Obstructive sleep-disordered breathing and fasting insulin levels in nonobese children

You Cannot Hit Snooze on OSA: Sequelae of Pediatric Obstructive Sleep Apnea

Pediatric obstructive sleep apnea (OSA) has been shown to not only affect the quality of sleep, but also overall health in general. Untreated or inadequately treated OSA can lead to long-term sequelae involving cardiovascular, endothelial, metabolic, endocrine, neurocognitive, and psychological consequences. The physiological effects of pediatric OSA eventually become pathological. As the complex effects of pediatric OSA are discovered, they must be identified early so that healthcare providers can be better equipped to treat and even prevent them. Ultimately, adequate management of OSA improves overall quality of life.

Sleep-Disordered Breathing and Cardiovascular Disease in Children and Adolescents: A Scientific Statement From the American Heart Association

Obstructive sleep apnea (OSA) is a known risk factor for cardiovascular disease in adults. It is associated with incident systemic hypertension, arrhythmia, stroke, coronary artery disease, and heart failure. OSA is common in children and adolescents, but there has been less focus on OSA as a primary risk factor for cardiovascular disease in children and adolescents. This scientific statement summarizes what is known regarding the impact of sleep‐disordered breathing and, in particular, OSA on the cardiovascular health of children and adolescents. This statement highlights what is known regarding the impact of OSA on the risk for hypertension, arrhythmia, abnormal ventricular morphology, impaired ventricular contractility, and elevated right heart pressure among children and adolescents. This scientific statement also summarizes current best practices for the diagnosis and evaluation of cardiovascular disease–related complications of OSA in children and adolescents with sleep apnea and highlights potential future research in the area of sleep‐disordered breathing and cardiovascular health during childhood and adolescence.

Phenotypic variance in pediatric obstructive sleep apnea

It is crucial that clinicians understand what underpins the considerable phenotypic variance in pediatric obstructive sleep apnea syndrome (OSAS), if they are to implement individually tailored phenotype-based approaches to diagnosis and management. This review summarizes the current literature on how disease severity, comorbidities, genetic and environmental/lifestyle factors interact to determine the overall OSAS phenotype. The first part discusses the impact of these factors on OSAS-related morbidity in the context of otherwise healthy children, whilst the second half details children with complex conditions, particularly focusing on the anatomical and functional abnormalities predisposing to upper airway obstruction unique to each condition. One can then understand the need for a multidimensional assessment strategy for pediatric OSAS; one that incorporates the history, physical examination, sleep study results, and biomarkers to enable precise stratification, so vital for effective determination of the timing and the nature of the therapeutic interventions required.

Obstructive sleep apnea and insulin resistance in children with obesity

STUDY OBJECTIVES

Because existing data investigating obstructive sleep apnea (OSA) and insulin resistance (IR) are inconsistent, we examine OSA and IR in a pediatric obesity clinic.

METHODS

Children (2-18 years) in the obesity clinic (2013-2017) undergoing polysomnography (PSG), anthropometric measurements, and fasting laboratory tests were included. Linear regression assessed OSA defined by the obstructive apnea-hypopnea index (oAHI) with the homeostatic model assessment of insulin resistance (HOMA-IR). Secondary aims assessed oxygen desaturation index (ODI) and age interactions with HOMA-IR. Logistic regression models and receiver operating characteristic analysis were performed to investigate optimal oAHI and ODI cutoffs relative to HOMA-IR ≥ 3.

RESULTS

Eighty children were included (mean age, 11.4 ± 4.0 years; 56% female; 46% Caucasian; median body mass index [BMI], 34.6 kg/m² [interquartile ratio, 29.9-40.1], median BMI z-score, 2.5 [interquartile ratio, 2.3-2.8); 46% with oAHI ≥ 5 events/h. HOMA-IR was higher in the OSA group (oAHI ≥ 5 events/h): 5 vs 3.8 (P = .034). After adjustment for sex, race, and BMI z-score, oAHI ≥ 5 events/h retained significance with HOMA-IR (P = .041). HOMA-IR increased in older children (age ≥ 12 years) when adjusting for waist circumference z-score and waist-height ratio (statistical interaction, P = .020 and .034, respectively). Receiver operating characteristic showed optimal cut points of oAHI and ODI for predicting significant IR 4.9 (area under the curve, 0.70; 95% confidence interval, 0.57-0.83; sensitivity, 0.76; specificity, 0.66) and 4.6 (area under the curve, 0.68; 95% confidence interval, 0.55-0.80; sensitivity, 0.70; specificity, 0.67), respectively.

CONCLUSIONS

In a clinic-based pediatric cohort with obesity, OSA is associated with increased IR even after adjusting for confounders including obesity defined by the BMI z-score. Age ≥ 12 years was associated with AHI relative to IR after adjustment for waist circumference z-score and waist-height ratio. Significant IR could be discriminated by oAHI ≥ 4.9 with moderate sensitivity/specificity. Future studies are needed to verify these findings.

Risk Factors for Obstructive Sleep Apnea Syndrome in Children: State of the Art

The obstructive sleep apnea syndrome (OSAS) represents only part of a large group of pathologies of variable entity called respiratory sleep disorders (RSD) which include simple snoring and increased upper airway resistance syndrome (UARS). Although the etiopathogenesis of adult OSAS is well known, many aspects of this syndrome in children are still debated. Its prevalence is about 2% in children from 2 to 8 years of age, mostly related to the size of the upper airways adenoid tissue. Several risk factors linked to the development of OSAS are typical of the pediatric age. The object of this paper is to analyze the state of the art on this specific topic, discussing its implications in terms of diagnosis and management.

Association of sleep disturbances with obesity, insulin resistance and the metabolic syndrome

Insufficient sleep, which has become endemic in recent years, has been variably associated with increased risk of obesity, disorders of glucose and insulin homeostasis, and the metabolic syndrome; to a lesser degree, so has excessive sleep. This review summarizes recent epidemiological and pathophysiological evidence linking sleep disturbances (primarily abnormalities of sleep duration) with obesity, insulin resistance, type 2 diabetes and the metabolic syndrome in children and adults.

Insulin Resistance and Hypertension in Obese Youth With Sleep-Disordered Breathing Treated With Positive Airway Pressure: A Prospective Multicenter Study

STUDY OBJECTIVES

There is evidence that cardiometabolic disease associated with obesity and sleep-disordered breathing (SDB) in adults is present in youth. SDB is often treated with positive airway pressure (PAP) in youth with obesity. Our aims were to determine: (1) the prevalence of cardiometabolic disease and (2) whether PAP improves markers of cardiometabolic disease, in youth with obesity and newly diagnosed moderate-severe SDB.

METHODS

A prospective multicenter cohort study was conducted in youth (8 to 16 years old) with obesity, prescribed PAP therapy for newly diagnosed moderate-severe SDB. Assessments occurred at baseline and at 6 and 12 months. Outcomes included markers of insulin resistance (change in homeostasis model assessment of insulin resistance (HOMA-IR) at 6 months = primary outcome), hypertension (24-hour ambulatory/blood pressure) and inflammation (high-sensitivity C-reactive protein: hs-CRP).

