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Genome-wide association studies (GWAS) have identified numerous body mass index (BMI) loci. However, most underlying mechanisms from risk locus to BMI remain unknown. Leveraging omics data through integrative analyses could provide more comprehensive views of biological pathways on BMI. We analyzed genotype and blood gene expression data in up to 5,619 samples from the Framingham Heart Study (FHS). Using 3,992 single nucleotide polymorphisms (SNPs) at 97 BMI loci and 20,692 transcripts within 1 Mb, we performed separate association analyses of transcript with BMI and SNP with transcript (PBMI and PSNP, respectively) and then a correlated meta-analysis between the full summary data sets (PMETA). We identified transcripts that met Bonferroni-corrected significance for each omic, were more significant in the correlated meta-analysis than each omic, and were at least nominally associated with BMI in FHS data. Among 308 significant SNP-transcript-BMI associations, we identified seven genes (NT5C2, GSTM3, SNAPC3, SPNS1, TMEM245, YPEL3, and ZNF646) in five association regions. Using an independent sample of blood gene expression data, we validated results for SNAPC3 and YPEL3. We tested for generalization of these associations in hypothalamus, nucleus accumbens, and liver and observed significant (PMETA<0.05 & PMETA
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BACKGROUND AND AIMS: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) promote weight loss by suppressing appetite, enhancing satiety, regulating glucose metabolism, and delaying gastric motility. We sought to determine whether GLP-1RA use could affect medical procedures such as EGD. METHODS: We conducted a retrospective study of 35,183 patients who underwent EGD between 2019 and 2023, 922 of whom were using a GLP-1 RAs. Data were collected regarding demographics, diabetes status, retained gastric contents during EGD, incidence of aborted EGD, and necessity for repeat EGD. RESULTS: GLP-1 RA use was associated with a 4-fold increase in the retention of gastric contents (P < .0001), 4-fold higher rates of aborted EGD (P < .0001), and twice the likelihood of requiring repeat EGD (P = .0001), even after stratifying for the presence of diabetes. CONCLUSIONS: GLP-1 RA use can lead to delayed gastric emptying, affecting EGD adequacy regardless of the presence of diabetes, and may warrant dose adjustment to improve the safety and efficacy of these procedures.
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Plants with the C4 photosynthesis pathway typically respond to climate change differently from more common C3-type plants, due to their distinct anatomical and biochemical characteristics. These different responses are expected to drive changes in global C4 and C3 vegetation distributions. However, current C4 vegetation distribution models may not predict this response as they do not capture multiple interacting factors and often lack observational constraints. Here, we used global observations of plant photosynthetic pathways, satellite remote sensing, and photosynthetic optimality theory to produce an observation-constrained global map of C4 vegetation. We find that global C4 vegetation coverage decreased from 17.7% to 17.1% of the land surface during 2001 to 2019. This was the net result of a reduction in C4 natural grass cover due to elevated CO2 favoring C3-type photosynthesis, and an increase in C4 crop cover, mainly from corn (maize) expansion. Using an emergent constraint approach, we estimated that C4 vegetation contributed 19.5% of global photosynthetic carbon assimilation, a value within the range of previous estimates (18-23%) but higher than the ensemble mean of dynamic global vegetation models (14 ± 13%; mean ± one standard deviation). Our study sheds insight on the critical and underappreciated role of C4 plants in the contemporary global carbon cycle.
