Supine sleep and positional sleep apnea after acute ischemic stroke and intracerebral hemorrhage

OBJECTIVE: Obstructive sleep apnea is frequent during the acute phase of stroke, and it is associated with poorer outcomes. A well-established relationship between supine sleep and obstructive sleep apnea severity exists in non-stroke patients. This study investigated the frequency of supine sleep and positional obstructive sleep apnea in patients with ischemic or hemorrhagic stroke. METHODS: Patients who suffered their first acute stroke, either ischemic or hemorrhagic, were subjected to a full polysomnography, including the continuous monitoring of sleep positions, during the first night after symptom onset. Obstructive sleep apnea severity was measured using the apnea-hypopnea index, and the NIHSS measured stroke severity. RESULTS: We prospectively studied 66 stroke patients. The mean age was 57.6+/-11.5 years, and the mean body mass index was 26.5+/-4.9. Obstructive sleep apnea (apnea-hypopnea index >= 5) was present in 78.8% of patients, and the mean apnea-hypopnea index was 29.7+/-26.6. The majority of subjects (66.7%) spent the entire sleep time in a supine position, and positional obstructive sleep apnea was clearly present in the other 23.1% of cases. A positive correlation was observed between the NIHSS and sleep time in the supine position (r(s) = 0.5; p<0.001). CONCLUSIONS: Prolonged supine positioning during sleep was highly frequent after stroke, and it was related to stroke severity. Positional sleep apnea was observed in one quarter of stroke patients, which was likely underestimated during the acute phase of stroke. The adequate positioning of patients during sleep during the acute phase of stroke may decrease obstructive respiratory events, regardless of the stroke subtype.

Association between sleep apnea severity and blood coagulability: Treatment effects of nasal continuous positive airway pressure

A prothrombotic state may contribute to the elevated cardiovascular risk in patients with obstructive sleep apnea (OSA). We investigated the relationship between apnea severity and hemostasis factors and effect of continuous positive airway pressure (CPAP) treatment on hemostatic activity. We performed full overnight polysomnography in 44 OSA patients (mean age 47+/-10 years), yielding apnea-hypopnea index (AHI) and mean nighttime oxyhemoglobin saturation (SpO2) as indices of apnea severity. For treatment, subjects were double-blind randomized to 2 weeks of either therapeutic CPAP (n = 18), 3 l/min supplemental nocturnal oxygen (n = 16) or placebo-CPAP (<1 cm H2O) (n = 10). Levels of von Willebrand factor antigen (VWF:Ag), soluble tissue factor (sTF), D-dimer, and plasminogen activator inhibitor (PAI)-1 antigen were measured in plasma pre- and posttreatment. Before treatment, PAI-1 was significantly correlated with AHI (r = 0.47, p = 0.001) and mean nighttime SpO2 (r = -0.32, p = 0.035), but these OSA measures were not significantly related with VWF:Ag, sTF, and D-dimer. AHI was a significant predictor of PAI-1 (R2 = 0.219, standardized beta = 0.47, p = 0.001), independent of mean nighttime SpO2, body mass index (BMI), and age. A weak time-by-treatment interaction for PAI-1 was observed (p = 0.041), even after adjusting for age, BMI, pre-treatment AHI, and mean SpO2 (p = 0.046). Post hoc analyses suggested that only CPAP treatment was associated with a decrease in PAI-1 (p = 0.039); there were no changes in VWF:Ag, sTF, and D-dimer associated with treatment with placebo-CPAP or with nocturnal oxygen. Apnea severity may be associated with impairment in the fibrinolytic capacity. To the extent that our sample size was limited, the observation that CPAP treatment led to a decrease in PAI-1 in OSA must be regarded as tentative.

