Search

Hybrid closed-loop (HCL) systems remain underexplored within aviation, and as atmospheric pressure changes can independently affect insulin pumps and continuous glucose monitoring readings, this preliminary study assessed the feasibility of HCL safety evaluation, in both fasting and post-prandial states, by using hypobaric chamber to simulate flights. Participants with type 1 diabetes and on HCL were studied: Medtronic Guardian 4-Medtronic 780G-SmartGuard (n = 4), Dexcom G6-Omnipod DASH-Android APS (n = 1), and Dexcom G6-Ypsomed Pump-CamAPS (n = 1). Flight cabin pressures of 550 mmHg and 750 mmHg were simulated in a hypobaric chamber. Seven-hundred-50 glucose measurements were taken, with glucose levels demonstrating a stable decline to 4 mmol/L during fasting. To maintain a tight fasting and post-prandial glucose range across the different pressure settings, the HCL administered insulin as expected. While not demonstrating any apparent issues, repeating flight simulation protocol with other systems, examining longer flights, and undertaking larger, powered randomised controlled trials can confirm their safety in aviation. [ABSTRACT FROM AUTHOR]

Black African-Caribbean (BAC) populations are at greater risk of cardiometabolic disease than White Europeans (WE), despite exhibiting lower fasting triacylglycerol (TAG) concentrations. However, limited data exist regarding postprandial fatty acid metabolism in BAC populations. This study determined the ethnic differences in postprandial fatty acid metabolism between overweight and obese WE and BAC men. WE [n = 10, age 33.3 ± 1.7 yr; body mass index (BMI) = 26.8 (25.8–31.0) kg/m2] and BAC [n = 9, age 27.9 ± 1.0 yr; BMI = 27.5 (26.0–28.6) kg/m2] men consumed two consecutive (at 0 and 300 min) moderate-to-high-fat meals—the first labeled with [U-13C]palmitate. The plasma concentration and appearance of meal-derived fatty acids in very-low-density lipoprotein (VLDL)-TAG, chylomicron-TAG, and nonesterified fatty acid (NEFA) were determined over an 8-h postprandial period. Indirect calorimetry with 13CO2 enrichment determined total and meal-derived fatty acid oxidation rates, and plasma β-hydroxybutyrate (3-OHB) concentration was measured to assess ketogenesis. BAC exhibited lower postprandial TAG [area under the curve (AUC0–480) = 671 (563–802) vs. 469 (354–623) mmol/L/min, P = 0.022] and VLDL-TAG [AUC0–480 = 288 ± 30 vs. 145 ± 27 mmol/L/min, P = 0.003] concentrations than WE. The appearance of meal-derived fatty acids in VLDL-TAG was lower in BAC than in WE (AUC0–480 = 133 ± 12 vs. 78 ± 13 mmol/L/min, P = 0.007). Following the second meal, BAC showed a trend for lower chylomicron-TAG concentration [AUC300–480 = 69 (51–93) vs. 43 (28–67) mmol/L/min, P = 0.057]. There were no ethnic differences in the appearance of chylomicron-TAG, cumulative fatty acid oxidation, and the NEFA:3-OHB ratio (P > 0.05). In conclusion, BAC exhibit lower postprandial TAG concentrations compared with WE men, driven by lower VLDL-TAG concentrations and possibly lower chylomicron-TAG in the late postprandial period. These findings suggest that postprandial fatty acid trafficking may be a less important determinant of cardiometabolic risk in BAC than in WE men. NEW & NOTEWORTHY: Postprandial TAG is lower in Black African-Caribbean men than in White European men, and this is likely driven by lower meal-derived VLDL-TAG in Black African-Caribbean men. This observation could suggest that fatty acid trafficking may be a less important determinant of cardiometabolic risk in Black Africans than in White European men. [ABSTRACT FROM AUTHOR]

Objective: This work aimed to investigate the effect of the SGLT2 inhibitor, dapagliflozin (DAPA), on cardiac function and the metabolic and hormonal response to moderate exercise in people with type 2 diabetes. Methods: This was a double-blind, placebo-controlled crossover study with a 4-week washout period. Nine participants were randomly assigned to receive either 4 weeks of DAPA or 4 weeks of placebo. After each treatment, they underwent an exercise protocol with 2 consecutive 10- minute stages at a constant load corresponding to 40% and 70% maximal oxygen consumption (VO2max), coupled with hormonal and metabolic analysis. A blinded transthoracic echocardiogram was performed 3 days later. Results: During the exercise protocol, glucose and lactate were lower (P<.0001 and P<.05, respectively) and β-hydroxybutyrate (BOBH) and growth hormone (GH) were higher (P<.0005 and P= .01) following DAPA treatment compared to placebo. There was a trend for lower insulin with DAPA. Adrenalin, noradrenalin, and glucagon were not different. Following DAPA participants demonstrated an increased mean peak diastolic mitral annular velocity (e') in comparison to placebo (P=.03). The indexed left atrial volume and right ventricular e" were reduced following DAPA compared with placebo (P=.045 and P=.042, respectively). Arterial stiffness was not different between treatments (DAPA 9.35±0.60 m/s; placebo 9.07±0.72 m/s). Conclusion: During exercise, GH may be more important than catecholamines in driving the shift from glucose to fatty acid metabolism by SGLT2 inhibitors. The 4-week crossover design showed changes in cardiac function were rapid in onset and reversible. [ABSTRACT FROM AUTHOR]

