Cross-neutralizing antibody against emerging Omicron subvariants of SARS-CoV-2 in infection-naïve individuals with homologous BNT162b2 or BNT162b2(WT + BA.4/5) bivalent booster vaccination.

Since the emergence of SARS-CoV-2, different variants and subvariants successively emerged to dominate global virus circulation as a result of immune evasion, replication fitness or both. COVID-19 vaccines continue to be updated in response to the emergence of antigenically divergent viruses, the first being the bivalent RNA vaccines that encodes for both the Wuhan-like and Omicron BA.5 subvariant spike proteins. Repeated infections and vaccine breakthrough infections have led to complex immune landscapes in populations making it increasingly difficult to assess the intrinsic neutralizing antibody responses elicited by the vaccines. Hong Kong's intensive COVID-19 containment policy through 2020-2021 permitted us to identify sera from a small number of infection-naïve individuals who received 3 doses of the RNA BNT162b2 vaccine encoding the Wuhan-like spike (WT) and were boosted with a fourth dose of the WT vaccine or the bivalent WT and BA.4/5 spike (WT + BA.4/5). While neutralizing antibody to wild-type virus was comparable in both vaccine groups, BNT162b2 (WT + BA.4/BA.5) bivalent vaccine elicited significantly higher plaque neutralizing antibodies to Omicron subvariants BA.5, XBB.1.5, XBB.1.16, XBB.1.9.1, XBB.2.3.2, EG.5.1, HK.3, BA.2.86 and JN.1, compared to BNT162b2 monovalent vaccine. The single amino acid substitution that differentiates the spike of JN.1 from BA.2.86 resulted in a profound antigenic change.

Antiviral therapies for influenza.

PURPOSE OF REVIEW: The heavily suppressed global influenza activity during the coronavirus disease 2019 (COVID-19) pandemic is expected to return upon relaxation of travel restriction and nonpharmaceutical interventions (NPI). We reviewed the four marketed neuraminidase inhibitors (NAI e.g., oseltamivir, zanamivir, peramivir, laninamivir) and the only endonuclease inhibitor (baloxavir) on their clinical therapeutic effects and the ability of viral suppression in various groups of patients of different clinical settings based on the latest evidence. RECENT FINDINGS: Early initiation, preferably within 48 h of symptom onsets, of antiviral treatments with NAI and baloxavir, is crucial to produce favourable outcomes in patients with influenza infection. Updated evidence does not suggest routine use of combined antiviral agents in patients with influenza infection. Treatment-emergent resistant influenza variants may occur during NAI and baloxavir use, but it has no major impact on subsequent recovery. Early treatment of index patients with influenza infection and post-exposure prophylaxis in specific populations is crucial in preventing influenza transmission. SUMMARY: Antiviral therapy is the major defence therapeutically in the community and hospital settings to expedite early recovery and reduce influenza-related complications. Early treatment of index patients and post-exposure prophylaxis in susceptible close contacts may mitigate the spread of infection.

Effect of Weight Loss and Continuous Positive Airway Pressure on Obstructive Sleep Apnea and Metabolic Profile Stratified by Craniofacial Phenotype: A Randomized Clinical Trial.

Rationale: Craniofacial structure is believed to modulate the effect of weight loss on obstructive sleep apnea (OSA), but whether this affects metabolic profile after weight loss compared with continuous positive airway pressure (CPAP) is unknown among obese Chinese patients with OSA. Objectives: To compare the change in metabolic profile between a lifestyle modification program (LMP), stratified by craniofacial phenotype, and CPAP therapy for 6 months. Methods: We randomly assigned 194 patients with body mass index ⩾ 25 kg/m2 and moderate to severe OSA to participate in the LMP or receive CPAP therapy for 6 months in a 2:1 ratio. Assessments included computed tomography for assessing maxillomandibular volume (MMV), hsCRP (high-sensitivity C-reactive protein), and insulin sensitivity. Measurements and Main Results: Among 128 and 66 subjects in the LMP and CPAP groups, respectively, hsCRP was reduced more in the LMP group than the CPAP group (median [interquartile range], -0.7 [-1.4 to -0.0] vs. -0.3 [-0.9 to 0.4] mg/L; P = 0.012). More patients in the LMP group achieved low hsCRP (<1 mg/L) than the CPAP group (21.1% vs. 9.1%; P = 0.04). Insulin sensitivity improved only in the LMP group, with 3.1 (95% confidence interval, 1.5-6.6) times more patients with normal glucose regulation after intervention. The LMP group was stratified into LMP-small MMV (n = 64) and LMP-large MMV (n = 64) groups according to the median MMV value of 233.2 cm3. There was no significant difference in hsCRP (median [interquartile range], -0.7 [-1.3 to 0.1] vs. -0.7 [-1.5 to -0.2] mg/L; P = 0.884) and insulin sensitivity (median [interquartile range], 0.5 [-0.2 to 1.9] vs. 0.6 [0.1 to 2.0]; P = 0.4860) between the LMP-small MMV and LMP-large MMV groups. Conclusions: Weight reduction alleviated subclinical inflammation and improved insulin sensitivity more than CPAP among obese Chinese patients with moderate to severe OSA, and this effect was not influenced by craniofacial structure. Clinical trial registered with www.clinicaltrials.gov (NCT03287973).

