A new tool to screen patients with severe obstructive sleep apnea in the primary care setting: a prospective multicenter study.

BACKGROUND: The coordination between different levels of care is essential for the management of obstructive sleep apnea (OSA). The objective of this multicenter project was to develop a screening model for OSA in the primary care setting. METHODS: Anthropometric data, clinical history, and symptoms of OSA were recorded in randomly selected primary care patients, who also underwent a home sleep apnea test (HSAT). Respiratory polygraphy or polysomnography were performed at the sleep unit to establish definite indication for continuous positive airway pressure (CPAP). By means of cross-validation, a logistic regression model (CPAP yes/no) was designed, and with the clinical variables included in the model, a scoring system was established using the ß coefficients (PASHOS Test). In a second stage, results of HSAT were added, and the final accuracy of the model was assessed. RESULTS: 194 patients completed the study. The clinical test included the body mass index, neck circumference and observed apneas during sleep (AUC 0.824, 95% CI 0.763-0.886, P < 0.001). In a second stage, the oxygen desaturation index (ODI) of 3% (ODI3% ≥ 15%) from the HSAT was added (AUC 0.911, 95% CI 0.863-0.960, P < 0.001), with a sensitivity of 85.5% (95% CI 74.7-92.1) and specificity of 67.8% (95% CI 55.1-78.3). CONCLUSIONS: The use of this model would prevent referral to the sleep unit for 55.1% of the patients. The two-stage PASHOS model is a useful and practical screening tool for OSA in primary care for detecting candidates for CPAP treatment. Clinical Trial Registration Registry: ClinicalTrials.gov; Name: PASHOS Project: Advanced Platform for Sleep Apnea Syndrome Assessment; URL: https://clinicaltrials.gov/ct2/show/NCT02591979 ; Identifier: NCT02591979. Date of registration: October 30, 2015.

Cluster-derived obstructive sleep apnea phenotypes and outcomes at 5-year follow-up.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is a heterogeneous, complex disease. We aimed to identify OSA phenotypes through cluster analysis and to perform a long-term follow-up to validate the phenotypes. METHODS: We applied a partitioning around medioids technique in a cohort of 1,217 participants recently diagnosed with OSA. We performed a 5-year follow-up analyzing the incidence of comorbidities, chronic medication, hospital admissions, mortality, and the influence of continuous positive airway pressure treatment on mortality risk. RESULTS: We identified three phenotypes: two predominantly male clusters, one composed of middle-aged participants with overweight, moderate OSA, and cardiovascular risk factors and the other consisting of older, obese participants with severe OSA, cardiovascular risk factors, ischemic heart disease (18.4%), and atrial fibrillation (9.7%). The third cluster was composed of 77% female participants with moderate OSA; cardiovascular risk factors; the highest prevalence of depression (15.7%); and high prescription of antidepressants (55.1%), anxiolytics (40.0%), hypnotics, sedatives (11.1%), nonsteroidal anti-inflammatory drugs (67.9%), and weak opioids (15.1%). The baseline characteristics of each cluster maintained the same trend over time regarding the incidence of new comorbidities, medication intake, hospitalization rates, and reasons for admission. The absence of continuous positive airway pressure treatment was associated with a significantly higher risk of all-cause mortality (hazard ratio 5.84, confidence interval 2.9-11.8), especially in the older men (hazard ratio 7.7, confidence interval 4.06-14.63) and predominantly female clusters (hazard ratio 2.79, confidence interval 1.34-5.79). CONCLUSIONS: We identified three phenotypes with relevant clinical and prognostic implications in order to improve personalized strategies in OSA management. CITATION: Silveira MG, Sampol G, Mota-Foix M, Ferrer J, Lloberes P. Cluster-derived obstructive sleep apnea phenotypes and outcomes at 5-year follow-up. J Clin Sleep Med. 2022;18(2):597-607.

Long-term Effect of CPAP Treatment on Cardiovascular Events in Patients With Resistant Hypertension and Sleep Apnea. Data From the HIPARCO-2 Study.

