Long-term effect of continuous positive airway pressure on BP in patients with hypertension and sleep apnea

OBJECTIVE: To analyze the long-term effect of continuous positive airway pressure (CPAP) on ambulatory BP in patients with obstructive sleep apnea (OSA) and hypertension, and to identify subgroups of patients for whom CPAP could be more effective. METHODS: We conducted a prospective, long-term follow-up trial (24 months) in 55 patients with OSA and hypertension (mean CPAP use, 5.3 +/- 1.9 h/d [+/- SD]). Twenty-four-hour ambulatory BP monitoring (ABPM) was measured at baseline and after intervention with CPAP on an intention-to-treat basis. In addition, the correlation between the changes in 24-h mean arterial pressure (24hMAP) and CPAP compliance, OSA severity, and baseline ABPM was assessed. RESULTS: At the end of follow-up, a significant decrease was shown only in diastolic BP (- 2.2 mm Hg; 95% confidence interval [CI], - 4.2 to - 0.1; p = 0.03) but not in 24hMAP or other ABPM parameters. However, a correlation between changes in 24hMAP and baseline systolic BP (r = - 0.43, p = 0.001), diastolic BP (r = - 0.38, p = 0.004), and hours of use of CPAP (r = - 0.30, p = 0.02) was observed. A significant decrease in the 24hMAP was achieved in a subgroup of patients with incompletely controlled hypertension at entry (- 4.4 mm Hg; 95% CI, - 7.9 to - 0.9 mm Hg; p = 0.01), as well as in those with CPAP compliance > 5.3 h/d (- 5.3 mm Hg; 95% CI, - 9.5 to - 1.2 mm Hg; p = 0.01). Linear regression analysis showed that baseline systolic BP and hours of CPAP were independent predictors of reductions in BP with CPAP. CONCLUSION: Long-term CPAP reduced BP modestly in the whole sample. However, patients with higher BP at entry and good CPAP compliance achieved significant reductions in BP.     

Impact of Baseline Renal Function on Outcomes of Renal Artery Stenting in Hypertensive Patients

Renal artery stenting may improve blood pressure (BP) and renal function in resistant hypertension patients; however, benefit may differ depending on the degree of renal dysfunction. The authors analyzed 67 consecutive patients receiving stenting for obstructive renal artery disease between 2002 and 2005. Patients were categorized as normal or mildly impaired according to estimated glomerular filtration rate (eGFR) (≥60 mL/min/1.73 m²), moderately impaired (eGFR 30 to 59 mL/min/1.73 m²), and severely impaired (eGFR <30 mL/min/1.73 m²). In patients with eGFR ≥60, systolic BP did not significantly improve from baseline. However, in patients with an eGFR between 30 and 59 mL/min/1.73 m², systolic BP decreased by 12 mm Hg at 6 months (P=.02) and 14 mm Hg at 12 months (P=.01). Greater benefit was observed in patients with eGFR <30 mL/min/1.73 m², with a 16 mm Hg (P=.10) and 21 mm Hg (P=.02) decrease at 6 and 12 months, respectively. Renal function was stable across all groups. Renal artery stenting reduced BP and produced greatest benefit in patients with baseline impaired renal function.     

Inhibition of awake sympathetic nerve activity of heart failure patients with obstructive sleep apnea by nocturnal continuous positive airway pressure

OBJECTIVES: This study was designed to determine whether reductions in morning systolic blood pressure (BP) elicited by treatment of moderate to severe obstructive sleep apnea (OSA) in heart failure (HF) patients are associated with a reduction in sympathetic vasoconstrictor tone. BACKGROUND: Daytime muscle sympathetic nerve activity (MSNA) is elevated in HF patients with coexisting OSA. In our recent randomized trial in HF, abolition of OSA by continuous positive airway pressure (CPAP) increased left ventricular ejection fraction (LVEF) and lowered morning systolic BP. METHODS: Muscle sympathetic nerve activity, BP, and heart rate (HR) of medically treated HF patients (EF <45%) and OSA (apnea-hypopnea index > or =20/h of sleep) were recorded on the morning after overnight polysomnography, and again one month after patients were randomly allocated nocturnal CPAP treatment or no CPAP (control). RESULTS: In nine control patients, there were no significant changes in the severity of OSA, MSNA, systolic BP, or HR. In contrast, in the 8 CPAP-treated patients, OSA was attenuated, and there were significant reductions in daytime MSNA (from 58 +/- 4 bursts/min to 48 +/- 5 bursts/min; 84 +/- 4 bursts/100 heart beats to 72 +/- 5 bursts/100 heart beats; p < 0.001 and p = 0.003, respectively), systolic BP (from 135 +/- 5 mm Hg to 120 +/- 6 mm Hg, p = 0.03), and HR (from 69 +/- 2 min(-1) to 66 +/- 2 min(-1); p = 0.013). CONCLUSIONS: Treatment of coexisting OSA by CPAP in HF patients lowers daytime MSNA, systolic BP, and HR. Inhibition of increased central sympathetic vasoconstrictor outflow is one mechanism by which nocturnal CPAP reduces awake BP in HF patients with moderate to severe OSA.     