Contemporary Concise Review 2021: COVID-19 and other respiratory infections.

Bats are likely the primary source of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Minks are highly susceptible to infection by SARS-CoV-2. Transmission from asymptomatic individuals was estimated to account for over 50% of all transmissions of coronavirus disease 2019 (COVID-19) cases. SARS-CoV-2 is evolving towards more efficient aerosol transmission. Remdesivir, baricitinib, tocilizumab and dexamethasone are frequently used for the treatment of patients with respiratory failure due to COVID-19. There is a rising incidence of non-tuberculous Mycobacterium pulmonary disease globally, with a higher prevalence in Asian countries than in the Western world. Protracted bacterial bronchitis is a common cause of chronic productive cough in childhood. Re-emergence of respiratory syncytial virus may occur after the relaxation of infection control measures and the reopening of borders during COVID-19 pandemic.

Implementation of evidence on management of pleural diseases: insights from a territory-wide survey of clinicians in Hong Kong.

BACKGROUND: Major advances in management of common pleural diseases have taken place in the past decade. However, pleural diseases are often managed by physicians of diverse training background and research on implementation of new knowledge is scanty. We aim to evaluate the practice pattern in pleural medicine among physicians in Hong Kong, for identification of possible gaps for clinical service improvement. METHODS: The Hong Kong Thoracic Society undertook a cross-sectional questionnaire survey in 2019, targeting clinicians of various subspecialties in internal medicine and levels of experience (basic and higher trainees, specialists) from twelve regional hospitals of diverse service scopes throughout Hong Kong. Respondents were selected by non-probability quota sampling. The questionnaire tool consisted of 46 questions covering diagnostic and therapeutic aspects of common pleural diseases. The responses were anonymous, and analysed independently using SPSS statistics software. RESULTS: The survey collected 129 responses, 47(36%) were from clinicians specialized in respiratory medicine. Majority of the respondents (98%) managed pleural diseases, including performing pleural procedures in their practice. Fifty-five percent of all the respondents had not received any formal training in transthoracic ultrasonography. A significant proportion of clinicians were unaware of pleuroscopy for investigation of exudative pleural effusion, indwelling pleural catheter for recurrent malignant pleural effusion, and combined intra-pleural Alteplase plus DNase for treatment of pleural infection (30%, 15% and 70% of non-respiratory clinicians respectively). Significant heterogeneity was found in the management of pleural infection, malignant pleural effusion and pneumothorax among respiratory versus non-respiratory clinicians. Contributing factors to the observed heterogeneity included lack of awareness or training, limited accessibility of drugs, devices, or dedicated service support. CONCLUSION: Significant heterogeneity in management of pleural diseases was observed among medical clinicians in Hong Kong. Continuous medical education and training provision for both specialists and non-specialists has to be strengthened to enhance the implementation of advances, improve quality and equity of healthcare provision in pleural medicine.