BACKGROUND: There is some controversy about the effect of continuous positive airway pressure (CPAP) on the incidence of cardiovascular events (CVE). However, the incidence of CVE among patients with both obstructive sleep apnea (OSA) ans resistant hypertension (HR) has not been evaluated. Our objective was to analyze the long-term effect of CPAP treatment in patients with RH and OSA on the incidence of CVE. METHODS: Multi-center, observational and prospective study of patients with moderate-severe OSA and RH. All the patients were followed up every 3-6 months and the CVE incidence was measured. Patients adherent to CPAP (at least 4h/day) were compared with those with not adherent or those who had not been prescribed CPAP. RESULTS: Valid data were obtained from 163 patients with 64 CVE incidents. Treatment with CPAP was offered to 82%. After 58 months of follow-up, 58.3% of patients were adherent to CPAP. Patients not adherent to CPAP presented a non-significant increase in the total CVE incidence (HR:1.6; 95%CI: 0.96-2.7; p=0.07). A sensitivity analysis showed that patients not adherent to CPAP had a significant increase in the incidence of cerebrovascular events (HR: 3.1; CI95%: 1.07-15.1; p=0.041) and hypertensive crises (HR: 5.1; CI95%: 2.2-11.6; p=0.006), but the trend went in the opposite direction with respect to coronary events (HR: 0.22; CI95%: 0.05-1.02; p=0.053). CONCLUSIONS: In patients with RH and moderate-severe OSA, an uneffective treatment with CPAP showed a trend toward an increase in the incidence of CVE (particularly neurovascular events and hypertensive crises) without any changes with respect to coronary events.

The HIPARCO-2 study: long-term effect of continuous positive airway pressure on blood pressure in patients with resistant hypertension: a multicenter prospective study.

INTRODUCTION: Short-term treatment with continuous positive airway pressure (CPAP) produces a clinically significant reduction in blood pressure (BP) in patients with obstructive sleep apnea (OSA) and resistant hypertension. However, it is unknown whether this effect continues over the long-term. Our objective was to assess the effect of long-term CPAP on BP in patients with OSA and resistant hypertension. METHODS: The study included 161 patients diagnosed with both OSA [apnea--hypopnea index (AHI) ≥15] and resistant hypertension diagnosed via 24-hour ambulatory BP measurement (24-h ABPM), in whom a second analysis via 24-h ABPM was performed at the end of the follow-up. RESULTS: Patients were followed up within 59 months [interquartile range (IQR): 44-70]. CPAP treatment was prescribed to 82% of the patients (70% with good adherence to CPAP defined as use of CPAP at least 4 h/night). A comparison between the adherent group and nonadherent group (including those with CPAP not prescribed) showed that CPAP adherents had a significant drop in the 24-h BP, both systolic [-3.9 mmHg; 95% confidence interval (CI): -8.1 to 0.3] and diastolic pressure (-3.5 mmHg [95% [CI]: -6.4-0.5]), with a higher magnitude during the night (-5.5 and -4.9 mmHg, respectively). The CPAP adherent group needed a mean of 1.1 less antihypertensive drugs (particularly spironolactone). Finally, there was a positive correlation between the drop in 24-h SBP and the hours of CPAP use (r = 0.24; P = 0.01). CONCLUSION: Good adherence to long-term CPAP treatment largely succeeded in significantly reducing BP in those patients with OSA and resistant hypertension, despite the use of a lower number of antihypertensive drugs.

Primary care and sleep unit agreement in management decisions for sleep apnea: a prospective study in Spain.

STUDY OBJECTIVES: Involvement of primary care teams in the care of patients with OSA is a focus of interest. The study objective was to compare diagnostic and therapeutic agreement between decisions taken by primary care professionals and sleep unit specialists. METHODS: This was a prospective multicenter study conducted at primary care and specialized care centers in the urban area of Barcelona, Spain. Men and women aged 18-75 years who visited the participating primary care centers for any reason were recruited. Both primary care physicians and sleep specialists made a diagnostic and therapeutic decision with clinical data and results of a home sleep apnea test. All patients were finally assessed with respiratory polygraphy or polysomnography as a gold-standard test. RESULTS: A total of 229 patients underwent a home sleep apnea test and were evaluated at the primary care centers and the sleep units. Diagnostic agreement using the same tools and excluding indeterminate decisions was 69.8% (Cohen's kappa = 0.64; 95% confidence interval, 0.56-0.72). Agreement for therapeutic decisions (PAP vs conservative treatment) was obtained in 82.5% of patients (Cohen's kappa = 0.62; 95% confidence interval, 0.51-0.73), increasing to 92.5% (Cohen's kappa = 0.49, 95% confidence interval, 0.40-0.58) when indeterminate options were excluded. As compared with the final therapeutic decisions made at the sleep unit with respiratory polygraphy/polysomnography, primary care physicians agreed regarding 83.3% (Cohen's kappa = 0.62; 95% confidence interval, 0.49-0.74) of patients. CONCLUSIONS: Primary care professionals may assume an important role in the management of OSA in coordination with sleep centers, identifying patients who require specific treatment and should be referred to specialized care. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: PASHOS Project: Advanced Platform for Sleep Apnea Syndrome Assessment; URL: https://clinicaltrials.gov/ct2/show/NCT02591979; Identifier: NCT02591979.

