Forward Stepwise Multiple Regression Research Articles

Prevalence of Cancer Patients Requiring Palliative Care in Outpatient Clinics in a Tertiary Hospital in Southern Thailand

Objective: To estimate the prevalence of patients requiring palliative care in outpatient clinics and associated factors.Materials and Methods: A cross-sectional study was conducted by retrospectively reviewing the electronic medical records of cancer patients visiting the outpatient clinics in the major tertiary care institution in southern Thailand during 1 January– 31 December 2018 from the Hospital Information System. The Supportive and Palliative Care Indicators Tool in Low Income Settings (SPICT-LISTM) was used to determine if the patients would benefit from palliative care. Forward stepwise multiple logistic regression was used to assess associations between potential factors and the need for palliative care.Results: Nine thousand nine hundred and ninety medical records were reviewed. 3,628 (36.3%) patients were male and 6,324 (63.3%) were female with a median age of 58.7 years. The prevalence of cancer patients requiring palliative care according to the SPICT-LISTM criteria was 7.8%. Age was the main factor associated with palliative care need [odds ratio (OR)=1.03, 95% confidence interval (CI)=1.02-1.04]. Muslim patients had a significantly higher requirement for palliative care compared with Buddhist patients (OR=1.62, 95% CI=1.09-2.37). Although not statistically significant, malignant neoplasms of bone and articular cartilage were associated with higher palliative care need than lip, oral cavity and pharynx cancers (OR=5.35, 95% CI=0.69-29.40).Conclusion: Muslim religion and having malignant neoplasms of bone and articular cartilage were associated with the highest palliative care need. Future studies should focus on more in-depth examination of the reasons these groups have higher needs for palliative care.

CENTRAL SYSTOLIC BLOOD PRESSURE RELATES INVERSELY TO NITRIC OXIDE SYNTHESIS IN YOUNG BLACK ADULTS: THE AFRICAN-PREDICT STUDY

Objective: Lower nitric oxide bioavailabilty associates with hypertension in diseased and elderly populations. With hypertension known to develop earlier in black populations, we compared both plasma and urinary nitric oxide-related markers and their associations with central systolic blood pressure and arterial stiffness in healthy young black and white adults. Design and method: We included healthy black and white men and women (n = 1110; 20–30 years) and measured central systolic blood pressure and pulse wave velocity, along with both plasma and urinary arginine, homoarginine, asymmetric dimethylarginine, symmetric dimethylarginine, as well as urinary ornithine/citrulline, nitrite and nitrate. Additionally, the urinary nitrate-to-nitrite ratio was calculated. Results: The black men and women had higher central systolic blood pressure and higher plasma arginine and asymmetric dimethylarginine, but lower urinary nitrate and urinary nitrate-to-nitrite ratio (all p< = 0.003) than their white counterparts. In single and forward stepwise multiple regression analyses, we found an inverse association of central systolic blood pressure (adj. R2 = 0.124; β= –0.134; p = 0.006) and plasma homoarginine in black men. Central systolic blood pressure associated inversely with urinary nitrate-to-nitrite ratio in black women only (adj. R2 = 0.171; β= –0.130; p = 0.029). In the white women, central systolic blood pressure associated positively with urinary asymmetric dimethylarginine (adj. R2 = 0.372; β= 0.162; p = 0.015). Pulse wave velocity associated inversely with plasma asymmetric dimethylarginine (adj. R2 = 0.253; β= –0.163; p = 0.024) in the white women only. Conclusions: The lower nitric oxide synthesis and the higher central systolic blood pressure in our black cohort support the notion of a potential increased risk for future large artery stiffness and hypertension development in later life.

