Interleukin 6 as a marker of depression in women with sleep apnea.

Depression is common in women with obstructive sleep apnea (OSA), but objective markers of depression have not yet been explored in such patients. We hypothesized that inflammation and antioxidant biomarkers may be associated with depression in a cohort of OSA women. We conducted a multicentre, cross-sectional study in 247 women diagnosed with moderate-to-severe OSA. Depression was assessed by the depression subscale of the Hospital Anxiety and Depression Questionnaire (HAD-D) and defined as a score ≥11. Associations between tumour necrosis factor α (TNFα), interleukin 6 (IL-6), C-reactive protein (CRP), intercellular adhesion molecule 1 (ICAM-1), catalase (CAT), superoxide dismutase (SOD) and brain-derived neurotrophic factor (BDNF) plasma levels and depression were assessed. The women had a median (25th-75th percentiles) age of 58 (51-65) years, body mass index (BMI) of 33.5 (29.0-38.3) Kg/m2 , Epworth Sleepiness Scale (ESS) score of 10 (6-13) and apnea-hypopnea index (AHI) of 33.3 (22.8-49.3). Logistic regression analyses revealed that only IL6 levels were associated with the presence of depression (adjusted odds ratio [OR], 1.20; 95% confidence interval [CI], 1.08-1.34), whereas linear regression further confirmed that IL6 levels were significantly associated with HAD-D scores (ß = .154; 95% CI, 0.03-0.30). Multivariate regression analysis showed that IL6 (OR, 1.22; 95% CI, 1.09-1.36), ESS (OR, 1.10; 95% CI 1.02-1.19) and physical activity <30 min/day (OR, 2.51; 95% CI, 1.25-5.05) were independent predictors of depression. Thus, we conclude that in a cohort of women with moderate-to-severe OSA, IL6 levels are independently associated with the presence of depression and correlate with depression scores. Low physical activity and higher ESS scores are also independent indicators of risk of depression in this population.

Conventional Polysomnography Is Not Necessary for the Management of Most Patients with Suspected Obstructive Sleep Apnea. Noninferiority, Randomized Controlled Trial.

RATIONALE: Home respiratory polygraphy may be a simpler alternative to in-laboratory polysomnography for the management of more symptomatic patients with obstructive sleep apnea, but its effectiveness has not been evaluated across a broad clinical spectrum. OBJECTIVES: To compare the long-term effectiveness (6 mo) of home respiratory polygraphy and polysomnography management protocols in patients with intermediate-to-high sleep apnea suspicion (most patients requiring a sleep study). METHODS: A multicentric, noninferiority, randomized controlled trial with two open parallel arms and a cost-effectiveness analysis was performed in 12 tertiary hospitals in Spain. Sequentially screened patients with sleep apnea suspicion were randomized to respiratory polygraphy or polysomnography protocols. Moreover, both arms received standardized therapeutic decision-making, continuous positive airway pressure (CPAP) treatment or a healthy habit assessment, auto-CPAP titration (for CPAP indication), health-related quality-of-life questionnaires, 24-hour blood pressure monitoring, and polysomnography at the end of follow-up. The main outcome was the Epworth Sleepiness Scale measurement. The noninferiority criterion was -2 points on the Epworth scale. MEASUREMENTS AND MAIN RESULTS: In total, 430 patients were randomized. The respiratory polygraphy protocol was noninferior to the polysomnography protocol based on the Epworth scale. Quality of life, blood pressure, and polysomnography were similar between protocols. Respiratory polygraphy was the most cost-effective protocol, with a lower per-patient cost of 416.7€. CONCLUSIONS: Home respiratory polygraphy management is similarly effective to polysomnography, with a substantially lower cost. Therefore, polysomnography is not necessary for most patients with suspected sleep apnea. This finding could change established clinical practice, with a clear economic benefit. Clinical trial registered with www.clinicaltrials.gov (NCT 01752556).

Effect of continuous positive airway pressure on blood pressure and metabolic profile in women with sleep apnoea.