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Dióxido de Carbono , Fotosíntesis , Dióxido de Carbono/metabolismo , Fotosíntesis/fisiología , Poaceae/metabolismo , Plantas/metabolismo , Zea mays/metabolismoRESUMEN
Background: Certification of obesity medicine for physicians in the United States occurs mainly via the American Board of Obesity Medicine (ABOM). Obesity medicine is not recognized as a subspecialty by the American Board of Medical Specialties (ABMS) or the American Osteopathic Association (AOA). This review examines the value of specialization, status of current ABOM Diplomates, governing bodies involved in ABMS/AOA Board Certification, and the advantages and disadvantages of an ABMS/AOA recognized obesity medicine subspecialty. Methods: Data for this review were derived from PubMed and appliable websites. Content was driven by the expertise, insights, and perspectives of the authors. Results: The existing ABOM obesity medicine certification process has resulted in a dramatic increase in the number of Obesity Medicine Diplomates. If ABMS/AOA were to recognize obesity medicine as a subspecialty under an existing ABMS Member Board, then Obesity Medicine would achieve a status like other ABMS recognized subspecialities. However, the transition of ABOM Diplomates to ABMS recognized subspecialists may affect the kinds and the number of physicians having an acknowledged focus on obesity medicine care. Among transition issues to consider include: (1) How many ABMS Member Boards would oversee Obesity Medicine as a subspecialty and which physicians would be eligible? (2) Would current ABOM Diplomates be required to complete an Obesity Medicine Fellowship? If not, then what would be the process for a current ABOM Diplomate to transition to an ABMS-recognized Obesity Medicine subspecialist (i.e., "grandfathering criteria")? and (3) According to the ABMS, do enough Obesity Medicine Fellowship programs exist to recognize Obesity Medicine as a subspecialty? Conclusions: Decisions regarding a transition to an ABMS recognized Obesity Medicine Subspecialty versus retention of the current ABOM Diplomate Certification should consider which best facilitates medical access and care to patients with obesity, and which best helps obesity medicine clinicians be recognized for their expertise.
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Introduction: Referrals to evidence-based weight management in the community-commercial sector are aligned with clinical recommendations but underutilized. Methods: This qualitative study explored patients' perceptions and expectations about obesity treatment in primary care and referral to community-commercial sector programs. Individual semi-structured interviews were conducted with a sample of US persons with obesity via telephone. Audiotape transcripts, interviewer notes, and independent review of data by two investigators allowed for data and investigator triangulation. Transcripts were analyzed using thematic analysis. Results: Data saturation was reached with 30 participants who had a mean age of 41.6 years (SD 9.4), 37% male, 20% Black/African American and 17% Hispanic, 57% college educated, and 50% were employed full-time. Three primary themes emerged: (1) frustration with weight management in primary care; (2) patients expect providers to be better informed of and offer treatment options; and (3) opportunities and challenges with referrals to community-commercial programs. Discussion: Patients expect that providers offer personalized treatment options and referrals to effective community-commercial programs are an acceptable option. If patient-level data are shared between clinical and community entities to facilitate referrals, then privacy and security issues need attention. Future research is needed to determine feasibility of implementing clinical to community-commercial referrals for obesity treatment in the United States.
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Obesidad , Atención Primaria de Salud , Adulto , Femenino , Humanos , Masculino , Negro o Afroamericano , Hispánicos o Latinos , Obesidad/terapia , Derivación y Consulta , Persona de Mediana EdadRESUMEN
Global warming and droughts push forests closer to their thermal limits, altering tree carbon uptake and growth. To prevent critical overheating, trees can adjust their thermotolerance (Tcrit ), temperature and photosynthetic optima (Topt and Aopt ), and canopy temperature (Tcan ) to stay below damaging thresholds. However, we lack an understanding of how soil droughts affect photosynthetic thermal plasticity and Tcan regulation. In this study, we measured the effect of soil moisture on the seasonal and diurnal dynamics of net photosynthesis (A), stomatal conductance (gs ), and Tcan , as well as the thermal plasticity of photosynthesis (Tcrit , Topt , and Aopt ), over the course of 1 yr using a long-term irrigation experiment in a drought-prone Pinus sylvestris forest in Switzerland. Irrigation resulted in higher needle-level A, gs , Topt , and Aopt compared with naturally drought-exposed trees. No daily or seasonal differences in Tcan were observed between treatments. Trees operated below their thermal thresholds (Tcrit ), independently of soil moisture content. Despite strong Tcan and Tair coupling, we provide evidence that drought reduces trees' temperature optimum due to a substantial reduction of gs during warm and dry periods of the year. These findings provide important insights regarding the effects of soil drought on the thermal tolerance of P. sylvestris.