SOLUBLE (PRO)RENIN RECEPTOR ASSOCIATES ADVERSELY WITH LEFT VENTRICULAR STRUCTURE AND FUNCTION IN YOUNG ADULTS

Objective: Most of the evidence on the role of (pro)renin receptor in blood pressure regulation and target organ damage emanate from animal models. Recent, though limited studies in humans confirm the contribution of soluble (pro)renin receptor (s(P)RR) to renin-angiotensin system (RAS) activation, volume retention and renal damage, with an apparent ethnic difference. This study aimed to compare levels of s(P)RR between black and white ethnicities and explore for the first time in a normotensive young bi-ethnic population the associations of s(P)RR with relative wall thickness (RWT), left ventricular mass index (LVMi), left ventricular ejection fraction (LVEF), stroke volume (SV), end-diastolic volume index (EDVI) and end-systolic volume index (ESVI). Design and method: The study population included 1175 apparently healthy young black (N = 588) and white (N = 587) participants aged 20–30 years old. We recorded ambulatory blood pressure. Echocardiography measurements were performed to determine RWT, LVMi, LVEF, SV (standardized for body height), EDVI and ESVI (both standardized for body surface area). s(P)RR was analyzed from serum, while plasma renin activity-surrogate (PRA-S) and angiotensin II were determined using the RAS™ Fingerprint. Results: s(P)RR, PRA-S, angiotensin II, SV, EDVI and ESVI were higher in the white group as compared to the black group (all P < 0.001). RWT and LVEF were higher in the black group (both P< = 0.012), while LVMi was similar between the two groups (P = 0.66). Using forward stepwise multiple regression analyses, we observed independent associations of s(P)RR with RWT (β=0.13; P = 0.009), LVEF (β=-0.12; P = 0.008), SV (β=-0.17; P < 0.001) and EDVI (β=-0.13; P = 0.006) only in white adults. The associations were independent of angiotensin II, which did not enter any of the models when included as a covariate. No associations were observed in the total or black group. Conclusions: s(P)RR associated with an increase in RWT and adversely with left ventricular function in normotensive young white adults and not in their black counterparts. These results suggest that s(P)RR has the potential to be an early marker of cardiac remodeling and dysfunction independent of hypertension and systemic renin-angiotensin activity in white populations.

EXCESS ALDOSTERONE RELATIVE TO PLASMA RENIN AND ANGIOTENSIN II ASSOCIATES POSITIVELY WITH CENTRAL SYSTOLIC BLOOD PRESSURE IN YOUNG BLACK AFRICANS

Objective: Populations of African ancestry usually present with a suppressed renin-angiotensin-aldosterone system (RAAS) attributed to excessive sodium retention and subsequently experience early and severe forms of hypertension-mediated organ damage. Central systolic blood pressure (cSBP) was previously found to be higher in young black adults as compared to their white counterparts. In the current study, we investigated associations of cSBP with a detailed RAAS profile in a healthy young population stratified according to ethnicity and sex. Design and method: This study included apparently healthy black men (N = 285) and women (N = 304), white men (N = 278) and women (N = 305) aged 20–30 years old. The SphygmoCor XCEL was used to derive cSBP. Aldosterone and equilibrium angiotensin levels were measured by LC-MS/MS and used for calculating angiotensin derived markers for plasma renin activity (PRA-S, Angiotensin I + Angiotensin II), angiotensin-converting enzyme (ACE-S, Angiotensin II/Angiotensin I), and two markers for adrenal effects of angiotensin II, the aldosterone-to-renin ratio (ARR-S, Aldosterone/PRA-S) and the aldosterone-to-angiotensin II-ratio (AA2-R, Aldosterone/Angiotensin II). Sodium and potassium were determined from 24-hour urine and then used to calculate sodium-to-potassium ratio. Results: Young black men and women presented with lower RAAS components and higher cSBP and urinary sodium-to-potassium ratio as compared to their white counterparts (all P < = 0.001). In forward stepwise multiple regression analyses, we observed the following associations: In black women, cSBP associated positively with ARR-S (β=0.269; P = 0.001) and AA2-R (β=0.263; P = 0.001), and negatively with PRA-S (β=-0.311; P < 0.001) and angiotensin II (β=-0.311; P < 0.001). In black men we observed a negative association between cSBP and PRA-S (β=-0.181; P = 0.047). None of the associations were present in white men and women. Conclusions: Positive associations of cSBP with the ratio of aldosterone to both PRA-S and angiotensin II in healthy young black women suggest that excess aldosterone may have deleterious effects on central blood pressure in this population group, which may lead to early target organ damage. The absence of any association between cSBP and RAAS components in white adults indicates an ethnic disparity in central pressure regulation.