Early Morning Surge and Dipping Status of Blood Pressure: Are These of Predictive Value for Silent Myocardial Ischemia?

To investigate the predictive value of morning surge (MS) and dipping status of blood pressure (BP) for ST-segment depression (ST depression) in hypertensive persons, the combined 24-hour ambulatory BP measurement and Holter electrocardiographic recordings of 344 patients (132 women and 212 men, 60±12 years) were analyzed. The morning BP surge was calculated as mean systolic BP during the 2 hours after awaking minus the mean systolic BP during the 1 hour that included the lowest sleep BP. Depending on the percentage decrease in systolic BP at night, patients were subdivided into extreme dippers, dippers, nondippers, and risers. ST depression was defined as horizontal or descending ST depression of 1 mm of 1 minute duration and a 1-minute interval after the previous episode or 24-hour mean ST-segment value <−0.1 mV. ST depression was observed in 76 (22.1%) of 344 patients. The mean MS in patients with ST depression was with 25±15 mm Hg and not significantly different when compared with patients without ST depression (26±15 mm Hg). The prevalence of ST depression was not significantly different in dippers, extreme dippers, nondippers, and risers (20%, 23.5%, 23%, and 25.5%, respectively). Systolic and diastolic BP values during ST depression were significantly higher in the morning as compared with ST depression in the evening (149/84 mm Hg vs 138/78 mm Hg, P <.05). In the present study, MS and dipping status of BP were not associated with ST depression. ST depression was, however, characterized by significantly higher BP peaks in the early morning hours.     

Continuous Positive Airway Pressure in Patients With Obstructive Sleep Apnea and Resistant Hypertension: A Meta‐Analysis of Randomized Controlled Trials

This study aimed to analyze the effect of continuous positive airway pressure (CPAP) on blood pressure (BP) in patients with obstructive sleep apnea (OSA) and resistant hypertension. Randomized controlled trials (RCTs) that evaluated the effect of CPAP on BP in patients with OSA and resistant hypertension, indexed in MEDLINE, Embase, and the Cochrane Library from inception until March 20, 2015, were included in the meta‐analysis. A total of five RCTs were identified to meet the inclusion criteria. The pooled changes after CPAP treatment for 24‐hour ambulatory systolic BP and diastolic BP (DBP) were −4.78 mm Hg (95% confidence interval [CI], −7.95 to −1.61) and −2.95 mm Hg (95% CI, −5.37 to −0.53) in favor of the CPAP group. CPAP was also associated with reduction in nocturnal DBP (mean difference, −1.53 mm Hg, 95% CI, −3.07 to 0). The results indicated a favorable reduction in BP with CPAP treatment in patients with OSA and resistant hypertension.     

