Obstructive sleep apnea in asthmatic children: a cross-sectional study about prevalence and risk factors.

OBJECTIVES: Primary objectives were to analyze the prevalence of obstructive sleep apnea in (1) boys and girls, and (2) severe asthma versus moderate and mild cases. The authors hypothesized that girls and severe asthma would have a higher prevalence of obstructive sleep apnea. METHODS: Cross-sectional evaluation of asthmatic children attending a tertiary Pediatric Pulmonology clinic. The authors performed a history, physical examination, pulmonary function test, and home sleep apnea test. RESULTS: The authors studied 80 consecutive patients, 7-18 years old, mean age of 11.6 years (standard deviation 2.7), 51.3% female, and 18.5% obese. Pulmonary function tests were obtained from 80 volunteers, 45% with obstruction pattern. Home sleep apnea tests were available from 76 volunteers, with a mean obstructive respiratory index of 1.8 events/h. Obstructive sleep apnea was found in 49 volunteers (61.2%). The authors did not find associations between obstructive sleep apnea and sex or asthma severity. CONCLUSIONS: Obstructive sleep apnea was frequent among these asthmatic children. Sex and asthma severity were not risk factors. Considering the interrelationship of both diseases, it is worth keeping in mind the possibility of obstructive sleep apnea among children and teenagers with asthma.

Obstructive sleep apnea in asthmatic children: a cross-sectional study about prevalence and risk factors

Abstract Objectives: Primary objectives were to analyze the prevalence of obstructive sleep apnea in (1) boys and girls, and (2) severe asthma versus moderate and mild cases. The authors hypothesized that girls and severe asthma would have a higher prevalence of obstructive sleep apnea. Methods: Cross-sectional evaluation of asthmatic children attending a tertiary Pediatric Pulmonology clinic. The authors performed a history, physical examination, pulmonary function test, and home sleep apnea test. Results: The authors studied 80 consecutive patients, 7-18 years old, mean age of 11.6 years (standard deviation 2.7), 51.3% female, and 18.5% obese. Pulmonary function tests were obtained from 80 volunteers, 45% with obstruction pattern. Home sleep apnea tests were available from 76 volunteers, with a mean obstructive respiratory index of 1.8 events/h. Obstructive sleep apnea was found in 49 volunteers (61.2%). The authors did not find associations between obstructive sleep apnea and sex or asthma severity. Conclusions: Obstructive sleep apnea was frequent among these asthmatic children. Sex and asthma severity were not risk factors. Considering the interrelationship of both diseases, it is worth keeping in mind the possibility of obstructive sleep apnea among children and teenagers with asthma.

One-month of a low-energy diet, with no additional effect of high-protein, reduces Obstructive Sleep Apnea severity and improve metabolic parameters in obese males.

PURPOSE: Obstructive Sleep Apnea (OSA) is closely associated with obesity. Weight loss ameliorates OSA and its associated metabolic disorders. A high protein intake may improve weight loss through increased energy expenditure, and fat-free mass maintenance during weight loss. OBJECTIVES: To evaluate the effects of a low-energy, high-protein diet on OSA severity and metabolic parameters in obese men. METHODS: Forty-five OSA obese (BMI ≥ 30 kg/m2) males were included in this randomized study and submitted to nocturnal polysomnography, body composition measured by plethysmography, biochemical analyses of blood glucose, insulin and lipids, and food intake evaluations before and after one month of a low-energy diet. Diets were designed to create a 30% deficit in total energy expenditure with 1.6 g of protein/kg/day (High Protein group - HP) or 0.8 g of protein/kg/day (Low Protein group - LP). RESULTS: Only a time effect of the intervention was observed in body mass (-3.7 ± 2.0% for the LP group and -4.0 ± 1.5% for the HP group; p < 0.001), Body Mass Index (p < 0.001), fat mass in kg (p < 0.01) and fat-free mass in kg (p < 0.01). Significant improvements in Apnea Hypopnea Index were observed in both groups (54.0 ± 25.0 to 33.7 ± 31.7 in LP group; 39.7 ± 24.3 to 21.4 ± 25.9 in HP group; p = 0.06). Improvements of 38% and 46% in the Apnea-Hypopnea Index were observed in the LP and HP groups, respectively. Both interventions provided equivalent metabolic benefits as reductions in glucose (p < 0.001), insulin (p < 0.001), HOMA-IR (p = 0.005), triglycerides (p = 0.002), and in total cholesterol (p = 0.004). CONCLUSION: One month of a low-energy diet resulted in significant improvements in OSA severity in obese men. Increased protein intake during a short period of low-energy diet had no further beneficial effects on OSA severity or biochemical parameters than a standard protein diet. Registered under ClinicalTrials.gov Identifier no. NCT01985035.