Use of Berlin questionnaire in comparison to polysomnography and home sleep study in patients with obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is a common disorder with significant morbidity and mortality. We aimed to evaluate the predictive accuracy of the Berlin questionnaire in patients with suspected OSAS undergoing PSG in the sleep laboratory setting against those going through the Embletta™ portable diagnostic system (Embletta PDS) at home. METHODS: Patients with suspected OSAS were recruited from respiratory clinics to complete Berlin questionnaire and Epworth Sleepiness Score (ESS). Patients were randomized to undergo either home-based sleep test (group A) or hospital-based polysomnography (PSG) (group B). RESULTS: Three hundreds and sixteen subjects with newly referred suspected OSAS were recruited and randomized into group A (n = 157) and group B (n = 159). The prevalence of moderate to severe OSAS defined as apnea-hypopnea index (AHI) ≥ 15/h was 54%. The Berlin questionnaire identified 69.7% (n = 99) of subjects as high risk in group A and 77.5% (n = 100) in group B. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the questionnaire to predict an AHI ≥ 15/h as diagnosed by PSG was 78, 23, 67 and 35%. When compared with Embletta PDS, the specificity and NPV increased to 48 and 63%. The area under the Receiver Operator Curve (ROC) based on PSG (AUC = 0.539, 95%CI 0.417, 0.661) and based on home Embletta (AUC = 0.712, 95%CI 0.617, 0.907). CONCLUSIONS: The questionnaire was not reliable in predicting OSAS through PSG AHI whereas there was some predictive ability in discriminating patients with OSAS from normal subjects based on home Embletta sleep test. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (Identifier: NCT01828216) on 10 April 2013.

Continuous positive airway pressure for obstructive sleep apnoea does not improve asthma control.

BACKGROUND AND OBJECTIVE: Unrecognized obstructive sleep apnoea syndrome (OSAS) may lead to poor asthma control despite optimal therapy. We assessed asthma control, airway responsiveness, daytime sleepiness and health status at baseline and 3 months after continuous positive airway pressure (CPAP) treatment among asthma patients with nocturnal symptoms and OSAS. METHODS: Patients with nocturnal asthma symptoms despite receiving at least moderate-dose inhaled corticosteroid and long-acting bronchodilators underwent a home sleep study using 'Embletta' portable diagnostic system. Patients with significant OSAS (apnoea-hypopnoea index (AHI) ≥10/h) were randomized to receive either CPAP or conservative treatment for 3 months. RESULTS: Among 145 patients recruited, 122 underwent sleep study with 41 (33.6%) having AHI ≥10/h. Patients with significant OSAS had higher BMI (27.4 (5.1) vs 25.1 (4.5) kg/m2 , P = 0.016), bigger neck circumference (36.6 (3.1) vs 34.8 (3.6) cm, P = 0.006) and lower minimum SaO2 (80.7 (6.6) vs 87.2 (3.9) %, P < 0.001). Using intention-to-treat analysis among 37 patients with AHI ≥10/h (CPAP group (n = 17) vs control group (n = 20)), there was no significant difference in Asthma Control Test score (CPAP 3.2 (2.7) vs control 2.4 (5.7), P = 0.568) but the CPAP group had a greater improvement in Epworth Sleepiness Scale (-3.0 (4.5) vs 0.5(3.8), P = 0.014), Asthma Quality of Life Questionnaire (0.6 (0.8) vs 0.02 (0.7), P = 0.022) and vitality domain in the SF-36 questionnaire (14.7 (16.8) vs 0.3 (16.2), P = 0.012) after 3 months. Data are presented as mean (SD) unless otherwise stated. CONCLUSION: A high prevalence of OSAS was found among patients with asthma and snoring. CPAP therapy for 3 months did not enhance asthma control but improved daytime sleepiness, quality of life and vitality.

Effects of CPAP therapy on visceral fat thickness, carotid intima-media thickness and adipokines in patients with obstructive sleep apnoea.

BACKGROUND AND OBJECTIVE: Obstructive sleep apnoea (OSA) is associated with an increased prevalence of metabolic syndrome. This study explores the effects of continuous positive airway pressure (CPAP) for patients with OSA on visceral and mesenteric fat thickness, carotid intima-media thickness (IMT) and adipokines. METHODS: A randomized controlled study was conducted at a teaching hospital on 90 patients newly diagnosed with OSA to receive either therapeutic CPAP or subtherapeutic CPAP for 3 months. Visceral fat thickness and carotid IMT were measured with B-mode ultrasound; adipokine levels were assessed at baseline and 3 months. RESULTS: Altogether, 45 patients received therapeutic CPAP and 45 received subtherapeutic CPAP without significant differences in age 50.3 (10.1) versus 48.7 (9.0) years, BMI 28.2 (3.9) versus 28.2 (4.5) kg/m2 , Epworth Sleepiness Scale (ESS) 12.4 (5.9) versus 11.3 (4.7), apnoea-hypopnoea index (AHI) 30.6 (21.4) versus 35.2 (25.5) /h, minimum SaO2 79.6 (10.8) versus 76.7 (12.4) % and existing co-morbidities. CPAP usage was therapeutic 4.2 (2.1) versus subtherapeutic 4.1 (2.0) h/night over 3 months. Adiponectin and irisin levels changed significantly following therapeutic CPAP for 3 months versus subtherapeutic CPAP (-1.6 vs 7.3, P = 0.042; 0.1 vs -0.1, P = 0.028 respectively) while only serum level of monocyte chemotactic protein 1 (MCP-1) at baseline was positively correlated with AHI (r = 0.278). No significant changes were observed in other adipokines, visceral fat thickness and IMT. CONCLUSION: Short-term therapeutic CPAP versus subtherapeutic CPAP does not significantly reduce visceral fat thickness and IMT, although it reduces adiponectin and increases irisin.

