Search results for "linear regression"
showing 10 items of 375 documents
Normal reference values of multilayer longitudinal strain according to age decades in a healthy population: A single-centre experience.
2017
Aims Recent advancements in echocardiographic technology allow to analyse myocardial strain in multiple layers. Little is known about the impact of age on layer-specific longitudinal strain in healthy subjects. The aim of this study was to analyse the influence of age on multilayer longitudinal strain and establish normal reference values of layer-specific strain according to age decades in a healthy population referring to our echo laboratory using 2D speckle-tracking echocardiography with layer-specific software. Methods and results Two-hundred sixty-six healthy, consecutive subjects (mean age = 39.2 ± 17.5 years, women/men = 137/129), free of cardiovascular risk factors, were enrolled. S…
Pulse pressure amplification and its determinants
2015
Background. Pulse pressure (PP) amplification expressed as the peripheral-to-central PP ratio has gained importance in the assessment of cardiovascular phenotypes and cardiovascular risk. The aim of the present study was to assess the relationship between PP amplification, large vessel parameters and peripheral blood pressure (BP) to gain insights into the amplification phenomenon. Methods. Peripheral BP, central BP and carotid-femoral pulse wave velocity (cfPWV) were assessed using the OMRON M6, SphygmoCor and Complior devices, respectively, in 741 adults attending the hypertension outpatient clinic. Analysis of covariance, partial correlations and multiple linear regression models were pe…
The relationship of ocular geometry with refractive error in normal and low birth weight adults
2020
Purpose Low birth weight (BW) individuals have an increased risk for myopic refractive error. However, it is unclear which ocular geometric alterations lead to an increase in myopic refractive error. This study aims to evaluate the impact of ocular biometry in interaction with BW on refractive error. Methods Participants of the prospective, observational, population-based Gutenberg Health Study (GHS) with self-reported BW aged 40–80 years and objective refraction and optical biometry were included. Linear regression analyses were conducted to evaluate associations between spherical equivalent with corneal power, anterior chamber depth, lens thickness and axial length and its interaction wit…
Symptoms of adjustment disorder and smoking predict long-term functional outcome after ankle and lower leg fracture
2020
Objective To examine the psychological, social, behavioural and injury-related factors impacting functional outcome in patients with ankle or lower limb fracture one year post-operation. Methods In this prospective study 66 patients with ankle or lower leg fracture were recruited and followed up one year post-operation. Possible associations between predictors and functional outcome were explored by regression analyses. Functional outcome was assessed with the American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score. Results Linear regression models revealed that smoking and elevated symptoms of adjustment disorder were associated with lower functional outcome one year post-operation…
Conditional Self-Entropy and Conditional Joint Transfer Entropy in Heart Period Variability during Graded Postural Challenge.
2015
Self-entropy (SE) and transfer entropy (TE) are widely utilized in biomedical signal processing to assess the information stored into a system and transferred from a source to a destination respectively. The study proposes a more specific definition of the SE, namely the conditional SE (CSE), and a more flexible definition of the TE based on joint TE (JTE), namely the conditional JTE (CJTE), for the analysis of information dynamics in multivariate time series. In a protocol evoking a gradual sympathetic activation and vagal withdrawal proportional to the magnitude of the orthostatic stimulus, such as the graded head-up tilt, we extracted the beat-to-beat spontaneous variability of heart per…
Motor Development and Physical Activity: A Longitudinal Discordant Twin-Pair Study.
2015
ntroduction : Previous longitudinal research suggests that motor proficiency in early life predicts physical activity in adulthood. Familial effects including genetic and environmental factors could explain the association, but no long-term follow-up studies have taken into account potential confounding by genetic and social family background. The present twin study investigated whether childhood motor skill development is associated with leisure-time physical activity levels in adulthood independent of family background. Methods : Altogether, 1550 twin pairs from the FinnTwin12 study and 1752 twin pairs from the FinnTwin16 study were included in the analysis. Childhood motor development wa…
Training at maximal power in resisted sprinting: Optimal load determination methodology and pilot results in team sport athletes.
2018
Aims: In the current study we investigated the effects of resisted sprint training on sprinting performance and underlying mechanical parameters (force-velocity-power profile) based on two different training protocols: (i) loads that represented maximum power output (Lopt) and a 50% decrease in maximum unresisted sprinting velocity and (ii) lighter loads that represented a 10% decrease in maximum unresisted sprinting velocity, as drawn from previous research (L10). Methods: Soccer [n = 15 male] and rugby [n = 21; 9 male and 12 female] club-level athletes were individually assessed for horizontal force-velocity and load-velocity profiles using a battery of resisted sprints, sled or robotic r…
Reliability and variability of bioimpedance measures in normal adults: Effects of age, gender, and body mass
2003
This study aimed to analyze the reliability and evaluate the causes of variability of bioimpedance parameters. Direct measures were analyzed because they are not affected by inappropriate prediction models. Resistance (R), reactance (Xc), and phase angle (PA) were determined at three fixed frequencies (5, 50, and 100 kHz) in 653 normal Germans (244 males and 409 females), aged 20-90 years, using a phase-sensitive whole-body tetrapolar bioimpedance analyzer (BIA 2000-M, Data Input, Germany). From these values, six bioimpedance ratios were calculated (R(5)/R(50), R(5)/R(100), Xc(5)/Xc(50), Xc(5)/Xc(100), PA(5)/PA(50), and PA(5)/PA(100)). Reliability of duplicate measurements, as determined by…
Prenatal Exposure to Polybrominated Flame Retardants and Fetal Growth in the INMA Cohort (Spain)
2015
Our aim was to investigate the relation between PBDEs and fetal growth or newborn anthropometry in a Spanish cohort (2003-2008). PBDE congeners (BDE-47, -99, -153, -154, and -209) were determined in serum of 670 mothers at gestational week 12 and in 534 umbilical cord samples. Abdominal circumference (AC), estimated fetal weight (EFW), femur length (FL), and biparietal diameter (BPD) during gestation were measured by ultrasounds. At birth, weight (BW), head circumference (HC), and length (BL) were also measured. We assessed growth in the intervals between 12-20 and 20-34 weeks of gestation and size at birth by standard deviation (SD)-scores adjusted for constitutional characteristics. We co…
Determination of the modulus of elasticity of bone material by an acoustical approach at the forearm distinguishes women with and without vertebral f…
2002
The modulus of elasticity is a parameter characterizing fracture stability of bone independent of bone mineral density. Measurement of acoustical properties of the forearm by determination of the resonant frequency of the ulna in longitudinal direction as a function of sound transmission velocity after adjustment of the measuring result by ulna length yields information about the modulus of elasticity. It was the aim of this study to investigate whether this parameter may distinguish between subjects with and without vertebral fractures independent of bone mineral density. Fifty females (61.1 +/- 9.1 years) were enrolled into the study, 25 with, and 25 age-matched without prevalent osteopor…