Endothelial dysfunction is believed to play a critical role in preeclampsia, however it is unclear whether this dysfunction precedes the pregnancy or is caused by early pathophysiological events. It is also unclear for how long vascular dysfunction may persist post-partum, and whether it represents a mechanism linking preeclampsia with future cardiovascular disease. Our objective was to determine whether women with preeclampsia have worse vascular function compared to women who did not have preeclampsia by performing systematic review and meta-analysis of studies that examined endothelial dysfunction using flow-mediated dilation (FMD). We included studies published before May 29, 2015 that examined FMD before, during and after preeclampsia. Differences in FMD between study groups were evaluated by standardized mean differences. Out of 610 abstracts identified through PubMED, EMBASE and Web of Science, 37 studies were eligible for the meta-analysis. When compared to women who did not have preeclampsia, women who had preeclampsia had lower FMD prior to the development of preeclampsia (~20–29 weeks gestation), at the time of preeclampsia, and for three years post-partum, with the estimated magnitude of the effect ranging between 0.5 and 3 standard deviations. Similar effects were observed when the analysis was limited to studies that excluded women with chronic hypertension, smokers, or both. Vascular dysfunction predates preeclampsia and may contribute to its pathogenesis. Future studies should address whether vascular changes that persist after preeclamptic pregnancies may represent a mechanistic link with the increased risk for future cardiovascular disease.

Reports highlighting the problems with the standard practice of using bar graphs to show continuous data have prompted many journals to adopt new visualization policies. These policies encourage authors to avoid bar graphs and use graphics that show the data distribution; however, they provide little guidance on how to effectively display data. We conducted a systematic review of studies published in top peripheral vascular disease journals to determine what types of figures are used, and to assess the prevalence of suboptimal data visualization practices. Among papers with data figures, 47.7% of papers used bar graphs to present continuous data. This primer provides a detailed overview of strategies for addressing this issue by (1) outlining strategies for selecting the correct type of figure depending on the study design, sample size, and the type of variable; (2) examining techniques for making effective dot plots, box plots, and violin plots; and (3) illustrating how to avoid sending mixed messages by aligning the figure structure with the study design and statistical analysis. We also present solutions to other common problems identified in the systematic review. Resources include a list of free tools and templates that authors can use to create more informative figures and an online simulator that illustrates why summary statistics are meaningful only when there are enough data to summarize. Last, we consider steps that investigators can take to improve figures in the scientific literature.

Numerous studies demonstrating that statistical errors are common in basic science publications have led to calls to improve statistical training for basic scientists. In this article, we sought to evaluate statistical requirements for PhD training and to identify opportunities for improving biostatistics education in the basic sciences. We provide recommendations for improving statistics training for basic biomedical scientists, including: 1. Encouraging departments to require statistics training, 2. Tailoring coursework to the students’ fields of research, and 3. Developing tools and strategies to promote education and dissemination of statistical knowledge. We also provide a list of statistical considerations that should be addressed in statistics education for basic scientists.

SummaryBackgroundSubclinical hypothyroidism (SCH) is defined as high TSH and normal thyroxine. Data on the effects of early substitution by levothyroxine on psychophysical health in SCH are still not consistent enough to support its introduction.MethodsClinical parameters, biochemical data and quality of life (Short Form 36 questionnaire) were measured before the intervention and 3 months after the euthyroid state had been achieved in SCH patients.ResultsSignificant reduction in body weight (p=0.030), systolic and diastolic blood pressure (p=0.024, p=0.019), homocysteine (p<0.001), leukocytes and neutrophils (p=0.011, p=0.001), INR (p=0.049), K levels (p=0.040, p=0.013), HbA1c (p=0.001), fasting insulin (p<0.001) and insulin resistance measured by HOMA index (p<0.001), lipid parameters (total cholesterol (p<0.001), LDL-cholesterol (p<0.001), triglycerides (p=0.007), apoB (p=0.022), Lp(a) (p<0.001), LDL/HDL (p=0.008), LAP (p=0.04) and apoB/apoA1 ratios (p<0.023)), TSH (p<0.001) and tAbs (p<0.001) was recorded. Frequency of fatty liver (20% to 2.9%, p=0.016), hyperlipidemia (85% to 65.7%, p=0.001) and metabolic syndrome (34.3% to 2.9%, p=0.070) significantly decreased. A statistically significant positive association was found between the average dose of levothyroxine and changes in physical functioning (r=0.391, p=0.020), vitality (r=0.393, p=0.020), mental health (r=0.374, p=0.027) and overall dimensions of mental health (r=0.376, p=0.026). With increasing doses of levothyroxine, the previously listed scores of SF 36 grew (r=0.296, p=0.084).ConclusionsEarly substitution of SCH improved the many clinical and biochemical parameters related to cardiovascular risk. Quality of life was also improved, and correlated only with thyroxine doses suggesting an indirect relationship between the degree of hypothyroidism and quality of life.

Objectives Preeclampsia, a pregnancy-specific hypertensive disorder, has been associated with cardiovascular risk factors and vascular changes, such as acute atherosis in placental blood vessels, which are similar to early-stage atherosclerosis. The objective of this study was to determine whether women with preeclampsia have increased atherosclerotic burden, as determined by carotid intima-media thickness (CIMT), when compared to women who did not have preeclampsia. Methods We conducted a systematic review and meta-analysis of studies that reported CIMT, a non-invasive, ultrasound-based measure of subclinical atherosclerosis, in women who did vs. did not have preeclampsia. Studies were eligible if they were conducted during pregnancy or during the first decade postpartum, and if CIMT was measured in the common carotid artery. Studies published before March 7, 2016 were identified through PubMED, EMBASE and Web of Science. Two reviewers used predefined forms and protocols to independently evaluate the eligibility of all titles and abstracts, perform full text screening, data abstraction and quality assessment. Heterogeneity was assessed using the I2 statistic. Standardized mean difference was used as a measure of effect size. Results Fourteen studies were included in the meta-analysis; 7 studies at the time of preeclampsia and 10 studies up to 10 years postpartum. Three studies included measurements at both time periods. Women who had preeclampsia had significantly higher CIMT compared to those who did not, either at the time of diagnosis (SMD: 1.10, 95% CI: 0.73-1.48, p<0.001), or in the first decade postpartum (SMD: 0.58, 95% CI: 0.36-0.79, p<0.001 Conclusions Atherosclerotic load is present at the time of preeclampsia and may be one mechanism associated with preeclampsia. CIMT may offer an opportunity for early recognition of premenopausal women with atherosclerotic burden after preeclamptic pregnancies.

