Fabry disease (FD) is a rare X-linked genetic disorder caused by the deficiency or absent activity of lysosomal α-galactosidase A. Cardiovascular remodelling is a hallmark of FD. The present study aimed to comprehensively evaluate the cardiac, vascular and microvascular status in a population of patients with genetic mutations for FD without left ventricular hypertrophy (LVH).

Methods and results

This study includes subjects carrying genetic mutations for FD (Fabry disease mutation-carrier, FDMC) without LVH (n?=?19). A group of control subjects (n?=?19) matched for age, sex, body mass index and cardiovascular risk factors were also included. All subjects underwent echocardiography, carotid ultrasound scan, endothelial flow-mediated dilatation (FMD) and nailfold capillaroscopy (NFC) assessment. When compared to the subjects in the control group, FDMC patients showed significantly lower mean values of systolic myocardial velocity (7.33?±?1.28 vs. 10.08?±?1.63 cm/s, p?<?0.0001), longitudinal systolic strain (?18.07?±?1.72 vs. ?21.15?±?2.22 %, p?<?0.0001), significantly higher E/E’ mean values (7.15?±?1.54 vs. 5.98?±?1.27, p?=?0.016) and intima-media thickness mean values (0.80?±?0.20 vs. 0.61?±?0.19 mm, p?=?0.005), significantly lower FMD (8.3?±?4.6 vs. 12.2?±?5.0 %, p?=?0.02), more atypical capillaries and irregular NFC architecture in FDMC than control subjects (52.6 vs. 0 %, p?<?0.0001; 78.9 vs. 36.8 %, p?=?0.02 respectively).

Conclusions

FD progressively involves cardiac, macrovascular and microvascular systems in an early stage. These features are present even in asymptomatic mutation carriers without LVH.     

Does bariatric surgery change olfactory perception? Results of the early postoperative course

Purpose

Changes of food preference toward foods with low caloric density have been demonstrated after bariatric surgery and may contribute to sustained body weight loss. It has been hypothesized that olfactory perception as an integral part of food selection might be altered after bariatric surgery.

Methods

Sniffin’ Sticks® were used to investigate the olfactory perception of morbidly obese patients undergoing either Roux-en-Y gastric bypass (RYGB, n?=?15) or sleeve gastrectomy (SG, n?=?15) before 1, 6, 12, and 24 weeks after surgery. Obese patients without surgical intervention served as controls (CG, n?=?12). Results are presented using the testing odor threshold, discrimination, and identification score (TDI; higher scores indicate better olfactory perception). Body weight loss was recorded.

Results

Initial BMI of the SG group (56.04?±?7.096 kg m^?2) was higher compared to the BMI of the RYGB (48.71?±?6.49 kg m^?2) and CG (50.35?±?6.78 kg m^?2); p?=?0.011. Body weight loss among the surgical groups was not different (p?=?0.011) while controls did not lose weight. Mean baseline TDI scores were significantly lower in the SG group 27.1?±?3.9 vs. 32.6?±?3.6 (RYGB) and 32.1?±?5.3 (CG), respectively, whereas there were after 24 weeks no changes in RYGB and CG patients; the TDI score in the SG group increased significantly to 31.1?±?3.5 (p?<?0.01).

Conclusions

Our data suggest that a substantial body weight loss per se does not affect olfactory perception. However, our results point towards improved olfactory perception after sleeve gastrectomy but not Roux-en-Y gastric bypass.     

Effects of calcium–vitamin D co-supplementation on metabolic profiles in vitamin D insufficient people with type 2 diabetes: a randomised controlled clinical trial

Aims/hypothesis

This study was performed to assess the effects of vitamin D and calcium supplementation on the metabolic profiles of vitamin D insufficient persons with type 2 diabetes.

Methods

In a parallel designed randomised placebo-controlled clinical trial, a total of 118 non-smoker individuals with type 2 diabetes and insufficient 25-hydroxyvitamin D, aged >30 years, were recruited from the Isfahan Endocrine and Metabolism Research Centre. Participants were randomly assigned to four groups receiving: (1) 50,000 U/week vitamin D + calcium placebo; (2) 1,000 mg/day calcium + vitamin D placebo; (3) 50,000 U/week vitamin D + 1,000 mg/day calcium; or (4) vitamin D placebo + calcium placebo for 8 weeks. A study technician carried out the random allocations using a random numbers table. All investigators, participants and laboratory technicians were blinded to the random assignments. All participants provided 3 days of dietary records and 3 days of physical activity records throughout the intervention. Blood samples were taken to quantify glycaemic and lipid profiles at study baseline and after 8 weeks of intervention.

Results

30 participants were randomised in each group. During the intervention, one participant from the calcium group and one from the vitamin D group were excluded because of personal problems. Calcium–vitamin D co-supplementation resulted in reduced serum insulin (changes from baseline: ?14.8?±?3.9 pmol/l, p?=?0.01), HbA_1c [?0.70?±?0.19% (?8.0?±?0.4 mmol/mol), p?=?0.02], HOMA-IR (?0.46?±?0.20, p?=?0.001), LDL-cholesterol (?10.36?±?0.10 mmol/l, p?=?0.04) and total/HDL-cholesterol levels (?0.91?±?0.16, p?=?0.03) compared with other groups. We found a significant increase in QUICKI (0.025?±?0.01, p?=?0.004), HOMA of beta cell function (HOMA-B; 11.8?±?12.17, p?=?0.001) and HDL-cholesterol (0.46?±?0.05 mmol/l, p?=?0.03) in the calcium–vitamin D group compared with others.