Long term oral appliance therapy decreases stress symptoms in patients with upper airway resistance syndrome.

STUDY OBJECTIVES: To evaluate the long-term effects of a mandibular advancement device (MAD) on stress symptoms and cognitive function in patients with upper airway resistance syndrome (UARS) compared with placebo. METHODS: This study was a randomized placebo-controlled clinical trial. Thirty UARS patients were randomized into 2 groups: placebo and MAD groups. UARS criteria were the presence of sleepiness (Epworth Sleepiness Scale ≥ 10) and/or fatigue (Modified Fatigue Impact Scale ≥ 38) associated with an apnea-hypopnea index ≤ 5 events/h and a respiratory disturbance index > 5 events/h of sleep, and/or flow limitation in more than 30% of total sleep time. All patients completed the Rey Auditory-Verbal Learning Test, the Logical Memory test, the Stroop Color Test, the Trail Making Test, the Digit Symbol Substitution Test, and Inventory of Stress Symptoms. Cognition protocol was defined based on the most used neuropsychological tests in the literature. Evaluations were performed before and after 1.5 years of treatment. RESULTS: Mean adherence to placebo and to MAD was 6.6 ± 2.6 and 6.1 ± 2.4 h/night, respectively. Side effects reported by MAD group were minor and short-term. There was no statistically significant difference in Rey Auditory-Verbal Learning Test, Logical Memory test, Stroop Color Test, Trail Making Test, and Digit Symbol Substitution Test before and after 1.5 years of treatment in both groups. Inventory of Stress Symptoms score decreased at the alert phase and the resistance phase after 1.5 years of MAD treatment compared to the placebo. CONCLUSIONS: Mandibular advancement devices were effective in decreasing stress symptoms in UARS patients after 1.5 years of treatment. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Efficacy of Oral Appliance for Upper Airway Resistance Syndrome; URL: https://clinicaltrials.gov/ct2/show/record/NCT02636621; Identifier: NTC02636621.

Sleep disorders in polycystic ovary syndrome: influence of obesity and hyperandrogenism.

OBJECTIVE: This study aims to evaluate the sleep of subjects with polycystic ovary syndrome (PCOS), with and without hyperandrogenism, in comparison with a healthy control group and examine the effects of hyperandrogenism and obesity on sleep parameters. METHODS: A total of 44 volunteers were recruited to participate in the study. Clinical, biochemical and polysomnographic parameters were used to diagnose PCOS and hyperandrogenism. The evaluation of sleep quality was made using validated questionnaires and polysomnography test. The frequency of obstructive sleep apnea was also compared between the groups. RESULTS: The study revealed that women with PCOS presented poorer subjective sleep quality, increased incidence of snoring and a higher risk of obstructive sleep apnea, based on the Berlin questionnaire. Also, after adjusting for body mass index, PCOS subjects had rapid eye movement (REM) time lower than those in the control group. PCOS women versus those without hyperandrogenism did not differ on any sleep measurement. Women with obstructive sleep apnea were only diagnosed in the PCOS group. CONCLUSIONS: Our results indicate that PCOS impairs subjective sleep quality, as well as objective sleep quality, due to a reduction in REM sleep stage time in women diagnosed with the syndrome. Obesity affected sleep-related parameters but hyperandrogenism had no effect. Only the PCOS group had obstructive sleep apnea diagnosis.