Continuous positive airway pressure (CPAP) reduces blood pressure levels in hypertensive patients with obstructive sleep apnoea (OSA). However, the role of CPAP in blood pressure and the metabolic profile in women has not yet been assessed. In this study we investigated the effect of CPAP on blood pressure levels and the glucose and lipid profile in women with moderate-to-severe OSA.A multicentre, open-label, randomised controlled trial was conducted in 307 women diagnosed with moderate-to-severe OSA (apnoea-hypopnoea index ≥15 events·h-1) in 19 Spanish Sleep Units. Women were randomised to CPAP (n=151) or conservative treatment (n=156) for 12 weeks. Changes in office blood pressure measures as well as in the glucose and lipid profile were assessed in both groups.Compared with the control group, the CPAP group achieved a significantly greater decrease in diastolic blood pressure (-2.04 mmHg, 95% CI -4.02- -0.05; p=0.045), and a nonsignificantly greater decrease in systolic blood pressure (-1.54 mmHg, 95% CI -4.58-1.51; p=0.32) and mean blood pressure (-1.90 mmHg, 95% CI -4.0-0.31; p=0.084). CPAP therapy did not change any of the metabolic variables assessed.In women with moderate-to-severe OSA, 12 weeks of CPAP therapy improved blood pressure, especially diastolic blood pressure, but did not change the metabolic profile, compared with conservative treatment.

Efficacy of continuous positive airway pressure treatment on 5-year survival in patients with ischaemic stroke and obstructive sleep apnea: a randomized controlled trial.

The main purpose of the present analysis is to assess the influence of introducing early nasal continuous positive airway pressure (nCPAP) treatment on cardiovascular recurrences and mortality in patients with a first-ever ischaemic stroke and moderate-severe obstructive sleep apnea (OSA) with an apnea-hypopnea index (AHI) ≥20 events h(-1) during a 5-year follow-up. Patients received conventional treatment for stroke and were assigned randomly to the nCPAP group (n = 71) or the control group (n = 69). Cardiovascular events and mortality were registered for all patients. Survival and cardiovascular event-free survival analysis were performed after 5-year follow-up using the Kaplan-Meier test. Patients in the nCPAP group had significantly higher cardiovascular survival than the control group (100 versus 89.9%, log-rank test 5.887; P = 0.015) However, and also despite a positive tendency, there were no significant differences in the cardiovascular event-free survival at 68 months between the nCPAP and control groups (89.5 versus 75.4%, log-rank test 3.565; P = 0.059). Early nCPAP therapy has a positive effect on long-term survival in ischaemic stroke patients and moderate-severe OSA.

Continuous Positive Airway Pressure Treatment Does not Reduce Uric Acid Levels in OSA Women.

OBJECTIVES: Although an association between uric acid (UA) levels and obstructive sleep apnea (OSA) has been reported, the effect of continuous positive airway pressure (CPAP) on this measure is yet unclear. We aimed to investigate the effect of CPAP therapy on serum UA levels in patients with OSA. METHODS: We conducted a multicenter, open-label, randomized controlled trial in 307 women diagnosed with moderate-to-severe OSA (apnea-hypopnea index [AHI]≥15) in 19 Spanish Sleep Units. Women were randomized to CPAP (n=151) or conservative treatment (n=156) for 12 weeks. Changes in serum UA measures were assessed on an intention-to-treat basis. Additional analyses were conducted in the subgroup of women with CPAP adherence ≥4h/night and those with UA levels ≥6mg/dl. RESULTS: Women had a mean (SD) age of 57.1 (10.1) years, median (first-third quartile) body mass index of 33.7 (29.0-38.5) mg/kg2 and AHI of 32.0 (22.6-48.5). The average serum UA measure was 5.11 (1.26) mg/dl, and 80 (26.1%) participants had UA≥6mg/dl. Compared with the control group, the CPAP group did not achieve any reduction in UA levels (non-adjusted intergroup difference -0.03mg/dl, 95%CI -0.20 to 0.13; p=0.702) after 12 weeks of follow-up. These results did not change when the analysis was restricted to women with CPAP adherence ≥4h/night, or the subgroup of women with hyperuricemia. CONCLUSIONS: Twelve weeks of CPAP therapy does not reduce UA levels compared to conservative treatment in women with moderate-to-severe OSA.

