Decrease in haematocrit with continuous positive airway pressure treatment in obstructive sleep apnoea patients.

Previous preliminary results have shown an overnight decrease in haematocrit and red cell count after the first night of treatment with nasal continuous positive airway pressure (CPAP) in obstructive sleep apnoea (OSA) patients. The present study was designed to confirm these preliminary data, and to analyse the long-term effects of CPAP. The haematocrit and red cell count (RCC) were measured in 80 OSA patients on two consecutive mornings, after an untreated night and after a CPAP treatment night. The haematocrit and RCC significantly decreased with CPAP (from 44.0 +/- 0.5 to 42.4 +/- 0.4%, p less than 0.0001 and from 4.769 +/- 0.051 to 4.597 +/- 0.052 x 10(12) red cells.l-1, p less than 0.0001, respectively). Neither the decrease in haematocrit nor the decrease in RCC were correlated with the decrease in urine volume or flow which occurred with CPAP. Thirty five of these patients remained untreated for 45 +/- 4 days, before home treatment with CPAP was initiated. The haematocrit and RCC had returned to values close to those before initial treatment and decreased again after the first treatment night. Twenty one of the patients were re-evaluated after at least one year of home treatment with CPAP, again on two consecutive nights either with CPAP or untreated. The follow-up, post-CPAP haematocrit and RCC were slightly and nonsignificantly higher than after the baseline CPAP night, but still lower than after the baseline untreated night (p less than 0.02). After the untreated follow-up night, no significant change in haematocrit was observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Nasal continuous positive airway pressure in stroke patients with sleep apnoea: a randomized treatment study.

The authors have investigated whether treatment of sleep apnoea with nasal continuous positive airway pressure (nCPAP) improves depressive symptoms, personal activities of daily living (ADL), cognitive functioning and delirium in patients that have suffered a stroke. Sixty-three patients consecutively admitted to a stroke rehabilitation unit 2-4 weeks after a stroke, with an apnoea/hypopnoea index > or =15, were randomized to either nCPAP treatment (n=33) or a control group (n=30). Four patients dropped out after randomization. Both groups were assessed at baseline and after 7 and 28 nights using the Montgomery-Asberg Depression Rating Scale (MADRS), Barthel-ADL index, and the Mini-Mental State Examination (MMSE) scale. Compared to the control group, depressive symptoms (MADRS total score) improved in patients randomized to nCPAP treatment (p=0.004). No significant treatment effect was found with regard to delirium, MMSE or Barthel-ADL index. Delirium and low cognitive level (MMSE score) explained poor compliance with nCPAP. Depressive symptoms are reduced through nasal continuous positive airway pressure treatment in patients with severe stroke and sleep apnoea. Compliance with nasal continuous positive airway pressure treatment is a problem in stroke patients, especially when delirium and severe cognitive impairment occur.     

Humidified nasal continuous positive airway pressure in obstructive sleep apnoea.

Heated humidification of nasal continuous positive airway pressure (nCPAP) reduces upper airway symptoms and improves initial use in obstructive sleep apnoea syndrome (OSAS). The present study aimed to assess the effect of heated humidification of nCPAP on upper airway symptoms and initial use in obstructive sleep apnoea. This study was of a randomised, crossover design. Subjects with polysomnographically confirmed OSAS were randomised to 3 weeks nCPAP treatment with heated humidification (nCPAP-humid) or placebo humidification (nCPAP pl-humid). Objective and subjective nCPAP use, upper airway symptoms, and treatment satisfaction were compared. Thirty seven of 42 patients completed the protocol. nCPAP-humid reduced the frequency of adverse upper airway symptoms. nCPAP use over 3 weeks was greater with nCPAP-humid compared with nCPAP pl-humid. No difference was found between the treatment arms in terms of subjective treatment satisfaction or alertness. Heated humidification of nasal continuous positive airway pressure reduces upper airway symptoms and is associated with a small increase in initial use but not subjective sleepiness or treatment satisfaction. The results support the use of heated humidification as a strategy to reduce side-effects related to continuous positive airway pressure but not routine initial use.     