Cues to starting CPAP in obstructive sleep apnoea : development and validation of the cues to CPAP Use Questionnaire (CCUQ)

Background: The reasons that a patient has to start treatment, their “Cues to Action”, are important for determining subsequent health behaviours. Cues to action are an explicit component of the Health Belief Model of CPAP acceptance adherence. At present there is no scale available to measure this construct for individuals with Obstructive Sleep Apnoea (OSA). This paper aims to develop, validate and describe responding patterns within an OSA patient sample to the Cues to CPAP Use Questionnaire (CCUQ).----- Method: Participants were 63 adult patients diagnosed with OSA who had never tried CPAP when initially recruited. The CCUQ was completed at one month after being prescribed CPAP.----- Results: Exploratory factor analysis (EFA) showed a three factor structure of the 9-item CCUQ, with “Health Cues”, “Partner Cues” and “Health Professional Cues” subscales accounting for 59.91% of the total variance. The CCUQ demonstrated modest internal consistency and split-half reliability. The questionnaire is brief and user-friendly, with readability at a 7th grade level. The most frequently endorsed cues for starting CPAP were Health Professional Cues (prompting by the sleep physician) and Health Cues such as tiredness and concern about health outcomes.----- Conclusions: This study validates a measure of an important motivational component of the Health Belief Model. Health Professional Cues and internal Health Cues were reported to be the most important prompts to commence CPAP by this patient sample.

Oximetry alone versus portable polygraphy for sleep apnea screening before bariatric surgery.

BACKGROUND: Screening for obstructive sleep apnea (OSA) is recommended as part of the preoperative assessment of obese patients scheduled for bariatric surgery. The objective of this study was to compare the sensitivity of oximetry alone versus portable polygraphy in the preoperative screening for OSA. METHODS: Polygraphy (type III portable monitor) and oximetry data recorded as part of the preoperative assessment before bariatric surgery from 68 consecutive patients were reviewed. We compared the sensitivity of 3% or 4% desaturation index (oximetry alone) with the apnea-hypopnea index (AHI; polygraphy) to diagnose OSA and classify the patients as normal (<10 events per hour), mild to moderate (10-30 events per hour), or severe (>30 events per hour). RESULTS: Using AHI, the prevalence of OSA (AHI > 10 per hour) was 57.4%: 16.2% of the patients were classified as severe, 41.2% as mild to moderate, and 42.6% as normal. Using 3% desaturation index, 22.1% were classified as severe, 47.1% as mild to moderate, and 30.9% as normal. With 4% desaturation index, 17.6% were classified as severe, 32.4% as mild, and 50% as normal. Overall, 3% desaturation index compared to AHI yielded a 95% negative predictive value to rule out OSA (AHI > 10 per hour) and a 100% sensitivity (0.73 positive predictive value) to detect severe OSA (AHI > 30 per hour). CONCLUSIONS: Using oximetry with 3% desaturation index as a screening tool for OSA could allow us to rule out significant OSA in almost a third of the patients and to detect patients with severe OSA. This cheap and widely available technique could accelerate preoperative work-up of these patients.

Prevalence and Diagnostic Approach to Sleep Apnea in Hemodialysis Patients: A Population Study.

BACKGROUND: Previous observations found a high prevalence of obstructive sleep apnea (OSA) in the hemodialysis population, but the best diagnostic approach remains undefined. We assessed OSA prevalence and performance of available screening tools to propose a specific diagnostic algorithm. METHODS: 104 patients from 6 Swiss hemodialysis centers underwent polygraphy and completed 3 OSA screening scores: STOP-BANG, Berlin's Questionnaire, and Adjusted Neck Circumference. The OSA predictors were identified on a derivation population and used to develop the diagnostic algorithm, which was validated on an independent population. RESULTS: We found 56% OSA prevalence (AHI ≥ 15/h), which was largely underdiagnosed. Screening scores showed poor performance for OSA screening (ROC areas 0.538 [SE 0.093] to 0.655 [SE 0.083]). Age, neck circumference, and time on renal replacement therapy were the best predictors of OSA and were used to develop a screening algorithm, with higher discriminatory performance than classical screening tools (ROC area 0.831 [0.066]). CONCLUSIONS: Our study confirms the high OSA prevalence and highlights the low diagnosis rate of this treatable cardiovascular risk factor in the hemodialysis population. Considering the poor performance of OSA screening tools, we propose and validate a specific algorithm to identify hemodialysis patients at risk for OSA for whom further sleep investigations should be considered.

