Obstructive Sleep Apnea: The Effect of Bariatric Surgery After Five Years-A Prospective Multicenter Trial.

BACKGROUND: The prevalence of obstructive sleep apnea (OSA) is high among the bariatric surgery candidates. Obesity is the most important individual risk factor for OSA. The aim of this study was to investigate the effect of a laparoscopic Roux-en-Y gastric bypass (LRYGB) on OSA 5 years after the surgery. PATIENTS AND METHODS: In this prospective multicenter study, standard overnight cardiorespiratory recording was conducted to 150 patients at baseline prior to bariatric surgery. A total of 111 (73.3%) patients of those had OSA. Cardiorespiratory recordings at 5 years after surgery were available for 70 OSA patients. The changes in anthropometric and demographic measurements including age, weight, body mass index (BMI), and waist and neck circumference were evaluated. Also, a quality of life (QoL) questionnaire 15D administered in a baseline was controlled at 5-year follow-up visit. RESULTS: At 5-year OSA was cured in 55% of patients, but moderate or severe OSA still persisted in 20% of patients after operation. Mean total AHI decreased from 27.8 events/h to 8.8 events/h (p < 0.001) at 5-year follow-up. A clinically significant difference in QoL was seen in mobility, breathing, sleeping, usual activities, discomfort and symptoms, vitality and sexual activity. The QoL total score improved more in OSA patient at 5-year follow-up. CONCLUSIONS: LRYGB is an effective treatment of OSA in obese patients and the achieved beneficial outcomes are maintained at 5-year follow-up.

Self-reported sleep bruxism among Finnish symphony orchestra musicians: Associations with perceived sleep-related problems and psychological stress.

OBJECTIVE: This study aimed to evaluate whether self-reported sleep bruxism among musicians is associated with sleep-related problems and/or psychological stress. METHODS: Eight hundred-thirty-one Finnish orchestra musicians completed a questionnaire that covered, among others, indicators of sleep-related problems, possible sleep bruxism, and stress. RESULTS: In total, 488 questionnaires were completed. The single variable ordinal logistic regression models revealed at least moderate associations between frequency of sleep bruxism and female gender, shorter sleep duration, longer sleep latency, problems in sleeping during concert season, feeling more often tired during the daytime, restless legs, a poor self-rated sleep quality, and more stress experience. The variables that remained in the final model were sleep duration, gender, and stress. CONCLUSION: Musicians who sleep 7 hours or less per night report more sleep bruxism, as compared to those who sleep 8 hours or more. Female gender and high-stress experience were associated with more sleep bruxism.

Mandibular advancement device therapy for obstructive sleep apnea: A longitudinal study among patients treated in community dental care in Finland - Potential for the precision medicine approach.

Objective: Obstructive sleep apnea (OSA) is an increasing health problem worldwide. The aim was to evaluate long-term mandibular advancement device (MAD) therapy outcomes in community dental care among OSA patients in Finland.Methods: In all, 142 (77.2%) respondents of a questionnaire, with recently initiated treatment, were included in the study in 2010. Follow-up questionnaires were mailed in 2012 and 2017.Results: Problems occurred with the device long-term. Orofacial pain was reported more often in 2012 than in 2010 (p < 0.01). Snoring (p < 0.01) and tiredness (p < 0.05) were also significantly increased. In 2017, 50 subjects were still continuing with MAD, 20 of them as a single treatment modality. Treatment modalities in combination with MAD were CPAP, nutrition counseling, and position treatment.Discussion: Long-term MAD treatment may lead to a changing treatment-mix and set-backs. This may not only be a treatment adherence issue but also a lack of precision medicine approach regarding OSA.

Oro-facial pain experience among symphony orchestra musicians in Finland is associated with reported stress, sleep bruxism and disrupted sleep-Independent of the instrument group.