Falls in blood pressure in patients with obstructive sleep apnoea after long-term nasal continuous positive airway pressure treatment

OBJECTIVES: Effective treatment of obstructive sleep apnoea (OSA) with nasal continuous positive airway pressure (nCPAP) lowers blood pressure (BP). The long-term effects of nCPAP treatment on BP in OSA patients are not well known. The time period of such treatment sufficient to lower BP in OSA patients is also not known. We investigated compliance with long-term nCPAP therapy and its effects on BP. METHODS: This observational study involved 66 OSA patients [59 men, seven women; mean age, 51 (48-54) years; body mass index (BMI), 28.7 (27.7-29.7) kg/m; apnoea and hypopnoea, 50.3 (45.6-55.0)/h; 95% confidence intervals]. BP and BMI were measured before the study and at two checkpoints after usage of nCPAP [620 (552-688) and 1071 (1000-1143) days]. RESULTS: The different times between the first and second checkpoints for detecting objective compliance were 17 (4-30) min (P = 0.003). Diastolic BP decreased by 5.9 (3.1-8.7) mmHg after 600 days nCPAP treatment and by 4.6 (2.0-7.2) mmHg after 1000 days (P = 0.0006). Systolic BP and BMI did not change significantly. Usage of nCPAP treatment for a daily average of 3 h was needed to achieve a significant decrease in diastolic BP [7.4 (4.3-10.6) mmHg, P < 0.0001]. Diastolic BP of normotensive OSA patients did not change significantly by nCPAP treatment, but that of hypertensive OSA patients decreased significantly within 1 month-3 years of nCPAP treatment whether or not medication was used. CONCLUSIONS: In patients with severe OSA, the use of nCPAP for a daily average of 3 h would be sufficient to decrease the diastolic BP of hypertensive OSA patients.     

Clinical side effects of continuous positive airway pressure in patients with obstructive sleep apnoea

CPAP is considered the gold standard treatment in OSA and is highly efficacious in controlling OSA symptoms. However, treatment effectiveness is limited because of many factors including low adherence due to side effects. This review highlights the range of side effects associated with CPAP therapy in patients with OSA. This information is important for the initiation of patients onto CPAP as well as their continued care while on treatment, given the increase in non‐medically supervised CPAP care models in use globally.     

Predicting optimal continuous positive airway pressure in Japanese patients with obstructive sleep apnoea syndrome

Background and objective: Several algorithms that predict the optimal CPAP have been developed for Caucasian patients with OSA syndrome, but these algorithms do not allow for racial differences in craniofacial anatomy. We investigated whether an equation that included data on craniofacial structure, physique and severity of OSA could more accurately predict the optimal CPAP for Japanese patients with OSA syndrome. Methods: In 170 Japanese patients with OSA syndrome, the optimal CPAP was determined by manual titration during polysomnography. An equation predicting the optimal pressure was derived from anthropometric, polysomnographic and cephalometric data. This equation was validated in another 110 Japanese patients with OSA syndrome. Results: Stepwise multiple regression analysis identified AHI, BMI, mean SaO₂ and a cephalometric parameter: the angle between a line from point B to the menton (Me) and a line from Me to the hyoid bone (H) (BMeH), as independent predictors of optimal CPAP. The following equation was constructed to predict the optimal CPAP: 27.78 + (0.041 × BMeH) + (0.141 × BMI) + (0.040 × AHI) ? (0.312 × mean SaO₂). This equation accounted for 47% of the variance in optimal pressure (R² = 0.47, P < 0.0001). The measured optimal pressure and the pressure calculated using this equation were very similar in the other 110 patients with OSA syndrome (9.5 ± 3.0 and 9.2 ± 2.1 cmH₂O, respectively). Conclusion: Optimal CPAP was more accurately predicted by combining a cephalometric parameter with BMI and polysomnographic data in Japanese patients with OSA, suggesting that craniofacial structure may be important in the pathogenesis of OSA syndrome among Asians.     