Morphometric endoscopic study of the pharynx in patients with sleep apnea

Purpose: The aims of the study were to measure endoscopically the retrolingual pharynx during wakefulness and sleep before and after maxillomandibular advancement surgery and to quantify the changes observed. Materials and Methods: Eighteen patients with mild to severe grade obstructive sleep apnea hypopnea were evaluated during wakefulness while sitting and lying down and during induced sleep in dorsal decubitus while breathing naturally. Images of the retrolingual region of the pharynx were captured with a nasofibroscope and recorded on a DVD using the Sony Vegas 8.0 software (Sony Creative Software, Madison, WI). The images captured in greater and smaller aperture were measured with the Image J software (produced by Wayne Rasband, United States National Institutes of Health, Bethesda, MD) in linear anteroposterior and linear laterolateral areas. A correction factor was then applied to equalize the size of the images and thus compare them to one another. Results: The postoperative dimensions of the pharynx always increased significantly in all measurements compared with the preoperative ones. During induced sleep in dorsal decubitus, there was a greater gain in the area of smaller aperture (201.33%). Conclusions: The proposed method showed that the dimensions of the pharynx always increased significantly after surgery for maxillomandibular advancement, although the gain was not homogeneous in all dimensions and also varied according to state of consciousness. The greatest gain was observed in the area of smaller aperture with the patient in induced sleep, thus reducing the collapse of the pharynx. (C) 2012 Elsevier Inc. All rights reserved.

Complete denture wear during sleep in elderly sleep apnea patients-a preliminary study

There is no consensus in the literature about the impact of complete denture wear on obstructive sleep apnea (OSA). The goal of this randomized clinical study was to assess if complete denture wear during sleep interferes with the quality of sleep. Elderly edentulous OSA patients from a complete denture clinic were enrolled and received new complete dentures. An objective sleep analysis was determined with polysomnography performed at the sleep laboratory for all patients who slept either with or without their dentures. Twenty-three patients (74% females) completed the study with a mean age of 69.6 years and a mean body mass index of 26.7 kg/m(2). The apnea and hypopnea index (AHI) was significantly higher when patients slept with dentures compared to without (25.9 +/- 14.8/h vs. 19.9 +/- 10.2/h; p > 0.005). In the mild OSA group, the AHI was significantly higher when patients slept with the dentures (16.6 +/- 6.9 vs. 8.9 +/- 2.4; p < 0.05), while in moderate to severe OSA patients, the AHI was not significantly different when sleeping with dentures (.30.8 +/- 15.6 vs. 25.7 +/- 7.5; p = 0.2). The supine AHI in mild patients was related to a higher increase in AHI while wearing dentures (12.7 +/- 8.4/h vs. 51.9 +/- 28.6/h; p < 0.001). A limitation of the study is that the mild OSA patients had a higher BMI when compared to the moderate to severe OSA patients. Ten out of 14 patients who preferred to sleep with their upper and lower dentures showed an increase in their AHI while wearing dentures to sleep. Contrary to previous studies, we found that OSA patients may experience more apneic events if they sleep with their dentures in place. Specifically, in mild OSAS patients, the use of dentures substantially increases the AHI especially when in the supine position.

Paediatric traffic accident and obstructive sleep apnoea by antrochoanal polyps: case report and literature review

Antrochoanal polyps are hyperplasias of the nasal mucosa, which have their origin in the maxillary sinus and extend through the nasal cavity and the choanae into the naso- and oropharynx. In children antrochoanal polyps represent one of the more frequent manifestations of paediatric nasal polyposis. Most studies on antrochoanal polyps in children report only on nasal obstruction, hyponasal speech and snoring, which are also encountered in the most common cause of obstructive sleep apnoea syndrome; i.e. adenoid or tonsillar hyperplasia. Only very few studies report on additional health hazards by antrochoanal polyps ranging from obstructive sleep apnoea syndrome to swallowing disorders and cachexia. We present the case of an 8 year old girl with a bicycle accident caused by excessive daytime sleepiness and obstructive sleep apnoea syndrome due to an extensive antrochoanal polyp. After a transnasal polypectomy and meatotomy type II the obstructive sleep apnoea and day time sleepiness resolved completely. Awareness of this additional health hazard is important and correct evaluation and timely diagnosis of a potential antrochoanal polyp is mandatory because minimally invasive rhinosurgery is highly curative in preventing further impending problems.