Conclusions/interpretation

Joint calcium and vitamin D supplementation might improve the glycaemic status and lipid profiles of vitamin D insufficient people with type 2 diabetes. Trial registration: ClinicalTrials.gov NCT01662193 Funding: Clinical Research Council, Isfahan University of Medical Sciences, Isfahan, Iran     

CPAP interface: satisfaction and side effects

Purpose

This study aimed to evaluate the care receiver's satisfaction with the continuous positive airway pressure (CPAP) interfaces.

Methods

A questionnaire with visual analog scales was sent to all our CPAP patients (0?=?absolutely unsatisfied, 100?=?very satisfied). From the ResMed ResScan program, we obtained the CPAP daily use and air leak values.

Results

We received 730 answers (70 % of participants); females comprised 22 %. A total of 391 patients had ResMed interfaces, 227 had Respironics, 87 had Fisher & Paykel (F&P), and 25 patients had other interfaces. Interfaces were nasal for 79 %, nasal pillows for 9 %, oronasal for 9 %, and unidentified for 3 % of cases. The mean?±?SD satisfaction rate was 68?±?25. No statistically significant differences were found regarding the type or brand of interface, previous interface experience, or the age or gender of the patient. Users of ResMed interfaces had significantly (p?<?0.01) fewer cases of disturbing leaks than did users of Respironics or F&P interfaces (60 vs. 70 and 72 %, respectively). The ResMed Ultra Mirage interface had the fewest cases of disturbing leaks. Values for the measured median leaks were a mean of 5.9?±?7.2 l/min, and those for the maximum leaks were 39.3?±?22.2 l/min with no differences between brands. The users of F&P interfaces experienced significantly (p?<?0.01) more comfort and used the CPAP device significantly (p?<?0.007) more than did users of ResMed or Respironics interfaces (88 % of cases vs. 65 and 57 % and 6.2?±?2.6 vs. 5.3?±?2.8 or 5.8?±?2.8 h/day, respectively).

Conclusions

The majority of patients consider the use of the CPAP interface disturbing even though the satisfaction rate is good with no differences between brands.     

Resting energy expenditure in OSAS: the impact of a single CPAP application

Purpose

Data on the impact of obstructive sleep apnea syndrome (OSAS) and its treatment on resting energy expenditure (REE) are currently few and conflicting. The purpose of the present study was to investigate the impact of OSAS on REE, as measured before and after sleep, and the changes in REE after a single continuous positive airway pressure (CPAP) application, for the first time in literature.

Methods

This is a nested case-control study. From the initial study population, two groups were formed, based on the results of nocturnal polysomnography: a group of male OSAS patients and a group of male, age-matched non-OSAS controls. REE was measured in both groups before and after sleep by indirect calorimetry, while patients repeated REE measurements before and after a single nasal CPAP application.

Results

Ninety-two male OSAS patients (45.3?±?12.8 years old) and 19 male non-OSAS controls (50.8?±?11.7 years old) were studied. REE/lean body mass (LBM) was higher among patients compared to controls both pre- (29.6?±?12 vs 22.9?±?7.9 kcal/kg; p?=?0.022, correspondingly) and post-sleep (26.4?±?9.6 vs 21.6?±?9 kcal/kg; p?=?0.047 correspondingly). REE/LBM decreased significantly after sleep in OSAS patients (p?=?0.002), but not in controls; this difference was most evident among patients with more severe disease and higher desaturation. A single nasal CPAP application diminished the pre-post REE/LBM difference (30.3?±?8.2 vs 28.3?±?10.3 kcal/kg; p?=?0.265), but only among responders.

Conclusions

In OSAS patients, REE values are high and vary significantly before and after sleep. A single nasal CPAP application diminishes this difference among responders, possibly through reversal of nocturnal desaturation.

     

Robotic ablation of atrial fibrillation with a new remote catheter system

Purpose

Pulmonary vein isolation (PVI) is widely established as a curative treatment option for atrial fibrillation (AF). A wide range of techniques to improve catheter manipulation and steerability has been developed over the past years. A new remote catheter system (RCS) has recently become available (Amigo Remote Catheter System, Catheter Robotics, Budd Lake, NJ, USA). Here, we present a dual-center study on the RCS for left atrial mapping and PVI in patients with paroxysmal AF compared to a control group undergoing conventional PVI.

Methods

One hundred nineteen patients who underwent PVI for paroxysmal AF were studied. Forty patients underwent PVI with the use of the RCS. Seventy-nine patients, who underwent conventional PVI, served as control group. Procedural data were compared between the two groups.

Results

PVI was achieved in all patients. In the RCS group compared to standard ablation group, there were no significant differences in procedure duration (159.1?±?45.4 vs. 146?±?30.1 min, p?=?0.19), total energy delivery (78,146.3?±?26,992.4 vs. 87,963.9?±?79,202.1 Ws, p?=?0.57), and total fluoroscopy time (21.2?±?8.6 vs. 23.9?±?5.4 min, p?=?0.15). Operator fluoroscopy exposure was significantly reduced in the RCS group (13.4?±?6.1 vs. 23.9?±?5.4 min, p?Conclusions These initial results suggest that left atrial mapping and PVI are feasible with the use of the Amigo RCS. Acute procedural efficacy is comparable to the standard approach. The use of the Amigo RCS leads to a significant reduction of operator fluoroscopy exposure.