Sleep disorders in polycystic ovary syndrome: influence of obesity and hyperandrogenism

SUMMARY OBJECTIVE: This study aims to evaluate the sleep of subjects with polycystic ovary syndrome (PCOS), with and without hyperandrogenism, in comparison with a healthy control group and examine the effects of hyperandrogenism and obesity on sleep parameters. METHODS: A total of 44 volunteers were recruited to participate in the study. Clinical, biochemical and polysomnographic parameters were used to diagnose PCOS and hyperandrogenism. The evaluation of sleep quality was made using validated questionnaires and polysomnography test. The frequency of obstructive sleep apnea was also compared between the groups. RESULTS: The study revealed that women with PCOS presented poorer subjective sleep quality, increased incidence of snoring and a higher risk of obstructive sleep apnea, based on the Berlin questionnaire. Also, after adjusting for body mass index, PCOS subjects had rapid eye movement (REM) time lower than those in the control group. PCOS women versus those without hyperandrogenism did not differ on any sleep measurement. Women with obstructive sleep apnea were only diagnosed in the PCOS group. CONCLUSIONS: Our results indicate that PCOS impairs subjective sleep quality, as well as objective sleep quality, due to a reduction in REM sleep stage time in women diagnosed with the syndrome. Obesity affected sleep-related parameters but hyperandrogenism had no effect. Only the PCOS group had obstructive sleep apnea diagnosis.

RESUMO OBJETIVO: Este estudo objetivou avaliar o sono de mulheres com síndrome do ovário policístico, com e sem hiperandrogenismo, em comparação com um grupo controle saudável, e estudar os efeitos do hiperandrogenismo e da obesidade nos parâmetros do sono. MÉTODOS: Um total de 44 voluntárias foram recrutadas para participar do estudo. Os parâmetros clínicos, bioquímicos e polissonográficos e foram usados para diagnosticar SOP e hiperandrogenismo. A avaliação da qualidade de sono foi feita usando questionários validados e o exame polissonográfico. A frequência de síndrome da apneia obstrutiva também foi comparada entre os grupos. RESULTADOS: O estudo revelou que mulheres com SOP apresentaram menor qualidade de sono subjetiva, incidência aumentada de ronco e maior risco para síndrome da apneia obstrutiva, baseada no questionário de Berlin. Ademais, após o ajuste para índice de massa corpórea, mulheres com SOP tiveram menor tempo de sono REM do que aquelas do grupo controle. Dentre as mulheres com SOP, aquelas com hiperandrogenismo não tiveram diferenças em nenhuma variável do sono. Mulheres com síndrome da apneia obstrutiva foram diagnosticadas no grupo SOP. CONCLUSÕES: Nossos resultados indicam que a SOP afeta a qualidade subjetiva de sono, bem como a qualidade objetiva e do sono, em razão da redução do tempo de sono REM em mulheres diagnosticadas com a síndrome. A obesidade afetou parâmetros relacionados ao sono, mas o hiperandrogenismo não teve efeito. A síndrome da apneia obstrutiva somente foi diagnosticada em mulheres com SOP.

Obstructive sleep apnoea as a risk factor for incident metabolic syndrome: a joined Episono and HypnoLaus prospective cohorts study.