BACKGROUND: To evaluate whether oro-facial pain experience was related to the type of musical instrument and to learn more about the roles of sleep and sleep-related issues in the pain among professional musicians. OBJECTIVES: A standard questionnaire was sent to all Finnish symphony orchestras (n = 19), with altogether 1005 professional musicians and other personnel. METHODS: The questionnaire covered descriptive data, instrument group, items on perceived quality of sleep, possible sleep bruxism, stress experience and oro-facial pain experience during the past 30 days. RESULTS: In the present study, which included the musicians only, the response rate was 58.7% (n = 488). All orchestras participated in the study, and there was no significant difference in the response rate between the orchestras. The mean age of men (52.3%) was 47.7 (SD 10.3) and of women (47.7%) was 43.4 (SD 9.8) years (P < 0.001). Overall, current pain in the oro-facial area was reported by 28.9%, frequent bruxism by 12.1% and frequent stress by 20.8%. According to Somers' d, there were statistically significant but moderate correlations between overall pain reports in the oro-facial area and disrupted sleep (d = 0.127, P = 0.001), sleep bruxism (d = 0.241, P < 0.001) and stress experiences (d = 0.193, P < 0.001). Logistic regression revealed, independent of the instrument group (string, woodwind, brass wind, percussion), that current oro-facial pain experience was significantly associated with disrupted sleep (P = 0.001), frequent sleep bruxism (P < 0.001) and frequent stress (P = 0.002) experiences. CONCLUSIONS: Among symphony orchestra musicians, oro-facial pain experience seems to be related to perceptions of stress, sleep bruxism and disrupted sleep rather than the instrument group.

Weight gain may affect mandibular advancement device therapy in patients with obstructive sleep apnea: a retrospective study.

PURPOSE: The aim was to analyze whether or not weight gain influences the treatment outcome of patients with obstructive sleep apnea (OSA) treated with mandibular advancement devices (MAD). METHODS: As a part of a follow-up study among OSA patients treated with MAD in primary oral health care, a group of 28 patients reporting worsening of daytime or nighttime symptoms of OSA was given closer examination. Altogether, 21 subjects had a complete set of recordings and were enrolled into the study. RESULTS: Only three subjects had lost weight during the study period. The mean weight gain of 3.6 kg ± 7.1 kg was significant (p = 0.035). According to linear regression, weight gain was independently significantly associated with lower mean peripheral oxygen saturation 92.4 (SD 1.8 (% per hour) (p = 0.019)) and lowest oxygen saturation 80.1 (SD 7.2 (%) (p = 0.024)) scores. CONCLUSIONS: Weight gain is detrimentally associated with MAD treatment in patients with OSA. These findings suggest that regular follow-up by an experienced dentist is advisable to assess for possible worsening of OSA. Patient support to encourage weight control may be an important adjunct to MAD treatment for OSA.

The Role of Weight Management in the Treatment of Adult Obstructive Sleep Apnea. An Official American Thoracic Society Clinical Practice Guideline.

BACKGROUND: Overweight/obesity is a common, reversible risk factor for obstructive sleep apnea severity (OSA). The purpose of this guideline is to provide evidence-based recommendations for the management of overweight/obesity in patients with OSA. METHODS: The Grading of Recommendations, Assessment, Development and Evaluation approach was used to evaluate the literature. Clinical recommendations were formulated by a panel of pulmonary, sleep medicine, weight management, and behavioral science specialists. RESULTS: Behavioral, pharmacological, and surgical treatments promote weight loss and can reduce OSA severity, reverse common comorbidities, and improve quality of life, although published studies have methodological limitations. After considering the quality of evidence, feasibility, and acceptability of these interventions, the panel made a strong recommendation that patients with OSA who are overweight or obese be treated with comprehensive lifestyle intervention consisting of 1) a reduced-calorie diet, 2) exercise or increased physical activity, and 3) behavioral guidance. Conditional recommendations were made regarding reduced-calorie diet and exercise/increased physical activity as separate management tools. Pharmacological therapy and bariatric surgery are appropriate for selected patients who require further assistance with weight loss. CONCLUSIONS: Weight-loss interventions, especially comprehensive lifestyle interventions, are associated with improvements in OSA severity, cardiometabolic comorbidities, and quality of life. The American Thoracic Society recommends that clinicians regularly assess weight and incorporate weight management strategies that are tailored to individual patient preferences into the routine treatment of adult patients with OSA who are overweight or obese.

