Relationships between body fat distribution, epicardial fat and obstructive sleep apnea in obese patients with and without metabolic syndrome

Osteocalcin is inversely associated with worse adipose tissue distribution and cardiovascular risk in autoimmune diabetes

BACKGROUND

Osteocalcin (OCN), whose release is impaired in diabetes, is suggested to regulate the adipose tissue (AT), being potentially associated with Cardiovascular risk (CVR). We aimed at evaluating whether OCN serum levels are associated with AT health and CVR in a primary CV prevention population with AD.

METHODS

Body mass composition was assessed in sixty-two people with AD.Serum levels of OCN, adipokines and markers of endothelial dysfunction were measured. Regression models were used to test the association of OCN with markers of AT, endothelial dysfunction and CVR categories as determined by the Steno Type 1 Risk Engine (ST1RE) score.

RESULTS

OCN was inversely associated with upper body fat deposition index (UBDFI) (Adj β coefficient -0.484, p value = 0.001). People in medium/high CV risk categories had higher UBFDI and lower OCN, while biomarkers of endothelial dysfunction were not different across CVR classes. A logistic binary regression for ST1RE score showed significant association of OCN with medium/high CVR category: OR [95 % CI for 1 SD increase: 0.541 [0.264--1.108], p = 0.093].

CONCLUSION

OCN is inversely associated with unhealthy AT, supporting the protective role of OCN in AT. Moreover, lower OCN levels are associated with increased CVR in AD population.

Epicardial fat thickness is increased in menopausal patients in comparison with premenopausal patients with similar excess weight: a cross-sectional study

BACKGROUND

The prevalence of excess weight and ageing is notably high in contemporary Western societies. The effectiveness of body mass index (BMI) and waist circumference as tools for identifying excess weight and ectopic fat deposition, both associated with an increased cardiovascular risk, is questionable.

METHODS

Our objective is to compare women affected by overweight and obesity during fertile years and menopausal time and identify easily accessible clinical parameters associated with ectopic fat deposition, providing valuable insights into cardiovascular risk. Over 1300 female patients with excess weight referred to the CASCO Centre (High Specialization Centre for the Care of Obesity) at Umberto I Polyclinic in Rome, Italy, were included. Each participant underwent a DXA scan and a cardiac ultrasound, and blood tests to verify menopausal status and evaluate metabolic profile and hepatic steatosis through indirect measurements.

RESULTS

775 patients were in the pre-menopausal phase and 617 in the post-menopausal phase. The two cohorts did not differ in BMI, total body fat and lean mass, or waist circumference. However, the post-menopausal group showed an increased visceral fat deposition, evaluated by waist-to-hip ratio and epicardial fat thickness (EFT), and a worse metabolic profile.

CONCLUSION

Menopause is associated with a worsening of the metabolic features observed in obesity, with an increase in visceral fat deposition. Of note, these alterations are more pronounced despite similar BMI and waist circumference.

Eating behavior patterns, metabolic parameters and circulating oxytocin levels in patients with obesity: an exploratory study

PURPOSE

Obesity is a complex heterogeneous disease often associated with dysfunctional eating behavior patterns. Oxytocin (OT) is a neurohormone involved in the regulation of energy metabolism and eating behavior. The aim of the present study was to evaluate in a population of patients with obesity circulating levels of OT and dysfunctional eating behaviors in relation to anthropometric, hormonal and metabolic parameters.

METHODS

A prospective, observational, single-center study was conducted at the Center of High Specialization for the Care of Obesity of Sapienza University of Rome. Adult subjects with body mass index (BMI) ≥ 30 kg/m2 were recruited. Body impedance assessment (BIA), biochemical and hormonal parameters, plasma OT concentration analysis and the Eating Behaviors Assessment for Obesity (EBA-O) questionnaire were evaluated.

RESULTS

A total of 21 patients, 16 females and 5 males, with a mean age of 45.7 ± 15.1 years, mean BMI of 40.89 ± 8.02 kg/m2 and plasma OT concentration of 1365.61 ± 438.03 pg/mL were recruited. The dysfunctional eating behavior traits investigated by the EBA-O appear significantly associated with metabolic derangements. In particular, night eating is associated with alterations in lipid metabolism (p < 0.01). Circulating OT correlates positively with BMI (r = 0,43; p < 0.05), and Hepatic Steatosis Index (HIS) (r = 0.46; p < 0.05), while its role in subjects with obesity and alterations in glucose metabolism is less clear. Interestingly, circulating OT levels < 1312.55 pg/mL may be predictive of food addiction (100% sensitivity; 62.5% specificity).

CONCLUSIONS

Despite the need for larger studies to confirm their validity, the clinical utility of the EBA-O and circulating OT in identifying dysfunctional eating behaviors appears promising.

Effects of a One-Year Intensified Weight Loss Program on Body Composition Parameters in Patients with Severe Obesity and Obstructive Sleep Apnea (OSA): A Randomized Controlled Trial

Background: Studies focusing on the effects of lifestyle strategies on patients with obstructive sleep apnea (OSA) that go beyond body weight and explore body composition are currently scarce and inconclusive. Objectives/Methods: The aim of this study was to evaluate the effects of a 12-month intensive life intervention program (ILI), based on a hypocaloric Mediterranean diet, on changes in the body composition parameters as assessed by abdominal computed tomography (CT) and the cardiorespiratory profile of patients with severe OSA and grade I-II obesity, compared to patients receiving standard care. Resultts:Thirty-four patients (30 males and four females) were randomly assigned to an intervention group (IG) (n = 18) or a control group (CG) (n = 16). We observed an improvement in OSA severity following the intervention. Patients in the IG lost 8.2% of their body weight compared to 0.1% of the patients in the CG (p < 0.001), and this loss was primarily due to reductions in total body fat, visceral adipose tissue index (VATI) [IG -19.4 (18.1) cm2/m2 versus CG 2.32 (11.6) cm2/m2, p < 0.001], and a tendency toward lower intramuscular adipose tissue index (IMATI) [IG -0.69 (0.85) cm2/m2 versus CG 0.04 (1.3) cm2/m2, p = 0.098]. These changes were associated with an improvement in patients' metabolic and inflammatory profile. Younger age and a higher degree of obesity at baseline were associated with greater weight loss. Conslusions: In conclusion, the ILI was effective in reducing 8.2% of body weight at 12 months, leading to favorable changes in patients' body composition profile that resulted in healthier metabolic and inflammatory parameters.

Cardio-Lipotoxicity of Epicardial Adipose Tissue

Epicardial adipose tissue is a unique visceral adipose tissue depot that plays a crucial role in myocardial metabolism. Epicardial adipose tissue is a major source of energy and free fatty acids for the adjacent myocardium. However, under pathological conditions, epicardial fat can affect the heart through the excessive and abnormal influx of lipids. The cardio-lipotoxicity of the epicardial adipose tissue is complex and involves different pathways, such as increased inflammation, the infiltration of lipid intermediates such as diacylglycerol and ceramides, mitochondrial dysfunction, and oxidative stress, ultimately leading to cardiomyocyte dysfunction and coronary artery ischemia. These changes can contribute to the pathogenesis of various cardio-metabolic diseases including atrial fibrillation, coronary artery disease, heart failure, and obstructive sleep apnea. Hence, the role of the cardio-lipotoxicity of epicardial fat and its clinical implications are discussed in this review.

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.

Body composition changes and their relationship with obstructive sleep apnoea symptoms, severity: The Sleeping Well Trial

BACKGROUND & AIMS

Obstructive sleep apnoea (OSA) and obesity share a complex bi-directional relationship as location of body fat and changes in regional body composition may be more important for OSA improvement than changes in total body weight only. The aim of this study was to evaluate the impact of a 6-month weight loss intervention for adults newly diagnosed with moderate-severe OSA and obesity on regional body composition. The secondary aims evaluated the relationship between changes in OSA symptoms and severity and anthropometry and regional body composition during the first 12-months after commencing CPAP and explored differences in outcomes between males and females.

METHODS

Participants (n = 59) received CPAP overnight at home alongside a 6-month modified fasting intervention with 12-months follow up. Regional body composition was measured by Dual X-ray absorptiometry, (DXA) and anthropometry before and after the lifestyle intervention. OSA severity was measured using the apnoea hypopnea index via overnight polysomnography and OSA symptoms were measured using the Epworth Sleepiness scale.