RESULTS

Twenty-seven participants were enrolled. Of those with baseline testing available, 10/25 (40%) had HOMA-IR above the 97th percentile, 10/23 (44%) were hypertensive, 16/23 (70%) had loss of nocturnal blood pressure dip and hs-CRP was elevated in 16/27 (64%). There were no significant changes over time in markers of metabolic dysfunction or blood pressure, nor between PAP-adherent and non-adherent subgroups.

CONCLUSIONS

In youth with obesity and SDB, metabolic dysfunction and hypertension were highly prevalent. There were no statistically significant improvements in cardiometabolic markers 1 year after the prescription of PAP therapy, although clinically relevant improvements were seen in insulin resistance and systolic blood pressure load, important predictors of future risk of cardiovascular disease. Larger, longer-term studies are needed to determine whether PAP improves cardiometabolic outcomes in obese youth.

COMMENTARY

A commentary on this article appears in this issue on page 1025.

Glycated hemoglobin and sleep apnea syndrome in children: beyond the apnea-hypopnea index

PURPOSE

Snoring and obstructive sleep apnea syndrome (OSA) are frequent conditions in pediatrics. Glycated hemoglobin (Hb_A1C) is a useful homeostatic biomarker of glycemia and may reflect alterations deriving from sleep breathing disorders. The aim of this study was to relate the severity of OSA with blood Hb_A1C levels in children.

METHODS

A descriptive observational study in snoring patients was performed. All patients underwent a sleep study and classified either as simple snorers (apnea-hypopnea index; AHI ≤ 1 episodies/h) or as OSA patients (AHI > 1 episodes/h). In the following morning, a blood glycemic profile (fasting glucose, insulin, Hb_A1C, and the HOMA index) was performed to every individual.

RESULTS

A total of 48 patients were included. Hb_A1C levels were shown to be increased in the moderate OSA (AHI > 5 episodes/h) group (5.05 ± 0.25 vs. 5.24 ± 0.29%; p = 0.019). Significant correlations were found between Hb_A1C values and AHI (r = 0.345; p = 0.016) and also with oxygen desaturation index (r = 0.40; p = 0.005). Correlations remained significant after adjusting by age and body mass index. The AHI-associated change in Hb_A1C was 13.4% (p = 0.011).

CONCLUSIONS

In the pediatric population, Hb_A1C is a biomarker associated with OSA severity, and this relationship is age- and obesity-independent. The fact that this association was observed in snoring patients could help the physician in the distinction between those patients affected with OSA and those with simple snoring. Therefore, Hb_A1C measurement could play a major role in the diagnosis and the management of the syndrome.

Pediatric OSA Syndrome Morbidity Biomarkers: The Hunt Is Finally On!

Since initial reports 40 years ago on pediatric OSA syndrome (OSAS) as a distinct and prevalent clinical entity, substantial advances have occurred in the delineation of diagnostic and treatment approaches. However, despite emerging and compelling evidence that OSAS increases the risk for cognitive, cardiovascular, and metabolic end-organ morbidities, routine assessment of such morbidities is seldom conducted in clinical practice. One of the major reasons for such discrepancies resides in the relatively labor-intensive and onerous steps that would be required to detect the presence of any of such morbidities, further adding to the already elevated cost of diagnosing the disorder. To circumvent these obstacles, the search for biomarker signatures of pediatric OSA and its cognitive and cardiometabolic consequences was launched, and considerable progress has occurred since then. Here, we review the current evidence for the presence of morbidity-related biomarkers among children with OSAS, and explore future opportunities in this promising arena.

Role of sleep quality in the metabolic syndrome

Emerging evidence has assigned an important role to sleep as a modulator of metabolic homeostasis. The impact of variations in sleep duration, sleep-disordered breathing, and chronotype to cardiometabolic function encompasses a wide array of perturbations spanning from obesity, insulin resistance, type 2 diabetes, the metabolic syndrome, and cardiovascular disease risk and mortality in both adults and children. Here, we critically and extensively review the published literature on such important issues and provide a comprehensive overview of the most salient pathophysiologic pathways underlying the links between sleep, sleep disorders, and cardiometabolic functioning.

Pediatric Sleep Apnea Syndrome: An Update

Obstructive sleep apnea syndrome (OSAS) may be central neurologic (<5%) or obstructive (>95%) in origin and is a relatively prevalent condition in children. It affects 1%-5% of children aged 2-8 years and is caused by a variety of different pathophysiologic abnormalities. Cardiovascular, metabolic, and neurocognitive comorbidities can occur in both children and adults when left untreated. It also can cause severe behavioral problems in children. The American Academy of Pediatrics recommends that all children be screened with an appropriate history and physical examination for symptoms and signs suggestive of OSAS. The diagnosis is primarily made clinically and confirmed by polysomnographic findings. Treatment depends on the child's age, underlying medical problems, polysomnography findings, and whether or not there is upper airway obstruction usually secondary to enlarged adenoids and/or tonsils, allergic and nonallergic rhinitis, acute and chronic sinusitis, and other upper airway pathology. If enlarged adenoid or tonsils or both conditions exist, an adenoidectomy, tonsillectomy, or adenotonsillectomy remains the treatment of choice. Pharmacotherapy of OSAS has shown some effect in children with mild symptoms. This paper reviews the prevalence, pathophysiology, clinical presentation, diagnosis, and treatment of OSAS.

Consequences of Obstructive Sleep Apnea in Children

Obstructive sleep apnea syndrome (OSAS) has various negative health and behavioral consequences in the pediatric population. As shown in adults, there are metabolic derangements such as obesity, insulin sensitivity, dyslipidemia, and metabolic syndrome, as well as cardiovascular derangements like hypertension, chronic inflammation, endothelial dysfunction, ventricular size/function abnormalities, and even elevated pulmonary arterial pressures, that can be seen in children with OSAS. The first two sections will discuss the metabolic and cardiovascular consequences on OSAS in children. The last section summarizes selected studies and reviews on the behavioral, neurocognitive and academic consequences of OSAS in children.

Sleep Disordered Breathing in Children

Sleep-disordered breathing (SDB) refers to a group of disorders characterized by abnormalities of respiration or ventilation during sleep. It encompasses obstructive sleep apnea (OSA), central sleep apnea (CSA) syndromes, sleep-related hypoventilation and sleep-related hypoxemia disorders. This review will concentrate on the disorder most prevalent in pediatrics, i.e., OSA, highlighting the most recent developments in our understanding of the etiology, pathophysiology and treatment options of this condition. OSA morbidities primarily involve the neurocognitive, cardiovascular and metabolic systems. However, there can be significant phenotypic variation in terms of end organ morbidity for the same OSA severity. This is likely due to the interplay between genetic and environmental factors; recent developments in the fields of genomics and proteomics have the potential to shed light on these complex pathological cascades. As we enter the era of personalized medicine, phenotyping patients to enable clinicians to tailor bespoke clinical management plans will be of crucial importance.

