The association of obstructive sleep apnea and left ventricular hypertrophy in obese and overweight children with history of elevated blood pressure

Hypoxia-Induced Insulin Resistance Mediates the Elevated Cardiovascular Risk in Patients with Obstructive Sleep Apnea: A Comprehensive Review

Patients with obstructive sleep apnea (OSA) experience insulin resistance and its clinical consequences, including hypertriglyceridemia, reduced high density lipoprotein-associated cholesterol (HDL-c), visceral adiposity, hepatic steatosis, increased epicardial fat thickness, essential hypertension, glucose intolerance, increased risk for type 2 diabetes, chronic kidney disease, subclinical vascular damage, and increased risk for cardiovascular events. Obesity is a major contributor to OSA. The prevalence of OSA is almost universal among patients with severe obesity undergoing bariatric surgery. However, insulin resistance and its clinical complications occur in OSA patients irrespective of general obesity (body mass index). In OSA patients, apnea episodes during sleep induce oxyhemoglobin desaturation and tissue hypoxia. Insulin resistance is an adaptive response to tissue hypoxia and develops in conditions with limited tissue oxygen supply, including healthy subjects exposed to hypobaric hypoxia (high altitude) and OSA patients. Indicators of oxyhemoglobin desaturation have been robustly and independently linked to insulin resistance and its clinical manifestations in patients with OSA. Insulin resistance mediates the elevated rate of type 2 diabetes, chronic kidney disease, and cardiovascular disease unexplained with traditional cardiovascular risk factors present in OSA patients. Pathophysiological processes underlying hypoxia-induced insulin resistance involve hypoxia inducible factor-1 upregulation and peroxisome proliferator-activated receptor-gamma (PPAR- γ ) downregulation. In human adipose tissue, PPAR- γ activity promotes glucose transport into adipocytes, lipid droplet biogenesis, and whole-body insulin sensitivity. Silencing of PPAR- γ in the adipose tissue reduces glucose uptake and fat accumulation into adipocytes and promotes insulin resistance. In conclusion, tissue hypoxia drives insulin resistance and its clinical consequences in patients with OSA, regardless of body mass index.

The effects of obstructive sleep apnea on blood pressure variability and load in patients with hypertension

BACKGROUND

Hypertension frequently coexists with obstructive sleep apnea (OSA), and their interplay substantially impacts the prognosis of affected individuals. Investigating the influence of OSA on blood pressure variability (BPV) and blood pressure load (BPL) in hypertensive patients has become a focal point of clinical research.

METHODS

This cross-sectional study recruited hypertensive patients (n = 265) without discrimination and classified them into four groups based on their apnea-hypopnea index (AHI): control group (n = 40), AHI < 5; mild group (n = 74), 5 ≤ AHI ≤ 15; moderate group (n = 68), 15 < AHI ≤ 30; severe group (n = 83), AHI > 30. All participants underwent comprehensive assessments, including polysomnography (PSG) monitoring, 24-h ambulatory blood pressure (ABP) monitoring, cardiac Doppler ultrasound, and additional examinations when indicated.

RESULTS

BPV and BPL exhibited significant elevations in the moderate and severe OSA groups compared to the control and mild OSA groups (P < 0.05). Moreover, interventricular septum thickness and left ventricular end-diastolic volume (LVEDV) demonstrated higher values in the moderate and severe OSA groups (P < 0.05). Multiple stepwise regression analysis identified noteworthy risk factors for elevated BPV in hypertensive patients with OSA, including AHI, maximum apnea time, total times of oxygen reduction, and mean time of apnea.

CONCLUSION

Hypertensive patients with moderate to severe OSA exhibited substantially increased BPV and BPL. Moreover, BPV was correlated with AHI, maximum apnea time, total times of oxygen reduction, and mean time of apnea in hypertensive patients with OSA.

Sleep-related breathing disorders and cardiometabolic risk factors in pediatric kidney transplant recipients

BACKGROUND

SRBDs have been shown to increase the risk of cardiovascular disease, which is a significant cause of mortality in kidney transplant recipients. Few studies have investigated the association between SRBDs and cardiometabolic risk factors in pediatric kidney transplant recipients.