RESULTS

Forty-seven adults (74% male) had complete measures available with a mean age of 50.0 y (SD 11.0) and BMI 34.1 kg/m2 (SD 5.0). Following the intervention average fat mass changed by -5.27 kg (5.36), p < 0.001) and visceral adipose tissue (-0.63 kg (0.67), p < 0.001) significantly decreased in males only with a maintenance of fat-free mass (mean -0.41 kg (1.80), p = 0.18). Females (n = 12) had significant decreases in waist circumference (mean -3.36 cm (3.18) p < 0.01), android lean (-0.12 kg (0.04), p < 0.05) and android total mass (-0.28 kg (0.39), p < 0.05) only. Regional body composition changes in males were positively associated with improvements in OSA severity (p < 0.01) but not OSA symptoms.

CONCLUSION

Improvements in regional body composition were seen in males only which were related to improvements in OSA severity but not OSA symptoms. Females may exhibit different OSA pathophysiology and may require different treatment approaches.

TRIAL REGISTRATION

https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=369975&isReview=trueAACTRN12616000203459 ACTRN12616000203459.

Understanding the Association Between Obesity and Obstructive Sleep Apnea Syndrome: A Case-Control Study

Introduction Obstructive sleep apnea (OSA) represents a sleep-related impairment linked to upper airway function. The question of whether OSA drives obesity or if shared underlying factors contribute to both conditions remains unresolved. Hence, this present study aims to understand the interplay between obstructive sleep apnea syndrome (OSAS) and obesity through in-depth analysis of anthropometric data within control subjects and OSA patients. Methodology A case-control study was conducted, which included 40 cases and 40 matched healthy controls. Study participants with reported symptoms of snoring, daytime drowsiness, or both were included in the study. All the study participants underwent comprehensive anthropometric assessments such as height, weight, body mass index (BMI), neck circumference, waist circumference, hip circumference, waist-to-hip ratio, skin-fold thickness, and thickness measurements of biceps, triceps, suprailiac, and subscapular muscles. Results Within the OSA group, significant disparities emerged in mean age, waist circumference, waist-to-hip ratio, and diverse fat accumulations encompassing visceral, subcutaneous, trunk, and subcutaneous leg fat. Notably, skin-fold thickness at specific sites - biceps, triceps, subscapula, and suprailiac - demonstrated considerable augmentation relative to the control group. Furthermore, mean values associated with height, weight, BMI, neck circumference, fat percentage, subcutaneous arm fat, entire arm composition, and trunk skeletal muscle either equaled or exceeded those in the control group. However, statistical significance was not attained in these comparisons. Conclusion This investigation underscored a pronounced correlation between numerous endpoints characterizing OSA patients and markers of obesity. Consequently, addressing altered levels of obesity-linked anthropometric variables through pharmacological interventions might hold promise as a pivotal strategy for improving symptoms associated with OSA.

Association Between Race and Opioid-Induced Respiratory Depression: An International Post Hoc Analysis of the Prediction of Opioid-induced Respiratory Depression In Patients Monitored by Capnography Trial

BACKGROUND

Opioid-induced respiratory depression (OIRD) is common on the medical and surgical wards and is associated with increased morbidity and health care costs. While previous studies have investigated risk factors for OIRD, the role of race remains unclear. We aim to investigate the association between race and OIRD occurrence on the medical/surgical ward.

METHODS

This is a post hoc analysis of the PRediction of Opioid-induced respiratory Depression In patients monitored by capnoGraphY (PRODIGY) trial; a prospective multinational observational blinded study of 1335 general ward patients who received parenteral opioids and underwent blinded capnography and oximetry monitoring to identify OIRD episodes. For this study, demographic and perioperative data, including race and comorbidities, were analyzed and assessed for potential associations with OIRD. Univariable χ 2 and Mann-Whitney U tests were used. Stepwise selection of all baseline and demographic characteristics was used in the multivariable logistic regression analysis.

RESULTS

A total of 1253 patients had sufficient racial data (317 Asian, 158 Black, 736 White, and 42 other races) for inclusion. The incidence of OIRD was 60% in Asians (N = 190/317), 25% in Blacks (N = 40/158), 43% in Whites (N = 316/736), and 45% (N = 19/42) in other races. Baseline characteristics varied significantly: Asians were older, more opioid naïve, and had higher opioid requirements, while Blacks had higher incidences of heart failure, obesity, and smoking. Stepwise multivariable logistic regression revealed that Asians had increased risk of OIRD compared to Blacks (odds ratio [OR], 2.49; 95% confidence interval [CI], 1.54-4.04; P = .0002) and Whites (OR, 1.38; 95% CI, 1.01-1.87; P = .0432). Whites had a higher risk of OIRD compared to Blacks (OR, 1.81; 95% CI, 1.18-2.78; P = .0067). The model's area under the curve was 0.760 (95% CI, 0.733-0.787), with a Hosmer-Lemeshow goodness-of-fit test P value of .23.

CONCLUSIONS

This post hoc analysis of PRODIGY found a novel association between Asian race and increased OIRD incidence. Further study is required to elucidate its underlying mechanisms and develop targeted care pathways to reduce OIRD in susceptible populations.

Growth Hormone Secretory Capacity Is Associated with Cardiac Morphology and Function in Overweight and Obese Patients: A Controlled, Cross-Sectional Study

Obesity is associated with increased cardiovascular morbidity. Adult patients with growth hormone deficiency (GHD) show morpho-functional cardiological alterations. A total of 353 overweight/obese patients are enrolled in the period between 2009 and 2019 to assess the relationships between GH secretory capacity and the metabolic phenotype, cardiovascular risk factors, body composition and cardiac echocardiographic parameters. All patients underwent GHRH + arginine test to evaluate GH secretory capacity, DEXA for body composition assessment and transthoracic echocardiography. Blood samples are also collected for the evaluation of metabolic parameters. In total, 144 patients had GH deficiency and 209 patients had normal GH secretion. In comparing the two groups, we found significant differences in body fat distribution with predominantly visceral adipose tissue accumulation in GHD patients. Metabolic syndrome is more prevalent in the GHD group. In particular, fasting glycemia, triglycerides and systolic and diastolic blood pressure are found to be linearly correlated with GH secretory capacity. Epicardial fat thickness, E/A ratio and indexed ventricular mass are worse in the GHD group. In the population studied, metabolic phenotype, body composition, cardiovascular risk factors and cardiac morphology are found to be related to the GH secretory capacity. GH secretion in the obese patient seems to be an important determinant of metabolic health.

Epicardial Adipose Tissue: A Novel Potential Imaging Marker of Comorbidities Caused by Chronic Inflammation

The observation of correlations between obesity and chronic metabolic and cardiovascular diseases has led to the emergence of strong interests in “adipocyte biology”, in particular in relation to a specific visceral adipose tissue that is the epicardial adipose tissue (EAT) and its pro-inflammatory role. In recent years, different imaging techniques frequently used in daily clinical practice have tried to obtain an EAT quantification. We provide a useful update on comorbidities related to chronic inflammation typical of cardiac adiposity, analyzing how the EAT assessment could impact and provide data on the patient prognosis. We assessed for eligibility 50 papers, with a total of 10,458 patients focusing the review on the evaluation of EAT in two main contexts: cardiovascular and metabolic diseases. Given its peculiar properties and rapid responsiveness, EAT could act as a marker to investigate the basal risk factor and follow-up conditions. In the future, EAT could represent a therapeutic target for new medications. The assessment of EAT should become part of clinical practice to help clinicians to identify patients at greater risk of developing cardiovascular and/or metabolic diseases and to provide information on their clinical and therapeutic outcomes.