Association of quality of life with structural, functional and molecular brain imaging in community-dwelling older adults

BackgroundAs the population ages, maintaining mental health and well-being of older adults is a public health priority. Beyond objective measures of health, self-perceived quality of life (QoL) is a good indicator of successful aging. In older adults, it has been shown that QoL is related to structural brain changes. However, QoL is a multi-faceted concept and little is known about the specific relationship of each QoL domain to brain structure, nor about the links with other aspects of brain integrity, including white matter microstructure, brain perfusion and amyloid deposition, which are particularly relevant in aging. Therefore, we aimed to better characterize the brain biomarkers associated with each QoL domain using a comprehensive multimodal neuroimaging approach in older adults. MethodsOne hundred and thirty-five cognitively unimpaired older adults (mean age ± SD: 69.4 ± 3.8 y) underwent structural and diffusion magnetic resonance imaging, together with early and late florbetapir positron emission tomography scans. QoL was assessed using the brief version of the World Health Organization's QoL instrument, which allows measuring four distinct domains of QoL: self-perceived physical health, psychological health, social relationships and environment. Multiple regression analyses were carried out to identify the independent global neuroimaging predictor(s) of each QoL domain, and voxel-wise analyses were then conducted with the significant predictor(s) to highlight the brain regions involved. Age, sex, education and the other QoL domains were entered as covariates in these analyses. Finally, forward stepwise multiple regressions were conducted to determine the specific items of the relevant QoL domain(s) that contributed the most to these brain associations. ResultsOnly physical health QoL was associated with global neuroimaging values, specifically gray matter volume and white matter mean kurtosis, with higher physical health QoL being associated with greater brain integrity. These relationships were still significant after correction for objective physical health and physical activity measures. No association was found with global brain perfusion or global amyloid deposition. Voxel-wise analyses revealed that the relationships with physical health QoL concerned the anterior insula and ventrolateral prefrontal cortex, and the corpus callosum, corona radiata, inferior frontal white matter and cingulum. Self-perceived daily living activities and self-perceived pain and discomfort were the items that contributed the most to these associations with gray matter volume and white matter mean kurtosis, respectively. ConclusionsBetter self-perceived physical health, encompassing daily living activities and pain and discomfort, was the only QoL domain related to brain structural integrity including higher global gray matter volume and global white matter microstructural integrity in cognitively unimpaired older adults. The relationships involved brain structures belonging to the salience network, the pain pathway and the empathy network. While previous studies showed a link between objective measures of physical health, our findings specifically highlight the relevance of monitoring and promoting self-perceived physical health in the older population. Longitudinal studies are needed to assess the direction and causality of the relationships between QoL and brain integrity.

Insulin resistance and the adiponectin/leptin ratio as a surrogate measure of insulin resistance in Japanese collegiate baseball players.

No study has previously investigated insulin resistance in collegiate baseball players. The purposes of this study were to examine: 1) the insulin resistance; and 2) the usefulness of the adiponectin/leptin (A/L) ratio compared with the homeostasis model assessment of insulin resistance (HOMA-IR) for assessing insulin resistance in collegiate baseball players. Twenty collegiate baseball players with abdominal obesity (AO group) defined by a waist circumference (WC) ≥85 cm, 65 lean baseball players with a WC<85 cm (L group), and 20 controls who were sedentary for at least 1 year (C group) were compared. The Body Mass Index, WC, systolic and diastolic blood pressures, fasting plasma glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, apolipoprotein B, insulin, leptin, adiponectin, and high-sensitivity C-reactive protein (hs-CRP) were measured. The AO group had a significantly higher insulin level, HOMA-IR, and leptin level, and lower A/L ratio than the L and C groups. The AO group had a significantly higher prevalence of insulin resistance (50%) than the L (14%) group. The A/L ratio was significantly negatively correlated with body weight, Body Mass Index, WC, triglycerides, triglycerides/HDL-C ratio, apolipoprotein B, hs-CRP, insulin, HOMA-IR, and leptin, and positively correlated with HDL-C, whereas HOMA-IR was significantly positively correlated with body weight, Body Mass Index, WC, systolic and diastolic blood pressures, fasting plasma glucose, and insulin, and negatively correlated with adiponectin and the A/L ratio. In the forward stepwise multiple regression analysis, WC, triglycerides, and hs-CRP were the significant determinants for the A/L ratio, whereas diastolic blood pressure and WC were the significant determinants for HOMA-IR. This model explained 53.7% of the variance in the A/L ratio and 13.6% of the variance in HOMA-IR. The present study suggested that the baseball players with abdominal obesity had a significantly higher prevalence of insulin resistance than the lean baseball group. The A/L ratio may be more useful than HOMA-IR to accurately assess insulin resistance in male collegiate baseball players.