Cross-sectional studies have demonstrated that obstructive sleep apnoea (OSA) and metabolic syndrome (MetS) are often associated, but whether a temporal relationship exists is unknown. We aimed to investigate the effect of OSA on the risk of developing MetS in the general population.A prospective study was conducted combining two population-based samples: Episono (Brazil) and HypnoLaus (Switzerland). MetS was assessed according to unified criteria. Polysomnography (PSG) was performed at baseline and follow-up in Episono, and at baseline in HypnoLaus. OSA was defined according to the apnoea-hypopnoea index as mild (≥5- <15 events h-1) and moderate-to-severe (≥15 events·h-1). We included 1853 participants (mean±sd age 52±13 years, 56% female) without MetS at baseline.After mean±sd 6±1 years, 318 (17.2%) participants developed MetS. Moderate-to-severe OSA was independently associated with incident MetS (OR 2.58, 95% CI 1.61-4.11) and increased the number of MetS components from baseline to follow-up through mediation of the percentage of time with arterial oxygen saturation <90%. Subset analysis in Episono confirmed that the increase in this parameter between baseline and follow-up PSGs represented a risk factor for incident MetS (OR 1.42, 95% CI 1.04-1.95, for each 10% increase).OSA is independently associated with an increased risk of developing MetS through mediation of nocturnal hypoxaemia in the general population.

Metabolic Profile in Patients with Mild Obstructive Sleep Apnea.

BACKGROUND: Mild obstructive sleep apnea (OSA) is a highly prevalent disorder in adults. However, it is not clear whether mild OSA has significant metabolic complications. This study examined the prevalence of metabolic syndrome (MS) in patients with mild OSA compared to control group. METHODS: Adults (18-65 years of age) of both genders with a body mass index (BMI) ≤35 kg/m2 were included. The mild OSA group comprised of patients with an apnea-hypopnea index (AHI) score of ≥5 but ≤15 events/hr of sleep, independent of other symptoms. The control group (CG) comprised individuals with an AHI of <5 events/hr of sleep and an Epworth Sleepiness Scale score of <10. The following were used for both groups: two questionnaires on sleepiness, the maintenance of wakefulness test, and full-night polysomnography. Anthropometric measurements and fasting blood samples were obtained, including fasting glucose and insulin, total cholesterol and its subfractions [low-density lipoprotein, very low-density lipoprotein, and low-density lipoprotein cholesterol (HDL-c)], triglycerides (TG), and the TG/HDL-c ratio. In addition, the quantitative insulin sensitivity check index and homeostasis model assessment indices were calculated. RESULTS: Thirty-two percent of mild OSA patients had MS, 43.5% of mild OSA patients had hypertension, 14% showed dyslipidemia, and 56% had prediabetes. The OSA group showed increased TG (CG: 90.0 ± 51.9 vs. OSA: 140.3 ± 78.2 mg/dL, P = 0.004), and TG/HDL-c (CG: 1.9 ± 1.4 vs. OSA: 3.1 ± 2.0, P = 0.05), independent of adjustments. Independent of obesity (BMI <30 kg/m2), there was a negative correlation between total cholesterol and TG with mean oxygen saturation, independent of obesity (BMI <30 kg/m2). CONCLUSIONS: Our findings showed dysregulation in lipid profiles after adjustments for confounders in the mild OSA group, and there was a correlation between these parameters and sleep hypoxemia. The TG/HDL-c ratio in particular was high, suggesting that it might be investigated as a marker of a detrimental metabolic profile in these patients.

IGF-1 Levels are Inversely Associated With Metabolic Syndrome in Obstructive Sleep Apnea.