Leptin: A Potential Link Between Obstructive Sleep Apnea and Obesity

Chronic intermittent hypoxia (CIH), a pathophysiological manifestation of obstructive sleep apnea (OSA), is strongly correlated with obesity, as patients with the disease experience weight gain while exhibiting elevated plasma levels of leptin. This study was done to determine whether a relationship may exist between CIH and obesity, and body energy balance and leptin signaling during CIH. Sprague-Dawley rats were exposed to 96 days of CIH or normoxic control conditions, and were assessed for measures of body weight, food and water intake, and food conversion efficiency. At the completion of the study leptin sensitivity, locomotor activity, fat pad mass and plasma leptin levels were determined within each group. Additionally, the hypothalamic arcuate nucleus (ARC) was isolated and assessed for changes in the expression of proteins associated with leptin receptor signaling. CIH animals were found to have reduced locomotor activity and food conversion efficiency. Additionally, the CIH group had increased food and water intake over the study period and had a higher body weight compared to normoxic controls at the end of the study. Basal plasma concentrations of leptin were significantly elevated in CIH exposed animals. To test whether a resistance to leptin may have occurred in the CIH animals due to the elevated plasma levels of leptin, an acute exogenous (ip) leptin (0.04 mg/kg carrier-free recombinant rat leptin) injection was administered to the normoxic and CIH exposed animals. Leptin injections into the normoxic controls reduced their food intake, whereas CIH animals did not alter their food intake compared to vehicle injected CIH animals. Within ARC, CIH animals had reduced protein expression of the short form of the obese (leptin) receptor (isoform OBR₁₀₀) and showed a trend toward an elevated protein expression of the long form of obese (leptin) receptor (OBRb). In addition, pro-opiomelanocortin (POMC) protein expression was reduced, but increased expression of the phosphorylated extracellular-signal-regulated kinase 1/2 (pERK1/2) and of the suppressor of cytokine signaling 3 (SOCS3) proteins was observed in the CIH group, with little change in phosphorylated signal transducer and activator of transcription 3 (pSTAT3). Taken together, these data suggest that long-term exposure to CIH, as seen in obstructive sleep apnea, may contribute to a state of leptin resistance promoting an increase in body weight.

Application of a Machine Learning Technology in the Definition of Metabolically Healthy and Unhealthy Status: A Retrospective Study of 2567 Subjects Suffering from Obesity with or without Metabolic Syndrome

The key factors playing a role in the pathogenesis of metabolic alterations observed in many patients with obesity have not been fully characterized. Their identification is crucial, and it would represent a fundamental step towards better management of this urgent public health issue. This aim could be accomplished by exploiting the potential of machine learning (ML) technology. In a single-centre study (n = 2567), we used an ML analysis to cluster patients with metabolically healthy (MHO) or metabolically unhealthy (MUO) obesity, based on several clinical and biochemical variables. The first model provided by ML was able to predict the presence/absence of MHO with an accuracy of 66.67% and 72.15%, respectively, and included the following parameters: HOMA-IR, upper body fat/lower body fat, glycosylated haemoglobin, red blood cells, age, alanine aminotransferase, uric acid, white blood cells, insulin-like growth factor 1 (IGF-1) and gamma-glutamyl transferase. For each of these parameters, ML provided threshold values identifying either MUO or MHO. A second model including IGF-1 zSDS, a surrogate marker of IGF-1 normalized by age and sex, was even more accurate with a 71.84% and 72.3% precision, respectively. Our results demonstrated high IGF-1 levels in MHO patients, thus highlighting a possible role of IGF-1 as a novel metabolic health parameter to effectively predict the development of MUO using ML technology.

Waist-To-Hip Ratio Predicts Abnormal Overnight Oximetry in Men Independent of Body Mass Index

Background: Ambulatory overnight oximetry (OXI) has emerged as a cost-effective initial test for sleep disordered breathing. Obesity is closely associated with obstructive sleep apnea (OSA); however, whether body mass index (BMI) or waist-to-hip ratio (WHR) predicts abnormal overnight OXI remains unknown. Methods: We performed a retrospective cross-sectional study of 393 men seen in the Executive Health Program at Mayo Clinic in Rochester, Minnesota who underwent ambulatory overnight OXI ordered by preventive medicine physicians between January 1, 2004 through December 31, 2010. We compared participant/spouse-reported symptoms (sleepiness, snoring), physician indications for OXI (obesity, fatigue), Epworth Sleepiness Scale scores, anthropomorphic measurements (WHR, BMI), and comorbid medical conditions (hypertension, diabetes) with OXI results. Results: 295 of the 393 men who completed OXI had abnormal results. During multivariate analysis, the strongest independent predictor of abnormal OXI for men was WHR (≥1.0, OR = 5.59) followed by BMI (≥30.0 kg/m2, OR = 2.75), age (≥55 yrs, OR = 2.06), and the presence of snoring (OR = 1.91, P < 0.05 for all). A strong association was observed between WHR and abnormal OXI in obese (BMI ≥ 30.0 kg/m2, OR = 6.28) and non-obese (BMI < 29.9 kg/m2, OR = 6.42, P < 0.01 for both) men. Furthermore, 88 men with abnormal OXI underwent polysomnography with 91% being subsequently diagnosed with OSA. Conclusions: In ambulatory, predominantly middle-aged men undergoing preventive services evaluation many physician indications for OXI were not predictors of abnormal results; however, WHR strongly predicted abnormal OXI in obese and non-obese men. As such, we suggest middle-aged men who snore and have a WHR ≥1.0 should be directly referred to a sleep clinic for polysomnography.

Different clinical parameters inform epicardial fat thickness in pre- and post-menopausal women with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is a sleep-related disorder with breathing difficulties. Previous studies revealed that epicardial fat thickness (EFT) correlates with OSA severity. Interestingly, female patients display a stronger EFT-OSA correlation than males. The purpose of this study is to investigate the relationship between EFT and different clinical characteristics in pre- and post-menopausal women diagnosed with OSA.

METHODS

Patients diagnosed with OSA were divided into pre/early peri-menopausal (Group 1) and post/late peri-menopausal (Group 2) according to the menopause status. EFT was obtained from parasternal long-axis echocardiographic images. We also collected general clinical characteristics of patients involved in this study, and performed spearman correlation analysis to explore the correlations between EFT and the general clinical characteristics. We further applied Multiple stepwise linear regression analysis to explore the predictors for EFT in both groups.

RESULTS

A total number of 23 and 59 patients were enrolled in Group 1 and Group 2 respectively. EFT in Group 2 was significantly higher than that of Group 1. In both groups, EFT was positively correlated with apnea-hypopnea index (AHI), percentage of total sleep time when blood oxygen saturation was less than 90% (T90), oxygen desaturation index (ODI) and glucose; while EFT was negatively correlated with mean and lowest SaO₂ (oxygen saturation) levels. However, EFT was positively correlated with total cholesterol (TC) only in Group 1 and body mass index (BMI) only in Group2, respectively. Multiple stepwise linear regression analysis showed that AHI was independently associated with EFT in Group 1. However, both AHI and BMI were independent predictors of EFT in Group 2.

CONCLUSION

EFT was notably correlated with menopausal status in women with OSA. AHI was the independent predictor of EFT in women with OSA. BMI was the independent predictor of EFT in post/late peri-menopausal women with OSA.

Time-dependence and comparison of regional and overall anthropometric features between Asian and Caucasian populations with obstructive sleep apnea: a cumulative meta-analysis

Background

Anthropometric measurements are simple and reachable tools for self-evaluating and screening patients with a high risk of obstructive sleep apnea (OSA). However, the accumulated relationship of obesity on the anthropometric characteristics of OSA is not well understood. The aim of the study was to show the time-dependent trend of OSA patients and compare overall and regional anthropometric between two ethnicities.

Methods

A cumulative meta-analysis was performed to assess obesity metrics in patients with and without OSA between Asians and Caucasians. We searched PubMed, Web of Science, Embase, and Scopus up to Jun 2020. Included studies used body mass index (BMI), neck circumference (NC), waist circumference (WC) and waist-to-hip ratio (WHR) as measures of anthropometric features in the adult OSA population and controls, utilized in-lab polysomnography or home sleep testing with apnea-hypopnea index (AHI) or respiratory disturbance index (RDI) classification, reported ethnicity/race, and were published in English. Any studies lacking one of these criteria or sufficient data were excluded.

Results

Forty studies with a total of 19,142 subjects were investigated. Comparison of changes between patients with and without OSA showed that OSA patients had a higher BMI [mean difference (MD) 3.12, 95% confidence interval (CI): 2.51–3.73], NC (MD 3.10, 95% CI: 2.70–3.51), WC (MD 9.84, 95% CI: 8.42–11.26) and waist-hip ratio (MD 0.04, 95% CI: 0.03–0.05) than the control subjects. The accumulated time-dependent increase in population with OSA was significantly apparent with all anthropometric features. BMI increased from 2000 (MD 0.50) to 2012 (MD 3.08–3.48) and remained stable afterwards (MD 2.70–3.17), NC increased from 2000 (MD 0.40) to 2013 (MD 3.09) and remained stable afterwards too (MD 3.06–3.21). WC increased from 2000 (MD 2.00) to 2012 (MD 9.37–10.03) and also remained stable afterwards (MD 8.99–9.84). WHR was stable from 2000 to 2004 with an MD of 0.01 and then stable from 2007 onwards with an increased MD of 0.03–0.04. Compared with Caucasian patients, Asian patients had lower obesity relevant variates.