Biomarkers associated with obstructive sleep apnea: A scoping review

The overall validity of biomarkers in the diagnosis of obstructive sleep apnea (OSA) remains unclear. We conducted a scoping review to provide assessments of biomarkers characteristics in the context of obstructive sleep apnea (OSA) and to identify gaps in the literature. A scoping review of studies in humans without age restriction that evaluated the potential diagnostic value of biological markers (blood, exhaled breath condensate, salivary, and urinary) in the OSA diagnosis was undertaken. Retained articles were those focused on the identification of biomarkers in subjects with OSA, the latter being confirmed with a full overnight or home-based polysomnography (PSG). Search strategies for six different databases were developed. The methodology of selected studies was classified using an adaptation of the evidence quality criteria from the American Academy of Pediatrics. Additionally the biomarkers were classified according to their potential clinical application. We identified 572 relevant studies, of which 117 met the inclusion criteria. Eighty-two studies were conducted in adults, 34 studies involved children, and one study had a sample composed of both adults and children. Most of the studies evaluated blood biomarkers. Potential diagnostic biomarkers were found in nine pediatric studies and in 58 adults studies. Only nine studies reported sensitivity and specificity, which varied substantially from 43% to 100%, and from 45% to 100%, respectively. Studies in adults have focused on the investigation of IL-6, TNF-α and hsCRP. There was no specific biomarker that was tested by a majority of authors in pediatric studies, and combinatorial urine biomarker approaches have shown preliminary promising results. In adults IL-6 and IL-10 seem to have a favorable potential to become a good biomarker to identify OSA.

The Effect of Adenotonsillectomy for Childhood Sleep Apnea on Cardiometabolic Measures

STUDY OBJECTIVES

Obstructive sleep apnea syndrome (OSAS) has been associated with cardiometabolic disease in adults. In children, this association is unclear. We evaluated the effect of early adenotonsillectomy (eAT) for treatment of OSAS on blood pressure, heart rate, lipids, glucose, insulin, and C-reactive protein. We also analyzed whether these parameters at baseline and changes at follow-up correlated with polysomnographic indices.

DESIGN

Data collected at baseline and 7-mo follow-up were analyzed from a randomized controlled trial, the Childhood Adenotonsillectomy Trial (CHAT).

SETTING

Clinical referral setting from multiple centers.

PARTICIPANTS

There were 464 children, ages 5 to 9.9 y with OSAS without severe hypoxemia.

INTERVENTIONS

Randomization to eAT or Watchful Waiting with Supportive Care (WWSC).

MEASUREMENTS AND RESULTS

There was no significant change of cardiometabolic parameters over the 7-mo interval in the eAT group compared to WWSC group. However, overnight heart rate was incrementally higher in association with baseline OSAS severity (average heart rate increase of 3 beats per minute [bpm] for apnea-hypopnea index [AHI] of 2 versus 10; [standard error = 0.60]). Each 5-unit improvement in AHI and 5 mmHg improvement in peak end-tidal CO2 were estimated to reduce heart rate by 1 and 1.5 bpm, respectively. An increase in N3 sleep also was associated with small reductions in systolic blood pressure percentile.

CONCLUSIONS

There is little variation in standard cardiometabolic parameters in children with obstructive sleep apnea syndrome (OSAS) but without severe hypoxemia at baseline or after intervention. Of all measures, overnight heart rate emerged as the most sensitive parameter of pediatric OSAS severity.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov (#NCT00560859).

Metabolic changes in normal- and underweight children with obstructive sleep-disordered breathing

OBJECTIVE

This study evaluates the metabolic profile of normal- and underweight children with sleep-disordered breathing (SDB) due to adenotonsillar hypertrophy.

METHODS

A total of 39 children aged 3-15 years with SDB and 28 age- and gender-matched controls were included in the study. Body mass index z score, blood pressure, and fasting serum levels of triglycerides (TGs), high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, very-low-density lipoprotein (VLDL), blood glucose, plasma insulin, and homeostatic model assessment (HOMA) were determined in both case patients and controls.

RESULTS

We observed significantly lower levels of fasting blood glucose (p = 0.015) and higher levels of HDL (p = 0.002), LDL (p = 0.002), and cholesterol (p = 0.001) in case patients than in controls. The mean values of fasting insulin and HOMA were higher in case patients (6.42 ± 6.47 and 1.40 ± 1.48) than in controls (5.31 ± 3.40 and 1.20 ± 0.84) respectively. No direct correlation between indices of severity of SDB and various metabolic and blood pressure parameters was found. When the effect of body weight was studied by subgrouping case patients according to normal weight and underweight, significant increases in the levels of fasting insulin (p = 0.039), HOMA (p = 0.017), and fasting blood glucose (p = 0.021) were observed. Also, a significant correlation was observed between the duration of illness and fasting insulin (p = 0.023), HOMA (p = 0.020), fasting glucose (p = 0.004), and diastolic blood pressure (p = 0.030).

CONCLUSION

This study shows an independent effect of body weight and duration of illness on various metabolic and blood pressure parameters in normal- and underweight children with SDB.

Diagnostic capability of biological markers in assessment of obstructive sleep apnea: a systematic review and meta-analysis

OBJECTIVE

The purpose of this systematic review is to evaluate the diagnostic value of biological markers (exhaled breath condensate, blood, salivary and urinary) in the diagnosis of OSA in comparison to the gold standard of nocturnal PSG.

METHODS

Studies that differentiated OSA from controls based on PSG results, without age restriction, were eligible for inclusion. The sample of selected studies could include studies in obese patients and with known cardiac disease. A detailed individual search strategy for each of the following bibliographic databases was developed: Cochrane, EMBASE, MEDLINE, PubMed, and LILACS. The references cited in these articles were also crosschecked and a partial grey literature search was undertaken using Google Scholar. The methodology of selected studies was evaluated using the 14-item Quality Assessment Tool for Diagnostic Accuracy Studies.

RESULTS

After a two-step selection process, nine articles were identified and subjected to qualitative and quantitative analyses. Among them, only one study conducted in children and one in adults found biomarkers that exhibit sufficiently satisfactory diagnostic accuracy that enables application as a diagnostic method for OSA.

CONCLUSION

Kallikrein-1, uromodulin, urocotin-3, and orosomucoid-1 when combined have enough accuracy to be an OSA diagnostic test in children. IL-6 and IL-10 plasma levels have potential to be good biomarkers in identifying or excluding the presence of OSA in adults.

Metabolic and glycemic sequelae of sleep disturbances in children and adults

The prevalence of obesity in adults and children has increased greatly in the past three decades, as have metabolic sequelae, such as insulin resistance and type 2 diabetes mellitus (T2DM). Sleep disturbances are increasingly recognized as contributors to this widespread epidemic in adults, and data are emerging in children as well. The categories of sleep disturbances that contribute to obesity and its glycemic co-morbidities include the following: (1) alterations of sleep duration, chronic sleep restriction and excessive sleep; (2) alterations in sleep architecture; (3) sleep fragmentation; (4) circadian rhythm disorders and disruption (i.e., shift work); and (5) obstructive sleep apnea. This article reviews current evidence supporting the contributions that these sleep disorders play in the development of obesity, insulin resistance, and T2DM as well as possibly influences on glycemic control in type 1 diabetes, with a special focus on data in pediatric populations.