Effect of continuous positive airway pressure on ambulatory blood pressure in patients with obstructive sleep apnoea

OBJECTIVES: Previous reports on the effects of continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea (OSA) on blood pressure has shown contradictory results. Accordingly, we have investigated the effects of CPAP on blood pressure and on the potential reversal of the diagnosis of hypertension in patients with OSA evaluated repeatedly by ambulatory blood pressure monitoring. METHODS: We studied 122 patients (104 men and 18 women), 55.1+/-10.5 years of age, with diagnosis of OSA corroborated by overnight polysomnography at the clinic. Among those patients, 83 were treated with CPAP after their first evaluation, while 39 remained without CPAP for the duration of the trial. Blood pressure was measured by ambulatory monitoring at 20-min intervals during the day and at 30-min intervals at night for 48 consecutive hours, at baseline and after 2 and 4 months of intervention. RESULTS: There was a small, but not statistically significant, reduction in ambulatory blood pressure in patients treated with CPAP (0.7 and 1.5 mmHg in 24-h mean of systolic and diastolic blood pressure after 2 months of therapy; 2.0 and 2.3 mmHg after 4 months; P>0.239). The blood pressure reduction was very similar in patients with OSA followed for 4 months without CPAP (1.9 and 2.2 mmHg in 24-h mean of systolic and diastolic blood pressure, respectively; P=0.543). We found a high (77%) prevalence of hypertension among the patients participating in this study, although only 37% were receiving antihypertensive medication at the time of recruitment. The prevalence of hypertension was slightly but not significantly reduced to just 74% after 4 months of treatment with CPAP. CONCLUSIONS: The small reduction in blood pressure for consecutive profiles of ambulatory monitoring can probably be explained by the documented 'ABPM pressor effect' on patients using the ambulatory device for the first time. The high prevalence of hypertension among patients with OSA is not significantly reduced by treatment with CPAP. These results suggest that patients with OSA should always be properly evaluated for diagnosis of hypertension, and provided, if needed, with antihypertensive treatment apart from the recommended CPAP.     

Treatment of obstructive sleep apnoea with nasal continuous positive airway pressure in stroke.

The prevalence of obstructive sleep apnoea (OSA) following stroke is high and OSA is associated with increased morbidity, mortality and poor functional outcome. Nasal continuous positive airway pressure (nCPAP) is the treatment of choice for OSA, but its effects in stroke patients are unknown. The effectiveness and acceptance of treatment with nCPAP in 105 stroke patients with OSA, admitted to rehabilitation was prospectively investigated. Subjective wellbeing was measured with a visual analogue scale in 41 patients and 24-h blood pressure was determined in 16 patients before and after 10 days of treatment. Differences were compared between patients who did and did not accept treatment. There was an 80% reduction of respiratory events with concomitant increase in oxygen saturation and improvement in sleep architecture. No serious side-effects were noticed. Seventy-four patients (70.5%) continued treatment at home. Nonacceptance was associated with a lower functional status, as measured by the Barthel Index, and the presence of aphasia. Ten days after initiation of nCPAP, compliant users showed a clear improvement in wellbeing (differences in visual analogue scale (deltaVAS) mean+/-SD 26+/-26 mm) versus noncompliant patients (deltaVAS 2+/-25 mm, p=0.021). Only the compliant group had a reduction in mean nocturnal blood pressure (deltaBP; -8+/-7.3 mmHg versus 0.8+/-8.4 mmHg, p=0.037). Stroke patients with obstructive sleep apnoea can be treated effectively with nasal continuous positive airway pressure and show a similar improvement and primary acceptance to obstructive sleep apnoea patients without stroke. Continuous positive airway pressure acceptance is associated with improved wellbeing and decreased nocturnal blood pressure.     