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Pinus sylvestris , Pinus , Pinus sylvestris/fisiología , Suelo , Temperatura , Hojas de la Planta/fisiología , Bosques , Fotosíntesis/fisiología , Árboles/fisiología , Sequías , Pinus/fisiologíaRESUMEN
The prevalence of obesity in the United States and across the world continues to climb, imparting increased risk of chronic disease. This impact is doubly felt in nephrology because obesity not only increases the risk of chronic kidney disease (CKD) but also exacerbates existing cardiovascular morbidity and mortality. The role of medical weight loss therapy in CKD has been debated, but increasing evidence suggests that intentional weight loss is protective against adverse kidney and cardiovascular outcomes. This may be particularly true with the advent of novel pharmacotherapies taking advantage of the incretin system, resulting in weight loss approaching that seen with surgical interventions. Moreover, these novel therapies have repeatedly demonstrated protective effects on the cardiovascular system. Here, we review the impact of obesity and weight loss on CKD, and the biological basis and clinical evidence for incretin therapy. This perspective provides recommended prescribing practices as a practical tool to engage nephrologists and patients with CKD in the treatment of obesity-related morbidity.
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Nefrólogos , Insuficiencia Renal Crónica , Humanos , Estados Unidos/epidemiología , Incretinas , Obesidad/complicaciones , Obesidad/tratamiento farmacológico , Obesidad/epidemiología , Insuficiencia Renal Crónica/tratamiento farmacológico , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/etiología , Pérdida de PesoRESUMEN
Evolutionary history plays a key role driving patterns of trait variation across plant species. For scaling and modeling purposes, grass species are typically organized into C3 vs C4 plant functional types (PFTs). Plant functional type groupings may obscure important functional differences among species. Rather, grouping grasses by evolutionary lineage may better represent grass functional diversity. We measured 11 structural and physiological traits in situ from 75 grass species within the North American tallgrass prairie. We tested whether traits differed significantly among photosynthetic pathways or lineages (tribe) in annual and perennial grass species. Critically, we found evidence that grass traits varied among lineages, including independent origins of C4 photosynthesis. Using a rigorous model selection approach, tribe was included in the top models for five of nine traits for perennial species. Tribes were separable in a multivariate and phylogenetically controlled analysis of traits, owing to coordination of important structural and ecophysiological characteristics. Our findings suggest grouping grass species by photosynthetic pathway overlooks variation in several functional traits, particularly for C4 species. These results indicate that further assessment of lineage-based differences at other sites and across other grass species distributions may improve representation of C4 species in trait comparison analyses and modeling investigations.
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Evolución Biológica , Poaceae , Poaceae/genética , Fotosíntesis , Hojas de la PlantaRESUMEN
BACKGROUND: Iron deficiency (ID), a known complication after metabolic surgery, is common among preoperative patients in the presence of inflammation. Evidence is now accumulating that preoperative ID may adversely affect perioperative outcomes. OBJECTIVES: To investigate the relationship between preoperative iron status and the risk of postoperative severe anemia. In addition, this study investigates the relationship between preoperative iron status and length of surgical stay SETTING: A large regional tertiary health system. METHODS: Among patients who underwent metabolic surgery between 2004 and 2020, 5171 patients had a full iron nutritional assessment prior to surgery. Study patients were divided into multiple smaller groups (10 female groups and 7 male groups) on the basis of levels of serum ferritin and Transferrin Saturation (T Sat) < or ≥20%. Study patients were followed after surgery and the time to the development of severe anemia (hemoglobin < 8 gm/dL) was recorded. Hospital length of stay (LOS) was analyzed in relation to preoperative iron status. RESULTS: Lower ferritin levels were associated with older age in males (P = .0001) and younger age in females (P < .0001). For males, after adjustment for age, body mass index (BMI), and year of surgery, surgical LOS was prolonged in those with T Sat <20% (P = .0041). For females the time until the development of severe anemia was associated with baseline iron status (P < .0001). CONCLUSIONS: Male preoperative patients for metabolic surgery with T Sat <20% are at risk for increased surgical LOS. Females with low ferritin levels consistent with ID are at increased risk for the development of postoperative severe anemia.