Glucose, insulin, and insulin resistance in normal-weight, overweight and obese children with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is associated with components of metabolic syndrome. Both body weight and OSA independently influence metabolic measurements. The goal of this study was to determine whether OSA in normal-weight, overweight or obese children, compared to matched control groups, was associated with increased levels of glucose, insulin and insulin resistance (IR).

METHODS

Age- and gender-specific body mass index (BMI) percentiles were determined and used to categorize subjects into normal-weight (BMI<85%) and overweight-obese (BMI≥85%) groups. In addition, subjects were divided into normal-weight (BMI<85%), overweight (BMI≥85% and <95%) and obese (BMI≥95%) groups. Polysomnography was conducted and morning levels of glucose and insulin were measured and IR was determined from the blood samples collected early in the morning after overnight fast. Results were compared between the subject groups. Effects of severity of OSA defined by apnea hypopnea index (AHI) and oxygen desaturation index (ODI) on glucose, insulin, and HOMA-IR were analyzed.

RESULTS

Glucose, insulin, and HOMA-IR in OSA and matched control groups were not significantly different for normal-weight, overweight and obese subjects. The ODI was significantly associated with elevated levels of glucose and HOMA-IR after adjustment for age, gender, race, and BMI Z-score.

CONCLUSIONS

IR levels between OSA and control for both normal-weight, overweight and obese subjects were not significantly different. The ODI was associated with increased IR in children with OSA. OSA-induced hypoxic events during sleep may be a potential mechanism of increased IR in children with OSA, independent of body weight.

Are frequency and severity of sleep-disordered breathing in obese children and youth with and without type 2 diabetes mellitus different?

Obstructive sleep apnea (OSA) is a risk factor for insulin resistance and type 2 diabetes mellitus (T2DM) in adults. Data in children are limited. The aim was to study the frequency and severity of OSA and its association with cardiometabolic risk factors in obese children and adolescents with and without T2DM. In this prospective cross-sectional study, obese children and adolescents with and without T2DM underwent polysomnography and blood tests for fasting lipids, insulin, glucose, liver functions, and C-reactive protein. All participants completed a questionnaire on past and present sleep-disordered breathing (SDB). Results were compared between T2DM and obese non-diabetic controls matched for body mass index-standard deviation score (BMI-SDS) and also according to the glycemic status: T2DM, impaired glucose tolerance (IGT), and normal glycemic control. Eleven patients with T2DM (age 15.9 ± 3.6 years) and 30 BMI-SDS matched non-diabetic subjects (age 12.7 ± 3.0 years) were studied. Among the entire cohort, 45 % had a history of snoring, 26 % reported apneic episodes during sleep, and 65 % had daytime fatigue. There were no significant between-group differences in SDB history or abnormal polysomnographic results [apnea-hypopnea index (AHI) >5/h]. The percentage of subjects with AHI >5/h was 45.5 % in T2DM patients, 25 % in obese patients with IGT, and 18.2 % in obese patients without IGT, although the difference was not statistically significant (p = 0.25). Plasma C-reactive protein levels were related to both glycemic status and OSA severity. The severity of OSA in obese children and adolescents is unrelated to the presence of diabetes. OSA may play a minor role in the development and progression of T2DM in children and adolescents. Further studies in larger cohorts are required.

Metabolic alterations in children with obstructive sleep apnea

IMPORTANCE

The incidence of obesity is rising in the United States and has been linked to Obstructive Sleep Apnea (OSA) even in young children. Understanding the role that obesity and OSA play in alterations in metabolic variables that can lead to serious health issues is essential to the care and counseling of affected children.

OBJECTIVES

To evaluate the association of alterations in metabolic variables, including insulin resistance, to OSA in young, obese children.

DESIGN

Retrospective, case-control series.

SETTING

Tertiary care children's hospital.

PARTICIPANTS

Obese children aged 2-12 years who had undergone overnight polysomography and routine laboratory testing for lipid levels, fasting glucose, and insulin from January 1, 2006 to December 31, 2012 were identified from a TransMed Bio-Integration Suite and Epic's clarity database search.

RESULTS

A total of 76 patients were included for analysis. Forty-three (56.6%) were male, and the mean age was 8.3±2.5 years (range, 2.4-11.9 years). The mean body mass index (BMI) z score was 2.8±0.75 (range, 1.7-6.3), and all patients were obese (BMI z score>95th percentile). Twenty two patients (28.9%) had an apnea-hypopnea index (AHI) <1/h (no OSA), 27 (35.5%) an AHI≥1<5/h, 12 (15.8%) had an AHI ≥5<9.99/h, and 15 (19.7%) had an AHI≥10/h. There was no significant difference in total cholesterol, triglycerides, high and low density lipoprotein levels, systolic and diastolic blood pressure in those patients with or without OSA. Fasting insulin, blood glucose, and homeostasis model assessment (HOMA) were significantly higher in patients with OSA compared to those with no OSA (p<0.01). AHI correlated to alterations in insulin as well as glucose homeostasis on multivariate analysis. Results from logistic regression analysis showed that fasting insulin (p<0.01), and HOMA (p<0.01) predicted severe OSA independent of age, gender, and BMI z score in these patients.

CONCLUSION

Metabolic alterations in glucose and insulin levels, known to be associated with obesity and increased risk for cardiovascular disease, appear to relate to the severity of OSA in young children.

Obstructive sleep apnea in children: a critical update

Obstructive sleep apnea (OSA) in children is a highly prevalent disorder caused by a conglomeration of complex pathophysiological processes, leading to recurrent upper airway dysfunction during sleep. The clinical relevance of OSA resides in its association with significant morbidities that affect the cardiovascular, neurocognitive, and metabolic systems. The American Academy of Pediatrics recently reiterated its recommendations that children with symptoms and signs suggestive of OSA should be investigated with polysomnography (PSG), and treated accordingly. However, treatment decisions should not only be guided by PSG results, but should also integrate the magnitude of symptoms and the presence or absence of risk factors and signs of OSA morbidity. The first-line therapy in children with adenotonsillar hypertrophy is adenotonsillectomy, although there is increasing evidence that medical therapy, in the form of intranasal steroids or montelukast, may be considered in mild OSA. In this review, we delineate the major concepts regarding the pathophysiology of OSA, its morbidity, diagnosis, and treatment.

Metabolic disregulation in obese adolescents with sleep-disordered breathing before and after weight loss

OBJECTIVE

Sleep-disordered breathing (SDB) is prevalent in obesity. Weight loss is one of the most effective treatment options. The aim was to assess the association of SDB and metabolic disruption before and after weight loss.