The role of sleepiness, sleep disorders, and the work environment on heavy-vehicle crashes in 2 Australian states

Heavy-vehicle driving involves a challenging work environment and a high crash rate. We investigated the associations of sleepiness, sleep disorders, and work environment (including truck characteristics) with the risk of crashing between 2008 and 2011 in the Australian states of New South Wales and Western Australia. We conducted a case-control study of 530 heavy-vehicle drivers who had recently crashed and 517 heavy-vehicle drivers who had not. Drivers' crash histories, truck details, driving schedules, payment rates, sleep patterns, and measures of health were collected. Subjects wore a nasal flow monitor for 1 night to assess for obstructive sleep apnea. Driving schedules that included the period between midnight and 5:59 am were associated with increased likelihood of crashing (odds ratio = 3.42, 95% confidence interval: 2.04, 5.74), as were having an empty load (odds ratio = 2.61, 95% confidence interval: 1.72, 3.97) and being a less experienced driver (odds ratio = 3.25, 95% confidence interval: 2.37, 4.46). Not taking regular breaks and the lack of vehicle safety devices were also associated with increased crash risk. Despite the high prevalence of obstructive sleep apnea, it was not associated with the risk of a heavy-vehicle nonfatal, nonsevere crash. Scheduling of driving to avoid midnight-to-dawn driving and the use of more frequent rest breaks are likely to reduce the risk of heavy-vehicle nonfatal, nonsevere crashes by 2–3 times.

Sleep complaints and polysomnographic findings: A study of nuclear power plant shift workers

The literature widely recognizes that shift workers have more health complaints than the general population. The objective of this study was to describe the prevalence of sleep complaints and verify the polysomnographic (PSG) variables of shift workers in two Brazilian nuclear power plants. We carried out a subjective evaluation with a sleep questionnaire. Based on these results, the interviewees that reported sleep-related complaints were referred for polysomnographic evaluation. of the 327 volunteers initially evaluated by the sleep questionnaire, 113 (35%) reported sleep complaints; they were significantly older, had higher body mass index (BMI), and worked more years on shifts than those without sleep complaints. of these 113, 90 met criteria for various sleep disorders: 30 (9%) showed obstructive sleep apnea (OSA), 18 (5.5%) showed limb movement, and 42 (13%) evidenced both sleep problems and had a significantly higher proportion of sleep stage 1 and arousals compared with the 23 shift workers that had no indices of sleep problems. The present study found that 90 (27.5%) of the evaluated participants met the PSG criteria of some type of clinical sleep disorder. This high proportion should be investigated for associations with other aspects of work, such as working hours, working schedule, years performing shift work, and access to health services. Due to the strong association between sleep disorders and the incidence of fatigue and sleepiness, the evaluation of the sleep patterns and complaints of shift workers is essential and should be considered to be one of the basic strategies of industry to prevent accidents.

Introducing non-linear analysis into sustained speech characterization to improve sleep apnea detection

We present a novel approach for detecting severe obstructive sleep apnea (OSA) cases by introducing non-linear analysis into sustained speech characterization. The proposed scheme was designed for providing additional information into our baseline system, built on top of state-of-the-art cepstral domain modeling techniques, aiming to improve accuracy rates. This new information is lightly correlated with our previous MFCC modeling of sustained speech and uncorrelated with the information in our continuous speech modeling scheme. Tests have been performed to evaluate the improvement for our detection task, based on sustained speech as well as combined with a continuous speech classifier, resulting in a 10% relative reduction in classification for the first and a 33% relative reduction for the fused scheme. Results encourage us to consider the existence of non-linear effects on OSA patients' voices, and to think about tools which could be used to improve short-time analysis.