METHODS

This was a cross-sectional study of pediatric kidney transplant recipients using baseline cardiometabolic data from a previous clinical trial (NCT01007994). Parents/guardians of pediatric kidney transplant recipients filled out 22-item PSQ. A score greater than 33% was defined as a diagnosis of a SRBD. Fisher's exact test, Mann-Whitney U test, and regressions were used to determine associations.

RESULTS

Among the 58 transplant recipients enrolled, 14.80% (n = 8) of participants identified as Black and 40.7% (n = 22) were male. The median age was 13 (IQR 8.25, 17) years and median number of years post-transplant for participants was 2 (IQR 1, 4). The prevalence of SRBDs was 26% (n = 14). The presence of a SRBD was associated with abnormalities in multiple cardiometabolic risk factors including total cholesterol level (β = 23.63; 95% CI 3.58-43.67), LDL level (β = 24.94; 95% CI 6.37-43.50), triglyceride level (β = 54.62; 95% CI 8.74-100.50), and LVH (OR = 5.12; 95% CI 1.12-23.45) when adjusted for age, sex, and race.

CONCLUSIONS

Similar to associations reported in the general pediatric and general CKD populations, SRBD is associated with increased cardiometabolic risk in pediatric kidney transplant recipients.

Aggravating effect of obstructive sleep apnoea on left ventricular remodelling and function disorder in patients with type 2 diabetes mellitus: a case-control study by 3D speckle tracking echocardiography

OBJECTIVES

The purpose of this study was to evaluate the early alterations of left ventricular (LV) structure and function in type 2 diabetes mellitus (T2DM) patients with or without obstructive sleep apnoea (OSA) using 3 D speckle tracking echocardiography (3DSTE).

METHODS

Eighty T2DM patients with preserved LVEF were included, half of whom had OSA as co-morbidity. Forty age- and sex-matched controls were also enrolled. LV structure and function were evaluated by conventional echocardiography and 3DSTE. LV global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS), and global radial strain (GRS) were all measured by 3DSTE.

RESULTS

Four geometric patterns (normal geometry, concentric remodelling, concentric and eccentric hypertrophy) occupied significantly different proportions within the three groups (p = .014). LV remodelling made up higher shares in two T2DM groups than in the controls, whereas LV hypertrophy appeared most frequently in the patients with T2DM and OSA. The patients with T2DM alone had significantly lower GLS and GCS than the controls (both p < .01). The patients with T2DM and OSA had significantly lower GLS, GCS, GAS, and GRS than the controls and the patients with T2DM alone (all p < .01). Fasting plasma glucose (FPG), OSA and BMI had negative impacts on all and part of the strain values in T2DM patients. The T2DM patients with moderate-to-severe OSA showed significantly lower GLS, GCS, GAS, and GRS than those with mild OSA (all p < .05).

CONCLUSIONS

The 3DSTE plus conventional echocardiography could detect the sub-clinical LV alterations in T2DM patients with or without OSA.

Associations of the Cardiometabolic Index with the Risk of Cardiovascular Disease in Patients with Hypertension and Obstructive Sleep Apnea: Results of a Longitudinal Cohort Study

Purpose

We aimed to explore the relationship between the cardiometabolic index (CMI) and cardiovascular disease (CVD) and its subtypes (coronary artery disease and stroke) in patients with hypertension and obstructive sleep apnea (OSA).

Methods

We conducted a retrospective cohort study enrolling 2067 participants from the Urumqi Research on Sleep Apnea and Hypertension study. The CMI was calculated as triglyceride to high‐density lipoprotein cholesterol ratio × waist‐to‐height ratio. Participants were divided into three groups (T1, T2, and T3) according to the tertile of CMI. The Kaplan-Meier method helped to calculate the cumulative incidence of CVD in different groups. We assessed the association of CMI with the risk of CVD and CVD subtypes by estimating hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox models.