Relationship between the endothelial dysfunction and the expression of the ß1-subunit of BK channels in a non-hypertensive sleep apnea group.

STUDY OBJECTIVES: Vascular damage must be diagnosed early in patients with hypertension. In this regard, endothelial dysfunction (ED) is an early sign of vascular disease and a predictor of cardiovascular diseases. In obstructive sleep apnea (OSA), intermittent hypoxia triggers ED, but mechanisms are not clear. In this context, it has been described that BK channels regulates arterial tone and that chronic and intermittent hypoxia downregulates the expression of the BK channel ß1-subunit facilitating vasoconstriction. Thus, we investigated the relationship among hypoxemia, ED, and mRNA expression of the ß1-subunit in patients with severe OSA. We aimed to assess (1) ED in non-hypertensive patients with OSA using laser-Doppler flowmetry, (2) BK ß1-subunit mRNA expression, and (3) the impact of continuous positive airway pressure (CPAP) treatment on ED and ß1-subunit regulation. METHODS: OSA patients underwent 24-hour blood pressure monitoring to exclude hypertension. Laser-Doppler flowmetry was performed to assess ED, and ß1-subunit mRNA expression was evaluated using a blood test of peripheral blood leukocytes at baseline and after 3 months of CPAP treatment. RESULTS: In normotensive patients with OSA, endothelial function correlated with the severity of OSA. CPAP improved endothelial function in normotensive OSA patients and the speed of the arterial response was significantly correlated with ß1-subunit mRNA expression. ß1-subunit mRNA expression at baseline correlated inversely with its change after CPAP. CONCLUSIONS: Sleep apnea is related to ED in normotensive patients with OSA. CPAP therapy improves endothelial function and regulates ß1-subunit mRNA expression.

Quality of life in patients with congestive heart failure and central sleep apnea.

OBJECTIVE: To assess the impact of Cheyne-Stoke respiration-central sleep apnea (CSR-CSA) on quality of life (QOL) in patients with congestive heart failure (CHF). QOL was established using the MLHFQ (Minnesota Living with Heart Failure Questionnaire), and the FOSQ (Functional Outcomes of Sleep Questionnaire). METHODS: We examined 90 patients with CHF. The diagnosis of CSR-CSA was performed by polysomnography. We established a correlation between the apnea-hypopnea index (AHI) and the MLHFQ and FOSQ scores. RESULTS: Five patients were excluded (obstructive sleep apnea). Of the 85 remaining patients, 25 presented CSR-CSA. The mean MLHFQ score was higher in patients with CHF and CSR-CSA (25.8+/-2.97 vs. 16.6+/-2.05; p=0.01), and showed a significant yet moderate correlation with the AHI. A lower mean FOSQ score was obtained for the group of patients with CHF and CSR-CSA (78.4+/-4.31 vs. 88.47+/-2.4; p=0.03), showing weak negative correlation with the AHI. CONCLUSION: According to the MLHFQ scores, it seems that CHF patients with CSR-CSA have a worse QOL than those with CHF alone. Although this could be attributable to a greater impairment of heart function in the former group, the FOSQ scores indicate some influence of their sleep disorder on the impairment of QOL.

Respiratory polygraphy with actigraphy in the diagnosis of sleep apnea-hypopnea syndrome.

OBJECTIVE: To determine the utility and reliability of a respiratory polygraphy (RP) device with actigraphy (Apnoescreen II; Erich Jaeger GMBH & CoKg; Wuerzburg, Germany) in the diagnosis of sleep apnea-hypopnea syndrome (SAHS). DESIGN: A prospective randomized study with blinded analysis. PATIENTS: Sixty-two patients with suspected SAHS. MEASUREMENTS: the following two RP studies were performed: one in the sleep laboratory (sleep laboratory RP [LRP]), simultaneously with polysomnography; and the other at home (home RP [HRP]). To study the interobserver reliability of RP, two manual analyses were carried out by two different researchers. RESULTS: In LRP, when the respiratory disturbance index was calculated using the total sleep time estimated by actigraphy (RDI) as a denominator, the sensitivity ranged between 94.6% and 100%, and the specificity between 88% and 96.7% for the different cutoff points of the apnea-hypopnea indexes studied. When the respiratory disturbance index was calculated according to the total recording time (RDITRT), the sensitivity was slightly lower (91.6 to 96.9%) and the specificity was similar (92 to 96.7%). In HRP, the sensitivity of the RDI ranged between 83.8% and 95.8%, and the specificity between 92% and 100%, whereas, when the RDITRT was used, the sensitivity was between 83.8% and 87.5%, and the specificity was between 94.7% and 100%. With regard to interobserver reliability, the intraclass correlation coefficient for the RDI of the two analyses of the RP was 0.99 for both LPR and HPR. CONCLUSION: HPR is an effective and reliable technique for the diagnosis of SAHS, although it is less sensitive than LRP. Wrist actigraphy improves the results of HRP only slightly.

