Machine learning allows robust classification of visceral fat in women with obesity using common laboratory metrics.

The excessive accumulation and malfunctioning of visceral adipose tissue (VAT) is a major determinant of increased risk of obesity-related comorbidities. Thus, risk stratification of people living with obesity according to their amount of VAT is of clinical interest. Currently, the most common VAT measurement methods include mathematical formulae based on anthropometric dimensions, often biased by human measurement errors, bio-impedance, and image techniques such as X-ray absorptiometry (DXA) analysis, which requires specialized equipment. However, previous studies showed the possibility of classifying people living with obesity according to their VAT through blood chemical concentrations by applying machine learning techniques. In addition, most of the efforts were spent on men living with obesity while little was done for women. Therefore, this study aims to compare the performance of the multilinear regression model (MLR) in estimating VAT and six different supervised machine learning classifiers, including logistic regression (LR), support vector machine and decision tree-based models, to categorize 149 women living with obesity. For clustering, the study population was categorized into classes 0, 1, and 2 according to their VAT and the accuracy of each MLR and classification model was evaluated using DXA-data (DXAdata), blood chemical concentrations (BLDdata), and both DXAdata and BLDdata together (ALLdata). Estimation error and R 2 were computed for MLR, while receiver operating characteristic (ROC) and precision-recall curves (PR) area under the curve (AUC) were used to assess the performance of every classification model. MLR models showed a poor ability to estimate VAT with mean absolute error ≥ 401.40 and R 2 ≤ 0.62 in all the datasets. The highest accuracy was found for LR with values of 0.57, 0.63, and 0.53 for ALLdata, DXAdata, and BLDdata, respectively. The ROC AUC showed a poor ability of both ALLdata and DXAdata to distinguish class 1 from classes 0 and 2 (AUC = 0.31, 0.71, and 0.85, respectively) as also confirmed by PR (AUC = 0.24, 0.57, and 0.73, respectively). However, improved performances were obtained when applying LR model to BLDdata (ROC AUC ≥ 0.61 and PR AUC ≥ 0.42), especially for class 1. These results seem to suggest that, while a direct and reliable estimation of VAT was not possible in our cohort, blood sample-derived information can robustly classify women living with obesity by machine learning-based classifiers, a fact that could benefit the clinical practice, especially in those health centres where medical imaging devices are not available. Nonetheless, these promising findings should be further validated over a larger population.

Sex and age significantly modulate cardiovascular disease presentation in type 2 diabetes: a large population-based cohort study.

Aims: We aimed to describe and compare the incidence of the first cardiovascular event and its major subtypes, coronary heart disease (CHD), cerebrovascular disease, heart failure (HF), or peripheral artery disease (PAD), according to age and sex in a population-based cohort of individuals with type 2 diabetes (T2D) from a Mediterranean region. Material and methods: We used linked primary care electronic medical reports, pharmacy-invoicing data, and hospital admission disease registry records from the SIDIAP database, which contains linked data for 74% of the Catalonian population. We selected individuals with T2D aged 30 to 89 years free of cardiovascular disease (CVD). The primary outcome was the first presentation of CVD. Results: The study cohort included 247,751 individuals (48.6% women, 66.8 ± 11.9 years). During a 6.99-year follow-up, the cumulative incidence of the first cardiovascular event was 23.4%. Men were at higher risk for CVD (hazard ratio [HR]: 1.47 95%CI: 1.45-1.50), CHD (HR: 1.52 95%CI: 1.47-1.57), cerebrovascular disease (HR:1.07 95%CI: 1.03-1.10) and PAD (HR: 2.30 95%CI: 2.21-2.39) than women but at a lower risk for HF (HR:0.70 95%CI: 0.68-0.73). CHD and PAD were the most frequent CVD presentations among men (28.1% and 27.5%) and HF (40.1%) in women. CHD predominated among young participants of both sexes, while HF predominated among women older than 65 and men older than 75. Conclusions: In individuals with T2D, the overall risk and the type of first CVD manifestation largely varied by sex and age. This epidemiological evidence should be considered in clinical practice.