Endocrine effects of nasal continuous positive airway pressure in male patients with obstructive sleep apnoea

OBJECTIVE: Obstructive sleep apnoea (OSA) is a relatively common condition producing disabling somnolence and profound physiological responses to hypoxaemic episodes during sleep, including significant oscillations in blood pressure. This study aimed to provide controlled data on the interaction between OSA and endocrine axes to establish whether overrepresentation of pathology such as hypertension and hypogonadism in OSA subjects might have an endocrine basis. DESIGN, SETTING AND SUBJECTS: Parallel randomized sham placebo controlled 1-month trial of nasal continuous positive airway pressure (nCPAP) in 101 male subjects with OSA presenting to a respiratory sleep clinic. METHODS: Analysis of gonadotrophins, testosterone, sex hormone binding protein (SHBG), prolactin, cortisol, thyroid stimulating hormone (TSH), free thyroxine (free T4), insulin-like growth factor-1 (IGF-1), renin and aldosterone were performed at baseline and after 1 month's active or placebo nCPAP intervention. Quality of life questionnaire scoring was also recorded over the same time period. RESULTS: Testosterone and SHBG showed significant negative correlations with baseline OSA severity. Active treatment of OSA produced SHBG elevation and TSH reduction (P< or =0.03). Both groups showed an increase in aldosterone (P<0.001) and IGF-1 (P< or =0.03), associated with a large improvement in subjective quality of life scoring. CONCLUSIONS: These findings demonstrate significant changes in endocrine axes not previously reported in a placebo-controlled trial. OSA is a recognized reversible cause of testosterone reduction; SHBG suppression correlating to baseline OSA severity supports a diagnosis of secondary hypogonadism. Significant rises in aldosterone and IGF-1 on treatment coincide with increased physical activity and an improved quality of life score.     

Long-term treatment with continuous positive airway pressure improves quality of life in obstructive sleep apnoea syndrome.

Continuous positive airway pressure (CPAP) is an established treatment of obstructive sleep apnoea syndrome (OSAS). While it is known that CPAP reverses the pathological breathing pattern and improves daytime sleepiness, there are no sufficient data on the long-term influence of CPAP on quality of life in patients with OSAS. Thirty-nine patients with polysomnographically verified OSAS (apnoea/hypopnoea index (AHI): (mean+/-SD) 46.8+/-21.8 events x h(-1)) were prospectively studied. All patients answered three quality of life measures (Complaint List, Nottingham Health Profile Part 1 (NHP), and Verbal Analogue-Scale "quality of life") prior to the initiation of CPAP therapy. After a mean of 9 months they were re-evaluated by polysomnography, and completed the questionnaires once again. As expected, CPAP was effective in treating the sleep-related breathing disorder. AHI decreased significantly from (mean+/-SD) 46.8+/-21.8 events x h(-1) to 3.3+/-6.3 events x h(-1), and minimum oxygen saturation increased from 77.1+/-9.3% to 89.9+/-3.4%, while body mass index did not change significantly (31.3+/-5.4 versus 30.8+/-4.8 kg x m(-2)). During long-term treatment with CPAP the Complaint List revealed a significant improvement of the extent of subjective impairment due to physical and general complaints (26.4+/-9.9 versus 20.4+/-11.1), and NHP a significant improvement of emotional reactions (19.8+/-21.7 versus 11.1+/-14.0) and energy (50.8+/-36.6 versus 32.1+/-36.7), but not of pain, physical mobility, sleep, social isolation, and quality of life as assessed by the It is concluded that long-term continuous positive airway pressure therapy is effective in improving not only pathological breathing patterns but also parameters that estimate quality of life in patients with obstructive sleep apnoea syndrome.     

Association between continuous positive airway pressure and circulating omentin levels in patients with obstructive sleep apnoea

Purpose

Inflammation and oxidative stress play important roles in the pathogenesis of obstructive sleep apnoea syndrome (OSAS). Omentin is expressed in visceral adipose tissue and is associated with the inflammatory response. The aim of this study was to assess the relationship between OSAS and omentin based on a comparison of its serum levels at baseline and after 3 months of continuous positive airway pressure (CPAP) therapy.