Health-related correlates of psychological well-being among girls and boys 6-8 years of age: The Physical Activity and Nutrition in Children study.

AIM: Due to limited knowledge on the differences in the correlates of psychological well-being (PSWB) between girls and boys, we compared the correlates of PSWB between primary school girls and boys. METHODS: A population sample of 412 children participated in the Physical Activity and Nutrition in Children study. Parents completed a questionnaire that included 19 questions on the components of PSWB, and a PSWB score was computed. We assessed correlates of PSWB, including physical activity, sedentary behaviour, cardiorespiratory fitness, diet quality, body fat content, sleep duration, sleep disordered breathing, prevalent diseases and parental characteristics. We used logistic regression to analyse the risk of being in the lowest third of the PSWB scores. RESULTS: Low parental education was associated with increased risk (odds ratio (OR) 2.34, P = 0.039) and high cardiorespiratory fitness with decreased risk (OR 0.26, P = 0.006) of poor PSWB in girls. At least 2 h of screen-based sedentary behaviour per day (OR 1.93, P = 0.037), daily parental smoking (OR 2.10, P = 0.034) and sleep disordered breathing (OR 4.24, P = 0.003) were related to increased risk of poor PSWB in boys. CONCLUSIONS: There are large differences in the correlates of PSWB between girls and boys. Most of these correlates are modifiable and related to the health behaviour of children and their parents.

Predictors of sleep disordered breathing in children: the PANIC study.

Objective: We studied longitudinally the associations of craniofacial morphology, mouth breathing, orthodontic treatment, and body fat content with the risk of having and developing sleep disordered breathing (SDB) in childhood. We hypothesized that deviant craniofacial morphology, mouth breathing, and adiposity predict SDB among children. Materials and methods: The participants were 412 children 6-8 years of age examined at baseline and 329 children aged 9-11 years re-examined at an average 2.2-year follow-up. An experienced orthodontist evaluated facial proportions, dental occlusion, soft tissue structures, and mode of breathing and registered malocclusions in orthodontic treatment. Body fat percentage was assessed by dual-energy X-ray absorptiometry and SDB symptoms by a questionnaire. Results: Children with SDB more likely had convex facial profile, increased lower facial height, mandibular retrusion, tonsillar hypertrophy, and mouth breathing at baseline and convex facial profile, mandibular retrusion, and mouth breathing at follow-up than children without SDB at these examinations. Male gender and body adiposity, mouth breathing, and distal molar occlusion at baseline were associated with SDB later in childhood. Adipose tissue under the chin, mandibular retrusion, vertically large or normal throat and malocclusion in orthodontic treatment at baseline predicted developing SDB during follow-up of among children without SDB at baseline. Limitations: We could not conduct polysomnographic examinations to define sleep disturbances. Instead, we used a questionnaire filled out by the parents to assess symptoms of SDB. Conclusions: The results indicate that among children, deviant craniofacial morphology, mouth breathing, body adiposity, and male gender seem to have implications in the pathophysiology of SDB.

Sleep of professional athletes: Underexploited potential to improve health and performance.