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Anemia Ferropénica , Anemia , Cirugía Bariátrica , Deficiencias de Hierro , Humanos , Masculino , Femenino , Relevancia Clínica , Hierro , Ferritinas , Anemia Ferropénica/complicacionesRESUMEN
Background: Obesity is a risk factor for COVID-19 severity. Recent studies suggest that prior metabolic surgery (MS) modifies the risk of COVID-19 severity. Methods: COVID-19 outcomes were compared between patients with MS (n = 287) and a matched cohort of unoperated patients (n = 861). Multiple logistic regression was used to identify predictors of hospitalization. A systematic literature review and pooled analysis was conducted to provide overall evidence of the influence of prior metabolic surgery on COVID-19 outcomes. Results: COVID-19 patients with MS had less hospitalization (9.8% versus 14.3%, p = 0.049). Age 70+, higher BMI, and low weight regain after MS were associated with more hospitalization after COVID-19. A systematic review of 7 studies confirmed that MS reduced the risk of post-COVID-19 hospitalization (OR = 0.71, 95%CI = [0.61-0.83], p < 0.0001) and death (OR = 0.44, 95%CI = [0.30-0.65], p < 0.0001). Conclusion: MS favorably modifies the risks of severe COVID-19 infection. Older age and higher BMI are major risk factors for severity of COVID-19 infection.
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INTRODUCTION: The rate of marginal ulcer (MU) following primary Roux-en-Y Gastric Bypass (RYGB) is approximately .6-16%. Few studies have evaluated recurrence rates following surgical revision for MU. The primary aim of this study was to determine the rate of MU recurrence following revision. The secondary aim was to evaluate the impact of truncal vagotomy (TV) on the recurrence rates and analyze potential risk factors associated with the recurrence of MU after revision. METHODS: We conducted a retrospective cohort study examining data at a single tertiary academic medical center. Adult patients with a history of RYGB who underwent gastrojejunostomy revision for recurrent MU between the years of 2003-2020 were included. We sought to determine our overall rate of MU following revision, with and without TV. Additionally, we examined the association of risk factors with MU recurrence. Fisher's exact test was used to determine the statistical significance of recurrence rates between the groups. RESULTS: We included 90 patients in the study. The overall recurrence rate for MU was 16.7%. Of the 90 patients, 35 (35.4%) patients underwent TV at the time of revision. The recurrence rate of MU after GJ revision with TV was 14.3% in comparison to those without TV, 18.2% (P = .775). Smoking, steroid, alcohol use, history of cardiac surgery/intervention, and helicobacter pylori were not significantly associated with recurrent MU following revision. CONCLUSIONS: The rate of recurrence after revision for MU is high. Adding TV trended towards decreased MU recurrence after revisional surgery, however not significant. Larger studies are needed to evaluate risk factors associated with recurrent MU after revision.
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Derivación Gástrica , Úlcera Péptica , Adulto , Humanos , Derivación Gástrica/efectos adversos , Estudios Retrospectivos , Úlcera Péptica/epidemiología , Úlcera Péptica/cirugía , Vagotomía Troncal , Reoperación/efectos adversosRESUMEN
This study examined the associations between overall diet quality and the risk of dementia in a rural cohort among the oldest old. Included in this prospective cohort study were 2232 participants aged ≥ 80 years and dementia-free at the baseline according to the Geisinger Rural Aging Study (GRAS), a longitudinal cohort in rural Pennsylvania. In 2009, diet quality was assessed by a validated dietary screening tool (DST). Incident cases of dementia during 2009-2021 were identified using diagnosis codes. This approach was validated by a review of electronic health records. Associations between diet quality scores and the incidence of dementia were estimated using the Cox proportional hazards models, adjusted for potential confounders. Across a mean of 6.90 years of follow-up, we identified 408 incident cases of all-cause dementia. Having a higher diet quality was not significantly associated with a lower risk for incidents of all-cause dementia (adjusted HR for the highest compared with the lowest tertile: 1.01, 95% CI: 0.79, 1.29, P-trend = 0.95). Similarly, we did not observe a significant association between diet quality and altered risks of Alzheimer's disease and other forms of dementia. Overall, having a higher diet quality was not significantly associated with a lower risk of dementia among the oldest old during the full follow-up.