Hypothalamic Inflammation Improves Through Bariatric Surgery, and Hypothalamic Volume Predicts Short-Term Weight Loss Response in Adults With or Without Type 2 Diabetes.

OBJECTIVE: Preclinical research implicates hypothalamic inflammation (HI) in obesity and type 2 diabetes pathophysiology. However, their pathophysiological relevance and potential reversibility need to be better defined. We sought to evaluate the effect of bariatric surgery (BS) on radiological biomarkers of HI and the association between the severity of such radiological alterations and post-BS weight loss (WL) trajectories. The utility of cerebrospinal fluid large extracellular vesicles (CSF-lEVs) enriched for microglial and astrocyte markers in studying HI was also explored. RESEARCH DESIGN AND METHODS: We included 72 individuals with obesity (20 with and 52 without type 2 diabetes) and 24 control individuals. Participants underwent lumbar puncture and 3-T MRI at baseline and 1-year post-BS. We assessed hypothalamic mean diffusivity (MD) (higher values indicate lesser microstructural integrity) and the volume of the whole and main hypothalamic subregions. CSF-lEVs enriched for glial and astrocyte markers were determined by flow cytometry. RESULTS: Compared with control group, the obesity and type 2 diabetes groups showed a larger volume and higher MD in the hypothalamic tubular inferior region, the area encompassing the arcuate nucleus. These radiological alterations were positively associated with baseline anthropometric and metabolic measures and improved post-BS. A larger baseline tubular inferior hypothalamic volume was independently related to lesser WL 1 and 2 years after BS. CSF-lEVs did not differ among groups and were unrelated to WL trajectories. CONCLUSIONS: These findings suggest HI improvement after BS and may support a role for HI in modulating the WL response to these interventions.

What is the evidence regarding the safety of new obesity pharmacotherapies.

The use of gut-hormone receptors agonists as new therapeutic options for obesity and some of its related comorbidities, such as type 2 diabetes, has resulted in an unprecedented efficacy in the medical management of people living with obesity (PLWO). Appraisal of the safety of these drugs is of utmost importance considering the large number of PLWO, and the potentially long exposure to these pharmacotherapies. In this narrative review we summarize the evidence on the safety of liraglutide, semaglutide, and tirzepatide as derived from randomized clinical trials conducted in adults living with obesity. Additionally, the safety of these drugs is put into perspective with that of other drugs currently approved for the treatment of PLWO. Overall, the available data support a favorable efficacy versus safety balance for gut-hormone hormone receptor analogues in the treatment of these subjects. Nonetheless, it should be acknowledged that in the context of a chronic disease that has reached epidemic proportions, data from randomized clinical trials aimed primarily at proving the efficacy of these drugs may have been insufficient to unveil all the safety issues. Thus, continuous surveillance on the adverse effects of liraglutide, semaglutide, and tirzepatide is required as we use these drugs in a broader population than that represented in currently available clinical trials.

Bariatric Surgery Outcomes in Patients with Chronic Kidney Disease.

Obesity increases the risk of developing chronic kidney disease (CKD), which has a major negative impact on global health. Bariatric surgery (BS) has demonstrated a substantial improvement of obesity-related comorbidities and thus, it has emerged as a potential therapeutic tool in order to prevent end-stage renal disease. A limited number of publications to date have examined the beneficial effects and risks of BS in patients with non-advanced stages of CKD. We aimed to investigate the safety of BS in patients with CKD stages 3-4 (directly related or not to obesity) and both the metabolic/renal outcomes post-BS. A total of 57 individuals were included (n = 19 for CKD-group; n = 38 for patients with obesity, but normal eGFR [control-group]). Weight loss and obesity comorbidities resolution after BS were similar in both groups. Renal function (eGFR [CKD-EPI]) improved significantly at the 1-year follow-up: Δ10.2 (5.2-14.9) (p < 0.001) for CKD-group and Δ4.0 (-3.9-9.0) mL/min/1.73 m2 (p = 0.043) for controls. Although this improvement tended to decrease in the 5-year follow-up, eGFR remained above its basal value for the CKD-group. Noteworthy, eGFR also improved in those patients who presented CKD not directly attributed to obesity. For patients with CKD, BS appears to be safe and effective regarding weight loss and obesity comorbidities resolution, irrespective of the main cause of CKD (related or not to obesity).