STUDY OBJECTIVES: This study examined insulin-like growth factor-1 (IGF-1) production and its association with the metabolic syndrome (MS) in men with obstructive sleep apnea (OSA). METHODS: In total, 47 overweight and obese men who had been referred for suspected OSA underwent polysomnography and were classified based on the apnea-hypopnea index (AHI) into three groups: no OSA, < 5 events/h (n = 11); mild OSA, ≥ 5 to < 15 events/h (n = 8); and moderate-severe OSA, ≥ 15 events/h (n = 28). The assessment of the somatotropic axis function included IGF-1 measurement. MS was diagnosed according to the National Cholesterol Education Program guidelines. RESULTS: IGF-1 level in the moderate-severe OSA group was lower than in the no-OSA group (156.8 ± 54.3 µg/L versus 225.5 ± 80.5 µg/L; p = 0.013). IGF-1 level was negatively correlated with body mass index, waist circumference (WC), AHI, and sleep duration with oxygen (O2) saturation < 90% and positively correlated with the average and minimum O2 saturation (p = 0.027). In a multivariable linear regression, considering WC and minimum O2 saturation as independent variables, only the minimum O2 saturation was a predictor of low IGF-1 levels. The proportions of patients with MS were different between the three groups (18.2% in no OSA; 25% in mild OSA, and 57.1% in moderate-severe OSA; p = 0.047). Furthermore, in the lowest tertile of IGF-1 value, 66.7% of patients were affected by MS (p = 0.049). Hemoglobin (Hb)A1c correlated negatively with the minimum O2 saturation and IGF-1 levels. However, in multivariable linear regression only IGF-1 levels were a predictor of HbA1c levels. CONCLUSION: The occurrence of OSA is associated with a reduction in IGF-1 levels. IGF-1 alterations in OSA also seem to be associated with a higher prevalence of MS.

Treatment of upper airway resistance syndrome in adults: Where do we stand?

OBJECTIVE: To evaluate the available literature regarding Upper Airway Resistance Syndrome (UARS) treatment. METHODS: Keywords "Upper Airway Resistance Syndrome," "Sleep-related Breathing Disorder treatment," "Obstructive Sleep Apnea treatment" and "flow limitation and sleep" were used in main databases. RESULTS: We found 27 articles describing UARS treatment. Nasal continuous positive airway pressure (CPAP) has been the mainstay therapy prescribed but with limited effectiveness. Studies about surgical treatments had methodological limitations. Oral appliances seem to be effective but their efficacy is not yet established. CONCLUSION: Randomized controlled trials with larger numbers of patients and long-term follow-up are important to establish UARS treatment options.

New insights on the pathophysiology of inspiratory flow limitation during sleep.

INTRODUCTION: Inspiratory flow limitation (IFL) is defined as a "flattened shape" of inspiratory airflow contour detected by nasal cannula pressure during sleep and can indicate increased upper airway resistance especially in mild sleep-related breathing disorders (SRBD). The objective of this study was to investigate the association between upper airway abnormalities and IFL in patients with mild SRBD. METHODS: This study was derived from a general population study consisting of selected individuals with apnea-hypopnea index (AHI) below 5 events/h of sleep, ("no obstructive sleep apnea" group) and individuals with AHI between 5 and 15 events/h ("mild obstructive sleep apnea" group). A total of 754 individuals were divided into four groups: group 1: AHI <5/h and <30 % of total sleep time (TST) with IFL (515 individuals), group 2: AHI <5/h and >30 % of TST with IFL (46 individuals), group 3: AHI: 5-15/h and <30 % of TST with IFL (168 individuals), and group 4: AHI: 5-15/h and >30 % of TST with IFL (25 individuals). RESULTS: Individuals with complains of oral breathing demonstrated a risk 2.7-fold larger of being group 4 compared with group 3. Abnormal nasal structure increased the chances of being in group 4 3.2-fold in comparison to group 1. Individuals with voluminous lateral wall demonstrated a risk 4.2-fold larger of being group 4 compared with group 3. CONCLUSION: More than 30 % of TST with IFL detected in sleep studies was associated with nasal and palatal anatomical abnormalities in mild SRBD patients.

Diagnostic accuracy of home-based monitoring system in morbidly obese patients with high risk for sleep apnea.