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Enfermedad de Alzheimer , Dieta , Anciano de 80 o más Años , Humanos , Envejecimiento , Estudios de Cohortes , Estudios ProspectivosRESUMEN
Forests account for nearly 90 % of the world's terrestrial biomass in the form of carbon and they support 80 % of the global biodiversity. To understand the underlying forest dynamics, we need a long-term but also relatively high-frequency, networked monitoring system, as traditionally used in meteorology or hydrology. While there are numerous existing forest monitoring sites, particularly in temperate regions, the resulting data streams are rarely connected and do not provide information promptly, which hampers real-time assessments of forest responses to extreme climate events. The technology to build a better global forest monitoring network now exists. This white paper addresses the key structural components needed to achieve a novel meta-network. We propose to complement - rather than replace or unify - the existing heterogeneous infrastructure with standardized, quality-assured linking methods and interacting data processing centers to create an integrated forest monitoring network. These automated (research topic-dependent) linking methods in atmosphere, biosphere, and pedosphere play a key role in scaling site-specific results and processing them in a timely manner. To ensure broad participation from existing monitoring sites and to establish new sites, these linking methods must be as informative, reliable, affordable, and maintainable as possible, and should be supplemented by near real-time remote sensing data. The proposed novel meta-network will enable the detection of emergent patterns that would not be visible from isolated analyses of individual sites. In addition, the near real-time availability of data will facilitate predictions of current forest conditions (nowcasts), which are urgently needed for research and decision making in the face of rapid climate change. We call for international and interdisciplinary efforts in this direction.
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To what degree plant ecosystems thermoregulate their canopy temperature (Tc ) is critical to assess ecosystems' metabolisms and resilience with climate change, but remains controversial, with opinions from no to moderate thermoregulation capability. With global datasets of Tc , air temperature (Ta ), and other environmental and biotic variables from FLUXNET and satellites, we tested the 'limited homeothermy' hypothesis (indicated by Tc & Ta regression slope < 1 or Tc < Ta around midday) across global extratropics, including temporal and spatial dimensions. Across daily to weekly and monthly timescales, over 80% of sites/ecosystems have slopes ≥1 or Tc > Ta around midday, rejecting the above hypothesis. For those sites unsupporting the hypothesis, their Tc -Ta difference (ΔT) exhibits considerable seasonality that shows negative, partial correlations with leaf area index, implying a certain degree of thermoregulation capability. Spatially, site-mean ΔT exhibits larger variations than the slope indicator, suggesting ΔT is a more sensitive indicator for detecting thermoregulatory differences across biomes. Furthermore, this large spatial-wide ΔT variation (0-6°C) is primarily explained by environmental variables (38%) and secondarily by biotic factors (15%). These results demonstrate diverse thermoregulation patterns across global extratropics, with most ecosystems negating the 'limited homeothermy' hypothesis, but their thermoregulation still occurs, implying that slope < 1 or Tc < Ta are not necessary conditions for plant thermoregulation.