Pneumomediastinum and subcutaneous emphysema complicating a patient with a lung abscess.

Pneumomediastinum and subcutaneous emphysema are conditions that carry significant morbidity. They are uncommonly seen as complications of lung abscess formation and prompt recognition and treatment is necessary. We present a 59-year-old male patient who complained of shortness of breath and chest pain for 2 weeks. Computed tomography (CT) of the thorax showed a left lower lobe lung abscess. This was associated with leucocytosis and raised C-reactive protein. Ultrasound-guided drainage revealed viscous pus requiring manual aspiration for adequate drainage. The patient later developed extensive pneumomediastinum and subcutaneous emphysema involving the pretracheal space, without evidence of pneumothorax. Left lower lobectomy was performed to control sepsis. The patient achieved a complete recovery following his surgery and antibiotic treatment, with interval resolution of pneumomediastinum and subcutaneous emphysema. We present the radiological and clinical features leading to the diagnosis of pneumomediastinum and subcutaneous emphysema.

Risk of air and surface contamination during application of different noninvasive respiratory support for patients with COVID-19.

OBJECTIVES: We compared the risk of environmental contamination among patients with COVID-19 who received high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), and conventional oxygen therapy (COT) via nasal cannula for respiratory failure. METHODS: Air was sampled from the hospital isolation rooms with 12 air changes/hr where 26 patients with COVID-19 received HFNC (up to 60 l/min, n = 6), NIV (n = 6), or COT (up to 5 l/min of oxygen, n = 14). Surface samples were collected from 16 patients during air sampling. RESULTS: Viral RNA was detected at comparable frequency in air samples collected from patients receiving HFNC (3/54, 5.6%), NIV (1/54, 1.9%), and COT (4/117, 3.4%) (P = 0.579). Similarly, the risk of surface contamination was comparable among patients receiving HFNC (3/46, 6.5%), NIV (14/72, 19.4%), and COT (8/59, 13.6%) (P = 0.143). An increment in the cyclic thresholds of the upper respiratory specimen prior to air sampling was associated with a reduced SARS-CoV-2 detection risk in air (odds ratio 0.83 [95% confidence interval 0.69-0.96], P = 0.027) by univariate logistic regression. CONCLUSION: No increased risk of environmental contamination in the isolation rooms was observed in the use of HFNC and NIV vs COT among patients with COVID-19 with respiratory failure. Higher viral load in the respiratory samples was associated with positive air samples.

Omicron BA.1-specific T-cell responses in adults vaccinated with CoronaVac or BNT162b2 in Hong Kong: an observational cohort study.