DESIGN AND METHODS

Obese adolescents were included when entering an in-patient weight loss program. Fasting blood analysis was performed at baseline and after 4-6 months. Sleep screening was done at baseline and at follow-up in case of baseline SDB.

RESULTS

224 obese adolescents were included. Median age was 15.5 years (10.1-18.0) and mean BMI z-score was 2.74 ± 0.42. About 30% had SDB at baseline (N = 68). High-density lipoprotein (HDL)-cholesterol was associated with mean nocturnal oxygen saturation (<SaO2>) (partial r = 0.21; P = 0.002). Aspartate aminotransferase (ASAT) and alanine aminotransferase were related with oxygen desaturation index (partial r = -0.15; P = 0.03 and partial r = -0.15; P = 0.02), but this became insignificant after correction for sex. After weight loss, 24% had residual SDB. Linear regression showed an association between ASAT and <SaO2> (partial r = -0.34; P = 0.002). There were no significant correlations between improvements in laboratory measurements and sleep parameters. HDL-cholesterol improved in relation with the decrease in BMI z-score.

CONCLUSION

SDB at baseline was associated with higher levels of liver enzymes and lower HDL-cholesterol concentration. Improvements in sleep parameters were not associated with improvements in laboratory measurements.

Comparing the clinical profile of non obese children with sleep apnea and snoring

Few studies in the literature have looked into the cardiovascular and metabolic effects of Obstructive Sleep Apnea Syndrome (OSAS) in children.

Objective

This study aims to evaluate the metabolic profile of non-obese children with OSAS.

Methods

Fifty-two children were enrolled in this study, 21 girls and 31 boys. Patients were divided into two groups: OSAS (28 children) and Snore (22 children) according to polysomnographic evaluation. All children were submitted to ENT examination, measurements of weight, height and blood pressure. Blood samples were tested for hemoglobin, hematocrit, fasting glucose, fasting insulin, triglycerides, total cholesterol, HDL, LDL, VLDL, TSH and T4. The gathered data sets were compared between groups and also within the OSAS group according to the severity of the syndrome.

Results

The children from both groups had no alterations in blood pressure levels. The results of the blood tests were normal for both groups. Results of hemoglobin, hematocrit, and HDL were all significantly higher in the Snore group when compared to the OSAS group; by their turn, VLDL levels were higher in the OSAS group. There was no statistical difference between the groups based on OSAS severity.

Conclusion

Non-obese children with OSAS present no significant alterations in metabolic tests or blood pressure levels.

Sleep fragmentation and intermittent hypoxemia are associated with decreased insulin sensitivity in obese adolescent Latino males

BACKGROUND

Although sleep-related breathing disorder (SRBD) has been linked to insulin resistance in adults, this has not been as well established in children. We hypothesized that the severity of SRBD in adolescents was associated with metabolic impairment.

METHODS

Polysomnography was performed on obese, Latino males referred for snoring. The frequently sampled intravenous glucose tolerance test was used to assess glucose homeostasis. Total-body dual-energy X-ray absorptiometry was used to quantify adiposity.

RESULTS

A total of 22 males (mean age ± SD: 13.4 ± 2.1 y, BMI z-score 2.4 ± 0.3, obstructive apnea hypopnea index 4.1 ± 3.2) were studied. After correcting for age and adiposity in multiple-regression models, Log frequency of desaturation (defined as ≥3% drop in oxygen saturation from baseline) negatively correlated with insulin sensitivity. Sleep efficiency was positively correlated with glucose effectiveness (S(G), the capacity of glucose to mediate its own disposal). The Log total arousal index was positively correlated with Log homeostasis model assessment-estimated insulin resistance.

CONCLUSION

Sleep fragmentation and intermittent hypoxemia are associated with metabolic impairment in obese adolescent Latino males independent of age and adiposity. We speculate that SRBD potentiates the risk for development of metabolic syndrome and type 2 diabetes in the obese adolescent population.

Diagnosis and management of childhood obstructive sleep apnea syndrome

OBJECTIVE

This technical report describes the procedures involved in developing recommendations on the management of childhood obstructive sleep apnea syndrome (OSAS).

METHODS

The literature from 1999 through 2011 was evaluated.

RESULTS AND CONCLUSIONS

A total of 3166 titles were reviewed, of which 350 provided relevant data. Most articles were level II through IV. The prevalence of OSAS ranged from 0% to 5.7%, with obesity being an independent risk factor. OSAS was associated with cardiovascular, growth, and neurobehavioral abnormalities and possibly inflammation. Most diagnostic screening tests had low sensitivity and specificity. Treatment of OSAS resulted in improvements in behavior and attention and likely improvement in cognitive abilities. Primary treatment is adenotonsillectomy (AT). Data were insufficient to recommend specific surgical techniques; however, children undergoing partial tonsillectomy should be monitored for possible recurrence of OSAS. Although OSAS improved postoperatively, the proportion of patients who had residual OSAS ranged from 13% to 29% in low-risk populations to 73% when obese children were included and stricter polysomnographic criteria were used. Nevertheless, OSAS may improve after AT even in obese children, thus supporting surgery as a reasonable initial treatment. A significant number of obese patients required intubation or continuous positive airway pressure (CPAP) postoperatively, which reinforces the need for inpatient observation. CPAP was effective in the treatment of OSAS, but adherence is a major barrier. For this reason, CPAP is not recommended as first-line therapy for OSAS when AT is an option. Intranasal steroids may ameliorate mild OSAS, but follow-up is needed. Data were insufficient to recommend rapid maxillary expansion.

Sleep, sleep-disordered breathing and lipid homeostasis: translational evidence from murine models and children

Impaired sleep, particularly in the context of sleep-disordered breathing (SDB), is associated with a vast array of comorbidities, including obesity. It is well known that the etiology of obesity is both complex and multifactorial. Recent trends have shown that obesity rates have risen at an alarming rate in children, and this has likely contributed to an increased prevalence of SDB in children. Like the 'chicken and the egg' hypothesis, the temporal relationship of obesity and SDB is unclear but it is speculated that these two conditions converge to promote a fundamental disruption to normal lipid homeostasis. In this review, the effect of sleep disruption and SDB on lipid homeostasis in both murine and human models will be critically examined, with the intent of demonstrating that disrupted sleep in children is itself a precursor to obesity via disordered lipid homeostasis.

Obstructive sleep apnea syndrome in children

The clinical syndrome of obstructive sleep apnea (OSAS) in children is a distinct, yet somewhat overlapping disorder with the condition that occurs in adults, such that the clinical manifestations, polysomnographic findings, diagnostic criteria and treatment approaches need to be considered in an age-specific manner. Childhood OSAS has now become widely recognized as a frequent disorder and as a major public health problem. Pediatric OSAS, particularly when obesity is concurrently present, is associated with substantial end-organ morbidities and increased healthcare utilization. Although adenotonsillectomy (T&A) remains the first line of treatment, evidence in recent years suggests that the outcomes of this surgical procedure may not be as favorable as expected, such that post-T&A polysomnographic evaluation may be needed, especially in high-risk patient groups. In addition, incorporation of nonsurgical approaches for milder forms of the disorder and for residual OSAS after T&A is now being investigated.