慢性间歇低氧对心脏B超和血压影响的观察

目的 探讨慢性间歇低氧对OSAHS患者左心功能的影响,以及持续气道正压通气(CPAP)治疗后左心功能和血压的变化.方法 顺序收集2007年5月至2008年12月于吉林大学第一医院就诊的、符合OSAHS诊断标准的门诊或住院患者75例(OSA组),其中非高血压者35例,合并高血压者40例.另选30名健康人为对照组,其中男20名,女10名,年龄30～65岁,与患者组年龄匹配,均为经系统检查无异常发现的健康人.对两组左心室射血分数(left ventricular ejection fraction,LVEF)、短轴缩短率(shortening fraction,FS)、E峰、A峰,并计算E/A进行比较.CPAP治疗后的血压、LVEF、E/A进行分析.结果 所有患者晨起血压(150.80±20.73/108.0±15.34)mm Hg(1 mm Hg=0.133 kPa)均较睡前血压(134.16±18.33/90.09±11.24)mm Hg明显升高.OSA组E/A明显降低(P<0.01),LVEF、FS明显降低(P<0.05);与对照组及OSA非高血压组比较,OSA合并高血压的患者左室射血分数和短轴缩短率均减少,提示高血压的出现是OSA左室收缩功能减退的重要因素;与对照组比较,OSA非高血压组E/A明显降低;非高血压组和高血压组比较,高血压组E/A下降显著,说明OSA本身可直接影响左心室舒张功能,而高血压的出现加重了左心室的舒张功能的降低.经CPAP治疗6个月后晨起血压(142.59±15.34/96.52±9.81)mmHg较治疗前(150.80±20.73/108.0±15.34) mm Hg显著下降(P<0.001);左室射血分数(59.70±11.1)%较治疗前(56.40±9.74)%增加(P<0.05);E/A值1.16±0.25较治疗前0.87±0.17明显增加(P<0.01).结论 (1)CIH可引起左心结构和功能发生改变,高血压的出现加重了这种变化.(2)CPAP对于纠正OSA患者高血压、改善左心功能,提高生活质量有重要意义.     

Prevalence of esophageal dysmotility in a cohort of patients with esophageal biopsies consistent with eosinophilic esophagitis

SUMMARY.  Eosinophilic esophagitis (EoE) is increasingly being diagnosed in adults presenting with dysphagia, food impactions, and chest pain. Studies to date provide conflicting data on the association of EoE and esophageal dysmotility. The objective of this study was to evaluate the prevalence of esophageal dysmotility in a cohort of patients with biopsies consistent with EoE at a military treatment facility. This is a prospective evaluation of consecutively identified patients at our institution diagnosed with EoE from March 1, 2005 to June 1, 2007. Thirty-two patients with biopsies consistent with EoE completed a symptom survey and 30 underwent esophageal manometry. The majority of EoE patients (23/30, 77%) had a normal end-expiratory lower esophageal sphincter (LES) pressure (normal range 10–35), whereas six patients had a low-normal LES pressure (6–9 mm Hg) and one patient had a decreased LES pressure (<5 mm Hg). Five patients (15.6%) were diagnosed with a nonspecific esophageal motor disorder (NSEMD). Two patients had high mean esophageal amplitude contractions >180 mm Hg (188 mm Hg, 209 mm Hg). No patient was diagnosed with nutcracker esophagus or diffuse esophageal spasm. Patients with and without NSEMD reported a similar degree of swallowing difficulty, heartburn, belching, chest pain, regurgitation, symptoms at night, and total symptom score. Likewise, eosinophil count on mucosal biopsy was similar between patients with and without a NSEMD. In this cohort, we found the prevalence of an NSEMD to be similar to that of a 10% prevalence found in a gastroesophageal reflux population.     

Comparison of severity scoring systems A-DROP and CURB-65 for community-acquired pneumonia

Background and objective:   The initial assessment of the severity of community-acquired pneumonia (CAP) is important for patient management. The Japanese Respiratory Society (JRS) has proposed a 6-point scale (0–5) to assess the clinical severity of CAP. The A-DROP scoring system assesses the following parameters: (i) A ge (male ≥ 70 years, female ≥ 75 years); (ii) D ehydration (blood urea nitrogen (BUN) ≥ 210 mg/L); (iii) R espiratory failure (SaO₂ ≤ 90% or PaO₂ ≤ 60 mm Hg); (iv) O rientation disturbance (confusion); and (v) low blood P ressure (systolic blood pressure ≤ 90 mm Hg). A-DROP is a modified version of CURB-65 (confusion, BUN > 7 mmol/L (200 mg/L), respiratory rate ≥ 30/min, low blood pressure (diastolic ≤ 60 mm Hg or systolic < 90 mm Hg, and age ≥ 65 years) proposed by the British Thoracic Society. However, validation of A-DROP has not been attempted nor has it been compared with CURB-65. The aim of this study was to confirm that A-DROP is equivalent to CURB-65 for predicting severity of CAP.
Methods:   A retrospective observational study was conducted of patients with CAP hospitalized at a single centre between November 2005 and January 2007. The 30-day mortality after admission was compared following assessment of severity using the A-DROP and CURB-65 scoring systems.
Results:   Three-hundred and twenty-nine patients were evaluated. The areas under the receiver operating characteristic curves were 0.846 (95% confidence interval (CI): 0.790–0.903) and 0.835 (95% CI: 0.763–0.908) for A-DROP and CURB-65, respectively.
Conclusion:   The JRS A-DROP can be used to assess severity of CAP, and gives similar results to CURB-65.     