Exocrine pancreatic insufficiency following bariatric surgery: unveiling alternative aetiology-case report and short review.

Bariatric surgery (BS) is currently the most effective treatment for severe obesity, requiring ongoing multidisciplinary follow-up to ensure proper progress and nutrition post-procedure. Despite its favourable safety profile, it is not exempt from complications, one of which being exocrine pancreatic insufficiency (EPI). The underlying pathophysiological mechanisms of EPI after BS are multifactorial, including poorly synchronized pancreatic enzyme secretion with the passage of nutrients (pancreaticocibal or postcibal asynchrony), insufficient pancreatic stimulation and bacterial overgrowth. We conducted a short literature review of the topic through a case of a patient who underwent BS in our centre and subsequently developed EPI and severe malnutrition. EPI initially was attributed to the surgery, but after a comprehensive evaluation, an unexpected cause was revealed.

Effects of Bariatric Surgery on Blood and Vascular Large Extracellular Vesicles According to Type 2 Diabetes Status.

CONTEXT: Large extracellular vesicles (lEVs) enriched for endothelial and blood cell markers are increased in metabolic conditions such as obesity or type 2 diabetes (T2D), actively contribute to the atherosclerotic process, and have been identified as diagnostic and prognostic biomarkers for cardiovascular disease (CVD). Although bariatric surgery (BS) in individuals with obesity is related to decreased cardiovascular (CV) risk and increased life expectancy, after BS these subjects are still at higher CV risk than the general population. OBJECTIVE: We aimed to compare the lEV profiles between individuals with obesity, with or without T2D, before and 1 year after BS, and normal-weight controls. METHODS: Prospective longitudinal study with individuals eligible for BS, with or without T2D (T2D and OB groups, respectively) and healthy controls (HC group) matched by age and sex. The concentration and phenotype of lEVs were assessed by flow cytometry. RESULTS: The study cohort included 108 individuals (age 48.0 ± 10.5 years; 84.3% females). Before BS, the OB group presented higher concentrations of lEV enriched for endothelial and blood cell biomarkers than the HC group, but lower concentrations than those observed in the T2D group (P < .05). BS resulted in a significant reduction in most of the lEVs enriched for cell-specific markers in both subgroups. lEV differences between OB and T2D groups were no longer observed after BS (P > .05). However, compared with HC group, OB and T2D groups still showed increased concentrations of lEVs enriched for platelet and endothelial cell markers (P < .05). CONCLUSION: At 1 year after BS, lEV concentrations remain above the physiological range. These abnormalities might contribute to explaining the increased CV risk after BS and underscore the importance of long-term CV risk factor control in post-BS individuals.

Total carotene plasma concentrations are inversely associated with atherosclerotic plaque burden: A post-hoc analysis of the DIABIMCAP cohort.

