Category: Statistics

J Sports Sci. 2021 Sep 28:1-10. doi: 10.1080/02640414.2021.1982516. Online ahead of print.

ABSTRACT

This study investigated the effect of crank length on biomechanical parameters and muscle activity during standing cycling. Ten participants performed submaximal cycling trials on a stand-up bicycle using four crank lengths. Joint angles, moments, powers, and works of the lower limbs were calculated from motion data and pedal reaction forces. Electromyographic (EMG) data were recorded from gluteus maximus (GM), vastus medialis, rectus femoris, biceps femoris (BF), gastrocnemius medialis, soleus, and tibialis anterior, and used to obtain the integrated EMG. Statistical parametric mapping was employed to analyse the biomechanical parameters throughout the pedalling cycle. Knee and hip flexion angles and hip power increased at the initiation (0-20%) of pedalling with increasing crank length, while the BF and GM muscle activities increased during propulsion (20-40%). Additionally, increasing the crank length resulted in increased knee power absorption during upstroke phase (70-100%). Peak knee extension moment increased with decreasing crank length during propulsion, but the moment at a short crank length during propulsion was comparable to fast walking. Consequently, longer crank lengths require increased propulsion power by the lower limb muscles during standing cycling compared to shorter crank lengths. Therefore, shorter crank lengths are recommended for stand-up bicycles to avoid fatigue.

PMID:34581253 | DOI:10.1080/02640414.2021.1982516

J Endovasc Ther. 2021 Sep 28:15266028211047954. doi: 10.1177/15266028211047954. Online ahead of print.

ABSTRACT

PURPOSE: Hybrid aortic arch repair (HAR) has been implemented for extended aortic arch and descending thoracic aortic disease since 2012 in our institution. This study aimed to estimate the early and mid-term efficacy and safety of HAR.

MATERIALS AND METHODS: From 2007 to 2019, 56 patients underwent HAR for extended aortic arch disease, and 75 patients underwent total arch replacement (TAR) for arch-limited disease. HAR comprises 3 procedures: replacement of the aorta, reconstruction of all arch vessels, and thoracic endovascular aortic repair (TEVAR) from zone 0 to the descending aorta after cardiopulmonary bypass is off in 1 stage. The type II-1 HAR procedure, in which the ascending aorta and aortic arch distal to the brachiocephalic artery are replaced, was the most frequently selected procedure (40/56 patients). The outcomes of the type II-1 HAR procedure were compared with those of TAR using the Cox regression analysis.

RESULTS: The median follow-up period was 36 months. In HAR, the operative mortality, in-hospital mortality, and postoperative permanent neurological deficits were not observed. The paraplegia rate was 1.8%. TEVAR-related complications occurred in 3 patients. Among the patients with non-ruptured atherosclerotic aortic arch aneurysm (31 type II-1 HAR patients and 36 TAR patients, the postoperative respiratory support time in those who underwent type II-1 HAR was quicker than in those who underwent TAR (p<0.01). The rate of 6 year freedom from all-cause death in type II-1 HAR (83.1%) was numerically higher than that in TAR (74.7%), and the rate of 6 year freedom from surgery-related complications in type II-1 HAR (90.3%) was numerically lower than that in TAR (96.9%) due to the occurrence of TEVAR-related complications, and the rate of 6 year freedom from reintervention to the descending thoracic aorta in type II-1 HAR (100%) seemed to be better than that in TAR (83.7%). However, Cox regression analysis did not reveal any statistical difference between the 2 procedures.

CONCLUSIONS: HAR, especially the type II-1 procedure, can treat extended aortic arch disease with acceptable survival outcomes. The development of TEVAR technology will further improve the outcomes of HAR in the future.

PMID:34581224 | DOI:10.1177/15266028211047954

AIDS Care. 2021 Sep 28:1-9. doi: 10.1080/09540121.2021.1981218. Online ahead of print.