Association of short and long sleep durations with insulin sensitivity in adolescents

OBJECTIVE

To characterize the relationship between insulin sensitivity, assessed with the homeostasis model of insulin (HOMA), and objective measurements of sleep duration in adolescents.

STUDY DESIGN

We conducted a cross-sectional analysis from two examinations conducted in the Cleveland Children's Sleep and Health Cohort (n = 387; 43% minorities). Biochemical and anthropometry measurements were made in a clinical research unit. Sleep duration was measured with actigraphy.

RESULTS

Decreased sleep duration was associated with increased adiposity and minority race. Sleep duration had a quadratic "u-shape" association with HOMA. When adjusted for age, sex, race, preterm status, and activity, adolescents who slept 7.75 hours had the lowest predicted HOMA (1.96, 95% confidence interval [CI], 1.82-2.10), and adolescents who slept 5.0 hours or 10.5 hours had HOMA indices that were approximately 20% higher (2.36; 95% CI, 1.94-2.86; and 2.41; 95% CI, 1.93-3.01, respectively). After adjusting for adiposity, the association between shorter sleep and HOMA was appreciably attenuated, but the association with longer sleep persisted.

CONCLUSIONS

Shorter and longer sleep durations are associated with decreased insulin sensitivity in adolescents. Although the association between shorter sleep duration with insulin sensitivity likely is explained by the association between short sleep duration and obesity, the association between longer sleep and insulin sensitivity is independent of obesity.

Effects of obstructive sleep apnea severity on serum lipid levels in Greek children with snoring

BACKGROUND

Although obstructive sleep apnea (OSA) is related to dyslipidemia in adults, limited data are available regarding its effects on serum lipids during childhood. Aim of this study was to assess the potential relationships between severity of OSA and cholesterol or triglyceride levels in a cohort of Greek children.

METHODS

Data from children with snoring who underwent polysomnography and complete serum lipids measurements during a specified study period were analyzed retrospectively.

RESULTS

Overall, obese children (n = 261) had lower HDL cholesterol levels than non-obese subjects (n = 113) (49.6 ± 10.5 vs. 53.9 ± 11.4 mg/dL; p = 0.001) and higher triglyceride concentrations (69.8 ± 32.2 vs. 63.2 ± 27 mg/dL; p = 0.041). Non-obese subjects with moderate-to-severe OSA did not differ in triglycerides, total, and LDL cholesterol concentrations but had lower HDL cholesterol, when compared to non-obese children with primary snoring/mild OSA (50.4 ± 13.1 vs. 54.9 ± 10.7 mg/dL; p = 0.008). The risk for having low HDL cholesterol (≤40 mg/dL) was threefold higher in non-obese subjects with moderate-to-severe OSA than in those with primary snoring/mild OSA, even after adjustment for age and gender [OR = 3.44 (95% CI 1.44 to 8.24; p = 0.006)]. Concentrations of serum lipids in obese children were not associated with severity of OSA. HDL cholesterol was 48.5 ± 8.7 mg/dL in subjects with moderate-to-severe OSA and 50.0 ± 11.1 mg/dL in children with primary snoring/mild OSA (p = 0.519).

CONCLUSIONS

HDL cholesterol levels are inversely related to severity of OSA in non-obese children with snoring.

Disorders of glucose metabolism in sleep-disordered breathing

Despite proliferating literature, the exact relationship between obstructive sleep apnea (OSA) and alterations in glucose metabolism is still controversial. There is growing evidence to suggest that OSA imposes adverse effects on glucose metabolism, but the translation into clinical effect is not well delineated. Many potential mechanisms are being explored, mostly relating to peripheral tissue response to insulin and more recently regarding pancreatic beta cell function of insulin secretion. The effect of OSA on glucose metabolism is likely to be influenced by many personal characteristics. Age, degree of adiposity, lifestyle, comorbidities, and even the stage of glucose disorder itself may modify the relationship between OSA and glucose metabolism. In the biologic system of the human body, all these interact to culminate in clinically relevant outcomes.

Sleep-disordered breathing in obese adolescents is associated with visceral adiposity and markers of insulin resistance

Sleep-disordered breathing is associated with obesity, insulin resistance, and the metabolic syndrome in adults. Similar data in children is limited and conflicting. This pilot study examined the relationships between sleep-disordered breathing, visceral adiposity, and cardiometabolic risk factors in obese adolescents. Twenty obese (body mass index ≥ 95(th) percentile), otherwise healthy adolescents (age 14.9 ± 2 years) underwent polysomnogram studies, fasting lipid profile and oral glucose tolerance tests, and measures of body composition (dual-energy X-ray absorptiometry) and visceral adiposity (abdominal computed tomography). The severity of sleep-disordered breathing (as measured by apnea-hypopnea index) was positively associated with visceral adipose tissue (r = 0.73, p < 0.001) but not with other measures of body composition. After controlling for body mass index, the severity of sleep-disordered breathing was positively associated with markers of insulin resistance (homeostasis model assessment and fasting insulin). Further study to allow for critical assessment of the relationships between sleep-disordered breathing and cardiometabolic risk factors in obese youth remains necessary.

Uric acid excretion in North American and Southeast European children with obstructive sleep apnea

BACKGROUND AND OBJECTIVES

Responses to nocturnal hypoxemia accompanying sleep-disordered breathing (SDB) may vary in different populations. Aims of this study were to (1) assess whether severity of SDB is related to uric acid excretion in North American and Southeast European children and (2) evaluate the interaction between nocturnal hypoxemia and country of children's origin in uric acid excretion.

METHODS

Consecutive US and Greek children with snoring who were referred for polysomnography were recruited. Uric acid excretion expressed as uric acid-to-creatinine concentrations ratio in a morning urine specimen was the primary outcome measure.

RESULTS

One hundred and twenty-six US children (6.8+/-0.7years old) and 123 Greek children (6.4+/-2.5years old) were recruited. Forty-three US and 53 Greek participants had moderate-to-severe nocturnal hypoxemia (SpO(2) nadir <90%). Obstructive apnea-hypopnea index and SpO(2) nadir were related to uric acid excretion in Greek (but not US) children after adjustment by age, gender and body mass index z-score (p<0.05). There was a significant interaction between severity of hypoxemia and country of children's origin in uric acid excretion after adjustment by age, gender and body mass index z-score (p=0.036). Greek children with moderate-to-severe hypoxemia had higher uric acid excretion (0.85+/-0.35) than those with mild/no hypoxemia (0.69+/-0.25) (p=0.005). US children with moderate-to-severe hypoxemia (0.41+/-0.20) did not differ in uric acid excretion from those with mild/no hypoxemia (0.42+/-0.22) (p=0.823).

CONCLUSIONS

Uric acid excretion differs in children with SDB and different ethnic backgrounds or environmental exposures.