BACKGROUND: No previous studies have validated the use of portable monitoring (PM) for the diagnosis of obstructive sleep apnea (OSA) in morbidly obese individuals. Our aim was to investigate the accuracy of PM for detecting respiratory events in morbidly obese patients that will be undergoing bariatric surgery. METHODS: This was a prospective study involving patients with body mass index (BMI) ≥35 kg/m(2) who were recruited from the Sleep Clinic of Universidade Federal de São Paulo. Sleep-disordered breathing (SDB) was evaluated during full-night polysomnography (PSG). PM use was randomized and used on two consecutive nights: (1) at home (STDHome) and (2) at the sleep laboratory with PSG (PSG_STDLab). RESULTS: Although 58 participants initially underwent the recordings, 26 (45%) were excluded because of technical problems. The patients' mean age was 42.9 ± 10.9 (SD) years, and 56% were female. The mean BMI was 40.8 ± 5.2 kg/m(2). All patients had high risk for OSA, as defined by the Stop-Bang questionnaire, and the mean apnea-hypopnea index (AHI) was 46.9 ± 30.4/h. The intraclass coefficient of the correlation between AHI_PSG and AHI_STDLab was r = 0.92 (p = 0.0001); the intraclass coefficient for AHI_PSG and AHI_STDHome was r = 0.84 (p = 0.0001). The Kappa index was 0.87 (p > 0.0001) for severe cases. The sensitivity and the positive predictive value increased with the disease severity. A Bland-Altman analysis showed good agreement between the investigated methods. CONCLUSIONS: PM is an efficacious method for diagnosing OSA in obese patients who have a high clinical probability of the disease. The method displays good sensitivity and specificity in severe cases; nevertheless, the high rate of data loss must be taken into account.

Obstructive sleep apnea predisposes to nonalcoholic Fatty liver disease in patients with polycystic ovary syndrome.

OBJECTIVE: Some studies have shown a higher prevalence of nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA) in patients with polycystic ovary syndrome (PCOS). The objective of this study was to assess NAFLD in PCOS women with and without OSA. A possible role of high serum androgen levels in the development of OSA in PCOS women was also investigated. METHODS: Biochemical, hormonal, and polysomnography parameters were determined in 38 premenopausal PCOS patients. NAFLD was evaluated by ultrasound. Testosterone was measured by an immunoassay. RESULTS: Serum androgen levels and the prevalence of NAFLD (83.3% vs. 26.9%; P<.001) were higher in patients with OSA than those without OSA. The mean apnea-hypopnea index (AHI) was higher in patients with NAFLD than in those without NAFLD (16.87 events [ev]/h vs. 1.57 ev/h; P<.002). On multivariate logistic regression, where body mass index ≥30 kg/m2, homeostasis model assessment for insulin resistance ≥2.7, and OSA (AHI ≥5 ev/h) were independent variables, only OSA was an independent predictor of NAFLD (odds ratio [OR], 7.63; P = .044). Free testosterone levels ≥1.07 ng/dL were also independently associated with OSA (OR, 8.18; P = .023). CONCLUSION: In PCOS women, the occurrence of OSA strongly predisposes them to development of NAFLD and a worse metabolic profile; hence, treatment of OSA might be beneficial for NAFLD.

Sleep disordered breathing in Parkinson's disease: a critical appraisal.

Parkinson's disease (PD) is the second most common neurodegenerative disorder, characterized by resting tremor, rigidity, bradykinesia and postural instability, and is associated with non-motor features, including sleep abnormalities. The high prevalence of excessive daytime sleepiness and snoring in PD patients has led to the suggestion that sleep disordered breathing (SDB) is more common in these individuals than in normal subjects. We aimed to review the literature on SDB prevalence and its clinical repercussions in PD. A PubMed search was performed to identify controlled studies, published from January 1990 through October 2012, which addressed the prevalence of SDB diagnosed by polysomnography in idiopathic PD. From the seven studies included, five reported similar or lower prevalence of SDB in patients when compared to healthy age-matched controls. Two studies reported less oxyhemoglobin desaturation during sleep among patients. These results did not support the idea that PD patients are at increased risk of SDB and indicate that they may not present significant hypoxemia. The prevalence of obstructive sleep apnea syndrome and the long-term outcomes of disordered breathing events during sleep have not been adequately studied in PD.

Obstructive sleep apnea: a cardiometabolic risk in obesity and the metabolic syndrome.