ABSTRACT

Understanding factors related to suboptimal adherence to antiretroviral therapy (ART) and detectable viral load (VL), especially among vulnerable populations, is needed to improve HIV outcomes. The Caribbean is highly impacted by HIV and socioeconomic inequalities, but few studies have been conducted there to explore food insecurity among people with HIV and factors associated with viral suppression in this vulnerable population. Using baseline data from a pilot intervention trial among people living with HIV and food insecurity in the Dominican Republic, we examined psychosocial and behavioral factors associated with viral suppression, ART adherence, and competing needs. Among participants (n = 115), 61% had a detectable VL; the strongest factor associated with detectable VL was having missed taking ART in the last six months due to not having food (OR = 2.68, p = 0.02). Greater odds of reporting missed ART doses due to not having food were associated with severe food insecurity (OR = 4.60, p = 0.006), clinical depression (OR = 2.76, p = 0.018), Haitian background (OR = 6.62 p = 0.017), and internalized HIV stigma (OR = 1.09, p = 0.041), while lower odds were associated with social support (OR = 0.89, p = 0.03) and having health insurance (OR = 0.27, p = 0.017). Ensuring that people with HIV and food insecurity have food to take with their ART is essential for viral suppression.

PMID:34581230 | DOI:10.1080/09540121.2021.1981218

J Am Heart Assoc. 2021 Sep 28:e021748. doi: 10.1161/JAHA.120.021748. Online ahead of print.

ABSTRACT

Background The treatment of aortic stenosis is evolving rapidly. Pace of change in the care of patients undergoing transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) differs. We sought to determine differences in temporal changes in 30-day mortality, 30-day readmission, and length of stay after TAVR and SAVR. Methods and Results We conducted a retrospective cohort study of patients treated in the United States between 2012 and 2019 using data from the Medicare Data Set Analytic File 100% Fee for Service database. We included consecutive patients enrolled in Medicare Parts A and B and aged ≥65 years who had SAVR or transfemoral TAVR. We defined 3 study cohorts, including all SAVR, isolated SAVR (without concomitant procedures), and elective isolated SAVR and TAVR. The primary end point was 30-day mortality; secondary end points were 30-day readmission and length of stay. Statistical models controlled for patient demographics, frailty measured by the Hospital Frailty Risk Score, and comorbidities measured by the Elixhauser Comorbidity Index (ECI). Cox proportional hazard models were developed with TAVR versus SAVR as the main covariates with a 2-way interaction term with index year. We repeated these analyses restricted to full aortic valve replacement hospitals offering both SAVR and TAVR. The main study cohort included 245 269 patients with SAVR and 188 580 patients with TAVR, with mean±SD ages 74.3±6.0 years and 80.7±6.9 years, respectively, and 36.5% and 46.2% female patients, respectively. Patients with TAVR had higher ECI scores (6.4±3.6 versus 4.4±3) and were more frail (55.4% versus 33.5%). Total aortic valve replacement volumes increased 61% during the 7-year span; TAVR volumes surpassed SAVR in 2017. The magnitude of mortality benefit associated with TAVR increased until 2016 in the main cohort (2012: hazard ratio [HR], 0.76 [95% CI, 0.67-0.86]; 2016: HR, 0.39 [95% CI, 0.36-0.43]); although TAVR continued to have lower mortality rates from 2017 to 2019, the magnitude of benefit over SAVR was attenuated. A similar pattern was seen with readmission, with a lower risk of readmission from 2012 to 2016 for patients with TAVR (2012: HR, 0.68 [95% CI, 0.63-0.73]; 2016: HR, 0.43 [95% CI, 0.41-0.45]) followed by a lesser difference from 2017 to 2019. Year over year, TAVR was associated with increasingly shorter lengths of stay compared with SAVR (2012: HR, 1.91 [95% CI, 1.84-1.98]; 2019: HR, 5.34 [95% CI, 5.22-5.45]). These results were consistent in full aortic valve replacement hospitals. Conclusions The rate of improvement in TAVR outpaced SAVR until 2016, with the recent presence of U-shaped phenomena suggesting a narrowing gap between outcomes. Future longitudinal research is needed to determine the long-term implications of lowering risk profiles across treatment options to guide case selection and clinical care.

PMID:34581191 | DOI:10.1161/JAHA.120.021748

J Am Heart Assoc. 2021 Sep 28:e020368. doi: 10.1161/JAHA.120.020368. Online ahead of print.