BackgroundThe scientific community increasingly is recognizing the need to bolster standards of data analysis given the widespread concern that basic mistakes in data analysis are contributing to the irreproducibility of many published research findings. The aim of this study was to investigate students’ attitudes towards statistics within a multi-site medical educational context, monitor their changes and impact on student achievement. In addition, we performed a systematic review to better support our future pedagogical decisions in teaching applied statistics to medical students.MethodsA validated Serbian Survey of Attitudes Towards Statistics (SATS-36) questionnaire was administered to medical students attending obligatory introductory courses in biostatistics from three medical universities in the Western Balkans. A systematic review of peer-reviewed publications was performed through searches of Scopus, Web of Science, Science Direct, Medline, and APA databases through 1994. A meta-analysis was performed for the correlation coefficients between SATS component scores and statistics achievement. Pooled estimates were calculated using random effects models.ResultsSATS-36 was completed by 461 medical students. Most of the students held positive attitudes towards statistics. Ability in mathematics and grade point average were associated in a multivariate regression model with the Cognitive Competence score, after adjusting for age, gender and computer ability. The results of 90 paired data showed that Affect, Cognitive Competence, and Effort scores demonstrated significant positive changes. The Cognitive Competence score showed the largest increase (M = 0.48, SD = 0.95). The positive correlation found between the Cognitive Competence score and students’ achievement (r = 0.41; p<0.001), was also shown in the meta-analysis (r = 0.37; 95% CI 0.32–0.41).ConclusionStudents' subjective attitudes regarding Cognitive Competence at the beginning of the biostatistics course, which were directly linked to mathematical knowledge, affected their attitudes at the end of the course that, in turn, influenced students' performance. This indicates the importance of positively changing not only students’ cognitive competency, but also their perceptions of gained competency during the biostatistics course.

Coronary artery bypass grafting (CABG) remains the most frequent surgery in the practice of an adult cardiac surgeon and the most frequently performed cardiac surgical procedure worldwide. Despite the ongoing debates regarding the superiority or inferiority of off-pump coronary artery bypass grafting, it still comprises 15–30% of all CABG cases varying in different national registries. We performed a propensity matched study of 302 consecutive CABG patients,143 off -pump cases performed by the four experienced off-pump surgeons and the on-pump CABG cases performed by those surgeons and four other experienced coronary surgeons. The five year follow up was performed and data collected comprised of mortality, rehospitalization due to cardiac origin, repeated revascularization, myocardial infarction and cerebrovascular accident. Overall, the off-pump group of patients had a higher risk profile than the patients in the on-pump group. After matching, fewer differences were found between the groups. Propensity score matching analysis showed no difference in long-term survival as well as MACCE and repeated revascularization. The higher risk profile of the patients subjected to OPCAB and the comparable survival to lower risk CPB patients in this series indicate that in experienced hands, OPCAB is a valuable option in this important subgroup of patients.

Introduction: Preeclampsia (PE) is a pregnancy-associated, multi-organ, life-threatening disease that appears after the 20th week of gestation. The aim of this study was to perform a systematic review and meta-analysis to determine whether women with PE have disrupted miRNA expression compared to women who do not have PE.Methods: We conducted a systematic review and meta-analysis of studies that reported miRNAs expression levels in placenta or peripheral blood of pregnant women with vs. without PE. Studies published before October 29, 2021 were identified through PubMed, EMBASE and Web of Science. Two reviewers used predefined forms and protocols to evaluate independently the eligibility of studies based on titles and abstracts and to perform full-text screening, data abstraction and quality assessment. Standardized mean difference (SMD) was used as a measure of effect size.Results: 229 publications were included in the systematic review and 53 in the meta-analysis. The expression levels in placenta were significantly higher in women with PE compared to women without PE for miRNA-16 (SMD = 1.51,95%CI = 0.55–2.46), miRNA-20b (SMD = 0.89, 95%CI = 0.33–1.45), miRNA-23a (SMD = 2.02, 95%CI = 1.25–2.78), miRNA-29b (SMD = 1.37, 95%CI = 0.36–2.37), miRNA-155 (SMD = 2.99, 95%CI = 0.83–5.14) and miRNA-210 (SMD = 1.63, 95%CI = 0.69–2.58), and significantly lower for miRNA-376c (SMD = –4.86, 95%CI = –9.51 to –0.20). An increased level of miRNK-155 expression was found in peripheral blood of women with PE (SMD = 2.06, 95%CI = 0.35–3.76), while the expression level of miRNA-16 was significantly lower in peripheral blood of PE women (SMD = –0.47, 95%CI = –0.91 to –0.03). The functional roles of the presented miRNAs include control of trophoblast proliferation, migration, invasion, apoptosis, differentiation, cellular metabolism and angiogenesis.Conclusion: miRNAs play an important role in the pathophysiology of PE. The identification of differentially expressed miRNAs in maternal blood creates an opportunity to define an easily accessible biomarker of PE.