A Home Blood Pressure Monitor Equipped With a Graphic Function Facilitates Faster Blood Pressure Control than the Conventional Home Blood Pressure Monitor

In this study, we evaluated whether antihypertensive therapy using a home blood pressure monitor (HBPM) equipped with a graphic display of weekly and monthly averaged blood pressure (BP) can obtain better BP control than the conventional HBPM. Sixty-five hypertensive outpatients who had HBP >135/85 mm Hg were enrolled by 8 doctors in 2 different hospitals. The patients were randomly assigned either a graph-equipped HBPM (graph-equipped HBPM group; n=33) or an HBPM without the graph function (conventional HBPM group; n=32). The patients were treated with antihypertensive medications targeting HBP <135/85 mm Hg. After 2 months, the home systolic BP level was lower in the graph-equipped HBPM group than in the conventional HBPM group (141.3±15.4 vs 147.7±10.8 mm Hg; P<.05); its reduction was significantly larger in the former group (11.9 vs 5.6 mm Hg; P<.05). Using an HBP device with a graphic display could accelerate the achievement of BP control.     

Olmesartan‐based monotherapy vs combination therapy in hypertension: A meta‐analysis based on age and chronic kidney disease status

Antihypertensive monotherapy is often insufficient to control blood pressure (BP). Several recent guidelines advocate for initial combination drug therapy in many patients. This meta‐analysis of seven randomized, double‐blind studies (N = 5888) evaluated 8 weeks of olmesartan medoxomil (OM)–based single‐pill dual‐combination therapy (OM+amlodipine/azelnidipine or hydrochlorothiazide) vs OM monotherapy in adults with hypertension. BP‐lowering efficacy, goal achievement, and adverse events were assessed in the full cohort and subgroups (elderly/nonelderly and patients with and without chronic kidney disease). In the full cohort at week 8, for dual therapy vs monotherapy, seated BP was lower (137.5/86.1 mm Hg vs 144.4/89.9 mm Hg), and the mean change from baseline in BP and BP goal achievement (<140/90 mm Hg) were greater (?22.7/?15.0 mm Hg vs ?16.0/?11.3 mm Hg and 51.2% vs 34.7%, respectively). Adverse events were similar between groups. BP‐lowering efficacy among subgroups mirrored the findings in the full cohort whereby changes were significantly greater following OM dual‐combination therapy vs OM monotherapy.     

Blood pressure changes after automatic and fixed CPAP in obstructive sleep apnea: relationship with nocturnal sympathetic activity

Treatment of obstructive sleep apnea (OSA) by continuous positive airway pressure (CPAP) usually causes a reduction in blood pressure (BP), but several factors may interfere with its effects. In addition, although a high sympathetic activity is considered a major contributor to increased BP in OSA, a relationship between changes in BP and in sympathetic nervous system activity after OSA treatment is uncertain. This study was undertaken to assess if, in OSA subjects under no pharmacologic treatment, treatment by CPAP applied at variable levels by an automatic device (APAP) may be followed by a BP reduction, and if that treatment is associated with parallel changes in BP and catecholamine excretion during the sleep hours. Nine subjects underwent 24-h ambulatory BP monitoring and nocturnal urinary catecholamine determinations before OSA treatment and 2 months following OSA treatment by APAP (Somnosmart2, Weinmann, Hamburg, Germany). Eight control subjects were treated by CPAP at a fixed level. After APAP treatment, systolic blood pressure (SBP) decreased during sleep (p < 0.05), while diastolic blood pressure (DBP) decreased both during wakefulness (p < 0.05) and sleep (p < 0.02). Similar changes were observed in subjects receiving fixed CPAP. Nocturnal DBP changes were correlated with norepinephrine (in the whole sample: r = .61, p < 0.02) and normetanephrine (r = .71, p < 0.01) changes. In OSA subjects under no pharmacologic treatment, APAP reduces BP during wakefulness and sleep, similarly to CPAP. A reduction in nocturnal sympathetic activity could contribute to the reduction in DBP during sleep following OSA treatment.     