Results

During a median follow-up of 6.83 years (interquartile range: 5.92-8.00 years), 326 incident CVD were identified, including 121 incident stroke and 205 incident coronary heart disease (CHD). Overall, after adjusting for confounding variables, CMI was positively associated with the risk of new-onset CVD (per SD increment, adjusted HR: 1.31; 95% CI: 1.20, 1.43), new-onset CHD (per SD increment, adjusted HR: 1.33; 95% CI: 1.20, 1.48), and new-onset stroke (per SD increment, adjusted HR: 1.27; 95% CI: 1.10, 1.47). Similar results were obtained in various subgroup and sensitivity analyses. Adding CMI to the baseline risk model for CVD improved the C-index (P < 0.001), continuous net reclassification improvement (P < 0.001), and integrated discrimination index (P < 0.001). Similar results were observed for CHD and stroke.

Conclusion

There was a positive association between CMI levels and the risk of new-onset CVD in patients with hypertension and OSA. This finding suggests that CMI may help identify people at high risk of developing CVD.

Cardiovascular implications in adolescent and young adult hypertension

Background

Hypertension is one of the most prevalent diseases in the United States, affecting an estimated 3.5% of children and adolescents. It can be adversely affect most organ systems but is particularly detrimental to the heart and vascular systems. The repercussions can be gauged through well-established measures of cardiovascular function including left ventricular mass index (LVMI), left ventricular hypertrophy (LVH), carotid intima media thickness (cIMT), and aortic stiffness. Cardiovascular function is also affected by underlying etiologies of hypertension including chronic kidney disease, polycystic kidney disease, coarctation of the aorta, adrenal disorders, renal artery stenosis, obstructive sleep apnea, as well as various drugs and medications (decongestants, stimulants, Non-steroidal Anti-inflammatory Drugs (NSAIDs), and steroids).

Methods

An exhaustive literature search was conducted for clinical data regarding pediatric hypertension. Sixty-seven articles were incorporated with data on 189,477 subjects total. The data was then extracted and categorized as relating to hypertension incidence, LVMI, LVH, cIMT, and/or aortic stiffness.

Results

The prevalence of pediatric ( < 18 years) hypertension extracted from 47 studies from 1994 to 2018 averaged 4%. The LVMI assessed over 7 studies (n = 661) averaged 39.3 g/ m 2.7 in the hypertensive cohort and 30.1 g/ m 2.7 in the control cohort. The cIMT assessed over 7 studies (n = 580) averaged 0.55 mm in the hypertensive cohort and 0.49 mm in the control cohort. Ambulatory arterial stiffness parameters assessed over 5 studies (n = 573) in the normotensive cohort averaged 99.73 mmHg, 69.81 mmHg, 76.85 mmHg, and 46.90 mmHg, for SBP, DBP, MAP, and PP respectively. Ambulatory arterial stiffness parameters assessed over 5 studies (n = 573) in the hypertensive cohort averaged 129.56 mmHg, 73.69 mmHg, 95.08 mmHg, and 56.80 mmHg, for SBP, DBP, MAP, and PP respectively.

Conclusions

The significance of pediatric hypertension is emphasized by evidence of early cardiovascular disease as demonstrated by non-invasive measures including cIMT and arterial stiffness parameters, and target organ damage and including LVH and LVMI factors. Thus, early diagnosis and treatment of high blood pressure is paramount for improving long term cardiovascular health and preventing long term morbidity and mortality.

Trends in Diagnosing Obstructive Sleep Apnea in Pediatrics

Obstructive sleep apnea in children has been linked with behavioral and neurocognitive problems, impaired growth, cardiovascular morbidity, and metabolic consequences. Diagnosing children at a young age can potentially prevent significant morbidity associated with OSA. Despite the importance of taking a comprehensive sleep history and performing thorough physical examination to screen for signs and symptoms of OSA, these findings alone are inadequate for definitively diagnosing OSA. In-laboratory polysomnography (PSG) remains the gold standard of diagnosing pediatric OSA. However, there are limitations related to the attended in-lab polysomnography, such as limited access to a sleep center, the specialized training involved in studying children, the laborious nature of the test and social/economic barriers, which can delay diagnosis and treatment. There has been increasing research about utilizing alternative methods of diagnosis of OSA in children including home sleep testing, especially with the emergence of wearable technology. In this article, we aim to look at the presentation, physical exam, screening questionnaires and current different modalities used to aid in the diagnosis of OSA in children.