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Ecosistema , Plantas , Regulación de la Temperatura Corporal , Temperatura , Cambio ClimáticoRESUMEN
OBJECTIVE: High BMI is associated with many comorbidities and mortality. This study aimed to elucidate the overall clinical risk of obesity using a genome- and phenome-wide approach. METHODS: This study performed a phenome-wide association study of BMI using a clinical cohort of 736,726 adults. This was followed by genetic association studies using two separate cohorts: one consisting of 65,174 adults in the Electronic Medical Records and Genomics (eMERGE) Network and another with 405,432 participants in the UK Biobank. RESULTS: Class 3 obesity was associated with 433 phenotypes, representing 59.3% of all billing codes in individuals with severe obesity. A genome-wide polygenic risk score for BMI, accounting for 7.5% of variance in BMI, was associated with 296 clinical diseases, including strong associations with type 2 diabetes, sleep apnea, hypertension, and chronic liver disease. In all three cohorts, 199 phenotypes were associated with class 3 obesity and polygenic risk for obesity, including novel associations such as increased risk of renal failure, venous insufficiency, and gastroesophageal reflux. CONCLUSIONS: This combined genomic and phenomic systematic approach demonstrated that obesity has a strong genetic predisposition and is associated with a considerable burden of disease across all disease classes.
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Diabetes Mellitus Tipo 2 , Fenómica , Humanos , Registros Electrónicos de Salud , Estudio de Asociación del Genoma Completo , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/genética , Polimorfismo de Nucleótido Simple , Genómica , Predisposición Genética a la Enfermedad , Obesidad/epidemiología , Obesidad/genética , Fenotipo , Costo de EnfermedadRESUMEN
Understanding and predicting the relationship between leaf temperature (Tleaf) and air temperature (Tair) is essential for projecting responses to a warming climate, as studies suggest that many forests are near thermal thresholds for carbon uptake. Based on leaf measurements, the limited leaf homeothermy hypothesis argues that daytime Tleaf is maintained near photosynthetic temperature optima and below damaging temperature thresholds. Specifically, leaves should cool below Tair at higher temperatures (i.e., > â¼25-30°C) leading to slopes <1 in Tleaf/Tair relationships and substantial carbon uptake when leaves are cooler than air. This hypothesis implies that climate warming will be mitigated by a compensatory leaf cooling response. A key uncertainty is understanding whether such thermoregulatory behavior occurs in natural forest canopies. We present an unprecedented set of growing season canopy-level leaf temperature (Tcan) data measured with thermal imaging at multiple well-instrumented forest sites in North and Central America. Our data do not support the limited homeothermy hypothesis: canopy leaves are warmer than air during most of the day and only cool below air in mid to late afternoon, leading to Tcan/Tair slopes >1 and hysteretic behavior. We find that the majority of ecosystem photosynthesis occurs when canopy leaves are warmer than air. Using energy balance and physiological modeling, we show that key leaf traits influence leaf-air coupling and ultimately the Tcan/Tair relationship. Canopy structure also plays an important role in Tcan dynamics. Future climate warming is likely to lead to even greater Tcan, with attendant impacts on forest carbon cycling and mortality risk.
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Ciclo del Carbono , Carbono , Bosques , Hojas de la Planta , Carbono/metabolismo , Hojas de la Planta/anatomía & histología , Hojas de la Planta/metabolismo , TemperaturaRESUMEN
BACKGROUND: Type 2 Diabetes Mellitus (T2DM) is highly prevalent comorbidity in patients with morbid obesity. It is still unclear whether a cutoff value of preoperative A1c represents an increased risk for major postoperative complications following Roux-en-Y Gastric Bypass (RYGB) and Sleeve Gastrectomy (SG). METHODS: Retrospective MBSAQIP Participant Use File cohort for both years 2017 and 2018 were analyzed to evaluate the relationship between HbA1c in patients with morbid obesity and T2DM undergoing bariatric surgery, and the 30 days postoperative major complications by Clavien-Dindo classification (III/IV). We used an HbA1c cutoff of <7, > =7, and stratified by 1% increment for a total of 11 groups. We used univariate and multivariate logistic regression to analyze the outcome of the complications. Predicted probabilities were calculated for major complications. All statistical tests were two-sided with a P-value of less than .05 considered as a cut-off for statistical significance. RESULTS: Of 42,181 patients that met inclusion criteria, there were 20,955 identified with HbA1c <7%, and 21,226 patients with HbA1c >7%. Utilizing HbA1c <7% as a cutoff, we found no consistent statistical significance in the major postoperative complication in patients with HbA1c >7%, and when stratified with 1% increment between groups. We also found no significance between groups with risk adjustment. CONCLUSIONS: Extensive analysis of the large MBSAQIP cohort didn't result in a clinically significant association between stratified HbA1c and 30-day Clavien-Dindo major complications (III/IV) following Roux-en-Y Gastric Bypass (RYGB) and (SG).