Obstructive sleep breathing disorders

Obstructive sleep apnea (OSA) is increasingly recognized in children. There is accumulating robust evidence to support early diagnosis and treatment of this condition. The purpose of this review is to provide an update on the epidemiology, clinical features, complications, and treatment of childhood OSA. The authors have also proposed an easy-to-follow flowchart on the management of children with snoring or sleep disturbance for clinical use by busy pediatricians.

Cardiovascular Risks Associated With Obesity in Children and Adolescents

Introduction: The aim of this paper is to review the cardiovascular (CVS) risks associated with obesity in children and adolescents. Both short-term and long-term CVS consequences, the mechanisms of how these develop and the measures that can alter or reverse these CVS events are reviewed. Materials and Methods:Selected publications include original articles and review papers that report on studies of CVS risks and consequences related to childhood obesity. Some papers that contain data from adults studies are also included if the contents help to explain some underlying mechanisms or illustrate the continuation of related CVS changes into adulthood. Results: Obese children and adolescents have an increased risk for CVS complications that include elevation of blood pressure, clustering of CVS risk factors (Metabolic Syndrome), changes to arterial wall thickness, elasticity and endothelium, as well as changes in left ventricular structure and function. Some of these cardiovascular problems may be initiated or potentiated by obstructive sleep apnoea that can accompany obesity in children. Many of such changes have been noted to reverse or improve with weight reduction. Conclusions:Early development of CVS risks in obese children and the possible continuation of CVS complications into adulthood have been observed. Obstructive sleep apnoea in obese children can further contribute to such CVS risks. These findings underscore the importance of prevention of childhood obesity as a priority over management of obesity in children. The prevalence of obesity has risen by three-folds or more in many countries since 1980. In 2005, it was estimated that globally there are about 1.6 billion overweight adults and at least 400 million of them are obese. This increase in the prevalence of adults being overweight and obese comes with a heavy price. The cost of healthcare has significantly increased and is expected to increase even more because of the close association between obesity and various chronic diseases. Key words: Endothelial function, Hypertension, Metabolic syndrome, Obstructive sleep apnoea

Pediatric sleep apnea: early onset of the 'syndrome'?

Obstructive sleep apnea is a common disorder in childhood, particularly in the last decade when an increased prevalence of obesity has been documented. The neurocognitive and behavioral problems associated with this disorder have been known for a long time. However, the increased knowledge of cardiovascular and metabolic complications in adults with sleep apnea has been followed by a better understanding of the systemic effects of upper airway obstruction in children. Obstructive sleep apnea (OSA) has been shown to induce autonomic imbalance in children and to affect blood pressure, cerebral blood flow and cardiac function in an early phase. OSA may also induce chronic systemic inflammation and may contribute to the development of metabolic syndrome in obese children. Very recent research indicates that in children primary snoring, the mildest form of the sleep-disordered breathing spectrum, may also be associated with morbidity. It is, therefore, likely that these respiratory sleep disorders do not simply influence children's' performance in private and social life, but may more seriously affect children's' health. The aim of this review is to outline early systemic complications of obstructive sleep apnea and primary snoring in infants and children.

Metabolic effects of the obstructive sleep apnea syndrome and cardiovascular risk

The obstructive sleep apnea syndrome (OSAS) is characterized by collapse of the upper airway during sleep, recurring apneas, intermittent hypoxemia and daytime somnolence. OSAS is often associated with obesity, and its prevalence is expected to rise due to the obesity epidemics worldwide. OSAS is associated with increased cardiovascular risk which appears to be normalized by treatment with nasal continuous positive airway pressure (nCPAP) during sleep, suggesting an independent role of OSAS in accelerating atherosclerosis. Insulin resistance (IR) and the metabolic syndrome (MetS) are often found in OSAS patients, but the relative role played by OSAS and obesity is still unclear. Both OSAS and MetS may exert negative synergistic effects on the cardiovascular system through multiple mechanisms (hypoxemia, sleep disruption, activation of the sympathetic nervous system, inflammatory activation). Besides nCPAP treatment, pharmacologic interventions to treat obesity and the MetS could improve cardiovascular prevention in OSAS.

Sleep-disordered breathing in children with metabolic syndrome: the role of leptin and sympathetic nervous system activity and the effect of continuous positive airway pressure

OBJECTIVE

The purpose of this work was to determine whether, in children with metabolic syndrome and sleep-disordered breathing, metabolic markers separate them from children with metabolic syndrome without sleep-disordered breathing and whether treatment of sleep-disordered breathing with continuous positive airway pressure is associated with an improvement in metabolic derangement.

PATIENTS AND METHODS

Subjects aged 7 to 19 years old with metabolic syndrome and a positive validated sleep questionnaire were recruited. Subjects underwent overnight polysomnography, during which sympathetic nervous system activity was assessed via 8-hourly measurements of norepinephrine and epinephrine, together with leptin. The next morning, a fasting 3-hour oral glucose-tolerance test was performed to calculate whole-body insulin sensitivity. A fasting lipid panel interleukin 6, adiponectin, and C-reactive protein levels were also measured. Children with sleep-disordered breathing were placed on continuous positive airway pressure for 3 months and studied again. Sleep-disordered breathing and no sleep-disordered breathing groups were compared by using Fisher's exact test and t test for independent samples with analysis of covariance to adjust for age and BMI.

RESULTS

Of 34 children studied, 25 had sleep-disordered breathing (apnea-hypopnea index: >1.5). Mean hourly norepinephrine and leptin levels were higher in the group with sleep-disordered breathing compared with the group without sleep-disordered breathing (P < .005), with no difference in whole-body insulin sensitivity. Eleven subjects with sleep-disordered breathing completed 3 months of nightly continuous positive airway pressure treatment. In the follow-up study, mean hourly leptin levels were significantly lower than in the initial study, with no change in BMI z score or other measurements.

CONCLUSION

Our findings support the hypothesis that sleep-disordered breathing in children with metabolic syndrome is associated with increased sympathetic nervous system activity and leptin levels but not worsening of insulin resistance. Treatment of sleep-disordered breathing with continuous positive airway pressure led to a significant decrease in leptin levels.

Obesity and Obstructive Sleep Apnoea Hypopnoea Syndrome in Singapore Children

Introduction: Obesity affects about 10% to 15% of our school-going population in Singapore and is a risk factor for development of obstructive sleep apnoea hypopnoea syndrome (OSAHS). This article reviews the prevalence, aetiology, pathophysiology, diagnosis, complications and treatment of obese children with OSAHS with particular reference to children in Singapore. Methods: Review of articles or conference papers reporting data with regards to OSAHS in Singapore children. Results: Prevalence of OSAHS was high in obese children in Singapore and was more common in males with no racial predisposition. Hypersomnolence as a presenting symptom was uncommon. Cognitive function, behaviour, attention and processing speed was affected and improved after intervention. Abnormalities of glucose metabolism were also found with the respiratory disturbance index (RDI) as an independent predictor of insulin resistance. Tonsillectomy and or adenoidectomy was efficacious as treatment and risk of complications was low. No significant increase in weight occurred post intervention in those enrolled in concurrent weight management programmes. Conclusions: Prevalence of OSAHS is high in obese Singapore children and many are ‘asymptomatic’. A low threshold for evaluation is necessary for early diagnosis and intervention for prevention of morbidity. Tonsillectomy and/or adenoidectomy is safe and efficacious and remains the first-line treatment in most obese patients. Key words: Complications, Diagnosis, Prevalence, Treatment

Absence of blood pressure, metabolic, and inflammatory marker changes after adenotonsillectomy for sleep apnea in Greek children

AIM

Pediatric studies revealed associations of obstructive sleep-disordered breathing (SDB) with inflammation, metabolic dysfunction, and elevated blood pressure. Evidence about effects of adenotonsillectomy on these abnormalities is scarce. Aim of this investigation was to assess changes in C-reactive protein (CRP), circulating intercellular adhesion molecule-1 (cICAM-1), insulin and blood pressure levels after adenotonsillectomy for SDB in Greek children.