Methods

Ninety-six newly diagnosed OSAS patients and 31 non-apnoeic controls were enrolled in this study. Blood samples were obtained in the morning after polysomnography. Within the OSAS group, 30 patients were started on CPAP therapy and then reassessed clinically, including a blood test for serum omentin and other biochemical analysis, at 3 months.

Results

Serum omentin levels were significantly lower in the OSAS group than in the control group (27.7?±?7.6 and 42.5?±?5.2 ng/mL, P?<?0.001). In the subgroup analysis, omentin concentrations were significantly lower in patients with severe OSAS than in those with mild/moderate OSAS (P?<?0.001). Circulating omentin levels were significantly correlated with the apnoea–hypopnoea index (AHI), mean SaO₂, oxygen desaturation index, and serum C-reactive protein levels. Treatment with CPAP resulted in a significant increase in circulating omentin levels after 3 months, from 22.7?±?1.4 to 41.2?±?3.3 ng/mL (P?<?0.001).

Conclusions

OSAS is associated with low serum omentin levels, and these levels can be reversed by effective CPAP treatment.

     

Optimal continuous positive airway pressure in patients with obstructive sleep apnoea: role of craniofacial structure

Although nasal continuous positive airway pressure (CPAP) is effective in improving nocturnal obstructive apnoea, daytime sleepiness and well-being in patients with obstructive sleep apnoea syndrome (OSAS), not all patients tolerate this treatment. Since optimal CPAP titration is essential to maintain compliance, it is important to elucidate the factors that help to determine the optimal pressure. However, the determinants of the optimal CPAP level are controversial. The subjects comprised 27 Japanese male patients with OSAS who underwent standard polysomnography (PSG), pulmonary function tests, arterial blood gas analysis, cephalometry and CPAP titration. Twenty normal controls also underwent cephalometric analysis. The apnoea-hypopnoea index (AHI), mean oxygen saturation (mean SaO2) and the lowest SaO2 during sleep were found to be 54.7+/-22.6, 89.0+/-5.6%, and 69.7+/-9.0%, respectively by PSG. The mean optimal CPAP was 9.6+/-1.8 cmH2O. The cephalometric angles (SNA, SNB and NSBa) were similar to those found in the control subjects. but MP-H, and PNS-P were significantly longer than those in the control subjects as shown by cephalometry. The optimal CPAP was correlated with the mean SaO2 (P<0.0001), neck circumference (P<0.05) and three cephalometric variables (NSBa: P<0.01, MP-H: P<0.05, PNS-P: P<0.05). Multiple, step-wise, regression analysis showed that the mean SaO2 and NSBa were independent variables that best predicted the optimal CPAP. These variables accounted for 57.5% of the total variance (R2=0.575, P<0.001). Optimal CPAP was closely correlated with oxygen desaturation during sleep. However, the craniofacial structure had additional effects such as an independent factor in determining the optimal CPAP level.     

Left ventricular function in patients with obstructive sleep apnoea syndrome before and after treatment with nasal continuous positive airway pressure