Can a community pharmacy sleep assessment tool aid the identification of patients at risk of sleep disorders in the community : a pilot study

Background: When experiencing sleep problems for the first time, consumers may often approach community pharmacists for advice as they are easily accessible health care professionals in the community. In Australian community pharmacies there are no specific tools available for use by pharmacists to assist with the assessment and handling of consumers with sleep enquiries. Objective: To assess the feasibility of improving the detection of sleep disorders within the community through the pilot of a newly developed Community Pharmacy Sleep Assessment Tool (COP-SAT). Method: The COP-SAT was designed to incorporate elements from a number of existing, standardized, and validated clinical screening measures. The COP-SAT was trialed in four Australian community pharmacies over a 4-week period. Key findings: A total of 241 community pharmacy consumers were assessed using the COP-SAT. A total of 74 (30.7%) were assessed as being at risk of insomnia, 26 (10.7%) were at risk of daytime sleepiness, 19 (7.9%) were at risk of obstructive sleep apnea, and 121 (50.2%) were regular snorers. A total of 116 (48.1%) participants indicated that they consume caffeine before bedtime, of which 55 (47%) had associated symptoms of sleep onset insomnia. Moreover, 85 (35%) consumed alcohol before bedtime, of which 50 (58%) experienced fragmented sleep, 50 (58%) were regular snorers, and nine (10.6%) had apnea symptoms. The COP-SAT was feasible in the community pharmacy setting. The prevalence of sleep disorders in the sampled population was high, but generally consistent with previous studies on the general population. Conclusion: A large proportion of participants reported sleep disorder symptoms, and a link was found between the consumption of alcohol and caffeine substances at bedtime and associated symptoms. While larger studies are needed to assess the clinical properties of the tool, the results of this feasibility study have demonstrated that the COP-SAT may be a practical tool for the identification of patients at risk of developing sleep disorders in the community.

Apneia obstrutiva do sono e função endotelial em pacientes com hipertensão arterial resistente

A apneia obstrutiva do sono (AOS) é considerada um fator de risco independente para as doenças cardiovasculares. Existem evidências de que indivíduos com apneia obstrutiva do sono podem apresentar elevação nos mediadores inflamatórios, alterações no perfil metabólico, aumento na atividade do sistema nervoso simpático, com consequente elevação da pressão arterial e disfunção endotelial. Nos últimos anos, inúmeros estudos tem apontado a AOS como um dos fatores responsáveis pela hipertensão resistente. O objetivo do estudo foi avaliar a presença da apneia obstrutiva do sono e o comportamento da função endotelial em pacientes com hipertensão resistente, comparando com hipertensos apresentando pressão arterial controlada com até 3 classes diferentes de fármacos anti-hipertensivos. Trata-se de um estudo transversal com 40 pacientes hipertensos: 20 com hipertensão arterial resistente (HAR) e 20 com pressão arterial controlada por medicação (hipertensão arterial controlada; HAC), sem distinção de raça ou gênero, com idade entre 18 e 75 anos. A pressão arterial casual e a monitorização ambulatorial da pressão arterial foram aferidas por método oscilométrico em aparelhos automáticos. A função endotelial e a presença da apneia obstrutiva do sono foram avaliadas através da tonometria arterial periférica pelos equipamentos Endo-PAT2000 e o aparelho portátil Watch-PAT200, respectivamente. A avaliação antropométrica foi realizada através das aferições das circunferências da cintura e do pescoço, índice de massa corporal (IMC), e relação cintura-estatura. A composição corporal foi avaliada por bioimpedância elétrica BIODYNAMICS 450. As análises estatísticas foram realizadas pelo software GraphPad PRISM, versão 6.01. A prevalência de AOS no grupo com HAR foi de 85% (Índice de apneia-hipopneia [AHI]= 12,391,89) e de 80% no grupo com HAC (AHI =20,744,69), sendo mais frequente em homens (p=0,04; OR=3,86; 95% IC 0,99 a 14,52). Os dois grupos apresentaram valores semelhantes das variáveis antropométricas avaliadas. A função endotelial avaliada pelo índice de hiperemia reativa foi similar nos dois grupos (grupo HAR: 1,880,09 vs. grupo HAC: 2,030,09; p=0,28). Apesar do número de dessaturações de oxigênio >4% ter apresentado diferença significativa entre os grupos (grupo HAR: 28,755,08 vs. grupo HAC: 64,1516,97; p=0,04), o tempo total de sono (grupo HAR: 309,515,27 vs. grupo HAC: 323,318,74 min) e a saturação mínima da oxi-hemoglobina (grupo HAR: 87,80,85 vs. grupo HAC: 83,32,37%) não mostraram essa diferença. Considerando todos os pacientes hipertensos, o AHI apresentou correlação significativa com o peso corporal (r=0,51; p=0,0007), o IMC (r=0,41; p=0,007), a circunferência da cintura (r=0,44; p=0,005), a circunferência do pescoço (r=0,38; p=0,01) e a relação cintura-estatura (r=0,39; p=0,01). Os pacientes sem AOS em comparação com os pacientes com AOS, apresentaram risco significativamente menor de apresentar comprometimento da função endotelial (OR=0,17; 95% IC 0,04-0,72; p=0,03). Os achados do presente estudo sugerem que a prevalência de AOS em pacientes com hipertensão resistente é elevada, porém semelhante a de indivíduos com hipertensão controlada. Pacientes com hipertensão resistente e controlada não apresentaram diferenças significativas em relação à função endotelial. A gravidade de AOS no grupo total de hipertensos se associou com maior risco de comprometimento da função endotelial.