ABSTRACT

Background Data comparing the frequency and outcomes of infective endocarditis (IE) after transcatheter (TAVR) to surgical aortic valve replacement (SAVR) are scarce. The objective of this study is to compare the incidence and outcomes of IE after TAVR using a supra-annular, self-expanding platform (CoreValve and Evolut) to SAVR. Methods and Results Data of 3 randomized clinical trials comparing TAVR to SAVR and a prospective continued TAVR access study were pooled. IE was defined on the basis of the modified Duke criteria. The cumulative incidence of IE was determined by modeling the cause-specific hazard. Estimates of all-cause mortality were calculated by means of the Kaplan-Meier method. Outcomes are reported for the valve-implant cohort. During a mean follow-up time of 2.17±1.51 years, 12 (0.5%) of 2249 patients undergoing TAVR and 21 (1.1%) of 1828 patients undergoing SAVR developed IE. Patients with IE more frequently had diabetes mellitus than those without (57.6% versus 34.2%; P=0.005). The cumulative incidence of IE was 1.01% (95% CI, 0.47%-1.96%) after TAVR and 1.58% (95% CI, 0.97%-2.46%) after SAVR (P=0.047) at 5 years. Among patients with IE, the rate of all-cause mortality was 27.3% (95% CI, 1.0%-53.6%) in the TAVR and 51.8% (95% CI, 28.2%-75.3%) in the SAVR group at 1 year (log-rank P=0.15). Conclusions Pooled prospectively collected data comparing TAVR with a supra-annular, self-expanding device to SAVR showed a low cumulative risk of IE irrespective of treatment modality, although the risk was lower in the TAVR implant group. Once IE occurred, mortality was high. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01240902, NCT01586910, NCT02701283.

PMID:34581194 | DOI:10.1161/JAHA.120.020368

Tuberk Toraks. 2021 Sep;69(3):297-306. doi: 10.5578/tt.20219701.

ABSTRACT

INTRODUCTION: Acute pulmonary thromboembolism (PTE) is a common cause of cardiovascular mortality. Right ventricular (RV) dysfunction is the most important cause of mortality. Computed Tomography Pulmonary Angiography (CTPA) can detect right ventricular enlargement which is an indicator of RV dysfunction at the time of diagnosis. This study aimed to determine the parameters indicating RV dysfunction in CTPA and correlation of early mortality findings.

MATERIALS AND METHODS: In this retrospective study, electronic files of patients diagnosed PTE with CTPA between January 2012 and December 2017 were evaluated. Measurements of heart chambers, IVC reflux, and IVS morphology were calculated. In-hospital mortality of the patients after acute PTE diagnosis was evaluated.

RESULT: There were 206 eligible patients. Among the evaluated radiological parameters, right atrium (RA) size (p= 0.002), PA size (p= 0.003), Ao size (p= 0.006), and the presence of IVC reflux (p= 0.001) were associated with mortality. No significant relationship was found between RV/LV ≥1 and mortality (p= 0.908). All patients with PTE-related mortality had RV/LV ratio ≥1 in CTPA and had IVC reflux. Patients with an RV/LV ratio of ≥1 had statistically significantly higher troponin levels (p= 0.004) and IVC reflux (p= 0.025) compared to patients with an RV/LV ratio of <1.

CONCLUSIONS: In conclusion, RV/LV ratio should be evaluated together with cardiac biomarkers to define mortality risk.

PMID:34581150 | DOI:10.5578/tt.20219701

J Agric Food Chem. 2021 Sep 28. doi: 10.1021/acs.jafc.1c05599. Online ahead of print.

ABSTRACT

The angiotensin-converting enzyme (ACE) inhibitory peptide QIGLF derived from egg white was shown to have significant in vivo antihypertensive effects in our previous study, but the intervention mechanisms at the metabolic level are still unclear. The UPLC-QTOF/MS-based untargeted metabolomics approach was used to clarify the potential antihypertensive mechanisms of QIGLF in the serum of spontaneously hypertensive rats (SHRs). Multivariate statistical analysis showed a clear difference in the metabolite profiles between the QIGLF and model groups. The results suggested that eight potential biomarkers were identified, that is, adrenic acid, ursodeoxycholic acid, glycocholic acid, taurocholic acid, tryptophan, acetylindoxyl, tyrosine, and 2-phenylethanol, which were mainly involved in aromatic amino acid biosynthesis and metabolism, biosynthesis of bile acid, and biosynthesis of unsaturated fatty acids. QIGLF might exert antihypertensive effects by improving endothelial dysfunction. This study provides a theoretical basis for future research and application of ACE inhibitory peptides in the prevention and improvement of hypertension.