Coordinated program between primary care and sleep unit for the management of obstructive sleep apnea.

The purpose of this study is to develop and validate a work model in the primary health-care setting for identifying patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) based on clinical variables and an ambulatory sleep monitoring study. After screening, patients with mild-moderate OSAHS could be managed by primary care physicians, whereas those identified with severe OSAHS would be referred to specialists from sleep units for starting specific treatment. The proposed model does not move the entire health-care process to a generally overburdened primary care level and favors the coordinated work and the necessary flexibility to adapt the model to challenges and perspectives of OSAHS.

Factors associated with the changes from a resistant to a refractory phenotype in hypertensive patients: a Pragmatic Longitudinal Study.

Refractory hypertension (RfH) is defined as a lack of blood pressure control despite the administration of at least 5 anti-hypertensive drugs. The factors associated with its natural history are unknown. This study aimed to evaluate both the incidence of RfH in an cohort of patients with resistant hypertension (RH) and the factors involved in that progression. This was an observational prospective multicenter study (24 centers) with 172 patients with confirmed RH (24-h ABPM) who underwent a further 24 h ABPM study at the end of the follow-up. Prospective information was obtained from all patients in their corresponding Hypertension Units via a standard clinical protocol, and they all underwent a sleep study. Thirty patients were diagnosed with RfH (17.4%) after a mean follow-up of 57 months, despite the prescription of a greater number of long-acting thiazide-like diuretics and mineralocorticoid receptor antagonists. The factors associated with progression to RfH were: a longer period since the diagnosis of RH (OR: 1.06, 95% CI: 1.01-1.1, p = 0.007); the HbA1c concentration (OR: 1.42, 95% CI: 1.42-1.8; p = 0.005); the initial heart rate (OR: 1.05, 95% CI: 1.01-1.09, p = 0.004); and poor adherence to continuous positive airway pressure (CPAP) in cases of obstructive sleep apnea (OR: 3.36, 95% CI: 1.47-7.7, p = 0.004). In conclusion, a considerable percentage of patients evolved from the RH to the RfH phenotype despite changes in their treatment. Some easily measurable variables, such as heart rate, the time since the diagnosis, the HbA1c level, and the presence of untreated obstructive sleep apnea (or poor adherence to CPAP) have been demonstrated to be prognostic factors in the progression to RfH.

Good long-term adherence to continuous positive airway pressure therapy in patients with resistant hypertension and sleep apnea.

Although adequate adherence is paramount in achieving the beneficial effects of continuous positive airway pressure therapy in patients with obstructive sleep apnea, long-term adherence and the variables involved in continuous positive airway pressure compliance in patients with resistant hypertension and obstructive sleep apnea are yet unknown. We conducted a prospective, multicentre, observational study in 177 patients recruited from hypertensive units with resistant hypertension confirmed by means of 24-hr blood pressure monitoring (blood pressure ≥ 130 and/or ≥ 80 mmHg, despite taking at least three antihypertensive drugs or < 130/80 mmHg with > 3 drugs) and obstructive sleep apnea (apnea-hypopnea index ≥ 5 in a respiratory polygraph) who were prescribed continuous positive airway pressure treatment. Good adherence was defined as an average cumulative continuous positive airway pressure use of ≥ 4 hr per night at the end of the follow-up. A multivariate Cox regression analysis was performed to identify independent predictors of continuous positive airway pressure adherence. Patients were followed for a median of 57.6 (42-72) months after initiating continuous positive airway pressure therapy. At the end of the follow-up, the median continuous positive airway pressure use was 5.7 (inter-quartile range 3.9-6.6) hr per night, and 132 patients (74.5%) showed good continuous positive airway pressure adherence. The only baseline variable associated with poor adherence was the presence of previous stroke (hazard ratio 4.00, 95% confidence interval 1.92-8.31). Adequate adherence at 1 month also predicted good adherence at the end of the follow-up (hazard ratio 14.4, 95% confidence interval 4.94-56). Both variables also predicted adherence at a threshold of 6 hr per night. Our results show that good continuous positive airway pressure adherence is an achievable and feasible goal in patients with resistant hypertension and obstructive sleep apnea. Previous stroke and short-term adherence predicted long-term adherence.