Conclusions

BMI, NC, WC and WHR are associated with OSA in both ethnic groups. Anthropometry for overall and regional obesity could facilitate differentiation of patients with OSA from individuals without OSA by ethnicity.

Nickel Sensitivity Is Associated with GH-IGF1 Axis Impairment and Pituitary Abnormalities on MRI in Overweight and Obese Subjects

Nickel (Ni) is a ubiquitous metal, the exposure of which is implied in the development of contact dermatitis (nickel allergic contact dermatitis (Ni-ACD)) and Systemic Ni Allergy Syndrome (SNAS), very common among overweight/obese patients. Preclinical studies have linked Ni exposure to abnormal production/release of Growth Hormone (GH), and we previously found an association between Ni-ACD/SNAS and GH-Insulin-like growth factor 1 (IGF1) axis dysregulation in obese individuals, altogether suggesting a role for this metal as a pituitary disruptor. We herein aimed to directly evaluate the pituitary gland in overweight/obese patients with signs/symptoms suggestive of Ni allergy, exploring the link with GH secretion; 859 subjects with overweight/obesity and suspected of Ni allergy underwent Ni patch tests. Among these, 106 were also suspected of GH deficiency (GHD) and underwent dynamic testing as well as magnetic resonance imaging for routine follow up of benign diseases or following GHD diagnosis. We report that subjects with Ni allergies show a greater GH-IGF1 axis impairment, a higher prevalence of Empty Sella (ES), a reduced pituitary volume and a higher normalized T2 pituitary intensity compared to nonallergic ones. We hypothesize that Ni may be detrimental to the pituitary gland, through increased inflammation, thus contributing to GH-IGF1 axis dysregulation.

Metabolic Syndrome and Abnormal Peri-Organ or Intra-Organ Fat (APIFat) Deposition in Chronic Obstructive Pulmonary Disease: An Overview

Chronic obstructive pulmonary disease (COPD) is a common disorder with an increasing prevalence, characterised by persistent respiratory symptoms and airflow limitation. Systemic inflammation is involved in the pathogenesis of COPD and can also predispose to metabolic disorders (e.g., metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD)). Such comorbidities can negatively affect COPD outcomes, cardiovascular risk, and quality of life. Apart from NAFLD, abnormal peri-organ or intra-organ fat (APIFat) could be considered as markers for cardiometabolic diseases and even for COPD. The present narrative review considers the associations of COPD with MetS, NAFLD, and other APIFat, including epicardial, perirenal, peripancreatic, and intramuscular adipose tissue. Further research is needed to define these relationships and identify any potential clinical implications.

Epicardial Adipose Tissue in Patients with Obstructive Sleep Apnea: A Systematic Review and Meta-analysis

Objective: Epicardial adipose tissue (EAT) is a potential risk factor for obstructive sleep apnea (OSA). We performed a meta-analysis to assess the association of EAT with OSA.Methods: The PubMed, EMBASE, Web of Science, Cochrane Library, and Wanfang databases were searched by two independent investigators for all observational studies assessing the association of EAT with OSA. Then we assessed the association of EAT thickness (EAT-t) and EAT volume (EAT-v) with OSA by a meta-analysis.Results: Ten studies were included in the final analysis. Compared with that in controls, EAT-t in OSA patients was significantly increased (standardized mean difference 0.88, 95% confidence interval 0.72‐1.05, P=0.000). Furthermore, EAT-t was greater in OSA patients than in controls with similar BMIs. However, we did not find significant differences in EAT-v between OSA patients and controls (standardized mean difference 2.46, 95% confidence interval −0.36 to 5.29, P=0.088). EAT-t in the mild, moderate, and severe OSA subgroups was greater than in the controls. In addition, there were significant differences in EAT-t among the mild, moderate, and severe OSA subgroups.Conclusions: EAT-t was greater in patients with OSA than in controls, and EAT-t was also associated with the severity of OSA. These findings may provide a new clue for the pathogenesis and treatment of OSA.

Association of epicardial adipose tissues with obstructive sleep apnea and its severity: A meta-analysis study

BACKGROUND AND AIMS

Obstructive sleep apnea (OSA) is a global disease that is a manifestation of metabolic syndrome. Epicardial adipose tissue (EAT), a special type of visceral adipose tissue, has been proposed to be an independent predictor of visceral adiposity. Both OSA and EAT have a close association with diabetes and coronary artery disease. Whether EAT thickness is associated with OSA is controversial.

METHODS AND RESULTS

Several databases were searched from their inception to October 13, 2019. We estimated the summarized weighted mean difference (WMD) with 95% confidence intervals (CIs) for EAT thickness in the OSA and non-OSA groups. Then, we conducted a meta-analysis to evaluate the association between EAT thickness and OSA. The relationship between EAT thickness and OSA severity was also assessed. Nine studies with a total of 1178 participants were included. Globally, patients with OSA had a higher EAT thickness than patients without OSA (WMD = 0.95, 95% CI: 0.73-1.16, P < 0.001). Compared to the non-OSA patients, those with mild, moderate, and severe OSA had a progressively higher EAT thickness (WMD = 0.62, 95% CI: 0.41-0.83; WMD = 0.83, 95% CI: 0.50-1.15; and WMD = 1.06, 95% CI: 0.70-1.43, respectively; all P < 0.001).

CONCLUSION

EAT thickness was shown to be higher in patients with OSA than in patients with non-OSA measured by echocardiography. The increase in the EAT thickness was associated with OSA severity.

Metabolic syndrome - Evidence-based strategies for patient optimization

With the increasing prevalence of obesity worldwide, it is inevitable that anesthesiologists will encounter patients with metabolic syndrome. Metabolic syndrome encompasses multiple diseases, which include central obesity, hypertension, dyslipidemia, and hyperglycemia. Given the involvement of multiple diseases, metabolic syndrome involves numerous complex pathophysiological processes that negatively impact several organ systems. Some of the organ systems that have been well-documented to be adversely affected include the cardiovascular, pulmonary, and endocrine systems. Metabolic syndrome also leads to prolonged hospital stays, increased rates of infections, a greater need for care after discharge, and overall increased healthcare costs. Several interventions have been suggested to mitigate these negative outcomes ranging from lifestyle modifications to surgeries. Therefore, anesthesiologists should understand metabolic syndrome and formulate management strategies that may modify perianesthetic and surgical risks.

Relationship of obstructive sleep apnoea severity and subclinical systemic atherosclerosis

Obstructive sleep apnoea (OSA) is a common form of sleep disordered breathing. Untreated OSA might accelerate atherosclerosis, potentially increasing the cardiovascular disease burden in patients. The present study aimed to evaluate the association between objectively measured OSA severity and the presence of subclinical systemic atherosclerosis using noninvasive measurements, including tomographic quantification of the calcium burden.A total of 2157 participants of the Korean Genome and Epidemiology Study, who were free of structural heart disease and underwent both in-home polysomnography and chest computed tomography, were cross-sectionally analysed. Participants were divided into three groups based on the severity of OSA: no OSA (apnoea-hypopnoea index (AHI) <5 events·h^-1, n=1096), mild OSA (AHI 5- <15 events·h^-1, n=700) and moderate-to-severe OSA (AHI ≥15 events·h^-1, n=361). Calcium deposits in the thoracic aorta and coronary arteries were measured by the Agatston score.Participants with moderate-to-severe OSA were 1.6 times (95% CI 1.18-2.15 times; p=0.002) more likely to have ascending thoracic aorta calcification (≥100 units) than those without OSA, after adjustment for cardiovascular risk factors. In addition, the association between moderate-to-severe OSA and ascending thoracic aorta calcification of subjects with higher epicardial fat volume was slightly stronger than that in patients without OSA and in the lowest epicardial fat volume tertile (OR 2.11, 95% CI 1.30-3.43).Severity of OSA in the general population was independently associated with subclinical systemic atherosclerosis. These findings highlight the potential importance of severe OSA, especially in subjects with higher epicardial fat, as a possible predictive factor for systemic atherosclerosis and cardiovascular disease.

