Sprint interval and sprint continuous training increases circulating CD34+ cells and cardio-respiratory fitness in young healthy women

The improvement of vascular health in the exercising limb can be attained by sprint interval training (SIT). However, the effects on systemic vascular function and on circulating angiogenic cells (CACs) which may contribute to endothelial repair have not been investigated. Additionally, a comparison between SIT and sprint continuous training (SCT) which is less time committing has not been made

The relationship between subtypes of depression and cardiovascular disease: a systematic review of biological models

A compelling association has been observed between cardiovascular disease (CVD) and depression, suggesting individuals with depression to be at significantly higher risk for CVD and CVD-related mortality. Systemic immune activation, hypothalamic–pituitary–adrenal (HPA) axis hyperactivity, arterial stiffness and endothelial dysfunction have been frequently implicated in this relationship. Although a differential epidemiological association between CVD and depression subtypes is evident, it has not been determined if this indicates subtype specific biological mechanisms. A comprehensive systematic literature search was conducted using PubMed and PsycINFO databases yielding 147 articles for this review. A complex pattern of systemic immune activation, endothelial dysfunction and HPA axis hyperactivity is suggestive of the biological relationship between CVD and depression subtypes. The findings of this review suggest that diagnostic subtypes rather than a unifying model of depression should be considered when investigating the bidirectional biological relationship between CVD and depression. The suggested model of a subtype-specific biological relationship between depression and CVDs has implications for future research and possibly for diagnostic and therapeutic processes

A genetic programming approach to development of clinical prediction models: A case study in symptomatic cardiovascular disease

BACKGROUND:Genetic programming (GP) is an evolutionary computing methodology capable of identifying complex, non-linear patterns in large data sets. Despite the potential advantages of GP over more typical, frequentist statistical approach methods, its applications to survival analyses are rare, at best. The aim of this study was to determine the utility of GP for the automatic development of clinical prediction models. METHODS:We compared GP against the commonly used Cox regression technique in terms of the development and performance of a cardiovascular risk score using data from the SMART study, a prospective cohort study of patients with symptomatic cardiovascular disease. The composite endpoint was cardiovascular death, non-fatal stroke, and myocardial infarction. A total of 3,873 patients aged 19-82 years were enrolled in the study 1996-2006. The cohort was split 70:30 into derivation and validation sets. The derivation set was used for development of both GP and Cox regression models. These models were then used to predict the discrete hazards at t = 1, 3, and 5 years. The predictive ability of both models was evaluated in terms of their risk discrimination and calibration using the validation set. RESULTS:The discrimination of both models was comparable. At time points t = 1, 3, and 5 years the C-index was 0.59, 0.69, 0.64 and 0.66, 0.70, 0.70 for the GP and Cox regression models respectively. At the same time points, the calibration of both models, which was assessed using calibration plots and the generalization of the Hosmer-Lemeshow test statistic, was also comparable, but with the Cox model being better calibrated to the validation data. CONCLUSION:Using empirical data, we demonstrated that a prediction model developed automatically by GP has predictive ability comparable to that of manually tuned Cox regression. The GP model was more complex, but it was developed in a fully automated way and comprised fewer covariates. Furthermore, it did not require the expertise normally needed for its derivation, thereby alleviating the knowledge elicitation bottleneck. Overall, GP demonstrated considerable potential as a method for the automated development of clinical prediction models for diagnostic and prognostic purposes

Common carotid intima-media thickness and arterial stiffness - Indicators of cardiovascular risk in high-risk patients - The SMART study (Second Manifestations of ARTerial disease)

Background-Common carotid intima-media thickness (IMT) and distensibility are markers of structural and functional vessel wall properties. Both parameters have been found in population-based studies to be associated with cardiovascular risk factors and prevalent cardiovascular disease. We investigated cross-sectionally whether IMT and distensibility are associated with cardiovascular risk in patients who already have vascular disease or atherosclerotic risk factors and evaluated the diagnostic ability of IMT and distensibility to discriminate between low- and high-risk patients. Methods and Results-IMT and distensibility (change of diameter) of the left and right common carotid arteries were measured in the first 570 patients (537 for distensibility) enrolled in the Second Manifestations of ARTerial disease (SMART) study, a cohort study among patients with a manifestation of vascular disease or cardiovascular risk factors. Three risk scores were used to classify each patient's vascular risk. Areas under the curve (AUCs) of receiver-operating characteristic curves were calculated for IMT and distensibility after the patients were dichotomized on the median of the risk scores as the outcome. Risk scores increased nearly linearly with increasing TMT and decreasing distensibility. The AUCs for IMT predicting high-risk patients were 0.77, 0.73, and 0.77 based on the 3 risk scores. The AUCs for distensibility were 0.65, 0.62, and 0.66. Conclusions-Common carotid IMT and distensibility are clear markers of cardiovascular risk in patients who already have vascular disease or atherosclerotic risk factors. IMT appears to discriminate between low- and high-risk patients better than distensibility