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BACKGROUND: Systemic arterial compliance and venous capacitance are typically impaired in patients with heart failure with preserved ejection fraction (HFpEF), contributing to hemodynamic congestion with stress. Sodium-glucose cotransporter-2 inhibitors reduce hemodynamic congestion and improve clinical outcomes in patients with HFpEF, but the mechanisms remain unclear. This study tested the hypothesis that Dapagliflozin would improve systemic arterial compliance and venous capacitance during exercise in patients with HFpEF. METHODS: In this secondary analysis from the CAMEO-DAPA trial (Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction Trial), 37 patients with HFpEF (mean age 68 ± 9 years, women 65%) underwent invasive hemodynamic exercise testing with simultaneous echocardiography at baseline and following treatment for 24 weeks with Dapagliflozin or placebo. Radial artery pressure (BP) was measured continuously using a fluid-filled catheter with transformation to aortic pressure, central hemodynamics were measured using high-fidelity micromanometers, and stressed blood volume was estimated from hemodynamic indices fit to a comprehensive cardiovascular model. RESULTS: There was no statistically significant effect of Dapagliflozin on resting BP, but Dapagliflozin reduced systolic BP during peak exercise (estimated treatment difference [ETD], −18.8 mm Hg [95% CI, −33.9 to −3.7] P =0.016). Reduction in BP was related to improved exertional total arterial compliance (ETD, 0.06 mL/mm Hg/m 2 [95% CI, 0.003–0.11] P =0.039) and aortic root characteristic impedance (ETD, −2.6 mm Hg/mL*sec [95% CI: −5.1 to −0.03] P =0.048), with no significant effect on systemic vascular resistance. Dapagliflozin reduced estimated stressed blood volume at rest and during peak exercise (ETD, −292 mm Hg [95% CI, −530 to −53] P =0.018), and improved venous capacitance evidenced by a decline in ratio of estimated stressed blood volume to total blood volume (ETD, −7.3% [95% CI, −13.3 to −1.3] P =0.020). Each of these effects of Dapagliflozin at peak exercise were also observed during matched 20W exercise intensity. Improvements in total arterial compliance and estimated stressed blood volume were correlated with decreases in body weight, and reduction in systolic BP with treatment was correlated with the change in estimated stressed blood volume during exercise (r=0.40, P =0.019). Decreases in BP were correlated with reduction in pulmonary capillary wedge pressure during exercise (r=0.56, P <0.001). CONCLUSIONS: In patients with HFpEF, treatment with Dapagliflozin improved systemic arterial compliance and venous capacitance during exercise, while reducing aortic characteristic impedance, suggesting a reduction in arterial wall stiffness. These vascular effects may partially explain the clinical benefits with sodium-glucose cotransporter-2 inhibitors in HFpEF. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04730947.