Left ventricular remodeling and dysfunction in obstructive sleep apnea : Systematic review and meta-analysis

Background

Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular mortality and morbidity. Several studies have reported that it affects the left ventricle; however, large randomized controlled trials are lacking. The current study aimed to summarize the association between OSAS and left ventricular (LV) structure and function.

Methods

Electronic databases (PubMed, Embase, and Cochrane) and references were searched for articles published until March 2018. A systematic review and meta-analysis were performed to assess LV structure and function in OSAS patients based on echocardiography.

Results

In total, 17 studies with 747 OSAS patients and 426 control participants were included. Patients with OSAS showed an increase in LV diastolic diameter (weighted mean difference [WMD], 95% CI: 1.24 [0.68, 1.80]; p < 0.001), LV systolic diameter (WMD, 95% CI: 1.14 [0.47, 1.81]; p = 0.001), and LV mass (WMD, 95% CI: 35.34 [20.67, 50.00]; p < 0.001). In addition, left ventricular ejection fraction (LVEF) significantly decreased in the OSAS group compared with the controls (WMD, 95% CIs: −1.82 [−2.76, −0.87]; p < 0.001), and the reduction in LVEF was consistent with the severity of OSAS. The OSAS group also showed an increase in left atrial diameter (WMD, 95% CI: 2.13 [1.48, 2.77]; p < 0.001) and left atrial diameter volume index (WMD, 95% CIs: 3.96 [3.32, 4.61]; p < 0.001).

Conclusion

Obstructive sleep apnea syndrome leads to atrial dilatation, left ventricular hypertrophy, enlargement, mass increase and reduction of systolic function. Treatments for OSAS might be beneficial for the preservation of left cardiac structure and function.

Electronic supplementary material

The online version of this article (10.1007/s00059-019-04850-w) contains supplementary material, which is available to authorized users.

Serum Uric Acid Is Independently Associated with Risk of Obstructive Sleep Apnea-Hypopnea Syndrome in Chinese Patients with Type 2 Diabetes

Purpose

We aimed to investigate the association between serum uric acid (SUA) levels and obstructive sleep apnea-hypopnea syndrome (OSAHS) in patients with type 2 diabetes.

Methods

A cross-sectional study of 212 type 2 diabetes mellitus (T2DM) patients was conducted in Xiamen, China. All patients underwent polysomnography (PSG) recordings for OSAHS diagnosis. Patients were grouped according to the apnea-hypopnea index (AHI) as mild (5-14.9), moderate (15-29.9), and severe (≧30) OSAHS. Patients with AHI ≤ 4.9 served as the control group. Weight, body mass index (BMI), SUA, liver function, renal function, blood pressure, lipid profiles, and glycemic parameters were measured.

Results

A total of 158 patients (101 men and 57 women) with complete data were analyzed in this study. 127 patients were identified as OSAHS. Among the 127 patients with OSAHS, 56 (44.1%), 37 (29.1%), and 34 (26.8%) had mild, moderate, and severe OSAHS, respectively. Correlation analyses showed that the SUA level was significantly related to the apnea-hypopnea index (AHI) (r = 0.194, p = 0.016). The level of SUA was significantly higher among OSAHS patients compared to the control group (control group: 333.14 ± 80.52 μmol/L, mild group: 345.50 ± 90.27 μmol/L, moderate group: 363.59 ± 134.26 μmol/L, and severe group: 428.37 ± 123.58 μmol/L and p = 0.029). Multivariable logistic regression analyses showed that SUA was the independent risk factor for OSAHS (OR: 1.006, 95% CI: 1.001-1.011, p = 0.020).

Conclusions

The SUA level is significantly associated with the severity of OSAHS and should be controlled when managing OSAHS.

Anthropometric Factors in the Assessment of Obstructive Sleep Apnea Risk in Patients with Metabolic Syndrome

Metabolic syndrome (MetS) and obstructive sleep apnea (OSA) are related to a higher incidence of cardio-vascular diseases and mortality in patients. The aim of the study was to define the potential use of anthropometric factors for the evaluation of OSA risk in patients with diagnosed MetS. The patient group consisted of 50 obese men with MetS (mean age 49 ± 9 years). The following anthropometric indices were assessed: body mass index (BMI), neck circumference (NC), waist circumference (WC), and waist-to-hip ratio (WHR). In addition, blood glucose and lipid profile were investigated. On the basis of polysomnography, clinical symptoms, and Epworth Sleep Scale, patients were stratified into the OSA group accompanied by MetS (n = 31) and the MetS alone group taken as control (n = 19). OSA was evaluated as severe in 26 out of the 31 patients (>30 apneic episodes per hour). We found a significantly larger NC in the OSA with MetS group then that in the MetS alone group. Further, NC associated with the increase in the apnea/hypopnea index. However, the other anthropometric indices investigated failed to differentiate the two groups. We conclude that increased neck circumference in patients suffering from metabolic syndrome is a risk factor for the development of OSA.

Obstructive sleep apnea and the metabolic syndrome: The road to clinically-meaningful phenotyping, improved prognosis, and personalized treatment

Obstructive sleep apnea (OSA) is an increasingly prevalent sleep disorder characterized by upper airway obstruction during sleep, resulting in breathing pauses, intermittent hypoxia, and fragmented sleep. In parallel, the constellation of adverse health outcomes associated with prolonged obesity, such as insulin resistance, elevated blood pressure, triglycerides, and reduced high-density lipoprotein cholesterol - termed metabolic syndrome -raises the risk of cardiovascular morbidity and mortality, type 2 diabetes, and all-cause mortality. Affecting 35-40% of U.S. adults, risk factors for metabolic syndrome, including obesity, middle age, sedentary behavior, and genetics, share considerable overlap with those for OSA. Thus, it has been difficult to disentangle cause, effect, and whether certain treatments, such as CPAP, can improve these outcomes. In this paper, we provide an update to our 2005 review which explored the association between OSA and metabolic syndrome, highlighting visceral obesity as the common etiological factor of both conditions. This update includes (a) recent data on physiological and biochemical mechanisms, (b) new data in nonobese men and women as well as children and adolescents, (c) insight from the latest treatment studies, (d) the role of aging in understanding clinically-meaningful phenotypes of the disorder, and (e) the potential diagnostic/prognostic utility of biomarkers in identifying OSA patients with the strongest cardiometabolic risk.

Association of epicardial fat thickness with clinical and polysomnographic parameters in non-obese obstructive sleep apnoea patients

OBJECTIVES

This study aimed to investigate the relationship of epicardial fat thickness with severity of obstructive sleep apnoea, and clinical and polysomnographic parameters, and to determine independent predictors for epicardial fat thickness.

METHODS

A total of 84 patients with a body mass index of less than 30 kg/m2 and suspected sleep-disordered breathing were included in the study. The correlations of epicardial fat thickness with polysomnographic and clinical data, and severity of obstructive sleep apnoea, were investigated.

RESULTS

Mean epicardial fat thickness was 3.75 ± 1.07 mm in the study group (n = 62) and 2.97 ± 0.62 mm in the control group (n = 22) (p < 0.001). There were significant positive correlations between epicardial fat thickness and: apnoea/hypopnoea index, oxygen desaturation index 3 and minimum oxygen saturation, as well as with age, body mass index, and neck and waist circumferences.

CONCLUSION

Non-obese obstructive sleep apnoea patients have thicker epicardial fat compared to controls. Oxygen desaturation index 3 has a strong correlation with epicardial fat thickness and is an independent predictor of it.

Circadian Impairment of Distal Skin Temperature Rhythm in Patients With Sleep-Disordered Breathing: The Effect of CPAP

Study objectives

Our aim was to evaluate the circadian rhythm of distal skin temperature (DST) in sleep-disordered breathing (SDB), its relation to excessive daytime sleepiness and the effect of continuous positive airway pressure (CPAP) on DST.

Methods

Eighty SDB patients (53.1 ± 1.2 years old, 27.6% women) and 67 healthy participants (52.3 ± 1.6 years old, 26.9% women) wore a temperature data logger for 1 week. On the last day of that week, SDB patients underwent a polysomnography followed by a Maintenance of Wakefulness Test (MWT), Multiple Sleep Latency Test, and Sustained Attention to Response Task protocol to objectively quantify daytime sleepiness. A subset of 21 moderate to severe SDB patients were treated with CPAP during at least 3 months and revaluated with the same procedure. A nonparametric analysis was performed to characterize DST to assess differences between groups and associations among DST, polysomnography, and daytime sleepiness measures.