Sleep disorders have become increasingly prevalent affecting health and working ability. Restorative sleep may be considered important for athletes' successful recovery and performance. However, some athletes seem to experience major problems in sleeping. Thus far, there is limited scientific information about their sleep. This study aimed to evaluate the quality of sleep and the prevalence of sleep disorders as well as the impact of a structured sleep counselling protocol in professional athletes. A total of 107 professional ice hockey players participated in the study. The exploratory observational 1-year follow-up study consisted of questionnaire-based sleep assessment followed by general sleep counselling and, when needed, polysomnography and an individual treatment plan. One in every four players was found to have a significant problem in sleeping. All athletes considered sleep essential for their health and three in every four players considered that counselling would improve their performance. Counselling and individual treatment were found to improve significantly the quality of sleep with the mean alteration of 0.6 (95% CI 0.2-1.0, P = 0.004) in a scale from 0 to 10. Our results support that sleep problems are common in professional athletes. However, systematic examination, counselling and individual treatment planning can improve the quality of their sleep.

Effect of oxygen desaturation threshold on determination of OSA severity during weight loss.

PURPOSE: Weight loss leads to improvement of obstructive sleep apnea (OSA), based on frequency of respiratory events (apnea-hypopnea index, AHI). However, AHI does not incorporate the severity of individual obstruction events. The American Academy of Sleep Medicine suggests two alternative oxygen desaturation thresholds (ODT) for scoring of hypopneas. We hypothesize that lowering the ODT level increases the determined impact of weight loss on OSA severity. We investigate this during weight change with AHI and adjusted AHI. Adjusted AHI is a novel parameter incorporating both severity and number of the events. METHODS: Ambulatory polygraphic data of 54 OSA patients (F 15/M 39, 51.7 ± 8.4 years), divided into weight loss (>5 %, n = 20), control (weight change 0-5 %, n = 26), and weight gain (>5 %, n = 8) groups, were evaluated at baseline and after 5-year follow-up. Effect of ODT (ODT2%-ODT6%) on AHI and adjusted AHI was investigated. RESULTS: The greatest changes in AHI (decrease in weight loss group and increase in weight gain group) were observed with ODT2%. Changes in AHI diminished with increasing ODT. In weight loss group, adjusted AHI showed a similar but non-significant trend. In contrast, the higher ODT was used in weight gain group, the greater increase in adjusted AHI resulted. Using adjusted AHI instead of AHI, led to a smaller number of patients (20 vs. 55 %, ODT3%) whose OSA severity category improved along weight loss. CONCLUSIONS: Weight loss significantly reduced AHI. This reduction was highly dependent on selected ODT. The change in adjusted AHI did not occur in the same extent. This was expected as the more severe events which tend to remain during the weight loss have greater importance in adjusted AHI, while the event severity is neglected in AHI.

Mild obstructive sleep apnea does not modulate baroreflex sensitivity in adult patients.

BACKGROUND: Obstructive sleep apnea (OSA) is a chronic and progressive disease. OSA is associated with increased cardiovascular morbidity and mortality, the risk being more frequently encountered with severe degrees of OSA. Increased sympathetic activation and impaired cardiac autonomic control as reflected by depressed baroreceptor reflex sensitivity (BRS) are possible mechanisms involved in the cardiovascular complications of OSA. However, it is not known at what stage of OSA that changes in BRS appear. The aim of this study was to evaluate BRS in patients with mild OSA. METHODS: The study population consisted of 81 overweight patients with mild OSA and 46 body weight-matched non-OSA subjects. BRS, apnea-hypopnea index, body mass index, and metabolic parameters were assessed. The phenylephrine test was used to measure BRS. RESULTS: Patients in the OSA group were slightly but significantly older than the non-OSA population (50.3±9.3 years vs 45.7±11.1 years, P=0.02). Body mass index, percentage body fat, blood pressure, fasting glucose, insulin, and lipid levels did not differ between the OSA patients and non-OSA subjects. Absolute BRS values in patients with mild OSA and non-OSA subjects (9.97±6.70 ms/mmHg vs 10.51±7.16 ms/mmHg, P=0.67) and BRS values proportional to age-related and sex-related reference values (91.4%±22.7% vs 92.2%±21.8%, P=0.84) did not differ from each other. BRS <50% of the sex-specific reference value was found in 6% of patients with mild OSA and in 2% of non-OSA subjects (P=0.29). CONCLUSION: Patients with mild OSA did not show evidence of disturbed BRS in comparison with weight-matched non-OSA controls.

