Changes in soluble LDL receptor and lipoprotein fractions in response to diet in the DIETFITS weight loss study.

Circulating levels of the soluble ligand-binding ectodomain of the LDL receptor (sLDLR) that is proteolytically cleaved from the cell surface have been shown to correlate with plasma triglycerides, but the lipid and lipoprotein effects of longitudinal changes in sLDLR have not been examined. We sought to assess associations between changes in sLDLR and detailed lipoprotein measurements between baseline and 6 months in participants in the DIETFITS (Diet Intervention Examining The Factors Interacting with Treatment Success) weight loss trial who were randomly assigned to the low-fat (n = 225) or low-carbohydrate (n = 236) diet arms. sLDLR was assayed using a proteomic procedure, lipids and apoprotein (apo) B and apoAI were measured by standard assays, and lipoprotein particle subfractions were quantified by ion mobility methodology. Changes in sLDLR were significantly positively associated with changes in plasma cholesterol, triglycerides, apoB, large-sized and medium-sized VLDL, and small and very small LDL, and inversely with changes in large LDL and HDL. The lipoprotein subfraction associations with sLDLR were independent of age, sex, diet, and BMI, but all except for large LDL were reduced to insignificance when adjusted for triglyceride change. Principal component analysis identified three independent clusters of changes in lipoprotein subfractions that accounted for 78% of their total variance. Change in sLDLR was most strongly correlated with change in the principal component that was loaded positively with large VLDL and small and very small LDL and negatively with large LDL and HDL. In conclusion, sLDLR is a component of a cluster of lipids and lipoproteins that are characteristic of atherogenic dyslipidemia.

How do we form and coordinate a national serosurvey of SARS-CoV-2 within the blood collection industry?

BACKGROUND: A national serosurvey of U.S. blood donors conducted in partnership with the Centers for Disease Control and Prevention (CDC) was initiated to estimate the prevalence of SARS-CoV-2 infections and vaccinations. METHODS: Beginning in July 2020, the Nationwide Blood Donor Seroprevalence Study collaborated with multiple blood collection organizations, testing labs, and leadership from government partners to capture, test, and analyze approximately 150,000 blood donation specimens per month in a repeated, cross-sectional seroprevalence survey. RESULTS: A CDC website (https://covid.cdc.gov/covid-data-tracker/#nationwide-blood-donor-seroprevalence) provided stratified, population-level results to public health professionals and the general public. DISCUSSION: The study adapted operations as the pandemic evolved, changing specimen flow and testing algorithms, and collecting additional data elements in response to changing policies on universal blood donation screening and administration of SARS-CoV-2 spike-based vaccines. The national serosurvey demonstrated the utility of serosurveillance testing of residual blood donations and highlighted the role of the blood collection industry in public-private partnerships during a public health emergency.

Reach, engagement and effectiveness of in-person and online lifestyle change programs to prevent diabetes.

BACKGROUND: COVID-19 has accelerated interest in and need for online delivery of healthcare. We examined the reach, engagement and effectiveness of online delivery of lifestyle change programs (LCP) modelled after the Diabetes Prevention Program (DPP) in a multistate, real-world setting. METHODS: Longitudinal, non-randomized study comparing online and in-person LCP in a large multistate sample delivered over 1 year. Sample included at-risk adults (n = 26,743) referred to online (n = 9) and in-person (n = 11) CDC-recognized LCP from a multi-state registry (California, Florida and Colorado) between 2015 and 2018. The main outcome was effectiveness (proportion achieving > 5% weight loss) at one-year. Our secondary outcomes included reach (proportion enrolled among referred) and engagement (proportion ≥ 9 sessions by week 26). We used logistic regression modelling to assess the association between participant- and setting -level characteristics with meaningful weight loss. RESULTS: Online LCP effectiveness was lower, with 23% of online participants achieving > 5% weight loss, compared with 35% of in-person participants (p < 0.001). More adults referred to online programs enrolled (56% vs 51%, p < 0.001), but fewer engaged at 6-months (attendance at ≥9 sessions 46% vs 66%, p < 0.001) compared to in-person participants. CONCLUSIONS: Compared to adults referred to in-person LCP, those referred to online LCP were more likely to enroll and less likely to engage. Online participants achieved modest meaningful weight loss. Online delivery of LCP is an attractive strategy to deliver and scale DPP, particularly with social distancing measures currently in place. However, it is unclear how to optimize delivery models for maximal impact given trade-offs in reach and effectiveness.

Secondary procedures following thoracic aortic stent grafting in the first 3 years of the VALOR test and VALOR II trials.

PURPOSE: To compare the durability of thoracic endovascular aortic repair (TEVAR) in two similar clinical trials that used early- and later-generation stent grafts. MATERIALS AND METHODS: Secondary procedures from the prospective, nonrandomized, multicenter, clinical trial databases of the test arm of the VALOR and VALOR II trials were analyzed at 3 years. Descriptive and statistical analyses were employed to compare the rate of and potential predictors for secondary procedures. RESULTS: A total of 127 and 96 patients were available for a minimum of 3 years of follow-up in the test arm of VALOR and VALOR II, respectively. By the first year after the index procedure, VALOR II patients were significantly less likely to have undergone a secondary procedure versus patients in the test arm of VALOR (odds ratio [OR], 0.08; 95% confidence interval [CI], 0.01-0.63; P = .02), with most procedures performed for type I endoleak. Multivariate predictors at 3 years for the need for a secondary procedure in the VALOR test arm were maximum aneurysm diameter (P = .002) and aneurysm length (P = .01), both of which remained significant at the end of the study period. The estimated freedoms from secondary procedures in the VALOR test arm and VALOR II at 3 years were 85.1% (95% CI, 78.5%-89.8%) and 94.9% (95% CI, 88.8%-97.7%), respectively (P < .001). CONCLUSIONS: The rate of secondary procedures after TEVAR differed between the two cohorts, being substantially lower in the VALOR II trial at 1 year of follow-up. This finding suggests significant benefit from advances in some combination of operator experience, imaging systems, treatment planning, and device design.

Engineering goals for future thoracic endografts-how can we make them more effective?

Endovascular treatments for catastrophic aortic conditions have gained increasing popularity over the past 20 years. Originally developed for abdominal aortic aneurysms (EVAR), treatment has been modified for use in thoracic aortic repair (TEVAR). As expanding numbers of patients with increasingly intractable conditions and more hostile anatomies are treated, endovascular stent designs are maturing to be suitable for these more demanding situations. This article discusses the engineering considerations that apply to changing stent graft designs for current and evolving thoracic applications. The biological parameters that differentiate thoracic from abdominal aortic environments are outlined. Factors concerning materials, sealing mechanisms, deployment, stent frame architecture, and migration resistance are described, and eagerly awaited potential future developments are summarized.