PMID:34581184 | DOI:10.1021/acs.jafc.1c05599

Huan Jing Ke Xue. 2021 Oct 8;42(10):4925-4932. doi: 10.13227/j.hjkx.202101043.

ABSTRACT

Antibiotics and heavy metals are both important environmental pollutants and selective stressors for antibiotic resistance. However, the impact of their environmental concentrations on antibiotic resistance levels is still unclear. In this paper, research published before 2019 reporting the abundance of antibiotic resistance genes(ARGs), antibiotics concentrations, or heavy metal concentrations were extracted from the Web of Science database, and then statistical regression was used to investigate their correlative association. The results show that antibiotic selection pressure has a statistically significant effect on the increase in the abundance of ARGs in environmental media such as surface water, sediment, and soil, even at very low antibiotic concentrations(P<0.05). Different classes of antibiotics show different potential to select and enrich ARGs. Heavy metals and the interaction between antibiotics and heavy metals also have significant effects on ARG transmission(P<0.05). Multivariate statistical regression models can better explain the variance of ARG abundance, with R² values for the water phase and solid phase environmental samples of 0.482 and 0.707 respectively, which are much higher than those achieved using univariate regression models. However, additional environmental factors not included may also affect ARG abundance. The results of this work provide a basis for the evaluation and control of environmental antibiotic resistance.

PMID:34581136 | DOI:10.13227/j.hjkx.202101043

Huan Jing Ke Xue. 2021 Oct 8;42(10):4897-4907. doi: 10.13227/j.hjkx.202012118.

ABSTRACT

This study used 21 rock samples and 193 sets of paddy soil and rice grain samples collected form Baiwang Town, an area of clastic sedimentary rocks in Guangxi, China, to evaluate the potential for selenium-rich agriculture. We analyzed the concentrations of selenium and heavy metals in the soil and rice samples, and discuss the influencing factors by means of statistics and correlation analysis. The results showed that the selenium-rich rate of paddy soil and rice grain in Baiwang Town were 67.4% and 64.8%, respectively, but the content of cadmium in the selenium-rich soil samples was generally higher than the baseline value for China and the background value for Guangxi. In comparison to the screening value of soil pollution risk for agricultural land(GB 15618-2018), the over-standard rate of cadmium was 46.1%, while the over-standard rates of other heavy metals were negligible. The comparison shows that the selenium-rich rate of rice was 61.1% in the southern area of Baiwang Town with a negligible heavy metal content, and the advantages of green selenium-rich rice planting were clear. The correlation analysis showed that secondary enrichment was the main form of selenium enrichment in the study area. The soil pH and texture of the root-zone soil also affected the selenium content of the soil. The selenium content of rice seeds was mainly affected by the selenium content, active selenium content, pH, and aluminum oxide content of the root-zone soil. The risk assessment showed that the level of dietary exposure to cadmium is generally within safe limits, but it is still necessary to strengthen the monitoring of cadmium in rice and control cadmium pollution to reduce the levels of dietary exposure, especially in the central region of Baiwang Town.

PMID:34581133 | DOI:10.13227/j.hjkx.202012118

Proc Natl Acad Sci U S A. 2021 Oct 5;118(40):e2105841118. doi: 10.1073/pnas.2105841118.

ABSTRACT

We present a comprehensive statistical framework to analyze data from genome-wide association studies of polygenic traits, producing interpretable findings while controlling the false discovery rate. In contrast with standard approaches, our method can leverage sophisticated multivariate algorithms but makes no parametric assumptions about the unknown relation between genotypes and phenotype. Instead, we recognize that genotypes can be considered as a random sample from an appropriate model, encapsulating our knowledge of genetic inheritance and human populations. This allows the generation of imperfect copies (knockoffs) of these variables that serve as ideal negative controls, correcting for linkage disequilibrium and accounting for unknown population structure, which may be due to diverse ancestries or familial relatedness. The validity and effectiveness of our method are demonstrated by extensive simulations and by applications to the UK Biobank data. These analyses confirm our method is powerful relative to state-of-the-art alternatives, while comparisons with other studies validate most of our discoveries. Finally, fast software is made available for researchers to analyze Biobank-scale datasets.

PMID:34580220 | DOI:10.1073/pnas.2105841118