BACKGROUND: The primary aim of using vaccines in public health responses to SARS-CoV-2 variants of concern is to reduce incidence of severe disease, for which T-cell responses are essential. There is a paucity of data on vaccine-induced T-cell immunity to omicron (B.1.1.529). We aimed to compare SARS-CoV-2 omicron BA.1-specific T-cell responses in adults vaccinated with CoronaVac or BNT162b2. METHODS: For this observational cohort, we recruited adults (aged ≥18 years) from three vaccination centres in Hong Kong. We included participants from four cohorts (cohort 1: participants who received two doses of either BNT162b2 or CoronaVac, cohort 2: participants who received two doses and a booster, cohort 3: participants who received two doses and a booster and had a breakthrough omicron infection, and cohort 4: participants who had a previous non-omicron infection and subsequently received one dose of vaccine). People with confirmed history of COVID-19 at recruitment were excluded from cohort 1 and cohort 2. We collected blood samples before vaccination (for cohort 1 and 2), 1-month following vaccination (for all cohorts), and during convalescence for cohort 3 and 4) and determined the proportion of IFNγ+CD4+ and IFNγ+CD8+ T cells in peripheral blood against SARS-CoV-2 using flow cytometry with peptide pools of SARS-CoV-2 wild type or omicron BA.1. The primary outcome was proportion of CD4+ and CD8+ T cells against SARS-CoV-2 1 month after exposure (ie, vaccination or breakthrough infection). FINDINGS: Overall, between May 21, 2020, and Aug 31, 2021, we recruited 659 participants (231 [35%] men and 428 [65%] women). Of these participants, 428 were included in cohort 1 (214 [50%] received BNT162b2 and 214 [50%] received CoronaVac); 127 in cohort 2 (48 [38%] received all BNT162b2, 40 [31%] received all CoronaVac, and 39 [31%] received two CoronaVac and a booster with BNT162b2); 58 in cohort 3, and 46 in cohort 4 (16 [35%] received CoronaVac and 30 [65%] received BNT162b2). Vaccine-induced T-cell responses to the wild-type and omicron BA.1 variants were generally similar in adults receiving two doses of either CoronaVac (CD4+ cells p=0·33; CD8+ cells p=0·70) or BNT162b2 (CD4+ cells p=0·28; CD8+ cells p=1·0). Using a peptide pool of all structural proteins for stimulation, BNT162b2 induced a higher median frequency of omicron-specific CD4+ T cells in adults younger than 60 years (CD4+ cells 0·012% vs 0·010%, p=0·031; CD8+ cells 0·003% vs 0·000%, p=0·055) and omicron-specific CD8+ T cells in people aged 60 years or older (CD4+ cells 0·015% vs 0·006%, p=0·0070; CD8+ cells 0·007% vs 0·000%, p=0·035). A booster dose of either BNT162b2 or CoronaVac after two doses of CoronaVac boosted waning T-cell responses, but T-cell responses did not exceed those at 1 month after the second dose (CoronaVac CD4+ p=0·41, CD8+ p=0·79; BNT162b2 CD4+ p=0·70 CD8+ p=0·80). INTERPRETATION: The evidence that mRNA and inactivated vaccines based on the ancestral SARS-CoV-2 virus elicited T-cell responses to SARS-CoV-2 omicron variants might explain the high observed vaccine effectiveness against severe COVID-19 shown by both types of vaccine, despite great differences in neutralising antibody responses. The use of either vaccine can be considered if the primary aim is to reduce severity and death caused by the new omicron subvariants; however, BNT162b2 is preferable for adults older than 60 years. FUNDING: The Health and Medical Research Fund Commissioned Research on the Novel Coronavirus Disease and S H Ho Foundation.

Neutralizing antibodies against the SARS-CoV-2 Omicron variant BA.1 following homologous and heterologous CoronaVac or BNT162b2 vaccination.

The Omicron variant is rapidly becoming the dominant SARS-CoV-2 virus circulating globally. It is important to define reductions in virus neutralizing activity in the serum of convalescent or vaccinated individuals to understand potential loss of protection against infection by Omicron. We previously established that a 50% plaque reduction neutralization antibody titer (PRNT50) ≥25.6 in our live virus assay corresponded to the threshold for 50% protection from infection against wild-type (WT) SARS-CoV-2. Here we show markedly reduced serum antibody titers against the Omicron variant (geometric mean titer (GMT) < 10) compared to WT virus 3-5 weeks after two doses of BNT162b2 (GMT = 218.8) or CoronaVac vaccine (GMT = 32.5). A BNT162b2 booster dose elicited Omicron PRNT50 titers ≥25.6 in 88% of individuals (22 of 25) who previously received 2 doses of BNT162b2 and 80% of individuals (24 of 30) who previously received CoronaVac. However, few (3%) previously infected individuals (1 of 30) or those vaccinated with three doses of CoronaVac (1 of 30) met this threshold. Our findings suggest that countries primarily using CoronaVac vaccines should consider messenger RNA vaccine boosters in response to the spread of Omicron. Studies evaluating the effectiveness of different vaccines against the Omicron variant are urgently needed.

Author Correction: A randomized controlled trial of an ambulatory approach versus the hospital-based approach in managing suspected obstructive sleep apnea syndrome.

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A randomized controlled trial of an ambulatory approach versus the hospital-based approach in managing suspected obstructive sleep apnea syndrome.