BACKGROUND: Previous studies have yielded disparate results regarding the effect of obstructive sleep apnoea (OSA) syndrome on left ventricular (LV) function. OBJECTIVES: In order to clarify this, we performed a prospective study investigating OSA patients with no history of systemic hypertension, coronary artery disease, myocardial, pericardial or valvular problems, asthma or chronic obstructive pulmonary disease before and after treatment with nasal continuous positive airway pressure (nCPAP). METHODS: Fifteen patients (3 women, 12 men) with an apnoea/hypopnoea index >15 (mean +/- SD = 52 +/- 21) were studied with complete polysomnography, ambulatory blood pressure monitoring, M-mode two-dimensional echocardiography and pulsed Doppler echocardiography in two phases, i.e. before and after 12-14 weeks of nCPAP therapy. We measured systolic and diastolic blood pressure (BP) separately in the daytime and night-time, isovolumic relaxation time (IVRT), the ratio of peak early filling velocity (E) to peak late velocity (A) diastolic transmitral flow (E/A), posterior wall thickness (PWT) and septal thickness (IVST). The shortening fraction (SF) was also calculated. Eleven overweight non-apnoeic normal subjects matched for age were used as the control group. RESULTS: Our results showed that the patient group exhibited, before treatment, LV diastolic, but not systolic, dysfunction compared with the normal group (IVRT = 94.3 +/- 11.6 ms, p < 0.05; E/A = 0.94 +/- 0.26, p < 0.02; SF = 39.9 +/- 4.1%, not significant (NS); IVST = 9.9 +/- 1.2 mm, NS; PWT = 8.3 +/- 1.2 mm, NS). Moreover, the patient group developed diastolic hypertension both in the daytime and night-time (BP/diastolic/daytime = 93.3 +/- 9.2 mm Hg, BP/diastolic/night-time = 90.3 +/- 10.7 mm Hg). After 12-14 weeks of nCPAP treatment (no change in body mass index), significant improvement in LV diastolic function and a drop in blood pressure were noticed (IVRT = 85.6 +/- 8.8 ms, p < 0.05; E/A = 1.07 +/- 0.3, p < 0.05; BP/diastolic/daytime = 86.3 +/- 5.5 mm Hg, p < 0.02; BP/diastolic/night-time = 83.9 +/- 8. 6 mm Hg, p < 0.05) in our patient group. CONCLUSIONS: We conclude that repetitive apnoeas/hypopnoeas are very important factors in the development of both LV diastolic dysfunction and diastolic systemic hypertension in patients with OSA syndrome. Treatment with nCPAP leads to significant improvement in both ventricular function and systemic hypertension.     

Efficacy of daytime continuous positive airway pressure titration in severe obstructive sleep apnoea.

The aim of this study was to evaluate manual nasal continuous positive airway pressure (nCPAP) titration during daytime polysomnography compared with conventional overnight titration for patients with severe obstructive sleep apnoea. Thirty-two patients who underwent daytime titration were retrospectively matched (for age, sex, body mass index and apnoea/hypopnoea index (AHI)) to a group titrated overnight during the same period. Successful titration was defined as the identification of the nCPAP level (effective nCPAP (Peff)) required to eliminate respiratory events during all sleep stages. After 3 months of therapy on nCPAP at Peff, nCPAP utilization history was obtained and a group of patients underwent a repeat polysomnogram (PSG) and completed a follow-up Epworth Sleepiness Scale (ESS) score. Initial titration was successful in 91% of daytime patients and 91% of overnight patients. The success of daytime titration was not related to diagnostic AHI or ESS score. Subjective nCPAP utilization was statistically similar in both groups. On the follow-up PSG, there were no significant differences between daytime (n=11) and overnight (n=11) patients in measures of sleep quality or respiratory disturbance. Both groups demonstrated similar and significant improvements in ESS score. These findings suggest that the effective nasal continuous positive airway pressure can be accurately established during daytime titration in a substantial proportion of severe, symptomatic obstructive sleep apnoea patients.     

Prevalence and treatment of central sleep apnoea emerging after initiation of continuous positive airway pressure in patients with obstructive sleep apnoea without evidence of heart failure

Background  

This study aimed to assess the prevalence of complex sleep apnoea (CompSA), defined as central sleep apnoea (CSA) emerging after the initiation of continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea (OSA), in patients with normal brain natriuretic peptide (BNP) levels, along with assessing the prevalence of CSA persisting in such patients after the onset of CPAP therapy. We hypothesised that the prevalence of CompSA and persistent CSA after CPAP initiation would be low in patients with OSA and normal BNP levels.     