Results

SDB patients showed an unstable, fragmented, flattened, phase-advanced, and less robust DST rhythm as compared to healthy participants. The more severe the SDB, the worse the DST pattern was, as indicated by the correlation coefficient. Sleepiness, according to MWT sleep latencies, was also associated with the higher fragmentation, lower amplitude, and less robustness of the DST rhythm. Treatment with CPAP improved DST pattern regularity and robustness.

Conclusion

DST is altered in SDB, exhibiting a direct relationship to the severity of this condition, and improves with CPAP treatment. DST independently correlates with sleepiness, thus, its measurement may contribute to the understanding of the pathophysiology of sleepiness in these patients.

Sleep-disordered breathing and epicardial adipose tissue in patients with heart failure

BACKGROUND AND AIMS

Sleep-disordered breathing (SDB) is common in patients with heart failure (HF), contributes to the progression of cardiac disease, and is associated with adverse prognosis. Previous evidence indicates that epicardial adipose tissue (EAT) is independently associated with sleep apnea in obese individuals. We explored the relationship between SDB and EAT in HF patients.

METHODS AND RESULTS

EAT thickness was assessed by echocardiography in 66 patients with systolic HF undergoing nocturnal cardiorespiratory monitoring. A significantly higher EAT thickness was found in patients with SDB than in those without SDB (10.7 ± 2.8 mm vs. 8.3 ± 1.8 mm; p = 0.001). Among SDB patients, higher EAT thickness was found in both those with prevalent obstructive sleep apnea (OSA) and those with prevalent central sleep apnea (CSA). Of interest, EAT thickness was significantly higher in CSA than in OSA patients (11.9 ± 2.9 vs. 10.1 ± 2.5 p = 0.022). Circulating plasma norepinephrine levels were higher in CSA than in OSA patients (2.19 ± 1.25 vs. 1.22 ± 0.92 ng/ml, p = 0.019). According to the apnea-hypopnea index (AHI), patients were then stratified in three groups of SDB severity: Group 1, mild SDB; Group 2, moderate SDB; Group 3, severe SDB. EAT thickness progressively and significantly increased from Group 1 to Group 3 (ANOVA p < 0.001). At univariate analysis, only left ventricular ejection fraction and AHI significantly correlated with EAT (p = 0.019 and p < 0.0001, respectively). At multivariate analysis, AHI was the only independent predictor of EAT (β = 0.552, p < 0.001).

CONCLUSIONS

Our results suggest an association between the presence and severity of sleep apneas and cardiac visceral adiposity in HF patients.

Circulating SIRT1 Increases After Intragastric Balloon Fat Loss in Obese Patients

BACKGROUND

Sirtuins (SIRTs), ubiquitous deacetylases, are main regulators of energy homeostasis and metabolism. SIRT1 has a positive impact on obesity, diabetes mellitus, liver steatosis, and other metabolic disorders. Lean subjects have higher expression of SIRT1 in the adipose tissue compared to obese. However, it is not known whether weight loss associates with changes in blood SIRT1. We evaluated the effect of weight loss on circulating SIRT1, metabolic parameters, and body composition.

METHODS

Thirty-two obese subjects were studied before and 6 months after BioEnterics® Intragastric Balloon (BIB®) [22 patients, BMI 41.82 ± 6.28 kg/m(2)] or hypocaloric diet [10 patients, BMI 38.95 ± 6.90 kg/m(2)]. Plasma SIRT1, body composition, measures of metabolic syndrome (waist circumference, fasting plasma glucose, blood pressure, HDL cholesterol, triglycerides), and inflammation markers (ESR, CRP, fibrinogen) were recorded.

RESULTS

SIRT1 levels showed a significant increase, together with a significant reduction of BMI, excess body weight, and total fat mass either after BIB or diet intervention. The percent excess body weight loss was 33.73 ± 19.06 and 22.08 ± 11.62 % after BIB and diet, respectively, a trend toward a metabolic and inflammatory amelioration was observed with both treatments. Negative correlation between SIRT1 and % fat mass (BIB, ρ = -0.537, p = 0.017; diet, ρ = -0.638, p = 0.047) was also seen.

CONCLUSIONS

The reduction of fat mass associates with increased plasma SIRT1 indicating that, besides tissue levels, circulating SIRT1 is stimulated by a negative caloric balance. The rise of plasma SIRT1 may represent a parameter associating with fat loss rather than weight lowering regardless of the weight reduction system method used.

Role of Epicardial Adipose Tissue in Health and Disease: A Matter of Fat?

Epicardial adipose tissue (EAT) is a small but very biologically active ectopic fat depot that surrounds the heart. Given its rapid metabolism, thermogenic capacity, unique transcriptome, secretory profile, and simply measurability, epicardial fat has drawn increasing attention among researchers attempting to elucidate its putative role in health and cardiovascular diseases. The cellular crosstalk between epicardial adipocytes and cells of the vascular wall or myocytes is high and suggests a local role for this tissue. The balance between protective and proinflammatory/profibrotic cytokines, chemokines, and adipokines released by EAT seem to be a key element in atherogenesis and could represent a future therapeutic target. EAT amount has been found to predict clinical coronary outcomes. EAT can also modulate cardiac structure and function. Its amount has been associated with atrial fibrillation, coronary artery disease, and sleep apnea syndrome. Conversely, a beiging fat profile of EAT has been identified. In this review, we describe the current state of knowledge regarding the anatomy, physiology and pathophysiological role of EAT, and the factors more globally leading to ectopic fat development. We will also highlight the most recent findings on the origin of this ectopic tissue, and its association with cardiac diseases. © 2017 American Physiological Society. Compr Physiol 7:1051-1082, 2017.

Pharyngeal constrictor muscle fatty change may contribute to obstructive sleep apnea-hypopnea syndrome: a prospective observational study

CONCLUSIONS

Pharyngeal constrictor muscle injury and fatty changes may play important roles in the pathogenesis and progression of OSAHS.

OBJECTIVE

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a respiratory disorder caused by upper airway obstruction during sleep. The primary objectives of this study were to determine the ultrastructural characteristics of the pharyngeal constrictor muscle in patients with OSAHS.

METHODS

A pharyngeal constrictor muscle specimen was collected from all subjects. The muscle cell ultrastructure was observed under electron microscopy.

RESULTS

Eighteen male patients with OSAHS (OSAHS group) and 10 male body mass index-matched patients with chronic tonsillitis (control group) were enrolled in this study. All patients were obese adults. The apnea-hypopnea index (41.22 ± 17.29 vs 2.30 ± 1.10 events/h) was significantly higher and the lowest arterial oxygen saturation (76.00 ± 8.57% vs 97.00 ± 2.00%) was significantly lower in the OSAHS group than in the control group (both p < 0.001). Myofibril disorder, mitochondrial edema, and intramyocellular lipid droplets were observed in patients with OSAHS. There was a significant correlation between the number of lipid droplets and the apnea-hypopnea index.

Perfis metabólico e nutricional como preditores da síndrome da apneia obstrutiva do sono

RESUMO Objetivo: Correlacionar os perfis metabólico e nutricional com a presença e gravidade da síndrome da apneia obstrutiva do sono. Métodos: Estudo transversal com pacientes adultos e idosos, de ambos os sexos, atendidos no Laboratório do Sono e Coração do Pronto Socorro Cardiológico Universitário de Pernambuco, entre junho e setembro de 2014. Os pacientes se submeteram à polissonografia, à bioimpedância elétrica e a aferições antropométricas. Foram verificadas a presença da síndrome metabólica e outras morbidades. Resultados: A amostra total foi constituída por 50 pacientes, com idade média de 57,52±9,80 anos, sendo que 94% receberam diagnóstico de síndrome da apneia obstrutiva do sono e 74% possuíam síndrome metabólica. As seguintes médias foram obtidas: índice de massa corporal (31,54±5,82 kg/m2); circunferência do pescoço (39,14±4,33 cm); circunferência da cintura (106,72±11,22 cm); diâmetro abdominal sagital (23,00 cm [21,00-24,00]). O índice de massa corporal, a circunferência da cintura e o diâmetro abdominal sagital apresentaram valores mais elevados (p<0,05) entre os pacientes com síndrome da apneia obstrutiva do sono grave, quando comparados aqueles com a forma leve. O diâmetro abdominal sagital apresentou moderada correlação com o índice de apneia e hipopneia e a gordura corporal apresentou fraca correlação. Conclusão: A obesidade, a circunferência do pescoço, o diâmetro abdominal sagital e a síndrome metabólica tiveram associação positiva com a gravidade da síndrome da apneia obstrutiva do sono. Dentre os parâmetros antropométricos avaliados, o diâmetro abdominal sagital mostrou ser o mais adequado preditor para avaliar a presença e gravidade da síndrome da apneia obstrutiva do sono.