[Severe obstructive sleep apnea syndrome in a toddler]. / Síndrome de apnea obstructiva del sueño infantil de presentación grave.

We report the case of a 3-year-old boy who had experienced intense snoring, frequent awakenings, intense respiratory effort during sleep, and delayed growth starting at the age of 15 months. He underwent adenoidectomy at 18 months. Symptoms initially improved but reappeared 3 months after surgery. He underwent a second adenoidectomy, this time with tonsillectomy, but there was no significant clinical improvement. Polysomnography revealed severe sleep apnea-hypopnea with an apnea-hypopnea index of 45. Continuous positive airway pressure improved sleep quality, although some symptoms, mainly snoring, persisted. A third adenoidectomy was necessary to normalize his breathing pattern during sleep.

[Blood uric acid levels in patients with sleep-disordered breathing]. / Valores de ácido úrico en sangre en pacientes con trastornos respiratorios del sueño.

OBJECTIVE: Recurrent hypoxia associated with sleep apnea-hypopnea syndrome (SAHS) leads to an increase in the degradation of adenosine triphosphatase to xanthine and, secondarily, to an increase in uric acid concentrations. The aim of the present study was to determine whether there is a correlation between uric acid levels in peripheral blood and sleep-disordered breathing, independently of known confounding factors. PATIENTS AND METHODS: We carried out a retrospective cross-sectional study of 1135 patients evaluated for suspected SAHS. For all patients, a medical history was taken using a standardized protocol. In addition, biochemical analysis of venous blood and an overnight sleep study (with either conventional polysomnography or home monitoring) were carried out. RESULTS: The mean (SD) concentration of uric acid was 6.31 (1.5) mg/dL, and 36% of patients had concentrations above established normal values for their sex. We found a significant correlation between uric acid levels and some sleep study parameters (number of respiratory events, number of desaturations, or the cumulative percentage of time with oxygen saturation less than 90%). Those patients with more respiratory events (apnea-hypopnea index or respiratory event index >or= 30) had higher uric acid levels than those with mild or no SAHS. However, this difference was not apparent in the univariate analysis of variance, in which body mass index and cholesterol and triglyceride levels were considered confounding factors. CONCLUSIONS: Uric acid levels are positively correlated with the number of obstructive respiratory episodes and oxygen desaturations during sleep, but this correlation seems to be influenced by other factors, such as obesity.

Brain natriuretic peptide in patients with congestive heart failure and central sleep apnea.

STUDY OBJECTIVE: To assess the possible relationship between Cheyne-Stokes respiration (CSR) associated with central sleep apnea (CSA) syndrome and brain natriuretic peptide (BNP) in an outpatient population presenting with stable congestive heart failure (CHF). MEASUREMENTS AND RESULTS: Ninety patients with CHF due to systolic dysfunction (left ventricular ejection fraction

Obstructive sleep apnoea syndrome, endothelial function and markers of endothelialization. Changes after CPAP.