Effect of continuous positive airway pressure in patients with true refractory hypertension and sleep apnea: a post-hoc intention-to-treat analysis of the HIPARCO randomized clinical trial.

RATIONALE: Continuous positive airway pressure (CPAP) can significantly reduce blood pressure (BP) levels in patients with resistant hypertension and sleep apnea (OSA); however, the effect on patients with refractory hypertension (RfH) is not known. This study seeks to evaluate the effect of CPAP treatment on BP levels in patients with OSA and RfH, compared with those with OSA and resistant hypertension. METHODS: Post-hoc analysis of the HIPARCO randomized clinical trial on the effect of CPAP treatment on BP levels in patients with resistant hypertension. Those patients with uncontrolled 24-h ambulatory BP monitoring readings (>130 and/or >80 mmHg) in SBP or DBP were considered to have resistant hypertension (if they were taking three or four antihypertensive drugs) or RfH (if they were taking at least five drugs). OSA patients were randomized to receive CPAP or usual care for 3 months. They underwent a second 24-h ambulatory BP monitoring study to establish the effect of CPAP treatment on BP levels in both groups. RESULTS: A total of 98 patients were randomized to CPAP (19 RfH/79 resistant hypertension) and 96 to usual care (21 RfH/75 resistant hypertension). BP readings dropped more marked in patients with RfH than resistant hypertension, in both 24-h SBP (-9 vs. -1.6 mmHg, P = 0.021) and 24-h DBP (-7.3 vs. -2.3 mmHg, P = 0.074), especially at night (-11.3 vs. -3.8, P = 0.121 and -8.8 vs. -2.2, P = 0.054) respectively. Adjusted difference between groups was statistically significant in 24-h SBP levels (-7.4 mmHg, P = 0.021). CONCLUSION: CPAP lowers BP levels in both resistant hypertension and RfH patients although the degree of this reduction is higher in those with RfH especially during the night.

Beyond Resistant Hypertension.

Obstructive sleep apnea (OSA) is an independent cause of resistant hypertension (RH) but its association with refractory hypertension (RfH), a recently described form of severe hypertension, has not yet been investigated. This study seeks to analyze the association between the presence and severity of OSA/OSA syndrome with RfH and to compare it with a group of patients with OSA/OSA syndrome and RH. We conducted a multicenter, cross-sectional study of consecutive patients diagnosed with RH by means of 24-hour ambulatory blood pressure monitoring. Those patients with blood pressure levels ≥130/80 mm Hg, despite taking at least 5 antihypertensive drugs, were considered to have true RfH. All patients underwent a sleep study and completed a detailed clinical history related to OSA, current medication, and cardiovascular diseases. Overall, 229 patients were included (mean age, 58.3 years; 63% male), of whom 42 (18.3%) satisfied the criteria for RfH. Compared with those with RH, patients with RfH had a higher cardiovascular risk profile, higher blood pressure measurements, and a 2-fold greater risk of having both severe OSA (odds ratio, 2.1, with a prevalence of apnea-hypopnea index ≥15, 95.2% and apnea-hypopnea index ≥30, 64.3%) and OSA syndrome (apnea-hypopnea index ≥5+Epworth Sleepiness Scale >10; odds ratio, 1.9; 52.4% versus 37.3%; P=0.023), as well as higher OSA severity (apnea-hypopnea index, 41.8 versus 33.8 events/h; P=0.026). Patients with RfH had an even greater prevalence and severity of OSA and OSA syndrome than RH patients, highlighting the need to identify these patients to refer them to sleep units on a preferential basis.

Precision Medicine in Patients With Resistant Hypertension and Obstructive Sleep Apnea: Blood Pressure Response to Continuous Positive Airway Pressure Treatment.