BACKGROUND AND AIMS: Atherosclerosis is the major risk factor for cardiovascular disease (CVD), the first cause of death worldwide. Chronic low-grade inflammation and a sustained oxidative milieu are causatively related to atherosclerosis onset and progression, and therefore, dietary patterns rich in bioactive compounds with anti-inflammatory and antioxidant activities might likely contribute to revert or slowing the progression of atherosclerosis. The aim of this study is to analyse the association between fruit and vegetables intake, quantitatively measured through carotene plasma concentrations, and atherosclerotic burden, as a surrogate biomarker of CVD, in free-living subjects from the DIABIMCAP cohort study. METHODS: The 204 participants of the DIABIMCAP Study cohort (Carotid Atherosclerosis in Newly Diagnosed Type 2 Diabetic Individuals, ClinicalTrials.gov Identifier: NCT01898572), were included in this cross-sectional study. Total, α-, and ß-carotenes were quantified by HPLC-MS/MS. Lipoprotein analysis in serum was performed by 2D- 1H NMR- DOSY, and atherosclerosis and intima media thickness (IMT) were measured through standardized bilateral carotid artery ultrasound imaging. RESULTS: Subjects with atherosclerosis (n = 134) had lower levels of large HDL particles than subjects without atherosclerosis. Positive associations were found between α-carotene and both large and medium HDL particles, and inverse associations were found between ß- and total carotene, and VLDL and its medium/small particles. Subjects with atherosclerosis presented significantly lower plasma concentrations of total carotene compared with subjects without atherosclerosis. Plasma concentrations of carotene decreased as the number of atherosclerotic plaques increased, although after multivariate adjustment, the inverse association between ß- and total carotene with plaque burden remained significant only in women. CONCLUSIONS: A diet rich in fruit and vegetables results in higher plasmatic carotene concentrations, which are associated with a lesser atherosclerotic plaque burden.

Limited Bariatric Surgery-induced Weight Loss in Subjects With Type 2 Diabetes: Predictor Variables in Adipose Tissue.

CONTEXT: The impact of type 2 diabetes mellitus (T2D) at baseline on limited weight loss (WL) after bariatric surgery (BS) remains controversial, and the potential underlying mechanisms incompletely understood. OBJECTIVE: We aimed at gaining further insight on this relationship and identifying novel associations between adipose tissue (AT) parameters and short-term WL outcomes in subjects with or without T2D undergoing BS. METHODS: Mid-term WL trajectories after BS have been evaluated in a cohort of 1659 subjects (cohort 1) with (n = 543) and without T2D (n = 1116). Paired subcutaneous and visceral AT samples were obtained from a cohort of 48 pairs of subjects with and without T2D matched for age, sex, BMI, and type of BS (cohort 2). Differences in AT parameters between groups were evaluated and potential associations with WL response explored. RESULTS: T2D was independently associated with a 5% lesser mid-term WL in cohort 1, while HbA1c, insulin treatment, and number of T2D medications prior to BS were only related to short-term WL outcomes. In cohort 2, a number of differentially expressed genes in AT were identified between groups, while fat cell size and fibrosis were comparable. Subcutaneous ATG7 expression was found as an independent predictor of limited WL 1 year after surgery (ß: -12.21 ± 4.41, P = .008) and its addition to a clinical model significantly improved the amount of WL variability explained (R2 = 0.131 vs R2 = 0.248, F change P = .009). CONCLUSION: Our results highlight the importance of T2D as determinant of limited WL following BS and suggest that dysregulated macroautophagy in subcutaneous AT may contribute to this association.

Pediatric Obesity: Primary Care Perspective and Prevention.

In 1997, the World Health Organization declared obesity a global epidemic. Despite multiple efforts, obesity rates have been exponentially increasing for the past few decades. In the last few years, obesity rates have reached an alarming number. Multiple factors play a role in pediatric obesity, such as diet, sedentarism, and poor sleep, as well as psychosocial and environmental factors. Pediatricians and primary care providers are key in the management of overweight and obesity. They have the advantage of observing children over a long period of time, having a family centered perspective, and often being seen as a reliable source of information. Studies have shown that not only is obesity underdiagnosed, but there is a lack of knowledge among physicians and available resources regarding pediatric obesity. This article reviews the principles of prevention in a primary care outpatient setting. Additionally, it discusses some of the challenges commonly faced when addressing pediatric obesity. [Pediatr Ann. 2023;52(2):e51-e56.].

Bariatric Surgery Outcomes in Patients with Kidney Transplantation.