STUDY OBJECTIVES: This study tries to assess the endothelial function in vivo using flow-mediated dilatation (FMD) and several biomarkers of endothelium formation/restoration and damage in patients with obstructive sleep apnoea (OSA) syndrome at baseline and after three months with CPAP therapy. DESIGN: Observational study, before and after CPAP therapy. SETTING AND PATIENTS: We studied 30 patients with apnoea/hypopnoea index (AHI) >15/h that were compared with themselves after three months of CPAP therapy. FMD was assessed non-invasively in vivo using the Laser-Doppler flowmetry. Circulating cell-free DNA (cf-DNA) and microparticles (MPs) were measured as markers of endothelial damage and the vascular endothelial growth factor (VEGF) was determined as a marker of endothelial restoration process. MEASUREMENTS AND RESULTS: After three month with CPAP, FMD significantly increased (1072.26 ± 483.21 vs. 1604.38 ± 915.69 PU, p< 0.005) cf-DNA and MPs significantly decreased (187.93 ± 115.81 vs. 121.28 ± 78.98 pg/ml, p<0.01, and 69.60 ± 62.60 vs. 39.82 ± 22.14 U/µL, p<0.05, respectively) and VEGF levels increased (585.02 ± 246.06 vs. 641.11 ± 212.69 pg/ml, p<0.05). These changes were higher in patients with more severe disease. There was a relationship between markers of damage (r = -0.53, p<0.005) but not between markers of damage and restoration, thus suggesting that both types of markers should be measured together. CONCLUSIONS: CPAP therapy improves FMD. This improvement may be related to an increase of endothelial restoration process and a decrease of endothelial damage.

Effect of snoring and obstructive respiratory events on sleep architecture in adolescents.

OBJECTIVE: To evaluate the effect of snoring and obstructive respiratory events on the distribution of sleep stages and arousals in a nonselected group of adolescents from the general population. DESIGN: Cross-sectional study. SETTING: Randomly selected secondary schools in Seville, Spain. Patients A general population sample of 43 adolescents (mean [SD] age, 13.6 [1.77] years). INTERVENTIONS: A questionnaire for the investigation of sleep-related breathing disorders was administered. Symptoms were evaluated according to a 4-point frequency scale. Snorers answered "sometimes" or "often" to the question about snoring, and nonsnorers answered "never" or "rarely." All subjects underwent standard polysomnography at the sleep laboratory. RESULTS: Twenty-eight subjects were snorers; 15 were nonsnorers. No statistically significant differences were noted between both groups in the percentages of sleep stages, arousal index, awakenings, or wakefulness during sleep. Snorers showed a significantly higher number of respiratory arousals than nonsnorers (mean [SD], 1.14 [1.5] vs 0.33 [0.6], P<.05). However, neither the apnea-hypopnea index (AHI) nor the oxygen desaturation index correlated with the arousal index. Twelve snorers (27.5%) had an AHI of 2 or more; 13 nonsnorers (30.2%) had an AHI of less than 2. Snorers with some obstructive respiratory events had a significantly higher number of awakenings, a lower percentage of stage 4 sleep, and a higher number of respiratory events compared with nonsnorers. However, the total number of arousals and the arousal index were similar for both groups. Wakefulness during sleep tended to be longer in snorers than in nonsnorers although differences were not significant. The percentage of respiratory events that terminated with an arousal was greater in snorers who had an AHI of 2 or more than in nonsnorers who had an AHI of less than 2 (mean [SD], 8.4% [9.5%] vs 4.9% [11.53%], P<.05). CONCLUSIONS: These data indicate normal sleep architecture in the adolescents. Although snorers as well as adolescents with some polysomnographic abnormality showed a higher number of respiratory arousals than control subjects, most obstructive events did not terminate with a cortical arousal, which may suggest that adolescents share with younger children this mechanism for preserving sleep architecture.

Echocardiographic parameters in adolescents with sleep-related breathing disorders.

Few data are known about the effects of sleep-related breathing disorders (SRBD) on the cardiovascular system in adolescents. Forty healthy adolescents (mean age, 13.7 +/- 1.6 years) answered a questionnaire regarding symptoms of sleep-related breathing disorders (SRBD) and underwent a cardiorespiratory polygraphy and echocardiography. Echocardiographic data in snorers with polygraphic abnormalities suggestive of SRBD (positive group, n = 29) were compared with the results in nonsnorers without polygraphic abnormalities (n = 11) who were included in the control group. Ventricular dimensions and indices of left ventricular systolic function were within normal limits and were not significantly different between the two groups. Indices of left ventricular diastolic function were also within normal limits, but isovolumetric relaxation time (IVRT) was significantly longer among the positive group (72.5 +/- 8.4 msec) than among the controls (65.1 +/- 7.9 msec) (P = 0.018). Multiple regression analysis showed that posterior wall thickness was predicted by a model that included cardiac events related with respiratory events and/or desaturations, and respiratory disturbance index (RDI) in supine position. Deceleration of early diastolic flow was predicted by RDI, percentage of total recording time with SaO(2) < 90% (CT(90)), and age; the variability of isovolumetric relaxation time was predicted by a model that included RDI in supine position. We found a significant relationship between polygraphic parameters suggestive of SRBD and echocardiographic measurements of ventricular dimensions and diastolic function. Also, echocardiographic parameters suggestive of some degree of left ventricular diastolic dysfunction were found in snoring adolescents with polygraphic abnormalities.