Hypoxia Promotes the Inflammatory Response and Stemness Features in Visceral Fat Stem Cells From Obese Subjects

Low-grade chronic inflammation is a salient feature of obesity and many associated disorders. This condition frequently occurs in central obesity and is connected to alterations of the visceral adipose tissue (AT) microenvironment. Understanding how obesity is related to inflammation may allow the development of therapeutics aimed at improving metabolic parameters in obese patients. To achieve this aim, we compared the features of two subpopulations of adipose-derived stem cells (ASC) isolated from both subcutaneous and visceral AT of obese patients with the features of two subpopulations of ASC from the same isolation sites of non-obese individuals. In particular, the behavior of ASC of obese versus non-obese subjects during hypoxia, which occurs in obese AT and is an inducer of the inflammatory response, was evaluated. Obesity deeply influenced ASC from visceral AT (obV-ASC); these cells appeared to exhibit clearly distinguishable morphology and ultrastructure as well as reduced proliferation, clonogenicity and expression of stemness, differentiation and inflammation-related genes. These cells also exhibited a deregulated response to hypoxia, which induced strong tissue-specific NF-kB activation and an NF-kB-mediated increase in inflammatory and fibrogenic responses. Moreover, obV-ASC, which showed a less stem-like phenotype, recovered stemness features after hypoxia. Our findings demonstrated the peculiar behavior of obV-ASC, their influence on the obese visceral AT microenvironment and the therapeutic potential of NF-kB inhibitors. These novel findings suggest that the deregulated hyper-responsiveness to hypoxic stimulus of ASC from visceral AT of obese subjects may contribute via paracrine mechanisms to low-grade chronic inflammation, which has been implicated in obesity-related morbidity.

Epicardial fat thickness regression with continuous positive airway pressure therapy in patients with obstructive sleep apnea: assessment by two-dimensional echocardiography

BACKGROUND

Obstructive sleep apnea (OSA) is a common syndrome in patients with metabolic syndrome (MetS). Epicardial fat thickness (EFT), an indicator of visceral adiposity, is a novel parameter for studying patients with OSA. Our aim was to investigate the effects of continuous positive airway pressure therapy (CPAP) therapy on EFT.

METHODS

A total of 162 subjects (68 women and 94 men) were included and divided into three groups: Group I: Apnea-hypopnea index (AHI) < 5 (n  = 45), Group II: AHI 5-15 (n  = 22), and Group III: AHI > 15 (n  = 95). All participants underwent full-night polysomnography and transthoracic echocardiography. There were 28 symptomatic patients with AHI > 15 who received compliant CPAP therapy for 24 weeks.

RESULTS

MetS was more frequent, and systolic blood pressure (SBP), diastolic blood pressure (DBP), blood glucose were higher in Group III compared with I (p  < 0.05). High-density lipoprotein (HDL) levels were lower in Group III compared with I (p < 0.05). Triglyceride levels and waist circumference were higher in Group III compared with I and II (p  < 0.05). EFT was higher in Group III compared with I and higher in Group II compared with I (p < 0.05). EFT was predicted by MetS and AHI. After CPAP therapy high-sensitive C-reactive protein (hsCRP) and EFT were reduced (p < 0.05).

CONCLUSION

EFT was significantly higher in patients with AHI > 15 and predicted by MetS and AHI. CPAP therapy reduced hsCRP levels and EFT.

Comparison of Anthropometric Data Between Asian and Caucasian Patients With Obstructive Sleep Apnea: A Meta-Analysis

Objectives

Obesity is considered to be one of the most important risk factors for obstructive sleep apnea (OSA) but less is known about the role of ethnicity in OSA. The purpose of this study was to investigate the interethnic difference of obesity-related phenotypes in OSA and to reveal the role of ethnicity in OSA.

Methods

We searched MEDLINE, LILACS, Scopus, and the Cochrane Library using the key words “sleep apnea,” “body mass index,” “neck circumference,” “waist circumference,” “waist to hip ratio,” etc. Inclusion criteria were adults over 18 years of age, and studies that included polysomnography, obesity-related parameters, and a clear demarcation of ethnicity in the patient population. Included studies were reviewed by 2 independent reviewers. The following information was collected for controls and OSA: number, age, gender, country, ethnicity (Asian or Caucasian), study design, apnea-hypopnea index/respiratory disturbance index, body mass index (BMI), neck circumference (NC), waist circumference (WC), and/or waist to hip ratio (WHR).

Results

A total of 8,312 publications were retrieved with a subsequent 19 manuscripts that met the selection criteria. A total of 2,966 patients were included for analysis. The main findings were as follows: There was no difference in BMI, WC, and WHR between patients with OSA and controls after accounting for publication bias; Patients with OSA have greater NC than controls (standard mean difference, 0.89; 95% confidence interval, 0.63 to 1.14); and There was no difference in NC between Asian and Caucasians patients (P=0.178).

Conclusion

OSA might not be related with BMI, WC, and WHR. Only NC demonstrated a strong association with OSA, and this finding was not different between Asians and Caucasians.

CPAP therapy induces favorable short-term changes in epicardial fat thickness and vascular and metabolic markers in apparently healthy subjects with obstructive sleep apnea-hypopnea syndrome (OSAHS)

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is an independent risk factor for hypertension, coronary artery disease, and diabetes mellitus. Epicardial fat has been recently recognized as a new risk factor and active participant on cardiometabolic risk. The aim of this study was to assess an independent relationship between sleep apnea severity, metabolic and vascular markers, and epicardial fat, at baseline and after 3 months of continuous positive airway pressure (CPAP) therapy.

MATERIALS AND METHOD

Our study group consisted of 48 patients with suspected OSAHS and no prior history of cardiovascular disease or diabetes mellitus. All patients underwent full overnight polysomnography. Thickness of epicardial and visceral adipose tissue, brachial artery flow-mediated dilation (FMD), carotid intima media thickness (cIMT), pulse wave velocity (PWV), plasma C-reactive protein (CRP) levels, fasting glucose levels, HbA1c, homeostatic model assessment of insulin resistance index (HOMA), and lipid profile were measured at baseline and after 3 months of CPAP use in patients with moderate to severe OSAHS.

RESULTS

In OSAHS patients (Apnea-hypopnea index (AHI) ≥15/h, N = 28), epicardial fat correlated with fasting glucose (rho = 0.406, p = 0.04) and HOMA (rho = 0.525, p = 0.049) but was not associated with visceral fat (rho = 0.126, p = 0.595). Epicardial adipose tissue (EAT) (p = 0.022) increased across AHI severity along with PWV (p = 0.045) and carotid intima media thickness (IMT) (p = 0.034) while FMD (p = 0.017) decreased. Therapy with CPAP reduced both epicardial (p < 0.001) and visceral fat (p = 0.001). Alterations in epicardial fat across the follow-up were associated with changes in PWV (p = 0.026) and HOMA (p = 0.037) independently of major confounders.

CONCLUSIONS

Epicardial fat thickness was associated with OSA severity and may be an additional marker of cardiovascular risk as well as of future diabetes in these patients. CPAP therapy reduced epicardial fat, suggesting its potentially beneficial role in reducing cardiometabolic risk in OSA patients.

Severe growth hormone deficiency and empty sella in obesity: a cross-sectional study

Obesity is associated with blunted growth hormone (GH) secretion. In some individuals, hypothalamic-pituitary (HP) structural lesions may contribute to GH deficiency (GHD). We explored pituitary morphology in obese patients with suspected GHD and its association with cardiovascular risk factors, body composition, and cardiac morphology. One hundred and eighty-four adults obese patients with symptoms and signs of GHD (147 females and 37 males; mean age 46.31 ± 12.11 years), out of 906 consecutive white obese outpatients, were evaluated. The main measures were anthropometric data, blood pressure, lipid profile, glycemic parameters, pituitary hormones, and insulin-like growth factor-1 values, echocardiography, magnetic resonance imaging (MRI) of the HP region, body composition, and growth hormone-releasing hormone plus arginine test. Seventy patients had GHD (GH peak values <4.2 μg/mL). GHD patients showed significantly higher body mass index and fat mass, lower lumbar bone mineral density, increased left ventricular mass index, and epicardial fat thickness. The MRI of the HP region showed empty sella (ES) in 69 and normal pituitary in one of the 70 GHD patients; the 114 patients with normal GH response had ES (n = 62, 54 %), normal pituitary (n = 37, 32 %), microadenomas (n = 10, 8 %), and other pituitary abnormalities (n = 5, 4 %). ES was a significant independent predictor of GH secretory capacity as determined by multiple regression analysis. The close relationship between ES and GH secretory capacity points out to the possibility of the organic nature of GHD in a portion of obese individuals and opens a new scenario with regard to the potential of GH treatment on metabolic consequences of obesity.

