Zimmowitch, Anaëlle

Abstract Rationale Oscillometry measures the mechanical properties of the respiratory system using the response to pressure signals superimposed on tidal breathing. The JaegerTM IOS device generates “pulse packets” of harmonic frequencies between 5 and 35 Hz in 5 Hz intervals, while the Resmon ProTM V3 FOT and Thorasys TremofloTM C-100 employ prime pseudorandom sine waveforms between 5-19 Hz and 5-37 Hz, respectively. Prior studies have raised concerns about harmonic distortion with the IOS technique, but a direct comparison of reproducibility using current devices has not been performed. Methods Healthy volunteers with normal spirometry performed weekly oscillometry following ERS technical standards using JaegerTM and ResmonTM or ThorasysTM oscillometers in random order for 10 consecutive weeks. Z scores were calculated using Berger and Oostveen normative equations. Means, pooled within-subject distributions and interquartile range, standard error (SEM), coefficient of variation (CVw%), absolute and relative minimal detectable change (MDC, MDC%), and between device and subject intraclass correlation coefficients (ICC) were calculated for R5, R10/R11, R20/R19, R5-R20/R5-R19, X5, AX, and Fres and compared. Results Fifteen participants completed 10 weekly measurement sessions with JaegerTM and ResmonTM and twelve with JaegerTM and ThorasysTM. One subject did not complete the ResmonTM analysis due to intolerance; another subject only completed three weeks of ThorasysTM prior to work assignment change. The majority (65%) were female with mean (SD) age of 37.7 (10.2) years and BMI 27 (5) kg/m2. Rrs reproducibility was excellent across devices (ICC > 0.89), with more variability for X5, AX, and Fres (ICC 0.66 - 0.93) and little difference between devices (Figure 1). Small, systematic increases in mean Rrs were seen with JaegerTM compared to ResmonTM (5-10%, p < 0.008) and TremofloTM (5-12%, p < 0.02), with higher mean AX vs ResmonTM (44%, p = 0.002) and lower Fres vs TremofloTM (19%, p = 0.02). There was high ICC (0.97-0.99) across ResmonTM and TremofloTM Rrs comparisons with minimal bias. Intra-subject reproducibility was similar between devices. MDC% was 22.7-39.4% for Rrs values, 52.7-70.8% for X5, and 131-142% for AX. Conclusions JaegerTM, ResmonTM, and ThorasysTM oscillometers performed similarly in healthy adults over 10 weeks, with small but systematic measurement differences seen with the JaegerTM device. Rrs and Fres values demonstrated the greatest reproducibility both within and between subjects. Reactance measurements had less between-device agreement and higher MDC. Rrs, X5, and AX changes of up to 40%, 70%, and 140% over time may be due to normal subject and measurement variation. This abstract is funded by: 2024 Pulmonary, Critical Care, and Sleep Medicine Schuen Family Innovation Award

Background: Pregnancy in teenagers and emerging adults is associated with an increased risk of adverse outcomes. Similarly, pregnancies complicated by pregestational and gestational diabetes mellitus (GDM) carry a higher risk of complications. However, limited data exist on the intersection of these two high-risk conditions. Our objective was to establish the prevalence of teenage and emerging adult pregnancies complicated by diabetes in a population-based cohort and compare outcomes to pregnancies uncomplicated by diabetes, noting a background prevalence of GDM of 8.1% and pregestational diabetes of 1.2% across all age groups in the United States. Methods: This is a retrospective cohort study conducted in Olmsted County, Minnesota, USA. It includes female residents aged ≤21 years with a pregnancy ICD-10 code between January 1, 2013, and December 31, 2022. The main outcome measures assessed include maternal characteristics and maternal and fetal pregnancy outcomes. Results: A total of 1491 pregnancies in 1379 individuals were identified and included. In total, 68 (4.6%) pregnancies were complicated by diabetes: 51 (3.4%) with GDM and 17 (1.1%) with pregestational diabetes. In this study, pregnancies with diabetes had higher rates of adverse outcomes including cesarean delivery (GDM 29.4% vs. pregestational 60.0% vs. no diabetes 17.0%, P < 0.001), preeclampsia (GDM 15.7% vs. pregestational 40.0% vs. no diabetes 7.3%, P < 0.001), large-for-gestational-age neonates (GDM 13.7% vs. pre-existing 50.0% vs. no diabetes 5.8%, P < 0.001), and neonatal hypoglycemia (GDM 42.6% vs. pregestational 60.0% vs. no diabetes 13.3%, P < 0.001). Conclusions: The prevalence of pregestational diabetes in our teenage and emerging adult population is similar to that of the general pregnancy population; however, the prevalence of GDM is significantly lower. Overall, diabetes in teenage pregnancy is associated with an elevated risk of adverse maternal and neonatal outcomes. Future research should evaluate interventions aimed at reducing adverse pregnancy outcomes in this vulnerable population.