Gender differences in obstructive sleep apnea syndrome: a clinical study of 1166 patients.

The objective of this study was to compare the frequency of some sociocultural, clinical, and anthropometric data between men and women in a sample of 1745 patients referred to a Sleep Unit for symptoms of obstructive sleep apnea (OSA). A standardized questionnaire was administered and anthropometric data were measured. Patients underwent a polysomnography (during a night or a nap) or an overnight home cardiorespiratory polygraphy. A total of 1166 patients (male/female ratio 4.9:1) fulfilled criteria of OSA (apnea-hypopnea index > or = 10). Women were employed, habitual drivers or workers at risk occupations in a lower percentage than men. Women came to the clinical interview accompanied by their partner less frequently than men. The frequency of snoring and daytime hypersomnolence was similar in both genders, although witnessed apneas were more frequent in males. Fatigue, morning headaches, insomnia, depression and use of sedatives were more frequent in women than in men. Women were older than men, more obese (although with an obesity pattern less centrally distributed), and referred hypertension more frequently. It is concluded that it is likely that women with OSA may be underdiagnosed due to circumstances related to the family lifestyle and sociocultural factors in addition to different OSA clinical expression.

Continuous Positive Airway Pressure Treatment Does not Reduce Uric Acid Levels in OSA Women / La presión positiva continua en las vías aéreas no reduce los niveles de ácido úrico en las mujeres con SAOS

Objectives: Although an association between uric acid (UA) levels and obstructive sleep apnea (OSA) has been reported, the effect of continuous positive airway pressure (CPAP) on this measure is yet unclear. We aimed to investigate the effect of CPAP therapy on serum UA levels in patients with OSA. Methods: We conducted a multicenter, open-label, randomized controlled trial in 307 women diagnosed with moderate-to-severe OSA (apnea-hypopnea index [AHI] ≥ 15) in 19 Spanish Sleep Units. Women were randomized to CPAP (n = 151) or conservative treatment (n = 156) for 12 weeks. Changes in serum UA measures were assessed on an intention-to-treat basis. Additional analyses were conducted in the subgroup of women with CPAP adherence ≥ 4 h/night and those with UA levels ≥ 6 mg/dl. Results: Women had a mean (SD) age of 57.1 (10.1) years, median (first-third quartile) body mass index of 33.7 (29.0-38.5) mg/kg2 and AHI of 32.0 (22.6-48.5). The average serum UA measure was 5.11 (1.26) mg/dl, and 80 (26.1%) participants had UA ≥ 6 mg/dl. Compared with the control group, the CPAP group did not achieve any reduction in UA levels (non-adjusted intergroup difference -0.03mg/dl, 95%CI -0.20 to 0.13; p = 0.702) after 12 weeks of follow-up. These results did not change when the analysis was restricted to women with CPAP adherence ≥4 h/night, or the subgroup of women with hyperuricemia. Conclusions: Twelve weeks of CPAP therapy does not reduce UA levels compared to conservative treatment in women with moderate-to-severe OSA