The article discusses the importance of managing health conditions, specifically diabetes, in pilots and air traffic control officers to ensure safe aviation operations. The study compares the use of Continuous Glucose Monitoring (CGM) and Self-Monitoring of Blood Glucose (SMBG) in pilots with diabetes, highlighting the benefits of CGM in terms of efficiency and user satisfaction. Pilots generally prefer CGM over SMBG due to its convenience and accuracy, potentially improving glucose management and preventing incapacitation during flights. The study suggests that CGMs hold promise in enhancing diabetes management in aviation, despite the need for calibration and frequent replacements. [Extracted from the article]

Non-alcoholic fatty liver disease (NAFLD) is associated with multi-organ (hepatic, skeletal muscle, adipose tissue) insulin resistance (IR). Exercise is an effective treatment for lowering liver fat but its effect on IR in NAFLD is unknown. We aimed to determine whether supervised exercise in NAFLD would reduce liver fat and improve hepatic and peripheral (skeletal muscle and adipose tissue) insulin sensitivity. Sixty nine NAFLD patients were randomized to 16 weeks exercise supervision (n = 38) or counselling (n = 31) without dietary modification. All participants underwent MRI/spectroscopy to assess changes in body fat and in liver and skeletal muscle triglyceride, before and following exercise/counselling. To quantify changes in hepatic and peripheral insulin sensitivity, a pre-determined subset (n = 12 per group) underwent a two-stage hyperinsulinaemic euglycaemic clamp pre- and post-intervention. Results are shown as mean [95% confidence interval (CI)]. Fifty participants (30 exercise, 20 counselling), 51 years (IQR 40, 56), body mass index (BMI) 31 kg/m² (IQR 29, 35) with baseline liver fat/water % of 18.8% (IQR 10.7, 34.6) completed the study (12/12 exercise and 7/12 counselling completed the clamp studies). Supervised exercise mediated a greater reduction in liver fat/water percentage than counselling [δ mean change 4.7% (0.01, 9.4); P<0.05], which correlated with the change in cardiorespiratory fitness (r = -0.34, P=0.0173). With exercise, peripheral insulin sensitivity significantly increased (following high-dose insulin) despite no significant change in hepatic glucose production (HGP; following low-dose insulin); no changes were observed in the control group. Although supervised exercise effectively reduced liver fat, improving peripheral IR in NAFLD, the reduction in liver fat was insufficient to improve hepatic IR. [ABSTRACT FROM AUTHOR]

Introduction: With the increasing use of aeromedical transport for critically ill patients, it is essential to understand the impact of pressure changes on drug infusion delivery systems. As airplanes ascend and descend, gases/bubbles are released from solutions when ambient pressure decreases and dissolves when pressure increases. This may affect mechanical fluid delivery systems and cause clinically significant changes, especially within a critical care setting. We aimed to evaluate the impact of pressure changes on volumetric pumps and syringe drivers., Methods: An in vitro study of six volumetric pumps and eight syringe drivers was conducted in a hypobaric chamber to mimic pressure changes during flights. Infusion devices were set to deliver water at 0.2 ml ⋅ h-1 and infused volumes were measured. There were 15 open-ended syringes also studied., Results: During ascent, syringe drivers and volumetric pumps over-delivered 173 µL and 38 µL of fluid. During descent, syringe drivers under-delivered by 166 µL, whereas volumetric pumps under-delivered by 9 µL. Syringe drivers experienced statistically significant changes in fluid delivery during both ascent and descent. In volumetric pumps, only the descent phase infusion differed significantly from other phases. The volume of fluid expansion is dependent on volume and the mechanical properties of the fluid., Discussion: Decreasing ambient pressure causes bubble formation, which displaces fluid, and increasing ambient pressure causes bubble reabsorption in mechanical infusion devices. Hence, atmospheric pressure changes during air travel may alter fluid delivery from medical fluid delivery systems and affect critically ill patients who require both aeromedical evacuation and accurate infusion of drugs. Fan KS, Paterson M, Shojaee-Moradie F, Manoli A, Edwards V, Lee V, Hutchison E, Gifford RM, Parsons IT, Koehler G, Mathieu C, Mader JK, King BR, Russell-Jones D; EASA Consortium. Performance of fluid infusion systems in the changing atmospheric pressures encountered in aviation. Aerosp Med Hum Perform. 2025; 96(1):4-11.