BACKGROUND: In patients with resistant hypertension (RH) and obstructive sleep apnea (OSA), the blood pressure response to continuous positive airway pressure (CPAP) treatment is highly variable and could be associated with differential micro-ribonucleic acid (miRNA) profiles. Currently, no available methods exist to identify patients who will respond favorably to CPAP treatment. OBJECTIVES: The aim of this study was to identify plasma miRNA profiles that predict blood pressure responses to CPAP treatment. METHODS: Cardiovascular system-focused circulating miRNA expression was evaluated in plasma samples using an 84-miRNA array among patients with RH and OSA at baseline and after 3 months of adherent CPAP use. Pathway analysis and miRNA target gene enrichment were performed in silico. Plasma levels of peptides and hormones related to cardiovascular function were also measured. RESULTS: The OSA responder group exhibited blood pressure decreases exceeding the observed median (>4.5 mm Hg) after CPAP, which were not present in the nonresponder group (≤4.5 mm Hg) (p < 0.01). Three miRNAs provided a discriminatory predictive model for such a favorable blood pressure response to CPAP (area under the curve: 0.92; p = 0.01). Additionally, CPAP treatment significantly altered a total of 47 plasma miRNAs and decreased aldosterone-to-renin ratios in the responder group (p = 0.016) but not in the nonresponder group. CONCLUSIONS: A singular pre-CPAP treatment cluster of 3 plasma miRNAs predicts blood pressure responses to CPAP treatment in patients with RH and OSA. CPAP treatment is accompanied by changes in cardiovascular system-related miRNAs that may potentially influence the risk for cardiovascular disease among patients with OSA and RH. (Effect of Continuous Positive Airway Pressure [CPAP] Treatment in the Control of Refractory Hypertension; NCT00616265).

A Bayesian cost-effectiveness analysis of a telemedicine-based strategy for the management of sleep apnoea: a multicentre randomised controlled trial.

BACKGROUND: Compliance with continuous positive airway pressure (CPAP) therapy is essential in patients with obstructive sleep apnoea (OSA), but adequate control is not always possible. This is clinically important because CPAP can reverse the morbidity and mortality associated with OSA. Telemedicine, with support provided via a web platform and video conferences, could represent a cost-effective alternative to standard care management. AIM: To assess the telemedicine impact on treatment compliance, cost-effectiveness and improvement in quality of life (QoL) when compared with traditional face-to-face follow-up. METHODS: A randomised controlled trial was performed to compare a telemedicine-based CPAP follow-up strategy with standard face-to-face management. Consecutive OSA patients requiring CPAP treatment, with sufficient internet skills and who agreed to participate, were enrolled. They were followed-up at 1, 3 and 6 months and answered surveys about sleep, CPAP side effects and lifestyle. We compared CPAP compliance, cost-effectiveness and QoL between the beginning and the end of the study. A Bayesian cost-effectiveness analysis with non-informative priors was performed. RESULTS: We randomised 139 patients. At 6 months, we found similar levels of CPAP compliance, and improved daytime sleepiness, QoL, side effects and degree of satisfaction in both groups. Despite requiring more visits, the telemedicine group was more cost-effective: costs were lower and differences in effectiveness were not relevant. CONCLUSIONS: A telemedicine-based strategy for the follow-up of CPAP treatment in patients with OSA was as effective as standard hospital-based care in terms of CPAP compliance and symptom improvement, with comparable side effects and satisfaction rates. The telemedicine-based strategy had lower total costs due to savings on transport and less lost productivity (indirect costs). TRIAL REGISTER NUMBER: NCT01716676.

Obstructive sleep apnoea in the elderly: role of continuous positive airway pressure treatment.

Almost all the information about the effect of continuous positive airway pressure (CPAP) in patients with obstructive sleep apnoea (OSA) comes from clinical trials involving only middle-aged patients. The objective of this study was to assess the effect of CPAP treatment in elderly patients with severe OSA on clinical, quality-of-life and neurocognitive spheres. We performed an open-label, randomised, multicentre clinical trial in a consecutive clinical cohort of 224 elderly (≥70 years old) patients with confirmed severe OSA (apnoea-hypopnea index ≥30) randomised to receive CPAP (n=115) or no CPAP (n=109) for 3 months. A sleep study was performed by either full polysomnography or respiratory polygraphy. CPAP titration was performed by an autoCPAP device. The primary endpoint was quality of life (Quebec Sleep Questionnaire) and secondary endpoints included sleep-related symptoms, presence of anxiety/depression, office-based blood pressure and some neurocognitive tests. The mean±sd age was 75.5±3.9 years. The CPAP group achieved a greater improvement in all quality-of-life domains (p<0.001; effect size: 0.41-0.98), sleep-related symptoms (p<0.001; effect size 0.31-0.91) as well as anxiety (p=0.016; effect size 0.51) and depression (p<0.001; effect size: 0.28) indexes and some neurocognitive tests (digit symbol test (p=0.047; effect size: 0.20) and Trail Making Test A (p=0.029; effect size: 0.44)) in an intention-to-treat analysis. In conclusion, CPAP treatment resulted in an improvement in quality of life, sleep-related symptoms, anxiety and depression indexes and some neurocognitive aspects in elderly people with severe OSA.