Objetivos: Aunque se ha determinado una asociación entre los niveles de ácido úrico (AU) y el síndrome de apnea obstructiva del sueño (SAOS), el efecto de la presión positiva continua en las vías aéreas (CPAP) en esta medida todavía no está claro. El objetivo fue determinar el efecto de la CPAP en los niveles séricos de AU en pacientes con SAOS. Métodos: Se llevó a cabo un ensayo abierto, aleatorizado, controlado, multicéntrico en 307 mujeres diagnosticadas con SAOS de moderado a grave (índice de apneas-hipopneas [IAH]≥15) en 19 unidades del sueño españolas. Fueron aleatorizadas a recibir CPAP (n=151) o tratamiento conservador (n=156) durante 12 semanas. Los cambios en las medidas de AU sérico se estimaron mediante análisis por intención de tratar. Se llevaron a cabo análisis adicionales en el subgrupo de mujeres con adherencia a CPAP ≥ 4 h/noche y en aquellas con niveles de AU ≥ 6mg/dl. Resultados: La edad media (DE) de las participantes fue 57,1 (10,1) años, la mediana (primer y tercer cuartil) del índice de masa corporal 33,7 (29,0-38,5) mg/kg2 y el IAH 32,0 (22,6-48,5). El nivel medio de AU fue 5,11 (1,26) mg/dl, y 80 (26,1%) participantes tuvieron AU≥6mg/dl. Comparado con el grupo control, el grupo CPAP no consiguió ninguna reducción de los niveles de AU (diferencia intergrupo no ajustada: -0,03 mg/dl; IC 95%: -0,20-0,13; p= 0,702) tras 12 semanas de seguimiento. El análisis no varió cuando se restringió a las mujeres con adherencia a CPAP ≥ 4h/noche o al subgrupo de mujeres con hiperuricemia. Conclusiones: Doce semanas de terapia con CPAP no reducen los niveles de AU en comparación con el tratamiento conservador en mujeres con SAOS de moderado a grave

Effectiveness of home single-channel nasal pressure for sleep apnea diagnosis.

INTRODUCTION: Home single-channel nasal pressure (HNP) may be an alternative to polysomnography (PSG) for obstructive sleep apnea (OSA) diagnosis, but no cost studies have yet been carried out. Automatic scoring is simpler but generally less effective than manual scoring. OBJECTIVES: To determine the diagnostic efficacy and cost of both scorings (automatic and manual) compared with PSG, taking as a polysomnographic OSA diagnosis several apnea-hypopnea index (AHI) cutoff points. METHODS: We included suspected OSA patients in a multicenter study. They were randomized to home and hospital protocols. We constructed receiver operating characteristic (ROC) curves for both scorings. Diagnostic efficacy was explored for several HNP AHI cutoff points, and costs were calculated for equally effective alternatives. RESULTS: Of 787 randomized patients, 752 underwent HNP. Manual scoring produced better ROC curves than automatic for AHI < 15; similar curves were obtained for AHI ≥ 15. A valid HNP with manual scoring would determine the presence of OSA (or otherwise) in 90% of patients with a polysomnographic AHI ≥ 5 cutoff point, in 74% of patients with a polysomnographic AHI ≥ 10 cutoff point, and in 61% of patients with a polysomnographic AHI ≥ 15 cutoff point. In the same way, a valid HNP with automatic scoring would determine the presence of OSA (or otherwise) in 73% of patients with a polysomnographic AHI ≥ 5 cutoff point, in 64% of patients with a polysomnographic AHI ≥ 10 cutoff point, and in 57% of patients with a polysomnographic AHI ≥ 15 cutoff point. The costs of either HNP approaches were 40% to 70% lower than those of PSG at the same level of diagnostic efficacy. Manual HNP had the lowest cost for low polysomnographic AHI levels (≥ 5 and ≥ 10), and manual and automatic scorings had similar costs for higher polysomnographic cutoff points (AHI ≥ 15) of diagnosis. CONCLUSION: Home single-channel nasal pressure (HNP) is a cheaper alternative than polysomnography for obstructive sleep apnea diagnosis. HNP with manual scoring seems to have better diagnostic accuracy and a lower cost than automatic scoring for patients with low apnea-hypopnea index (AHI) levels, although automatic scoring has similar diagnostic accuracy and cost as manual scoring for intermediate and high AHI levels. Therefore, automatic scoring can be appropriately used, although diagnostic efficacy could improve if we carried out manual scoring on patients with AHI < 15. CLINICAL TRIALS INFORMATION: Clinicaltrials.gov identifier: NCT01347398.