Endoscopic dacryocystorhinostomy as treatment for lower lacrimal pathway obstructions in adults: Review article.

Obstruction of the lacrimal pathway is manifested by epiphora, infection, and blurred vision as well as ocular and facial pain. Conservative treatments only achieve temporary relief of symptoms, thus surgery is the treatment of choice. Dacryocystorhinostomy (DCR) is recognized as the most suitable treatment for patients with obstructions of the lacrimal system at the level of the sac or in the nasolacrimal duct. The aim of this operation is to create a bypass between the lacrimal sac and the nasal cavity. During the past 2 decades, advances in rigid endoscopic equipment and other instruments have made it possible to obtain more information about the anatomic landmarks of the nasolacrimal system, which led to the development of less-invasive and safer endoscopic techniques. However, many parts of the treatment process related to endoscopic endonasal dacryocystorhinostomy (EN-DCR) still remain controversial. This article reviews the published literature about the technical issues associated with the success of EN-DCR, and clarifies the pros and cons of different pre- and postoperative procedures in adults with lower lacrimal pathway obstructions.

Lateral facial profile may reveal the risk for sleep disordered breathing in children--the PANIC-study.

OBJECTIVE: To evaluate the lateral view photography of the face as a tool for assessing morphological properties (i.e. facial convexity) as a risk factor for sleep disordered breathing (SDB) in children and to test how reliably oral health and non-oral healthcare professionals can visually discern the lateral profile of the face from the photographs. MATERIALS AND METHODS: The present study sample consisted of 382 children 6-8 years of age who were participants in the Physical Activity and Nutrition in Children (PANIC) Study. Sleep was assessed by a sleep questionnaire administered by the parents. SDB was defined as apnoeas, frequent or loud snoring or nocturnal mouth breathing observed by the parents. The facial convexity was assessed with three different methods. First, it was clinically evaluated by the reference orthodontist (T.I.). Second, lateral view photographs were taken to visually sub-divide the facial profile into convex, normal or concave. The photos were examined by a reference orthodontist and seven different healthcare professionals who work with children and also by a dental student. The inter- and intra-examiner consistencies were calculated by Kappa statistics. Three soft tissue landmarks of the facial profile, soft tissue Glabella (G`), Subnasale (Sn) and soft tissue Pogonion (Pg`) were digitally identified to analyze convexity of the face and the intra-examiner reproducibility of the reference orthodontist was determined by calculating intra-class correlation coefficients (ICCs). The third way to express the convexity of the face was to calculate the angle of facial convexity (G`-Sn-Pg`) and to group it into quintiles. For analysis the lowest quintile (≤164.2°) was set to represent the most convex facial profile. RESULTS: The prevalence of the SDB in children with the most convex profiles expressed with the lowest quintile of the angle G`-Sn-Pg` (≤164.2°) was almost 2-fold (14.5%) compared to those with normal profile (8.1%) (p = 0.084). The inter-examiner Kappa values between the reference orthodontist and the other examiners for visually assessing the facial profile with the photographs ranged from poor-to-moderate (0.000-0.579). The best Kappa values were achieved between the two orthodontists (0.579). The intra-examiner Kappa value of the reference orthodontist for assessing the profiles was 0.920, with the agreement of 93.3%. In the ICC and its 95% CI between the two digital measurements, the angles of convexity of the facial profile (G`-Sn-Pg`) of the reference orthodontist were 0.980 and 0.951-0.992. CONCLUSION: In addition to orthodontists, it would be advantageous if also other healthcare professionals could play a key role in identifying certain risk features for SDB. However, the present results indicate that, in order to recognize the morphological risk for SDB, one would need to be trained for the purpose and, as well, needs sufficient knowledge of the growth and development of the face.

Effect of different oxygen desaturation threshold levels on hypopnea scoring and classification of severity of sleep apnea.