Continuous positive airway pressure in heart failure patients with obstructive sleep apnoea

Background: The aim of the study was to study the effect of 6 months of continuous positive airway pressure (CPAP) in community heart failure (HF) patients with obstructive sleep apnoea (OSA). Methods: Clinically stable outpatients with HF and OSA (left ventricular ejection fraction (LVEF) <45%, apnoea/hypopnoea index >15/h, n = 19) treated with CPAP and a control group (LVEF <45%, apnoea/hypopnoea index <10/h, n = 7) were compared at baseline and at 6 months by Minnesota heart failure score, Epworth sleepiness score, shuttle walk distance, brain natriuretic peptide, urinary catecholamines and echocardiographic indices using paired t‐test, McNemar’s tests and effect sizes. Results: In HF patients with OSA, CPAP improved LVEF (35.9 ± 6.1% to 40.6 ± 8.0%, P = 0.015), decreased LV end‐systolic volume (152 ± 74 to 135 ± 62 cm³, P = 0.03), systolic blood pressure (P = 0.04) and sleepiness (Epworth sleepiness score 8.8 ± 4.8 to 6.3 ± 3.2, P = 0.01), whereas walk distance, catecholamines, brain natriuretic peptide levels and symptoms were unchanged. These outcomes did not change in the HF control group. Conclusion: In community HF patients with OSA, CPAP therapy over 6 months improved LVEF, systolic blood pressure and sleepiness, but not sympathetic activation, brain natriuretic peptide or exercise levels. Acceptance was relatively low, potentially limiting therapeutic effectiveness.     

Continuous positive airway pressure therapy in sleep apnoea

Sleep apnoea is associated with increased mortality and morbidity. The treatment goal is to reduce the neurocognitive and cardiovascular sequelae. CPAP therapy in sleep apnoea is discussed in two parts in the article. The first part will consider CPAP therapy in the more common form of sleep apnoea (i.e. obstructive or mixed sleep apnoea) and the second part will consider CPAP therapy in central sleep apnoea. Alternative positive airway pressure modalities are discussed. CPAP therapy has been extensively studied and it remains the mainstay of treatment in obstructive sleep apnoea, as it is still the most consistently efficacious and safe option. However, its major disadvantage is that it does not confer a cure to this disorder and hence therapy is generally life long with its usual treatment compliance problems. As such, there are continuous improvement strategies. The role of CPAP therapy in central sleep apnoea is more limited. There has been increasing data on the beneficial effect of CPAP on central sleep apnoea/Cheyne-Stokes respiration in congestive heart failure. Evidence for CPAP therapy in sleep apnoea has evolved significantly over the last decade. However, more research and publication of large-scale long-term randomized trials of treatment in sleep apnoea to assess patient-orientated outcomes and preferences are necessary.     

Ethnicity and socioeconomic status predict initial continuous positive airway pressure compliance in New Zealand adults with obstructive sleep apnoea

Background: Understanding factors that contribute to low continuous positive airway pressure (CPAP) compliance will lead to improvements in the long‐term outcome of patients with obstructive sleep apnoea (OSA) syndrome. Both cultural and socioeconomic factors are likely to be important but have not been systematically studied. Aim: To examine the effect of ethnicity and socioeconomic status on initial CPAP usage for people with OSA in New Zealand. Methods: We retrospectively collected demographic, clinical and CPAP treatment‐related data on patients undergoing a 1‐month CPAP trial for a 10‐month period. We compared objectively measured CPAP usage (by anova ) with self‐identified ethnicity; levels of socioeconomic deprivation (NZDep06 index), Epworth Sleepiness Scale (ESS) and Apnoea‐Hypopnoea Index (AHI). Results: A total of 214 patients with a mean age of 52.7 (±11.8) years, mean AHI 57.3 (±35.8) events per hour and mean ESS 13 (±5.58)/24 made up the cohort. CPAP usage which averaged 5.13 ± 2.34 h per night was significantly lower in patients of non‐European ethnicity (P = 0.019 univariate) and remained significant after socioeconomic status was added to the model (P = 0.048). Patients living in the most socioeconomically deprived areas showed significantly lower compliance with CPAP on univariate analysis (P = 0.024, NZDep06 scores 1&2, average 5.3 per night compared to score NZDep06 scores 9&10, average 4.3 h per night), but this effect was no longer significant once ethnicity was added to the model (P = 0.28). Conclusion: CPAP usage in New Zealand is affected by both ethnicity and level of socioeconomic deprivation. We recommend further research to unravel specific cultural and socioeconomic reasons for the variance reported.