Effect of continuous positive airway pressure and upper airway surgery on exhaled breath condensate and serum biomarkers in patients with sleep apnea.

INTRODUCTION: Studies on inflammation biomarkers in serum and in exhaled breath condensate (EBC) in obstructive sleep apnea (OSA) have shown conflicting results. The objective of this study is to assess EBC and serum biomarkers in OSA patients at baseline and after continuous positive airway pressure (CPAP) or upper airway surgery (UAS). PATIENTS AND METHODS: Nine OSA patients referred for UAS were matched for anthropometric characteristics and apnea-hypopnea index with 20 patients receiving CPAP. pH, nitrite (NO2(-)), nitrate and interleukin 6 in EBC and NO2(-), nitrate, leukotriene B4 and interleukin 6 in serum were determined. EBC and serum samples were collected at baseline and 3 months after CPAP or UAS. RESULTS: Patients' mean body mass index was 30 (range 24.9-40) kg/m(2). EBC biomarker levels at baseline were within normal range and did not differ significantly after CPAP or UAS. No significant changes were observed in the serum concentration of the biomarkers determined after CPAP but the serum concentration of NO2(-) increased significantly at 3 months after UAS (P=.0078). CONCLUSION: In mildly obese OSA patients, EBC biomarkers of inflammation or oxidative stress were normal at baseline and remained unchanged 3 months after UAS or CPAP. Although UAS was not effective in terms of reducing OSA severity, it was associated with an increase in serum NO2(-).

A randomized controlled study of CPAP effect on plasma aldosterone concentration in patients with resistant hypertension and obstructive sleep apnea.

OBJECTIVE: The high prevalence of obstructive sleep apnea in patients with resistant hypertension could be mediated by an activation of the renin-angiotensin-aldosterone system. This study assessed the impact of continuous positive airway pressure (CPAP) treatment on plasma aldosterone concentration (PAC). METHODS: One hundred and twenty-four patients with resistant hypertension were assessed, and those who fulfilled inclusion criteria (n = 116) underwent full night polysomnography, 24-h ambulatory blood pressure monitoring, and PAC measurement. Patients with an apnea-hypopnea index above 15 (n = 102) were randomized to CPAP (n = 50) or to conventional treatment (n = 52) for 3 months. RESULTS: Seventy-eight patients completed the follow-up (36 CPAP, 42 conventional treatment); 58 had true resistant hypertension (74.3%), whereas 20 had white-coat resistant hypertension (25.6%). Most patients were men (70.7%), age 58.3 ±â€Š9.4 years, and the mean apnea-hypopnea index was 50.1 ±â€Š21.6. In patients with true resistant hypertension, CPAP achieved a significant decrease in most 24-h BP measurements and a nonsignificant decrease in PAC (25 ±â€Š8.7 vs. 22.7 ±â€Š9 ng/dl; P < 0.182). In patients with white-coat resistant hypertension, CPAP achieved a significant decrease in PAC (26.1 ±â€Š11.2 vs. 18.9 ±â€Š10.1 ng/dl; P < 0.041) and in night-time DBP. After adjustment, a weak but significant association was found between cumulative time spent with SaO2 below 90% (CT90%) and baseline PAC (P < 0.047, R 0.019), and between changes in PAC and changes in office DBP (P < 0.020, R 0.083) CONCLUSIONS:: Night-time hypoxemia and changes in DBP showed an association with baseline and changes in PAC, respectively. CPAP achieved a significant reduction in PAC only in patients with white-coat resistant hypertension, although the CPAP effect on BP was highest in patients with true resistant hypertension.

Effect of CPAP on blood pressure in patients with obstructive sleep apnea and resistant hypertension: the HIPARCO randomized clinical trial.