Comparisons of home-based versus hospital-based approach in managing patients with suspected obstructive sleep apnoea syndrome(OSAS). A prospective, controlled CPAP parallel study of new referrals with suspected OSAS randomized into group A) home-based or B) hospital-based approach. Following detection of AHI ≥ 15/hr by Embletta sleep study (group A) or polysomnography (group B), patients received CPAP for 3 months after an overnight autoCPAP titration at home or in hospital respectively. Modified intention-to-treat analysis of those with AHI ≥ 15/hr on CPAP (n = 86 vs 86) showed no difference in Epworth sleepiness score, the primary endpoint, but greater improvement in Sleep-Apnoea-Quality-of-Life-Index[difference 0.3,(95%CI 0.02, 0.6), p = 0.033] at 3 months in group A. The mean costs for the patients in group A and group B were HK$8479(989) and HK$22,248(2407) respectively. The mean difference between groups was HK$-13,769(USD 1770 equivalent) per patient with 95% CI. (-14324, -13213), p < 0.001. The waiting time of patients with AHI ≥ 15/hr who were started on CPAP treatment from the first clinic consultation to the diagnostic sleep test, autoCPAP titration, and CPAP treatment was 189.6, 148.8 and 145.0 days shorter in group A than group B respectively. Home-based approach is non-inferior to hospital-based approach in managing patients with suspected OSAS, with shorter waiting time, and substantial cost savings.

Prevalence of obstructive sleep apnea syndrome and CPAP adherence in the elderly Chinese population.

BACKGROUND: This study assessed the prevalence of obstructive sleep apnea syndrome (OSAS) and CPAP adherence in the elderly Chinese in Hong Kong. METHODS: We conducted a sleep questionnaire survey among the elders aged ≥60 years in the community centres followed by level 3 home sleep study (Embletta). Subjects with an apnea hypopnea index (AHI) ≥ 15/hr alone and those with AHI ≥ 5/hr plus either cardiovascular risk factors or Epworth Sleepiness Score (ESS) ≥ 10 were offered CPAP treatment. RESULTS: Altogether 819 subjects were interviewed with mean (SD) age of 73.9 (7.5) years, BMI 24.2 (3.6) kg/m2, neck circumference 34.9 (3.4) cm and ESS 6.6 (5.2). Daytime sleepiness was reported by 72.4%, snoring loudly 5.1% and witnessed apnea 4%. Among 234 subjects who underwent home sleep study, 156 (66.7%), 102 (43.6%), 70 (29.9%) and 45 (19.2%) had AHI ≥ 5, ≥ 10, ≥ 15 and ≥ 20/hr respectively, with the prevalence increasing with age and BMI. In the sample, 149 subjects (63.7%) were classified as having OSAS, as defined by an AHI ≥ 5/hr with associated symptoms, involving 81 men (74.3%) and 68 women (54.4%). Neck circumference and snoring frequency were the only positive independent factors associated with the AHI and the diagnosis of OSAS. Among 141 subjects who were offered CPAP treatment, 30 accepted CPAP prescription with improvement of ESS and cognitive function over 12 months with CPAP usage of 4.2 (2.2) h/night. CONCLUSION: This study showed a high prevalence of OSAS among the community elders in Hong Kong. Home CPAP acceptance was low but there was significant improvement of subjective sleepiness and cognitive function among those on CPAP treatment.

A Randomized Controlled Study to Examine the Effect of a Lifestyle Modification Program in OSA.

BACKGROUND: Obesity is an important risk factor for OSA. This study aimed to assess the effect of weight reduction through a lifestyle modification program (LMP) on patients with moderate to severe OSA. METHODS: This was a parallel group, randomized controlled trial. Altogether, 104 patients with moderate to severe OSA diagnosed on portable home sleep monitoring were randomized to receive a dietician-led LMP or usual care for 12 months. The primary outcome was reduction of apnea-hypopnea index (AHI) at 12 months as assessed by portable home sleep monitoring. RESULTS: In the intention-to-treat analysis (ITT), LMP (n = 61) was more effective in reducing AHI from baseline (16.9% fewer events in the LMP group vs 0.6% more events in the control group, P = .011). LMP was more effective in reducing BMI (-1.8 kg/m2, 6.0% of the initial BMI; -0.6 kg/m2, 2.0% of the initial BMI in control group; P < .001). The reduction in daytime sleepiness as assessed by Epworth Sleepiness Scale was not significant in ITT but was more in the LMP group (-3.5 in the LMP group vs -1.1 in the control group, P = .004) by treatment per protocol analysis. There was modest improvement in mental health in the Short Form Health Survey. Eating behavior was improved with increased intake of protein and fiber. These changes were observed 4 months after the initial intensive diet counseling and persisted at 12 months. CONCLUSIONS: LMP was effective in reducing the severity of OSA and daytime sleepiness. The beneficial effect was sustained in 12 months. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01384760; URL: www.clinicaltrials.gov.