ImportanceIncreases in pulmonary capillary wedge pressure (PCWP) during exercise reduce pulmonary artery (PA) compliance, increase pulsatile right ventricular (RV) afterload, and impair RV-PA coupling in patients with heart failure with preserved ejection fraction (HFpEF). The effects of the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin on pulmonary vascular properties and RV-PA coupling are unknown.ObjectiveTo test the effect of dapagliflozin on right ventricular performance and pulmonary vascular load during exertion in HFpEF.Design, Setting, and ParticipantsEvaluation of the Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction (CAMEO-DAPA) randomized clinical trial demonstrated improvement in PCWP at rest and exercise over 24 weeks with dapagliflozin compared with placebo with participants recruited between February 2021 and May 2022. This secondary analysis evaluates the effects of dapagliflozin on pulsatile pulmonary vascular load and RV-PA coupling using simultaneous echocardiography and high-fidelity invasive hemodynamic testing with exercise. This was a single-center study including patients with hemodynamically confirmed HFpEF with exercise PCWP of 25 mm Hg or greater.InterventionsDapagliflozin or placebo for 24 weeks.Main Outcomes and MeasuresPulsatile pulmonary vascular load (PA compliance and elastance) and right ventricular performance (PA pulsatility index, RV systolic velocity [s′]/PA mean) during rest and exercise.ResultsAmong 37 randomized participants (mean [SD] age, 67.4 [8.5] years; 25 female [65%]; mean [SD] body mass index, 34.9 [6.7]; calculated as weight in kilograms divided by height in meters squared), there was no effect of dapagliflozin on PA loading or RV-PA interaction at rest. However, with exercise, dapagliflozin improved PA compliance (placebo-corrected mean difference, 0.57 mL/mm Hg; 95% CI, 0.11-1.03 mL/mm Hg; P = .02) and decreased PA elastance (stiffness; −0.17 mm Hg/mL; 95% CI, −0.28 to −0.07 mm Hg/mL; P = .001). RV function during exercise improved, with increase in PA pulsatility index (0.33; 95% CI, 0.08-0.59; P = .01) and increase in exercise RV s′ indexed to PA pressure (0.09 cm·s−1/mm Hg; 95% CI, 0.02-0.16 cm·s−1/mm Hg; P = .01). Improvements in pulsatile RV load and RV-PA coupling were correlated with reduction in right atrial (RA) pressure (PA elastance Pearson r = 0.55; P =.008; RV s′/PA elastance Pearson r = −0.60; P =.002) and PCWP (PA elastance Pearson r = 0.58; P &amp;lt;.001; RV s′/PA elastance Pearson r = −0.47; P = .02). Dapagliflozin increased resistance-compliance time (dapagliflozin, median [IQR] change, 0.06 [0.03-0.15] seconds; placebo, median [IQR] change, 0.01 [−0.02 to 0.05] seconds; P =.046), resulting in higher PA compliance for any exercise pulmonary vascular resistance.Conclusions and RelevanceResults of this randomized clinical trial reveal that treatment with dapagliflozin for 24 weeks reduced pulsatile pulmonary vascular load and enhanced dynamic RV-PA interaction during exercise in patients with HFpEF, findings that are related to the magnitude of PCWP reduction. Benefits on dynamic right ventricular–pulmonary vascular coupling may partially explain the benefits of SGLT2 inhibitors in HFpEF.Trial RegistrationClinicalTrials.gov Identifier: NCT04730947

Background National guidelines recommend that waist circumference (WC) be measured in patients with a body mass index (BMI) 27–35 kg/m2. Unfortunately, perhaps due to logistical reasons, WC is seldom measured in clinical settings. Herein, we describe the performance of a self-operated waist measurement device (SOWMD) as a potential means to overcome barriers to measuring WC. Materials and methods Ten volunteers underwent WC measures by professionals and SOWMD on 5 separate days to assess the reproducibility and accuracy. We then compared SOWMD measures with CT-derived fat content by recruiting 81 patients scheduled for a diagnostic abdominal CT scan. Results There was no difference between professionally measured and SOWMD-measured WC; the intraindividual coefficient of variation over the 5 days was between 0.4% and 2.2%. The WC measured manually, by SOWMD and CT scan were highly correlated (r=0.90–0.92, all p<0.001). The minimal WC measured by SOWMD was a better predictor (r=0.81 for all patients, r=0.87 for men, both p<0.001) of CT-measured visceral adipose tissue volume than other approaches. The minimal WC measured by SOWMD was correlated with fasting plasma glucose (r=0.40, p<0.05), triglyceride (r=0.41, p<0.01) and high-density cholesterol (r=−0.49, p<0.001) concentrations. Conclusion SOWMD is a reproducible, accurate and convenient way to measure WC that can provide added value for health care providers when combined with BMI information.

BACKGROUND. Upper-body obesity (UBO) results in insulin resistance with regards to free fatty acid (FFA) release; how this differs by fat depot and sex between adults with UBO and lean adults is unknown. We tested the hypothesis that insulin suppression of FFA release from the splanchnic bed, leg fat, and upper-body nonsplanchnic (UBNS) adipose tissue would be impaired in UBO. METHODS. Fourteen volunteers with UBO (7 men and 7 women) and 14 healthy volunteers with normal weight (7 men and 7 women) participated in studies that included femoral artery, femoral vein, and hepatic vein catheterization. We then measured leg and splanchnic plasma flow as well as FFA kinetics (using isotopic tracers) under overnight fasting as well as low- and high-dose insulin infusion using the insulin clamp technique. RESULTS. We found the expected insulin resistance in UBO; the most quantitatively important difference between adults with UBO and lean adults was greater FFA release from UBNS adipose tissue when plasma insulin concentrations were in the postprandial, physiological range. There were obesity, but not sex, differences in the regulation of splanchnic FFA release and sex differences in the regulation of leg FFA release. CONCLUSION. Reversing the defects in insulin-regulated UBNS adipose tissue FFA release would have the greatest effect on systemic FFA abnormalities in UBO. FUNDING. These studies were supported by the US Public Health Service (grants DK45343 and DK40484), the Novo Nordic Foundation (grant NNF18OC0031804 and NNF16OC0021406), and the Independent Research Fund Denmark (grant 8020-00420B).