PURPOSE: Recently, there has been a debate about the rules used to score hypopnea events. The purpose of this study was to examine the effect of different oxygen desaturation threshold (ODT) levels on the apnea-hypopnea index (AHI) and on a recently introduced parameter, adjusted AHI. Adjusted AHI incorporates the severity of individual breathing cessation events. We also aimed to clarify the impact of the different ODT levels on the current classification of obstructive sleep apnea (OSA) severity. METHODS: Ambulatory polygraphic recordings of 68 patients (19 F/49 M, median age 53.2 years, AHI ≥5) were analyzed retrospectively. Hypopneas were defined as ≥30% drop in airflow for ≥10 s associated with ≥2% oxygen desaturation (ODT2%), and after that, using stricter ODT criteria (ODT3%-ODT8%). RESULTS: Compared to ODT4%, the ODT3% resulted in 5.6 events/h higher median conventional AHI, but only 1.5 events/h higher median adjusted AHI. A significant rearrangement of patients between the clinical severity categories took place when using different ODTs. When assessing with ODT3% instead of ODT4%, the portion of the patients with moderate or severe OSA (AHI ≥15) raised from 29.4 to 73.5% using conventional AHI, but only marginally, i.e., from 73.5 to 77.9%, using the adjusted AHI. CONCLUSIONS: The conventional AHI was found to be susceptible even to minor changes in ODT level which may lead to substantial variability in AHI-based classification of disease severity. Since the adjusted AHI comprises information on severity of individual breathing cessations, it reduces the variability related to ODT levels used in hypopnea scoring and can increase the accuracy of estimation of OSA severity.

Upregulation of inflammatory genes in the nasal mucosa of patients undergoing endonasal dacryocystorhinostomy.

BACKGROUND: Epiphora is a common complaint of nasolacrimal duct obstruction (NLDO) in adults. The precise pathogenesis of NLDO is still unknown, but inflammatory processes are believed to be predisposing factors. Endoscopic dacryocystorhinostomy (EN-DCR) is an effective surgical technique for treating symptomatic NLDO. The purpose of the procedure is to relieve the patient's symptoms by creating an opening, ie, a rhinostoma, between the lacrimal sac and the nasal cavity. Although the success rates after EN-DCR are high, the procedure sometimes fails due to onset of a fibrotic process at the rhinostomy site. The aim of this prospective comparative study was to investigate inflammation-related gene expression in the nasal mucosa at the rhinostomy site. METHODS: Ten participants were consecutively recruited from eligible adult patients who underwent primary powered EN-DCR (five patients) or septoplasty (five controls). Nasal mucosa specimens were taken from the rhinostomy site at the beginning of surgery for analysis of gene expression. Specimens were taken from the same site on the lateral nasal wall for controls. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed for the inflammatory genes interleukin (IL)-6, IL-1ß, and CCL2, and because of a clear trend of increased inflammation in the EN-DCR samples, a wider PCR array was performed to compare inflammation-related gene expression in EN-DCR subjects and corresponding controls. RESULTS: Our qRT-PCR results revealed a clear trend of increased transcription of IL-6, IL-1ß, and CCL2 (P=0.03). The same trend was also evident in the PCR array, which additionally revealed notable differences between EN-DCR subjects and controls with regard to expression of several other inflammation-related mediators. At 6-month follow-up, the success rate after primary EN-DCR was 60%, ie, in three of five patients. CONCLUSION: The present study demonstrates that there is an intense inflammation gene expression response in the nasal mucosa of patients undergoing EN-DCR.

The impact of weight reduction in the prevention of the progression of obstructive sleep apnea: an explanatory analysis of a 5-year observational follow-up trial.