Refractory hypertension and sleep apnoea: effect of CPAP on blood pressure and baroreflex.

This study was undertaken to determine whether abolition of obstructive sleep apnoea (OSA) by continuous positive airway pressure (CPAP) could reduce blood pressure (BP) in patients with refractory hypertension. In 11 refractory hypertensive patients with OSA, the acute effects of CPAP on nocturnal BP were studied during sleep and its longer term effects on 24-h ambulatory BP after 2 months. During a single night's application, CPAP abolished OSA and reduced systolic BP in stage 2 sleep from 138.3 +/- 6.8 to 126.0 +/- 6.3 mmHg. There was also a trend towards a reduction in average diastolic BP (from 77.7 +/- 4.5 to 72.9 +/- 4.5). CPAP usage for 2 months was accompanied by an 11.0 +/- 4.4 mmHg reduction in 24-h systolic BP. In addition, both the nocturnal and daytime components of systolic BP fell significantly by 14.4 +/- 4.4 and 9.3 +/- 3.9 mmHg, respectively. Diastolic BP was reduced significantly at night by 7.8 +/- 3.0 mmHg. In patients with refractory hypertension, acute abolition of obstructive sleep apnoea by continuous positive airway pressure reduces nocturnal blood pressure. These data also suggest that continuous positive airway pressure may reduce nocturnal and daytime systolic blood pressure chronically. Randomised trials are needed to confirm the latter results.     

Blood Pressure Control in Hypertensive Patients in Irish Primary Care Practices

In Ireland, cardiovascular disease is a major cause of death. However, blood pressure (BP) goal achievement is unsatisfactory. The authors aimed to document BP control and increase awareness. A total of 1534 patients were enrolled in the study, with a mean age of 64.7±11.9 years (53.8% women). Duration of hypertension was 8.7±7.7 years, and 14.6% had diabetes, 13.8% had coronary artery disease, and 40.5% were taking antihypertensive monotherapy. β-Blockers (39.8%), angiotensin-converting enzyme inhibitors (32.2%), and angiotensin receptor blockers (22.0%) were prescribed most frequently. Mean BP was 136.0±6.1 mm Hg/89.5±5.0 mm Hg in nondiabetic patients (48.6% <140/90 mm Hg) and 131.0±7.4 mm Hg/81.7±4.6 mm Hg in diabetic patients (16.7% <130/80 mm Hg). Diet, exercise, and lifestyle modifications (63.5%) were frequently recommended. Increased patient awareness and compliance together with the adherence of physicians to current guidelines and greater willingness to take action in patients with uncontrolled hypertension should help in improving BP control and thus reduce cardiovascular risk.     

Left ventricular hypertrophy is a common echocardiographic abnormality in severe obstructive sleep apnea and reverses with nasal continuous positive airway pressure

STUDY OBJECTIVES: To determine cardiac structural abnormalities by echocardiography in subjects with severe obstructive sleep apnea (OSA), and to determine the long-term effects of nasal continuous positive airway pressure (CPAP) on such abnormalities. DESIGN: Polysomnography was conducted on oximetry-screened patients who showed a desaturation index > 40/h and > or = 20% cumulative time spent below 90%. From these, 25 patients with severe OSA but without daytime hypoxemia underwent echocardiography prior to, then 1 month and 6 months following initiation of CPAP treatment. SETTING: Outpatient sleep disorders center. RESULTS: Of the 25 patients, 13 patients (52%) had hypertension by history or on physical examination. Baseline echocardiograms showed that severe OSA was associated with numerous cardiovascular abnormalities, including left ventricular hypertrophy (LVH) [88%], left atrial enlargement (LAE) [64%], right atrial enlargement (RAE) [48%], and right ventricular hypertrophy (16%). In all patients (intent to treat) as well as those patients compliant with CPAP therapy (84% > 3 h nightly), there was a significant reduction in LVH after 6 months of CPAP therapy as measured by interventricular septal distance (baseline diastolic mean, 13.0 mm; 6-month mean after CPAP, 12.3 mm; p < 0.02). RAE and LAE were unchanged after CPAP therapy. CONCLUSIONS: LVH was present in high frequency in subjects with severe OSA and regressed after 6 months of nasal CPAP therapy.     