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.

Cardiovascular issues in obstructive sleep apnoea in children: A brief review

Obstructive sleep apnoea (OSA) is a very common disease with a prevalence that ranges from 1% to 6% in children. It is characterized by intermittent partial or complete occlusion of the upper airway during sleep, leading to recurrent arousals and disturbed sleep architecture, to neurocognitive disorders and alterations in homeostatic gas exchange. Cardiovascular complications may develop in children with OSA through various mechanisms including activation and dysregulation of the sympathetic nervous system, induction of pro-inflammatory and pro-oxidant status and increased risk of systemic hypertension. As the deleterious effects of OSA on the cardio-vascular system may start early in life, in this brief review we focused our attention both on early and late cardiological changes induced by apnoeic events in the paediatric population, by reviewing recent findings in the literature.

Association of Sleep Quality With Greater Left Ventricular Mass in Children Aged 9 to 11 Years

OBJECTIVE

Research has consistently found associations between sleep characteristics and cardiovascular disease risk in children, adolescents, and adults. Although primarily investigated in clinical samples (e.g., in those with sleep disorders), greater left ventricular mass is associated with poor sleep quality in nonclinical adult populations as well; however, this has not been evaluated in children or adolescents. Our study aim was to consider the relationship between objectively measured sleep characteristics and left ventricular mass in children.

METHODS

We assessed sleep and cardiac structure in a biracial sample of 9- to 11-year-old children (n = 176; 41% White, 59% Black; 50% female). Sleep was assessed with actigraphy for five nights. Cardiac dimensions were assessed using echocardiography.

RESULTS

After adjusting for covariates, we found that poor sleep quality was associated with significantly greater left ventricular mass (β = 0.13, t(167) = 2.14, p = .034, Cohen d = 0.16, for activity during sleep; β = 0.15, t(167) = 2.43, p = .016, Cohen d = 0.18, for sleep fragmentation). Other cardiac dimensions (namely, relative wall thickness and right ventricular dimension) were also significantly associated with sleep characteristics. Notably, associations did not differ as a function of sex or race.

CONCLUSIONS

The present findings are novel and unique because no prior reports have systematically documented the association between poor sleep quality with potentially detrimental cardiac remodeling in a nonclinical sample of children. However, the novelty and importance of these findings require additional research for confirmation.

Association Between Intermittent Hypoxia and Left Ventricular Remodeling in Patients With Obstructive Sleep Apnea-Hypopnea Syndrome

The present study was undertaken to examine the association between intermittent hypoxia and left ventricular (LV) remodeling and explore which parameter of intermittent hypoxia is most relevant to LV remodeling in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). Two hundred eighty six patients underwent polysomnographic examination were enrolled. Based on apnea-hypoxia index (AHI), patients were divided into no, mild, moderate and severe OSAHS groups. Between-group differences in LV remodeling and the association between parameters of intermittent hypoxia and LV remodeling was evaluated. Patients with severe OSAHS were more likely to have hypertension, and higher values of LV mass (LVM) and LVM index (LVMI). In univariate regression analysis, male, body mass index (BMI), systolic and diastolic blood pressure (BP), statins, antihypertensive drugs, creatinine, and parameters of intermittent hypoxia (AHI, obstructive apnea index [OAI], lowest oxygen saturation [LSpO₂], oxygen desaturation index [ODI], time spent below oxygen saturation of 90% [TS90%], and mean nocturnal oxygen saturation [MSpO₂]) were associated with LVMI. After multivariate regression analyses, only male gender, BMI, systolic BP, creatinine, and ODI remained significantly associated with LVMI. Compared to those without LV hypertrophy (LVH), patients with LVH had higher ODI. Compared to patients with normal LV, concentric remodeling and eccentric LVH, those with concentric LVH had higher ODI. In conclusion, intermittent hypoxia was significantly associated with left ventricular remodeling; and among various parameters of intermittent hypoxia, ODI was the most relevant to LV remodeling.