BACKGROUND: Obstructive sleep apnea (OSA) is a chronic progressive disease, and it is well-documented that severe OSA is associated with an increased cardiovascular morbidity and mortality. Weight reduction has been shown to improve OSA; however, we need further evidence to determine if it may prevent the progression of OSA in the long term. The aim of our study was to assess the impact of weight change during a 5-year observational follow-up of an original 1-year randomized controlled trial. METHODS: The participants were divided into the two groups according to the weight change at 5-year follow-up using the 5% weight loss as a cutoff point, which was later referred to as the successful (n = 20) or unsuccessful groups (n = 27). The change in apnea-hypopnea index (AHI) was the main objective outcome variable. RESULTS: Fifty-seven patients participated in the 5-year follow-up. At 5 years from the baseline, the change in AHI between the groups was significant in the successful group (-3.5 [95% confidence interval {CI}, -6.1 to -0.9]) compared with the unsuccessful group (5.0 [95% CI, 2.0-8.5]) (P = .002). Successful weight reduction achieved an 80% reduction in the incidence of progression of OSA compared to the unsuccessful group (log-rank test, P = .016). CONCLUSIONS: A moderate but sustained weight reduction can prevent the progression of the disease or even cure mild OSA in obese patients.

Endothelial function is well preserved in obese patients with mild obstructive sleep apnea.

PURPOSE: Endothelial dysfunction is one of the early markers of cardiovascular complications in obstructive sleep apnea (OSA). The aim of our study was to evaluate whether overweight patients with mild OSA displayed endothelial dysfunction, and to assess the effect of 1-year lifestyle intervention with an early very low calorie diet in endothelial function. METHODS: At baseline, the study population consisted of 83 overweight patients with mild OSA and 46 weight-matched non-OSA subjects. OSA patients were further randomized into a 1-year supervised lifestyle intervention group or control group which received routine lifestyle counselling. Endothelial function measured by brachial artery flow-mediated dilatation (FMD), apnea-hypopnea index (AHI), body mass index (BMI), and metabolic parameters were assessed at baseline and 12 months. RESULTS: No correlations between endothelial function and mild OSA were detected. However, patients with impaired endothelial function had lower mean saturation and impaired endothelial function correlated significantly with glucose intolerance and dyslipidemia. After the lifestyle intervention and successful weight reduction, AHI, BMI, serum triglycerides and insulin improved significantly; however, no improvement in FMD was detected. CONCLUSIONS: Mild OSA was not observed to be associated with endothelial dysfunction. Although in mild OSA endothelial function is still preserved, lifestyle intervention with weight reduction did achieve an improvement in other obesity-related risk factors for cardiovascular diseases, thus highlighting the importance of early intervention.

Cholesterol metabolism and weight reduction in subjects with mild obstructive sleep apnoea: a randomised, controlled study.

To evaluate whether parameters of obstructive sleep apnoea (OSA) associate with cholesterol metabolism before and after weight reduction, 42 middle-aged overweight subjects with mild OSA were randomised to intensive lifestyle intervention (N = 23) or to control group (N = 18) with routine lifestyle counselling only. Cholesterol metabolism was evaluated with serum noncholesterol sterol ratios to cholesterol, surrogate markers of cholesterol absorption (cholestanol and plant sterols) and synthesis (cholestenol, desmosterol, and lathosterol) at baseline and after 1-year intervention. At baseline, arterial oxygen saturation (SaO2 ) was associated with serum campesterol (P < 0.05) and inversely with desmosterol ratios (P < 0.001) independently of gender, BMI, and homeostasis model assessment index of insulin resistance (HOMA-IR). Apnoea-hypopnoea index (AHI) was not associated with cholesterol metabolism. Weight reduction significantly increased SaO2 and serum cholestanol and decreased AHI and serum cholestenol ratios. In the groups combined, the changes in AHI were inversely associated with changes of cholestanol and positively with cholestenol ratios independent of gender and the changes of BMI and HOMA-IR (P < 0.05). In conclusion, mild OSA seemed to be associated with cholesterol metabolism independent of BMI and HOMA-IR. Weight reduction increased the markers of cholesterol absorption and decreased those of cholesterol synthesis in the overweight subjects with mild OSA.