The nucleus of the solitary tract and the coordination of respiratory and sympathetic activities

It is well known that breathing introduces rhythmical oscillations in the heart rate and arterial pressure levels. Sympathetic oscillations coupled to the respiratory activity have been suggested as an important homeostatic mechanism optimizing tissue perfusion and blood gas uptake/delivery. This respiratory-sympathetic coupling is strengthened in conditions of blood gas challenges (hypoxia and hypercapnia) as a result of the synchronized activation of brainstem respiratory and sympathetic neurons, culminating with the emergence of entrained cardiovascular and respiratory reflex responses. Studies have proposed that the ventrolateral region of the medulla oblongata is a major site of synaptic interaction between respiratory and sympathetic neurons. However, other brainstem regions also play a relevant role in the patterning of respiratory and sympathetic motor outputs. Recent findings suggest that the neurons of the nucleus of the solitary tract (NTS), in the dorsal medulla, are essential for the processing and coordination of respiratory and sympathetic responses to hypoxia. The NTS is the first synaptic station of the cardiorespiratory afferent inputs, including peripheral chemoreceptors, baroreceptors and pulmonary stretch receptors. The synaptic profile of the NTS neurons receiving the excitatory drive from afferent inputs is complex and involves distinct neurotransmitters, including glutamate, ATP and acetylcholine. In the present review we discuss the role of the NTS circuitry in coordinating sympathetic and respiratory reflex responses. We also analyze the neuroplasticity of NTS neurons and their contribution for the development of cardiorespiratory dysfunctions, as observed in neurogenic hypertension, obstructive sleep apnea and metabolic disorders.

Mobilisation des dépôts ectopiques de tissu adipeux : ses implications dans la résolution des comorbidités associées à l'obésité sévère suivant une chirurgie bariatrique