Obesity and kidney transplantation (KTx) are closely related. Obesity increases the risk of chronic kidney disease and can be a relative contraindication for KTx. Besides, KTx recipients are predisposed to obesity and its comorbidities. Consequently, bariatric surgery (BS) emerges as a powerful therapeutic tool either before or after KTx. Since evidence regarding the best approach is still scarce, we aimed to describe renal and metabolic outcomes in a single centre with more than 15-year experience in both surgeries. METHODS: A retrospective study including patients who had received a KTx either before or after BS. Usual metabolic and renal outcomes, but also new variables (as renal graft dysfunction) were collected for a minimum follow-up of 1-year post-BS. RESULTS: A total of 11 patients were included: n = 6 (BS-post-KTx) and n = 5 (BS-pre-KTx). One patient was assessed in both groups. No differences in the main outcomes were identified, but BS-post-KTx group tended to gain more weight during the follow-up. The incidence of renal graft dysfunction was comparable (4/6 for BS-post-KTx, 3/5 for BS-pre-KTx) between groups. CONCLUSIONS: BS in patients with KTx appears to be safe and effective attending to metabolic and renal outcomes. These results seem irrespective of the time course, except for weight regain, which appears to be a common pattern in the BS-post-KTx group.

Enrichment of Astrocyte-Derived Extracellular Vesicles from Human Plasma.

Extracellular vesicles (EVs) are biological nanoparticles secreted by all cells for cellular communication and waste elimination. They participate in a vast range of functions by acting on and transferring their cargos to other cells in physiological and pathological conditions. Given their presence in biofluids, EVs represent an excellent resource for studying disease processes and can be considered a liquid biopsy for biomarker discovery. An attractive aspect of EV analysis is that they can be selected based on markers of their cell of origin, thus reflecting the environment of a specific tissue in their cargo. However, one of the major handicaps related to EV isolation methods is the lack of methodological consensuses and standardized protocols. Astrocytes are glial cells with essential roles in the brain. In neurodegenerative diseases, astrocyte reactivity may lead to altered EV cargo and aberrant cellular communication, facilitating/enhancing disease progression. Thus, analysis of astrocyte EVs may lead to the discovery of biomarkers and potential disease targets. This protocol describes a 2-step method of enrichment of astrocyte-derived EVs (ADEVs) from human plasma. First, EVs are enriched from defibrinated plasma via polymer-based precipitation. This is followed by enrichment of ADEVs through ACSA-1-based immunocapture with magnetic micro-beads, where resuspended EVs are loaded onto a column placed in a magnetic field. Magnetically labeled ACSA-1+ EVs are retained within the column, while other EVs flow through. Once the column is removed from the magnet, ADEVs are eluted and are ready for storage and analysis. To validate the enrichment of astrocyte markers, glial fibrillary acidic protein (GFAP), or other specific astrocytic markers of intracellular origin, can be measured in the eluate and compared with the flow-through. This protocol proposes an easy, time-efficient method to enrich ADEVs from plasma that can be used as a platform to examine astrocyte-relevant markers.

Positive Effects of a Mediterranean Diet Supplemented with Almonds on Female Adipose Tissue Biology in Severe Obesity.

It has been suggested that weight-loss-independent Mediterranean diet benefits on cardiometabolic health and diabetes prevention may be mediated, at least in part, through the modulation of white adipose tissue (WAT) biology. This study aimed to evaluate the short-term effects of a dietary intervention based on the Mediterranean diet supplemented with almonds (MDSA) on the main features of obesity-associated WAT dysfunction. A total of 38 women with obesity were randomly assigned to a 3-month intervention with MDSA versus continuation of their usual dietary pattern. Subcutaneous (SAT) and visceral adipose tissue (VAT) biopsies were obtained before and after the dietary intervention, and at the end of the study period, respectively. MDSA favored the abundance of small adipocytes in WAT. In SAT, the expression of angiogenesis genes increased after MDSA intervention. In VAT, the expression of genes implicated in adipogenesis, angiogenesis, autophagy and fatty acid usage was upregulated. In addition, a higher immunofluorescence staining for PPARG, CD31+ cells and M2-like macrophages and increased ADRB1 and UCP2 protein contents were found compared to controls. Changes in WAT correlated with a significant reduction in circulating inflammatory markers and LDL-cholesterol levels. These results support a protective effect of a Mediterranean diet supplemented with almonds on obesity-related WAT dysfunction.

