The paradoxical influence of the COVID-19 lockdown period on different types of preterm births in Alberta: a provincial study.

Objectives: The objective of this study was to determine if the COVID-19 pandemic impacted different types of preterm birth rates in Alberta, Canada. Methods: A population-based, retrospective, cohort study was conducted from March 15, 2015 to December 31, 2020 using provincial data. The primary exposure was the COVID-19 lockdown period, and the primary outcome was the incidence of preterm birth (<37 weeks gestational age). Multivariable analyses in the complete lockdown and overall lockdown (partial and complete lockdown) periods were performed to test the association between the year of birth and preterm birth status and were adjusted for various independent variables. Preterm birth status was adjusted for various confounding factors. Results: Following the analysis of n = 41,187 mothers and their singleton infants, we found that the lockdown due to COVID-19 had no impact in reducing the overall preterm birth rate. However, a paradoxical influence was observed with an increase of extremely low preterm births in the overall lockdown period, and a decrease in moderate preterm births during the complete lockdown period. Conclusions: The results of this study demonstrated that there was a decrease in moderate and increase in extremely low preterm birth rates as a result of the COVID-19 lockdown. However, the COVID-19 lockdown did not impact the very preterm and late preterm birth rate in Alberta.

Neuroprotection care bundle implementation is associated with improved long-term neurodevelopmental outcomes in extremely premature infants.

OBJECTIVE: To study the impact of an evidence-based neuroprotection care (NPC) bundle on long-term neurodevelopmental impairment (NDI) in infants born extremely premature. STUDY DESIGN: An NPC bundle targeting predefined risk factors for acute brain injury in extremely preterm infants was implemented. We compared the incidence of composite outcome of death or severe neurodevelopmental impairment (sNDI) at 21 months adjusted age pre and post bundle implementation. RESULTS: Adjusting for confounding factors, NPC bundle implementation associated with a significant reduction in death or sNDI (aOR, 0.34; 95% CI 0.17-0.68; P = 0.002), mortality (aOR, 0.31; 95% CI (0.12-0.79); P = 0.015), sNDI (aOR, 0.37; 95% CI: 0.12-0.94; P = 0.039), any motor, language, or cognitive composite score <70 (aOR, 0.48; 95% CI: 0.26-0.90; P = 0.021). CONCLUSION: Implementation of NPC bundle targeting predefined risk factors is associated with a reduction in mortality or sNDI in extremely preterm infants.

Defects in oxygen supply to skeletal muscle of prediabetic ZDF rats.

In humans, prediabetes is characterized by marked increases in plasma insulin and near normal blood glucose levels as well as microvascular dysfunction of unknown origin. Using the extensor digitorum longus muscle of 7-wk inbred male Zucker diabetic fatty rats fed a high-fat diet as a model of prediabetes, we tested the hypothesis that hyperinsulinemia contributes to impaired O(2) delivery in skeletal muscle. Using in vivo video microscopy, we determined that the total O(2) supply to capillaries in the extensor digitorum longus muscle of prediabetic rats was reduced to 64% of controls with a lower O(2) supply rate per capillary and higher O(2) extraction resulting in a decreased O(2) saturation at the venous end of the capillary network. These findings suggest a lower average tissue Po(2) in prediabetic animals. In addition, we determined that insulin, at concentrations measured in humans and Zucker diabetic fatty rats with prediabetes, inhibited the O(2)-dependent release of ATP from rat red blood cells (RBCs). This inability to release ATP could contribute to the impaired O(2) delivery observed in rats with prediabetes, especially in light of the finding that the endothelium-dependent relaxation of resistance arteries from these animals is not different from controls and is not altered by insulin. Computational modeling confirmed a significant 8.3-mmHg decrease in average tissue Po(2) as well as an increase in the heterogeneity of tissue Po(2), implicating a failure of a regulatory system for O(2) supply. The finding that insulin attenuates the O(2)-dependent release of ATP from RBCs suggests that this defect in RBC physiology could contribute to a failure in the regulation of O(2) supply to meet the demand in skeletal muscle in prediabetes.

Development of a beta-trace protein based formula for estimation of glomerular filtration rate.

Beta-trace protein (BTP) is a novel marker of glomerular filtration rate (GFR). To date, no pediatric formula for calculating GFR based on BTP has been developed. We measured GFR, serum creatinine and BTP in 387 children who underwent 474 (99m)Tc-diethylene triamine pentaacetic acid renal scans. A BTP-based formula for estimating GFR was derived using stepwise linear regression analysis. A separate control group of 116 measurements in 99 children was used to validate the novel formula. A formula was also developed for each gender. The novel formula is: [formula: see text]. The Spearman rank correlation coefficient between the BTP-derived GFR estimate and the measured GFR was 0.80 [95% confidence interval (CI) 0.76-0.83], which is substantially better than that derived with the Schwartz formula (r = 0.70, 95% CI 0.65-0.74). The Bland-Altman analysis revealed a mean bias of 1.21% [standard deviation (SD) 28%] in the formula development dataset, which was virtually identical to the 1.03% mean bias (29.5% SD) in the validation group and no different from the Schwartz formula bias. The percentage of values within 10% (33.0 vs. 28.3%) and 30% deviation (76.8 vs. 72.6%) were better for BTP-based formula than for the Schwartz formula. Separate formulas according to gender did not perform better than that for the pediatric population. This BTP-based formula was found to estimate GFR with reasonable precision and provided improved accuracy over the Schwartz GFR formula.