IMPORTANCE: More than 70% of patients with resistant hypertension have obstructive sleep apnea (OSA). However, there is little evidence about the effect of continuous positive airway pressure (CPAP) treatment on blood pressure in patients with resistant hypertension. OBJECTIVE: To assess the effect of CPAP treatment on blood pressure values and nocturnal blood pressure patterns in patients with resistant hypertension and OSA. DESIGN, SETTING, AND PARTICIPANTS: Open-label, randomized, multicenter clinical trial of parallel groups with blinded end point design conducted in 24 teaching hospitals in Spain involving 194 patients with resistant hypertension and an apnea-hypopnea index (AHI) of 15 or higher. Data were collected from June 2009 to October 2011. INTERVENTIONS: CPAP or no therapy while maintaining usual blood pressure control medication. MAIN OUTCOMES AND MEASURES: The primary end point was the change in 24-hour mean blood pressure after 12 weeks. Secondary end points included changes in other blood pressure values and changes in nocturnal blood pressure patterns. Both intention-to-treat (ITT) and per-protocol analyses were performed. RESULTS: A total of 194 patients were randomly assigned to receive CPAP (n = 98) or no CPAP (control; n = 96). The mean AHI was 40.4 (SD, 18.9) and an average of 3.8 antihypertensive drugs were taken per patient. Baseline 24-hour mean blood pressure was 103.4 mm Hg; systolic blood pressure (SBP), 144.2 mm Hg; and diastolic blood pressure (DBP), 83 mm Hg. At baseline, 25.8% of patients displayed a dipper pattern (a decrease of at least 10% in the average nighttime blood pressure compared with the average daytime blood pressure). The percentage of patients using CPAP for 4 or more hours per day was 72.4%. When the changes in blood pressure over the study period were compared between groups by ITT, the CPAP group achieved a greater decrease in 24-hour mean blood pressure (3.1 mm Hg [95% CI, 0.6 to 5.6]; P = .02) and 24-hour DBP (3.2 mm Hg [95% CI, 1.0 to 5.4]; P = .005), but not in 24-hour SBP (3.1 mm Hg [95% CI, -0.6 to 6.7]; P = .10) compared with the control group. Moreover, the percentage of patients displaying a nocturnal blood pressure dipper pattern at the 12-week follow-up was greater in the CPAP group than in the control group (35.9% vs 21.6%; adjusted odds ratio [OR], 2.4 [95% CI, 1.2 to 5.1]; P = .02). There was a significant positive correlation between hours of CPAP use and the decrease in 24-hour mean blood pressure (r = 0.29, P = .006), SBP (r = 0.25; P = .02), and DBP (r = 0.30, P = .005). CONCLUSIONS AND RELEVANCE: Among patients with OSA and resistant hypertension, CPAP treatment for 12 weeks compared with control resulted in a decrease in 24-hour mean and diastolic blood pressure and an improvement in the nocturnal blood pressure pattern. Further research is warranted to assess longer-term health outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00616265.

Neurophysiological two-channel polysomnographic device in the diagnosis of sleep apnea.

STUDY OBJECTIVE: Our objective was to evaluate a portable device (Somté, Compumedics, Australia), which incorporates 2 neurophysiological channels (electroencephalography and electrooculography) with cardiorespiratory monitoring for the diagnosis of obstructive sleep apnea (OSA). METHOD: Full polysomnography (PSG) and Somté recordings were simultaneously performed in 68 patients with suspected OSA. Data were analyzed blindly by 2 scorers. RESULTS: A good agreement between methods in sleep efficiency was observed (68.8% [18.4] with PSG vs 68% [19.1] with Somté [p: n.s.] for scorer 1, and 67.5% [19.1] vs 68.4% [18.5; p: n.s.] for scorer 2). The apnea-hypopnea index (AHI) obtained with Somté was lower than with PSG: 19 (17.8) vs 21.7 (19) (p < 0.001) for scorer 1, and 16.6 (16.7) vs 20 (18.8) (p < 0.001) for scorer 2. The sensitivity of Somté for a PSG-AHI > 5 was 91% for scorer 1 and 90% for scorer 2, while specificity was 77% and 90%, respectively. The areas under the receiver operating curve for different PSG-AHI cutoff points (≥ 5, ≥ 15, and ≥ 30) were 0.81, 0.90, and 0.86, respectively, for scorer 1, and 0.90, 0.88, and 0.83 for scorer 2. CONCLUSIONS: These data suggest that Somté is an effective device to identify sleep and respiratory variables in patients with suspected OSA.