Left Ventricular Geometrical Changes in Severely Obese Adolescents: Prevalence, Determinants, and Clinical Implications

Left ventricular hypertrophy (LVH) is independently associated with a higher risk of cardiovascular morbidity and mortality in adults. Adiposity is a risk factor for LVH, independent of blood pressure. Potential causes of this nonhemodynamic pathogenesis identified in adults include adverse body fat distribution, insulin resistance, dyslipidemia, and obstructive sleep apnea syndrome (OSA). In severely obese adolescents, the determinants of obesity-induced changes in left ventricular structure are poorly characterized. Cardiac ultrasonographic, demographic, anthropometric, and comorbidity-related data were prospectively collected in adolescents with severe obesity refractory to conservative treatment who presented for surgical therapy. Differences between adolescents with LVH and without LVH were evaluated using independent samples t, chi-square, or Fisher's exact test. Multivariable linear regression analysis was performed to evaluate associations with left ventricular structural changes, corrected for body mass index (BMI) z score. Forty-three patients entered analysis, of whom 24 (55.8%) showed LVH. The most common geometrical change was eccentric LVH (eLVH), occurring in 21 subjects (48.8%). Demographic and anthropometric variables did not differ between patients with and without LVH. Independent of BMI z score, left ventricular mass index was significantly associated with apnea-hypopnea index (AHI) (regression parameter B = 0.8; 95% CI 0.3 to 1.2). Interventricular septum thickness (IVST) was significantly associated with HOMA-IR values (B = 0.1; 95% CI 0.04 to 0.2), HDL-cholesterol (B = - 1.2; 95% CI - 2.2 to 0.1), and triglyceride levels (B = 0.5; 95% CI 0.001 to 0.9). LVH, especially eLVH, is highly prevalent amongst severely obese adolescents. Adverse changes in cardiac structure, increased IVST in particular, are independently associated with several nonhemodynamic comorbidities that are common in this population, namely OSA, insulin resistance, and dyslipidemia.

Does obstructive sleep apnoea contribute to obesity, hypertension and kidney dysfunction in children? A systematic review protocol

INTRODUCTION

Childhood obstructive sleep apnoea (OSA) is a highly prevalent disorder that may directly contribute to the development of obesity, hypertension and renal injury. Although those associations seem to be clearer in adults, studies in children have revealed conflicting results and updated synthesis of the evidence is lacking. The aim of this systematic review is to summarise the available evidence on the effect of OSA on obesity, systemic blood pressure and kidney function, to help to elucidate whether respiratory interventions to correct OSA would have the potential to improve those outcomes.

METHODS AND ANALYSIS

A systematic literature review search was created by a medical librarian and peer-reviewed by a second librarian prior to running. Ovid Medline, Ovid Embase, CINAHL via EbscoHOST, Wiley Cochrane Library and ProQuest Dissertations and Theses Global were searched on 25 February 2020. Titles and abstracts will be screened by two independent reviewers for inclusion, followed by full-text screening of relevant articles. Studies in children will be included if they report data on OSA and weight, systemic blood pressure or kidney parameters. The extracted data will be combined for analysis and the information subcategorised in groups based on outcome. Risk of bias will be determined using tools specific to study methodology and certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations approach.

ETHICS AND DISSEMINATION

This study will provide essential information for healthcare professionals to better understand the relationship between childhood OSA and changes in body mass index, systemic blood pressure and kidney function indicators. Our findings will be disseminated through conferences and publications. The results of this review may guide the initiation of new strategies and the development of future research studies. This research did not involve human subjects and therefore did not undergo research ethical review.

PROSPERO REGISTRATION NUMBER

CRD42020171186.