The associations between cardiometabolic risk factors and visceral fat measured by a new dual-energy X-ray absorptiometry-derived method in lean healthy Caucasian women

Excess visceral adipose tissue (VAT) is associated with a cluster of metabolic abnormalities. A new dual-energy X-ray absorptiometry (DXA)-based VAT measurement approach, CoreScan™, computes VAT mass and volume within the android region of a total body DXA scan. However, there have been no reference values developed for this method. The objective of this study was to determine the normal reference ranges for DXA-derived VAT in young, healthy, premenopausal women. We also sought associations between VAT, blood lipids, glucose, insulin and insulin resistance. In 120 randomly selected, normal weight, Caucasian women aged 20-40 years, we measured body fat (BF), VAT and lean mass by DXA. We also assessed blood pressure, waist and hip circumference, waist-to-hip ratio, body mass index, fasting glucose, insulin, triglycerides (TG), and high- (HDL) and low-density lipoproteins. Insulin resistance was evaluated by the homeostasis model assessment (HOMA). VAT mass accounted for 0.37 ± 0.3 % of weight and 1.11 ± 0.72 % of BF. Mean VAT mass and volume were 235.9 ± 183 g (95 % CI 202.7-269.1) and 250.3 ± 194.5 cm(3) (95 % CI 215.1-285.4), respectively. Anthropometric indices moderately correlated with VAT. VAT significantly correlated with HDL (R = -0.193; P = 0.03), glucose (R = 0.252; P = 0.005) and HOMA (R = 0.184; P = 0.049). In this study, we provide normal values of VAT mass and volume measured by DXA and determined for healthy, normal weight, Caucasian women aged 20-40 years. Even in such strictly selected population VAT correlated positively with insulin resistance and inversely with HDL.

Early major medical complications after surgical management of obstructive sleep apnea: a retrospective cohort analysis and case series

PURPOSE

The purpose of this study was to determine the frequency and relative risk (RR) of early postoperative major medical complications after surgery for the management of obstructive sleep apnea.

PATIENTS AND METHODS

This was a retrospective cohort analysis of patients who had undergone surgery for the treatment of polysomnogram-confirmed obstructive sleep apnea at 2 hospitals in Pittsburgh, PA, between 1992 and 2013. Early postoperative major medical complications were defined as either a life-threatening complication requiring intensive care unit intervention or death within the immediate hospital course. Standard demographic data, apnea-hypopnea index, Epworth Sleepiness Score, minimum nocturnal oxygen saturation, and body mass index were collected. The 2-tailed independent t test, Fisher exact test, and RR with 95% confidence interval were used.

RESULTS

A total of 267 consecutive patients who underwent surgery for obstructive sleep apnea and met the inclusion criteria were included in this study. A total of 6 patients (6 of 267, 2.2%) had early major medical postoperative complications. When stratified by surgical group (intrapharyngeal vs extrapharyngeal), there were 162 intrapharyngeal patients with 2 complications (1.2%) and 105 extrapharyngeal patients with 4 complications (3.8%). We found no statistically significant difference in frequency (2 of 162 intrapharyngeal patients [1.2%] vs 4 of 105 extrapharyngeal patients [3.8%], P = .17) or RR (3.1; 95% confidence interval, 0.58 to 16.55; P = .1885) between the groups. There were statistically significant differences for mean age, apnea-hypopnea index, Epworth Sleepiness Score, minimum nocturnal oxygen saturation, and body mass index between the surgical groups.

CONCLUSIONS

The overall frequency of early major medical postoperative complications in upper airway surgery for obstructive sleep apnea is low, with no statistically significant difference in frequency and RR between intrapharyngeal and extrapharyngeal surgery. There may, however, be a clinically significance difference in RR possibly because of associated differences in risk factors between the groups.

Impact of lifestyle on metabolic syndrome in apparently healthy people

Parallel to the increase in obesity, the prevalence of metabolic syndrome (MetS) is continually increasing, with increased risk of diabetes and cardiovascular atherosclerosis diseases. Despite the importance of this public health problem, the relative impact of diet and physical activity on MetS prevalence has yet to be established. We investigated the association between lifestyle, in terms of both habitual dietary pattern and physical activity, and MetS in a cohort of adults without known diabetes and atherosclerotic cardiovascular disease. Four hundred seventy-seven randomly selected adult participants were cross-sectionally investigated. Each participant answered a food frequency questionnaire and a questionnaire on physical activity, and underwent routine laboratory blood measurements. MetS was identified in 24.7% of the cohort. Dietary patterns were not significantly different (P = 0.31) between the groups (with or without MetS). The habitual physical activity level was significantly lower (P = 0.011) in the group with MetS. In particular, the prevalence of sedentary participants was 58.1% in the group with MetS, and 43.9% in the group without MetS. Multivariate analysis revealed that MetS was associated with age (OR = 1.06, 95% CI 1.03-1.08) and physical activity level (light vs. sedentary: OR = 0.53, 95% CI 0.32-0.87; moderate/heavy vs. sedentary: OR = 0.31, 95% CI 0.13-0.75). This study suggests that inadequate physical activity level is associated with MetS. Our results are therefore consonant with the notion of healthier lifestyle changes to counteract the epidemic of diabetes and cardiovascular disease, though adequate interventional trials will be needed in high-risk populations.

The link between sleep disturbance and depression among Mexican Americans: a Project FRONTIER study

OBJECTIVE

To examine the link between disturbed sleep and depression scores in Mexican Americans and non-Hispanic Whites.

METHODS

Data were analyzed for 566 participants (45% Mexican Americans) who were part of a rural healthcare study, Project FRONTIER. Mean age was 55.5 years for Mexican Americans (70% female) and 65.6 years for non-Hispanic Whites (69% female). Self-reported sleep disturbance was entered as the predictor, GDS-30 total and factor scores as the outcome variables, and age, sex, education, BMI, and medical diagnoses (hyperlipidemia, diabetes mellitus, and hypertension) entered as covariates.

RESULTS

Mexican Americans reported higher rates of sleep disturbances (25%) than non-Hispanic whites (17%). Sleep disturbances were significantly associated with GDS-30 total scores and the factors Dysphoria and Cognitive Impairment in both Mexican Americans and non-Hispanic whites.

CONCLUSIONS

In this study, Mexican Americans reported higher rates of sleep disturbances than non-Hispanic whites. Disturbed sleep was positively associated with depression and the factor scores for Dysphoria and Cognitive Impairment in both groups. Given the paucity of research on sleep disorders in Mexican Americans, identifying what sleep disorders are present and the impact treating these sleep disorders have on depression warrant further investigation.

Epicardial fat and vascular risk: a narrative review

PURPOSE OF REVIEW

We comment on the associations between epicardial adiposity and cardiovascular disease (CVD) and associated risk factors. The effects of lifestyle measures and CVD drugs on cardiac adipose tissue are also discussed.

RECENT FINDINGS

Epicardial adipose tissue exerts cardioprotective properties; however, in cases of pathological enlargement, epicardial fat can lead to myocardial inflammation and dysfunction as well as left ventricular hypertrophy and coronary artery disease (CAD) due to paracrine actions that include increased production of reactive oxygen species, atherogenic and inflammatory cytokines. Cardiac adiposity is associated with CAD, obesity, type 2 diabetes, metabolic syndrome, nonalcoholic fatty liver disease, and chronic kidney disease, as well as with CVD risk factors such as lipids, hypertension, obesity markers, and carotid atherosclerosis.

SUMMARY

Due to its anatomical and functional proximity to the coronary circulation, epicardial adipose tissue may represent an even more direct CVD risk marker than central adiposity. Lifestyle measures and certain drugs may affect its thickness, although there are limited data currently available. The clinical implications of epicardial fat in daily practice remain to be established in future studies.