METHODS

Polysomnography was performed pre- and postoperatively in children with SDB and controls undergoing adenotonsillectomy for recurrent tonsillitis or otitis. Outcome measures were changes in serum markers and blood pressure.

RESULTS

Fifty-eight patients (6.2 +/- 2.5 years old) and 17 controls (6.5 +/- 2) were studied. After surgery, apnea-hypopnea index (AHI) decreased (mean: -5.9 episodes/hr; 95% confidence interval: -7.8 to -4) in patients. Patients and controls were similar regarding outcomes: CRP (-0.11 mg/dl [-0.25 to 0.02] vs. 0.13 [-0.19 to 0.46]; P = 0.11), cICAM-1 (-11.6 ng/ml [-38.6 to 15.4] vs. -46.6 [-101.7 to 8.6]; P = 0.23), insulin (2.49 mU/L [0.32-4.67] vs. -0.16 [-2.47 to 2.16]; P = 0.21), systolic blood pressure index (5.2% [2.1-8.3] vs. 10.8 [3.6-17.9]; P = 0.1) and diastolic blood pressure index (-3.2% [-7.2 to 0.8] vs. 2.8 [-5.5 to 11.2]; P = 0.16). Patients with CRP > 0.3 mg/dl had reduced values after AT (P = 0.003) and those with postoperative AHI < or = 1 had a decrease in diastolic blood pressure (P = 0.02).

CONCLUSIONS

Although adenotonsillectomy improves SDB, it has variable effects on inflammatory and metabolic markers or blood pressure.

Association of sleep apnea severity and obesity with insulin resistance, C-reactive protein, and leptin levels in male patients with obstructive sleep apnea

Obesity is the major confounding factor in the relationship between obstructive sleep apnea and increased risk for cardiovascular disease. The aim of the study was to investigate the association of sleep apnea severity with insulin resistance, leptin, and CRP levels in a cohort of male patients. Sixty-seven men referred to our sleep laboratory for evaluation of suspected obstructive sleep apnea syndrome (OSAS) were divided into three groups according to apnea severity: non-OSAS group (n=15), mild to moderate OSAS group (n=26), and severe OSAS (n=26). Insulin resistance was estimated by the homeostasis model assessment method. HOMA values were similar in the three groups: (3.2+/-2.2 vs. 3.3+/-1.8 vs. 3.6+/-1.5, respectively, p=0.71). Leptin levels were higher in the mild to moderate OSAS group (23.1+/-21.8 ng/ml, p<0.05) and in the severe OSAS group (20.2+/-17.5 ng/ml, p<0.05) than in the non-OSAS group (9.4+/-6.4 ng/ml). CRP levels were significantly higher in severe sleep apnea (0.35+/-0.3 vs. 0.19+/-0.1 mg/dl, p<0.05). In multiple regression analyses, waist-to-hip ratio (WHR) was the most significant determinant of HOMA estimation for insulin resistance. WHR and the percentage of total sleep time spent with hypoxemia (%TST with SaO2 <90%) were significant predictors for leptin levels, while body mass index (BMI) and the %TST with SaO2 <90% were the best predicting parameters for CRP levels. Insulin resistance estimated by the HOMA method in male patients with OSAS was not associated with sleep apnea severity independent of obesity. The severity of nocturnal hypoxemia was associated with leptin and CRP levels independent of obesity.

Pediatric obstructive sleep apnea: complications, management, and long-term outcomes

Obstructive sleep apnea (OSA) in children has emerged not only as a relatively prevalent condition but also as a disease that imposes a large array of morbidities, some of which may have long-term implications, well into adulthood. The major consequences of pediatric OSA involve neurobehavioral, cardiovascular, and endocrine and metabolic systems. The underlying pathophysiological mechanisms of OSA-induced end-organ injury are now being unraveled, and clearly involve oxidative and inflammatory pathways. However, the roles of individual susceptibility (as dictated by single-nucleotide polymorphisms), and of environmental and lifestyle conditions (such as diet, physical, and intellectual activity), may account for a substantial component of the variance in phenotype. Moreover, the clinical prototypic pediatric patient of the early 1990s has been insidiously replaced by a different phenotypic presentation that strikingly resembles that of adults afflicted by the disease. As such, analogous to diabetes, the terms type I and type II pediatric OSA have been proposed. The different manifestations of these two entities and their clinical course and approaches to management are reviewed.

Metabolic alterations and systemic inflammation in obstructive sleep apnea among nonobese and obese prepubertal children

RATIONALE

Obstructive sleep apnea (OSA) has been associated with a higher prevalence and severity of the metabolic syndrome in adult patients, even after controlling for obesity. In contrast, OSA in prepubertal children does not appear to correlate with the magnitude of such metabolic derangements.

OBJECTIVES

To further establish the potential mechanistic role of OSA in metabolic regulation in prepubertal children.

METHODS

Fasting glucose, insulin, C-reactive protein, apolipoprotein B, and serum lipid concentrations were determined during the initial polysomnographic diagnosis of OSA and 6-12 months after adenotonsillectomy in both obese and nonobese children.

MEASUREMENTS AND MAIN RESULTS

Sixty-two children with OSA (37 obese and 25 nonobese), age 7.40 +/- 2.6 years (mean +/- SD) completed the study. After adenotonsillectomy, significant improvements in apnea-hypopnea index and sleep fragmentation occurred, particularly among nonobese children. In nonobese children, adenotonsillectomy was associated with mild increases in body mass index z scores, no changes in either fasting glucose or insulin, significant increases in high-density lipoprotein and reciprocal decreases in low-density lipoprotein, and reductions in plasma C-reactive protein and apolipoprotein B levels. In obese children, adenotonsillectomy did not result in body mass index or glucose changes, but was associated with marked improvements in all other measures.

CONCLUSIONS

OSA does not appear to induce insulin resistance in nonobese pediatric patients but seems to play a significant role in obese patients. The significant improvements in lipid profiles, C-reactive protein, and apolipoprotein B after adenotonsillectomy in the two groups suggest a pathogenic role for OSA in lipid homeostasis and systemic inflammation independent of the degree of adiposity.