Prevalence of low skeletal muscle mass following bariatric surgery.

BACKGROUND AND AIMS: Evidence on the occurrence of low skeletal muscle mass (low-SMM) following bariatric surgery (BS) as well as on the impact of low-SMM antedating BS on post-surgical body composition (BC) are scant. In this context, we aimed to prospectively evaluate the prevalence of low-SMM prior to and up to 5 years after BS, and to evaluate pre-surgical low-SMM as an independent risk factor for the presence of low-SMM after BS. METHODS: Retrospective analysis of prospectively collected database. BC was assessed by bioelectrical impedance analysis (BIA). A BIA-based formula was used to calculate skeletal muscle mass (SMM). Class I and class II low-SMM were defined respectively as a SMM index (SMMI = SMM/height2) value between -1 and -2, or > -2 standard deviations from the gender-specific regression line of the BMI versus the SMMI relationship in our reference group. RESULTS: A total 952 subjects were included, with BC being available for 877 (92%) subjects at 12 months and for 576 subjects (60%) at 60 months after BS. Prior to surgery, and at 12-, or at 60-months after surgery, class I and class II low-SMM was ascertained respectively in 15.6% and 4.6%, 5.3% and 1.4%, and 16.6% and 6.3% of the study participants. Logistic regression analysis showed that the occurrence of low-SMM at 12- and 60-months follow-up, was independently predicted not only by age at the time of surgery [respectively, HR: 1.052 (95% CI 1.020-1.084), p = 0.001; and 1.042 (95% CI 1.019-1.066); p < 0.001] but also by the presence of low-SMM prior to surgery [respectively, HR: 10.717 (95% CI 5.771-19.904), p < 0.001; and 5.718 (95% CI 3.572-9.153); p < 0.001]. CONCLUSIONS: Our data suggest that a low-SMM phenotype occurs not only in obesity surgery candidates but also after BS, and that low-SMM prior to surgery is an important risk factor for low-SMM throughout post-surgical follow-up.

Low Percentage of Vegetable Fat in Red Blood Cells Is Associated with Worse Glucose Metabolism and Incidence of Type 2 Diabetes.

The identification of nutritional patterns associated with the development of type 2 diabetes (T2D) might help lead the way to a more efficient and personalized nutritional intervention. Our study is aimed at evaluating the association between fatty acids (FA) in red blood cell (RBC) membranes, as a quantitative biomarker of regular dietary fat intake, and incident type 2 diabetes in a Spanish population. We included 1032 adult Spaniards (57% women, age 49 ± 15 years, 18% prediabetes), without diabetes at study entry, from the Di@bet.es cohort. Incident diabetes was diagnosed at the end of the study follow-up. The FA percentage in RBC was determined at baseline by gas chromatography. Participants were followed on average 7.5 ± 0.6 years. Lower percentages of linoleic acid (LA), α-linolenic (ALA), and eicosapentaenoic acid (EPA), and higher percentages of docosahexaenoic acid (DHA) in RBC membranes were associated, independently of classical risk factors, with worse glucose metabolism at the end of the study follow-up. In addition, higher percentages of ALA and EPA, and moderate percentages of DHA, were associated with lower risk of diabetes. No significant associations were found for LA and diabetes risk. Dietary patterns rich in vegetables are independently associated with lower risk of both deterioration of glucose regulation and incident diabetes, and should be reinforced for the prevention of diabetes.

Hypothalamic pregnenolone mediates recognition memory in the context of metabolic disorders.