Obstructive sleep apnea (OSA) is an underdiagnosed condition characterized by recurrent episodes of obstruction of the upper airway leading to sleep fragmentation and intermittent hypoxia during sleep. Obesity predisposes to OSA, and the prevalence of OSA is increasing worldwide because of the ongoing epidemic of obesity. Recent evidence has shown that surrogate markers of cardiovascular risk, including sympathetic activation, systemic inflammation, and endothelial dysfunction, are significantly increased in obese patients with OSA versus those without OSA, suggesting that OSA is not simply an epiphenomenon of obesity. Moreover, findings from animal models and patients with OSA show that intermittent hypoxia exacerbates the metabolic dysfunction of obesity, augmenting insulin resistance and nonalcoholic fatty liver disease. In patients with the metabolic syndrome, the prevalence of moderate to severe OSA is very high (∼60%). In this population, OSA is independently associated with increased glucose and triglyceride levels as well as markers of inflammation, arterial stiffness, and atherosclerosis. A recent randomized, controlled, crossover study showed that effective treatment of OSA with continuous positive airway pressure for 3 months significantly reduced several components of the metabolic syndrome, including blood pressure, triglyceride levels, and visceral fat. Finally, several cohort studies have consistently shown that OSA is associated with increased cardiovascular mortality, independent of obesity. Taken together, these results support the concept that OSA exacerbates the cardiometabolic risk attributed to obesity and the metabolic syndrome. Recognition and treatment of OSA may decrease the cardiovascular risk in obese patients.

Consequences of obstructive sleep apnea on metabolic profile: a Population-Based Survey.

OBJECTIVE: Epidemiologic studies that control for potential confounders are needed to assess the independent associations of obstructive sleep apnea (OSA) with metabolic abnormalities. The aim of our study was to evaluate the associations of OSA with metabolic abnormalities among the adult population of Sao Paulo, Brazil. DESIGN AND METHODS: Questionnaires were applied face-to-face, full night polysomnography (PSG) was performed, and blood samples were collected in a population-based survey in Sao Paulo, Brazil, adopting a probabilistic three-stage cluster sample method. The metabolic profile included fasting glucose, insulin, and lipid levels. The hepatic insulin resistance index was assessed by the homeostasis model assessment-estimated insulin resistance (HOMAIR ). RESULTS: A total of 1,042 volunteers underwent PSG. Mild OSA and moderate to severe OSA comprised 21.2% and 16.7% of the population, respectively. Subjects with severe to moderate OSA were older, more obese, had higher fasting glucose, HOMAIR , and triglycerides (TG) levels than did the mild and non-OSA group (P < 0.001). Multivariate regression analyses showed that an apnea-hypopnea index (AHI) ≥ 15 and a time of oxy-hemoglobin saturation <90% were independently associated with impaired fasting glucose, elevated TG, and HOMAIR . CONCLUSIONS: The results of this large cross-sectional epidemiological study showed that the associations of OSA and metabolic abnormalities were independent of other risk factors.

Sleep-disordered breathing changes after kidney transplantation: a polysomnographic study.

BACKGROUND: Sleep disorders are common in patients with end-stage renal disease (ESRD) and are not improved by either conventional haemodialysis or peritoneal dialysis. Sleep-disordered breathing (SDB) is associated with cardiovascular disease and contributes to high mortality found in patients with ESRD. Cure of SDB after transplantation has been anecdotally reported. METHODS: Thirty-four non-diabetic patients with ESRD were studied, and clinical, laboratory test and polysomnographic features were determined and compared prior to and after transplantation and between groups with or without SDB, defined as having an apnoea-hypopnoea index (AHI) >or=5. RESULTS: An AHI >or=5 was present in nine patients (26.5%) prior to and seven (21%) after transplantation, and no significant reduction of mean AHI was found between study phases (5.3 +/- 7.3 vs 3.1 +/- 4.5; P > 0.05). Transplantation was associated with a significant improvement in sleep architecture. CONCLUSIONS: Kidney transplantation is associated with an improvement in sleep architecture, but does not cure SDB in all patients.