In patients with minimally symptomatic OSA can baseline characteristics and early patterns of CPAP usage predict those who are likely to be longer-term users of CPAP

Background

Long-term continuous positive airway pressure (CPAP) usage varies between individuals. It would be of value to be able to identify those who are likely to benefit from CPAP (and use it long term), versus those who would not, and might therefore benefit from additional help early on. First, we explored whether baseline characteristics predicted CPAP usage in minimally symptomatic obstructive sleep apnoea (OSA) patients, a group who would be expected to have low usage. Second, we explored if early CPAP usage was predictive of longer-term usage, as has been shown in more symptomatic OSA patients.

Methods

The MOSAIC trial was a multi-centre randomised controlled trial where minimally symptomatic OSA patients were randomised to CPAP, or standard care, for 6 months. Here we have studied only those patients randomised to CPAP treatment. Baseline characteristics including symptoms, questionnaires [including the Epworth sleepiness score (ESS)] and sleep study parameters were recorded. CPAP usage was recorded at 2–4 weeks after initiation and after 6 months. The correlation and association between baseline characteristics and 6 months CPAP usage was assessed, as was the correlation between 2 and 4 weeks CPAP usage and 6 months CPAP usage.

Results

One hundred and ninety-five patients randomised to CPAP therapy had median [interquartile range (IQR)] CPAP usage of 2:49 (0:44, 5:13) h:min/night (h/n) at the 2–4 weeks visit, and 2:17 (0:08, 4:54) h/n at the 6 months follow-up visit. Only male gender was associated with increased long-term CPAP use (male usage 2:56 h/n, female 1:57 h/n; P=0.02). There was a moderate correlation between the usage of CPAP at 2–4 weeks and 6 months, with about 50% of the variability in long-term use being predicted by the short-term use.

Conclusions

In patients with minimally symptomatic OSA, our study has shown that male gender (and not OSA severity or symptom burden) is associated with increased long-term use of CPAP at 6 months. Although, in general, early patterns of CPAP usage predicted longer term use, there are patients in whom this is not the case, and patients with low initial usage may need to extend their CPAP trial before a decision about longer-term use is made.     

Efficacy of an Olmesartan Medoxomil–Based Treatment Algorithm in Patients Stratified by Age, Race, or Sex

J Clin Hypertens (Greenwich). 2010;12:3–13. ^© 2009 Wiley Periodicals, Inc.
Demographic factors are known to influence the prevalence of hypertension, and evidence suggests that they may also influence the response of patients with hypertension to blood pressure (BP)–lowering therapies. To determine the effect of demographic factors on the efficacy and safety of an olmesartan medoxomil (OM)–based treatment regimen, we performed a prespecified subgroup analysis of a 12-week, randomized, placebo-controlled, titrate-to-goal study in patients with hypertension, stratifying patients into treatment groups according to age, sex, or race. After 12 weeks, OM–based therapy significantly reduced BP from baseline in blacks, non-blacks, men, women, and patients younger than 65 or 65 years and older compared with placebo, and enabled 51.9% to 79.5% of patients to achieve a BP goal of <140/90 mm Hg. The differences in BP-lowering efficacy of OM–based therapy between subgroups were not clinically significant, and treatment was generally well tolerated in all groups. This study demonstrates that an OM-based treatment algorithm is an effective and safe option for achieving recommended BP goal in patients with hypertension including blacks, non-blacks, men, women, and patients younger than 65 or 65 years and older.     