La prévalence de l’obésité sévère ne cesse d’augmenter. La problématique associée à l’obésité sévère est la présence possible de nombreuses comorbidités qui peuvent coexister et altérer le système cardiovasculaire, pulmonaire, endocrinien, articulaire et même favoriser le développement de certains cancers. L’excès de poids, plus particulièrement l’excès de tissu adipeux, sont tous deux liés au développement de ces comorbidités. Aucune donnée n’est disponible quant au rôle de la déposition ectopique du tissu adipeux. Considérant le caractère morbide de l’obésité sévère, la mortalité de toute cause augmentée et l’espérance de vie réduite, à ce jour le seul traitement dit efficace à long terme pour le traitement de l’obésité sévère est la chirurgie bariatrique. L’efficacité est définie par la perte de poids, le maintien à long terme de cette perte de poids ainsi que par l’amélioration ou la résolution des comorbidités. L’intérêt clinique et scientifique pour la chirurgie bariatrique est grandissant. Un nombre important d’études s’intéresse aux mécanismes sous-jacents de la résolution des comorbidités. Le diabète de type 2 est la comorbidité la plus étudiée et peu d’études se sont intéressées aux déterm meil.inants de la résolution de l’hypertension artérielle et de l’apnée obstructive du som Comme premier objectif, cette thèse visait à caractériser les différences de la composition corporelle et de la distribution du tissu adipeux de patients obèses sévères avec ou sans diagnostic de diabète de type 2, d’hypertension artérielle et d’apnée obstructive du sommeil. Le deuxième objectif de cette thèse visait à comparer l’évolution postopératoire suite à une chirurgie bariatrique sur les changements de la composition corporelle et de la distribution du tissu adipeux selon le statut de résolution du diabète de type 2, de l’hypertension artérielle et de l’apnée obstructive du sommeil. De plus, considérant le peu d’évidences dans la littérature au sujet des déterminants de la résolution de l’hypertension artérielle et de l’apnée obstructive du sommeil, l’évaluation du profil inflammatoire, des adipokines et de l’activité du système nerveux autonome ont aussi été caractérisés. Premièrement, nous avons documenté qu’en présence d’obésité sévère, la déposition ectopique du tissu adipeux était plus importante chez les patients avec un diabète de type 2, une hypertension artérielle et une apnée obstructive du sommeil comparativement à ceux n’ayant pas ces comorbidités. Nous avons par la suite montré que la résolution du diabète de type 2 et de l’hypertension artérielle était caractérisée par une réduction plus importante du tissu adipeux viscéral. Au contraire, la résolution de l’apnée obstructive du sommeil était plutôt caractérisée par une réduction plus importante du tissu adipeux sous-cutané à la mi-cuisse et par une tendance à une perte de poids plus élevée. De plus, nous avons observé que chez les patients qui n’avaient pas résolu leur diabète de type 2, leur hypertension artérielle et leur apnée obstructive du sommeil, la quantité de tissu adipeux viscéral, à 12 mois suivant la chirurgie bariatrique, était plus importante comparativement à celle mesurée chez les patients n’ayant pas résolu ces comorbidités. Spécifiquement à l’évaluation du profil inflammatoire et des adipokines, nous avons observé que chez les patients obèses sévères, la présence de l’hypertension artérielle et de l’apnée obstructive du sommeil n’était pas caractérisée par un profil altéré au niveau des marqueurs inflammatoires et des adipokines. Également, nous n’avons pas observé de changements majeurs qui pouvaient expliquer, en partie, la résolution de l’hypertension artérielle et de l’apnée obstructive du sommeil. Quant à l’activité du système nerveux autonome, nous avons observé une faible activité du système nerveux parasympathique chez les patients obèses sévères avec hypertension artérielle et apnée obstructive du sommeil. Nous avons également documenté que la résolution de l’hypertension artérielle et de l’apnée obstructive du sommeil était associée à une tendance à une augmentation plus importante de l’activité parasympathique du système nerveux autonome. Les résultats obtenus au cours de ce doctorat supportent l’importance de la déposition ectopique du tissu adipeux en situation d’obésité sévère, particulièrement le rôle du tissu adipeux viscéral, dans le développement du diabète de type 2, de l’hypertension artérielle et de l’apnée obstructive du sommeil ainsi que dans la résolution de ces comorbidités suivant une chirurgie bariatrique. D’autres recherches devront davantage s’intéresser à la mobilisation des dépôts ectopiques de tissu adipeux comme un déterminant important dans la résolution à plus long terme de ces comorbidités.