Obesity and type 2 diabetes are associated with cognitive dysfunction. Because the hypothalamus is implicated in energy balance control and memory disorders, we hypothesized that specific neurons in this brain region are at the interface of metabolism and cognition. Acute obesogenic diet administration in mice impaired recognition memory due to defective production of the neurosteroid precursor pregnenolone in the hypothalamus. Genetic interference with pregnenolone synthesis by Star deletion in hypothalamic POMC, but not AgRP neurons, deteriorated recognition memory independently of metabolic disturbances. Our data suggest that pregnenolone's effects on cognitive function were mediated via an autocrine mechanism on POMC neurons, influencing hippocampal long-term potentiation. The relevance of central pregnenolone on cognition was also confirmed in metabolically unhealthy patients with obesity. Our data reveal an unsuspected role for POMC neuron-derived neurosteroids in cognition. These results provide the basis for a framework to investigate new facets of POMC neuron biology with implications for cognitive disorders.

Weight-loss thresholds after bariatric surgery and cardiovascular outcomes: more is better.

BACKGROUND/OBJECTIVES: Whether the extent of weight loss (WL) modulates bariatric surgery (BS) cardiovascular benefits has scarcely been assessed. Several WL thresholds have been commonly used to classify BS patients as good or poor responders without a proven clinical relevance. We examined the relationship between the magnitude of WL after BS and post-surgery major adverse cardiovascular-event (MACE) incidence. We also compared the performance of three different insufficient weight-loss (IWL) criteria for their association with MACE. SUBJECTS AND METHODS: All individuals who underwent a primary Roux-en Y gastric bypass (RYGB) or sleeve gastrectomy (SG) in our institution at least six years before data analysis (12/2020) were included in the study. Data on MACE were available in 1638 of 1700 participants (96.4%). Proportional-hazard Cox analyses were performed to ascertain the association between MACE, WL, and the three IWL criteria. IWL was defined as: <50% excess weight loss (<50% EWL), <20% total body-weight loss (<20% TBWL), and -1 standard deviation of alterable weight-loss percentage (<1 SD% AWL). RESULTS: During a mean follow-up of 10.2 ± 2.8 years, 86 participants experienced a first post-surgery MACE. Higher WL at one year (HR: 0.77 (95% CI: 0.61-0.98)) and 5 years (HR: 0.63 (95% CI: 0.42-0.92)) was related to a lower incidence of MACE. All short-term criteria for defining IWL were similarly associated with MACE, yet <1 SD% AWL identified more at-risk subjects. Five-year TBWL < 20% and 5-year <1 SD-AWL% were significantly associated with a higher risk for CV events. TBWL < 20% identified more subjects at risk. CONCLUSIONS: The extent of WL is closely related to long-term MACE incidence. Patients who lost -1SD% AWL at one year or <20% TBWL at five years may be considered poor responders.

Characterizing methane and total non-methane hydrocarbon levels in Los Angeles communities with oil and gas facilities using air quality monitors.

Over the past decade, sensor networks have been proven valuable to assess air quality on highly localized scales. Here we leverage innovative sensors to characterize gaseous pollutants in a complex urban environment and evaluate differences in air quality in three different Los Angeles neighborhoods where oil and gas activity is present. We deployed monitors across urban neighborhoods in South Los Angles adjacent to oil and gas facilities with varying levels of production. Using low-cost sensors built in-house, we measured methane, total non-methane hydrocarbons (TNMHCs), carbon monoxide, and carbon dioxide during three deployment campaigns over four years. The multi-sensor linear regression calibration model developed to quantify methane and TNMHCs offers up to 16% improvement in coefficient of determination and up to a 22% reduction in root mean square error for the most recent dataset as compared to previous models. The deployment results demonstrate that airborne methane concentrations are higher within a 500 m radius of three urban oil and gas facilities, as well as near a natural gas distribution pipeline, likely a result of proximity to sources. While there are numerous additional sources of TNMHCs in complex urban environments, some sites appear to be larger emitters than others. Significant methane emissions were also measured at an idle site, suggesting that fugitive emissions may still occur even if production is ceased. Episodic spikes of both compounds suggested an association with oil and gas activities, demonstrating how sensor networks can be used to elucidate community-scale sources and differences in air quality moving forward.