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

Aim

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

Patients and methods

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

Results

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

Conclusions

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

White‐Coat Effect Among Older Adults: Data From the Jackson Heart Study

Many adults with elevated clinic blood pressure (BP) have lower BP when measured outside the clinic. This phenomenon, the “white‐coat effect,” may be larger among older adults, a population more susceptible to the adverse effects of low BP. The authors analyzed data from 257 participants in the Jackson Heart Study with elevated clinic BP (systolic/diastolic BP [SBP/DBP] ≥140/90 mm Hg) who underwent ambulatory BP monitoring (ABPM). The white‐coat effect for SBP was larger for participants 60 years and older vs those younger than 60 years in the overall population (12.2 mm Hg, 95% confidence interval [CI], 9.2–15.1 mm Hg and 8.4 mm Hg, 95% CI, 5.7–11.1, respectively; P=.06) and among those without diabetes or chronic kidney disease (15.2 mm Hg, 95% CI, 10.1–20.2 and 8.6 mm Hg, 95% CI, 5.0–12.3, respectively; P=.04). After multivariable adjustment, clinic SBP ≥150 mm Hg vs <150 mm Hg was associated with a larger white‐coat effect. Studies are needed to investigate the role of ABPM in guiding the initiation and titration of antihypertensive treatment, especially among older adults.     

Comparison of empirical continuous positive airway pressure (CPAP) treatment versus initial portable sleep monitoring followed by CPAP treatment for patients with suspected obstructive sleep apnoea

Background: Polysomnography is labour‐intensive for diagnosing obstructive sleep apnoea (OSA). We compared two algorithms for initiating continuous positive airway pressure (CPAP) treatment for patients with suspected OSA. Methods: Symptomatic OSA patients were randomised into either algorithm I or II. Algorithm I consisted of an empirical CPAP trial whereas algorithm II utilised an Apnea Risk Evaluation System, a wireless device applied on the forehead, for establishing a diagnosis before a CPAP trial for 3 weeks. Primary outcome was success of CPAP trial, defined as CPAP usage > 4 h/night and willingness to continue CPAP. Subjective usefulness of CPAP, accuracy of Apnea Risk Evaluation System versus polysomnography and CPAP adherence at 6 months were secondary end‐points. Results: Altogether 138 patients in algorithm I and 110 patients in algorithm II completed the CPAP trial. There were no significant differences between these algorithms with respect to the primary end‐point. The sensitivity and specificity of algorithm I versus II as a diagnostic test for OSA were 0.3, 0.8 versus 0.31, 1.00 respectively. In predicting CPAP adherence at 6 months, the likelihood ratio positive for algorithms I and II was 2.7 and 5.27 respectively. The mean (SE) time taken from the first consultation to the end of CPAP trial in algorithm I and algorithm II was 60 (2) and 98 (5) days, respectively, P < 0.01. Conclusion: An ambulatory approach with portable sleep monitoring for diagnosing OSA before a CPAP trial can identify more patients who would adhere to CPAP at 6 months than empirical CPAP treatment alone.     

Effect of Continuous Positive Airway Pressure on Glucose and Lipid Profiles in Patients With Obstructive Sleep Apnoea: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and aimContinuous Positive Airway Pressure (CPAP) is the most effective therapy for symptomatic obstructive sleep apnoea (OSA). However, uncertainty remains about the effectiveness of CPAP in improving OSA-related metabolic dysregulation. This meta-analysis of randomized controlled trials (RCTs) aimed to investigate whether CPAP, compared to other control treatments, could improve glucose or lipid metabolism in OSA patients.MethodsRelevant articles were searched in three different databases (MEDLINE, EMBASE and Web of Science) from inception to 6th Feb 2022 through specific search terms and selection criteria.ResultsFrom a total of 5553 articles, 31 RCTs were included. CPAP modestly improved insulin sensitivity as determined by mean fasting plasma insulin and Homeostasis Model Assessment of Insulin Resistance reduction of 1.33 mU/L and 0.287, respectively. In subgroup analyses pre-diabetic/type 2 diabetic patients as well as those with sleepy OSA showed a greater response to CPAP. Regarding lipid metabolism, CPAP was associated with a mean total cholesterol reduction of 0.064 mmol/L. In subgroup analyses, the benefit was higher in patients that showed more severe OSA and oxygen desaturations at the baseline sleep study as well as in younger and obese subjects. Neither glycated haemoglobin nor triglycerides, HDL- and LDL-cholesterol were reduced by CPAP.ConclusionCPAP treatment may improve insulin sensitivity and total cholesterol levels in OSA patients but with low effect size. Our results suggest that CPAP does not substantially improve metabolic derangements in an unselected OSA population, but the effect may be higher in specific subgroups of OSA patients.