Long-term effect of obstructive sleep apnoea management on blood pressure in patients with resistant hypertension: the SARAH study.

BACKGROUND: There is a close relationship between obstructive sleep apnoea (OSA) and resistant hypertension (RH). However, studies assessing the long-term effect of diagnosing and treating OSA on blood pressure (BP) control in these patients are lacking. METHODS: To address this gap, we recruited 478 RH patients from hypertension units and followed them prospectively after they were screened for OSA through a sleep study. By performing 24-h ambulatory BP monitoring (ABPM) annually, the effect of OSA management was assessed. RESULTS: The patients had a median (interquartile range (IQR)) age of 64.0 (57.2-69.0) years, 67% were males and most were nonsleepy, with a median (IQR) apnoea-hypopnoea index (AHI) of 15.8 (7.9-30.7) events·h-1. The median (IQR) follow-up time was 3.01 (2.93-3.12) years. At baseline, severe OSA was associated with uncontrolled BP, nocturnal hypertension and a nondipper circadian BP pattern. Moreover, these patients had higher BP values during follow-up than did patients in the other groups. However, among patients with moderate and severe OSA, the management of sleep disordered breathing, including the implementation of continuous positive airway pressure treatment, was associated with a reduction in 24-h ABPM parameters, especially night-time BP values, at the 1-year follow-up. These benefits were attenuated over time and only subjects with severe OSA maintained an ABPM night-time reduction at 3 years. Furthermore, clinical variables such as uncontrolled BP, sex and age showed a predictive value for the BP response at 1 year of follow-up. CONCLUSION: A favourable long-term decrease in BP was detected by diagnosing and treating OSA in a cohort of RH patients from hypertension units, but over time this decrease was only partially maintained in severe OSA patients.

Prevalence, Characteristics, and Association of Obstructive Sleep Apnea with Blood Pressure Control in Patients with Resistant Hypertension.

Rationale: Obstructive sleep apnea (OSA) is associated with poor blood pressure (BP) control and resistant hypertension (RH). Nevertheless, studies assessing its prevalence, characteristics, and association with BP control in patients with RH are limited.Objectives: The aim of this multicenter study was to assess the prevalence of OSA in a large cohort of subjects with RH and to evaluate the association of OSA with BP control.Methods: We recruited consecutive subjects with RH from three countries. A formal sleep test and blood pressure measurements, including 24-hour ambulatory blood pressure monitoring, were performed in all participants.Results: In total, 284 subjects with RH were included in the final analysis. Of these, 83.5% (95% confidence interval [CI], 78.7-87.3%) had OSA (apnea-hypopnea index ≥ 5 events/h); 31.7% (95% CI, 26.5-37.3%) had mild OSA, 25.7% (95% CI, 21-31.1%) had moderate OSA, and 26.1% (95% CI, 21.3-31.5%) had severe OSA. Patients with severe OSA had higher BP values than subjects with mild to moderate or no OSA. A greater effect was observed on the average nighttime BP, with an adjusted effect of 5.72 mm Hg (95% CI, 1.08-10.35 mm Hg) in severe OSA compared with participants without OSA. A dose-response association between the severity of OSA and BP values was observed. The prevalence of severe OSA was slightly higher in uncontrolled participants (adjusted odds ratio, 1.69; 95% CI, 0.97-2.99) but was not statistically significant.Conclusions: The present study confirms the high prevalence of OSA in participants with RH. Furthermore, it shows a dose-response association between OSA severity and BP measurements, especially in the nighttime.Clinical trial registered with www.clinicaltrials.gov (NCT03002558).

Adaptación estructural del diafragma en pacientes con Enfermedad Pulmonar Obstructiva Crónica (EPOC)

Introducción: La función de los músculosrespiratorios de pacientes con enfermedad pulmonar obstructiva crónica (EPOC) está alterada, entre otros, por eventos mecánicos como la hiperinsuflación pulmonar, trastornos nutricionales (i.e., desnutrición) y cambios metabólicos (i.e., hipoxemia). Sin embargo, un estudio reciente postuló que el músculo puede compensar en alguna medida los efectos deletéreos de la hiperinsuflación. Objetivos: Describir los cambios ultraestructurales del diafragma humano en pacientes con EPOC y relacionarlos con el estado nutricional y la función pulmonar y muscular respectiva. Diseño: estudio observacional prospectivo y descriptivo (serie de casos). Pacientes y Métodos: Se estudiaron 22 pacientes llevados a toracotomía por neoplasia pulmonar localizada (estadio TMN I). Se evaluaron previos a la cirugía el estado nutricional, función pulmonar y mecánica del diafragma y de los demás músculos inspiratorios. Durante la intervención se tomaron muestras del diafragma costal que fueron procesadas para estudios histoquímicos y de microscopía electrónica. resultados: Los pacientes mostraron un volumen espiratorio en el primer segundo (FEV1) de 73+-16 por ciento pred; relación volumen residual/capacidad pulmonar total (RV/TLC), 43+-12 por ciento; y una presión transdiafragmática máxima de 93+-30 cmH2O. En las células musculares del diafragma se evidenciaron 56+-17 secciones mitocondriales por 100um2 (Nmit), una longitud sarcomérica (Lsar) de 2.15+-0.17um, y un área de depósitos de glicógeno (Agly) de 9.6+-4.4 por ciento del área celular total analizada. Se evidenciaron diferencias en elcontenido mitocondrial en asociación con el FEV1, ya que aquellos pacientes con el FEV1 menor de 75 porciento pred tenían mayor Nmit (63+-14 vs 46+-16 mit/100um2, p<0.05). El porcentaje FEV1 correlacionó en forma inversa con Nmit (r=0.53, p<0.01). Por otra parte, las muestras musculares de pacientes con una relación RV/TLC mayor de 35 por ciento mostraron mayores...