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Cirugía Bariátrica , Diabetes Mellitus Tipo 2 , Derivación Gástrica , Obesidad Mórbida , Cirugía Bariátrica/efectos adversos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/cirugía , Gastrectomía/efectos adversos , Derivación Gástrica/efectos adversos , Hemoglobina Glucada , Humanos , Obesidad Mórbida/complicaciones , Obesidad Mórbida/cirugía , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Body fat distribution is a major, heritable risk factor for cardiometabolic disease, independent of overall adiposity. Using exome-sequencing in 618,375 individuals (including 160,058 non-Europeans) from the UK, Sweden and Mexico, we identify 16 genes associated with fat distribution at exome-wide significance. We show 6-fold larger effect for fat-distribution associated rare coding variants compared with fine-mapped common alleles, enrichment for genes expressed in adipose tissue and causal genes for partial lipodystrophies, and evidence of sex-dimorphism. We describe an association with favorable fat distribution (p = 1.8 × 10-09), favorable metabolic profile and protection from type 2 diabetes (~28% lower odds; p = 0.004) for heterozygous protein-truncating mutations in INHBE, which encodes a circulating growth factor of the activin family, highly and specifically expressed in hepatocytes. Our results suggest that inhibin ßE is a liver-expressed negative regulator of adipose storage whose blockade may be beneficial in fat distribution-associated metabolic disease.
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Diabetes Mellitus Tipo 2 , Subunidades beta de Inhibinas/genética , Tejido Adiposo , Adiposidad/genética , Diabetes Mellitus Tipo 2/genética , Exoma/genética , Humanos , MutaciónRESUMEN
BACKGROUND: Exome sequencing in hundreds of thousands of persons may enable the identification of rare protein-coding genetic variants associated with protection from human diseases like liver cirrhosis, providing a strategy for the discovery of new therapeutic targets. METHODS: We performed a multistage exome sequencing and genetic association analysis to identify genes in which rare protein-coding variants were associated with liver phenotypes. We conducted in vitro experiments to further characterize associations. RESULTS: The multistage analysis involved 542,904 persons with available data on liver aminotransferase levels, 24,944 patients with various types of liver disease, and 490,636 controls without liver disease. We found that rare coding variants in APOB, ABCB4, SLC30A10, and TM6SF2 were associated with increased aminotransferase levels and an increased risk of liver disease. We also found that variants in CIDEB, which encodes a structural protein found in hepatic lipid droplets, had a protective effect. The burden of rare predicted loss-of-function variants plus missense variants in CIDEB (combined carrier frequency, 0.7%) was associated with decreased alanine aminotransferase levels (beta per allele, -1.24 U per liter; 95% confidence interval [CI], -1.66 to -0.83; P = 4.8×10-9) and with 33% lower odds of liver disease of any cause (odds ratio per allele, 0.67; 95% CI, 0.57 to 0.79; P = 9.9×10-7). Rare coding variants in CIDEB were associated with a decreased risk of liver disease across different underlying causes and different degrees of severity, including cirrhosis of any cause (odds ratio per allele, 0.50; 95% CI, 0.36 to 0.70). Among 3599 patients who had undergone bariatric surgery, rare coding variants in CIDEB were associated with a decreased nonalcoholic fatty liver disease activity score (beta per allele in score units, -0.98; 95% CI, -1.54 to -0.41 [scores range from 0 to 8, with higher scores indicating more severe disease]). In human hepatoma cell lines challenged with oleate, CIDEB small interfering RNA knockdown prevented the buildup of large lipid droplets. CONCLUSIONS: Rare germline mutations in CIDEB conferred substantial protection from liver disease. (Funded by Regeneron Pharmaceuticals.).