Abstract Objective The pathological expansion of white adipose tissue (WAT) in obesity involves adipocyte hypertrophy accompanied by expansion of the collagen‐rich pericellular extracellular matrix (ECM) and development of crown‐like structures (CLS). Traditionally, WAT morphology is assessed through immunohistochemical analysis of WAT sections. However, manual analysis of large histological sections is time‐consuming, and the available digital tools for analyzing adipocyte size and pericellular ECM are limited. To address this gap, the authors developed the Adipose Tissue Analysis Toolkit (ATAT), an ImageJ plugin facilitating analysis of adipocyte size, WAT ECM, and CLS. Methods and Results ATAT utilizes local and image‐level differentials in pixel intensity to independently threshold image background, distinguishing adipocyte‐free tissue without user input. It accurately captures adipocytes in histological sections stained with common dyes and automates the analysis of adipocyte cross‐sectional area, total‐field, and localized region‐of‐interest ECM. ATAT allows fully automated batch analysis of histological images using default or user‐defined adipocyte detection parameters. Conclusions ATAT provides several advantages over existing WAT image analysis tools, enabling high‐throughput analyses of adipocyte‐specific parameters and facilitating the assessment of ECM changes associated with WAT remodeling due to weight changes and other pathophysiological alterations that affect WAT function.

Background A multitude of studies have suggested that there is a link between obesity and inflammation. Various in vitro and animal studies have shown that saturated fatty acids are largely responsible for the induction of various pro‐inflammatory pathways. As vegetarians consume about half the amount of saturated fat as omnivores, we hypothesized that they would have less inflammation for any given amount of obesity. Objective To quantitate the inflammatory status of adipose tissue from obese vegetarians and omnivores. Methods The study included 8 obese vegetarians (1 male) and 8 obese omnivores matched for age, sex, and BMI. Body composition was measured by DXA. A blood sample was collected to measure plasma free fatty acids (FFA), subcutaneous adipose tissue biopsies to measure macrophage content and muscle biopsies to quantify diacylglycerol (DAG) and ceramide content. Each participant also completed a Food Frequency Questionnaire (FFQ) to determine their average dietary intake. Results By design there were no differences in age, weight, BMI, percentage body fat, fat free mass or adipocyte size between the omnivore and vegetarian group. We found that vegetarians consume lower amounts of saturated fatty acids and cholesterol while consuming higher amounts of fiber and vitamin C than the omnivore participants ( p = 0.06, 0.04, 0.004, 0.04 respectively). The plasma FFA of vegetarians revealed that they had greater proportions of the polyunsaturated fatty acids linoleic, linolenic ( p = 0.01, 0.02 respectively) as well as increased monounsaturated oleic acid ( p = 0.04). The inflammatory status of adipose tissue was quantified by measuring macrophage content (total, pro‐inflammatory M1, and anti‐inflammatory M2 macrophages). The vegetarian group had significantly lower adipose tissue total ( p = 0.004), M1 ( p = 0.002), and M2 ( p = 0.01) macrophage burden when compared the omnivore group. There was a difference, however, in muscle DAG and ceramide content between the two groups. Conclusions As expected, vegetarians consume a diet that varies in key macro‐ and micronutrients that may affect inflammatory status. Indeed, the vegetarian group had significantly lower adipose tissue macrophage burden than the omnivore participants despite their obese state. While these variations in dietary intake seem to have a positive impact on the adipose tissue immune cell milieu there was no difference in the potential inflammatory cell signaling components of the muscle tissue, DAGs and ceramides, between the two groups. These promising results display the importance of dietary intake in modulating adipose tissue inflammation and potentially chronic disease.