Determination of the oxidative stability of biodiesel fuels by near-infrared spectroscopy

In this work, Near Infrared Spectroscopy (NIRS) has been developed as a technique for the rapid measurements of the oxidative stability of biodiesel fuels. Firstly, use of near-infrared spectroscopy for rapid determination of the oxidation level in biodiesel, a new calibration model was developed based on nine different biodiesel oxidation properties: conjugated diene value (CD), P-anisidine value (P-AV), Peroxide value (PV), Viscosity at 40 °C and 100 °C, Iodine Value (IV), Bis Allylic Position Equivalent (BAPE), Degree of Unsaturation factor, and values of the oxidative stability Index (OSI). Partial least squares regression and forward stepwise multiple linear regressions were used to quantify the spectral data with the using the second derivative of the spectra. In order to validate the calibration model, three separate biodiesel samples were used and analysed. In this work it is successfully demonstrated that NIR spectroscopy-based non-destructive technique gives fast measurements within less than 60 s of time and more accurate measurements with very low error of 1.1%. Statistical t-test showed that all the t-values of the validation samples were less than tc (t critical), giving t-value of 1.466 for linseed, 1.2556 for Algae and 0.4816 RME (Rapeseed Methyl Ester) compared with tc value of 2.365. This established that the proposed NIR method correlate well with the standard methods. The accuracy of the results for these samples for the different oxidative stability properties obtained from NIRS techniques was validated against the known value of all the oxidative properties and the percentage error was calculated and presented.

Impacts of phosphorus loads on the water quality and the proliferation of harmful cyanobacteria in Foum-Gleita Reservoir (Mauritania)

Excess phosphorus and nitrogen inputs into freshwater ecosystems is one of the main causes of expansion of harmful cyanobacterial blooms worldwide. This work was conducted to study the impacts of phosphorus leaching from the exploitation of phosphate mines present in the watershed of Foum-Gleita Reservoir (Mauritania) on the water quality and its major contribution to the proliferation of harmful cyanobacteria throughout the year. The physicochemical parameters, the occurrence and abundance of phytoplankton (including cyanobacteria), and the microcystins concentration were monitored monthly from September 2017 to August 2018. The relationships between limnological and biological variables were explored by using Pearson's correlation and forward stepwise multiple linear regression (MLR) analysis. Microcystins were detected by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Our results showed that this reservoir can be classified as hypereutrophic throughout the year and that Microcystis aeruginosa (M. aeruginosa) and Dolichospermum flos-aquae (D. flos-aquae) were dominant species during the rainy season (July-September), and only the congener microcystin-LR (MC-LR) was detected with a peak at 3.55 µg L−1. Pearson's correlation and MLR analysis showed that water temperature pH, phosphorus, nitrogen, and iron concentrations were the most important variables accounting for M. aeruginosa and D. flos-aquae abundance and MC-LR concentration. Our study provides new insight into the effects of moderate nitrogen concentrations on phytoplankton community composition with dominance of the cyanobacteria phylum in phosphorus-rich freshwater ecosystems.

A Generalized Equation for Prediction of VO2peak from a Step Test.

This study aimed to develop an equation to reduce variability of VO2peak prediction from a step test and compare VO2peak prediction from the new equation to the Queen's College Step Test (QCST). The development group (n=86; 21.7±2 years) was utilized to develop the SDState step test equation to predict relative VO2peak. The cross-validation group (n=99; 21.6±2 years) was used to determine the validity of the SDState step test VO2peak prediction equation. A regression analysis was used to identify the best model to predict VO2peak. Analysis of variance (ANOVA) was further used to determine differences among predicted and measured VO2peak values. Forward stepwise multiple regression identified age, sex, abdominal circumference, and active heart rate at the 3-min mark of the step test to be significant predictors of VO2peak (mL·kg-1·min-1). No differences among measured VO2peak (47.3±7.1 mL·kg-1·min-1) and predicted VO2peak (QCST, 46.9±9.3 mL·kg-1·min-1; SDState 48.3±5.7 mL·kg-1·min-1) were found. Pearson correlations, ICC, SEE, TEE, Bland-Altman plots, and Mountain plots indicate the SDState step test equation provides less variation in the prediction of VO2peak compared to the QCST. The SDState step test equation is effective for predicting VO2peak from the YMCA step test in young, healthy adults.

Central systolic blood pressure relates inversely to nitric oxide synthesis in young black adults: the African-PREDICT study.

Lower nitric oxide (NO) bioavailabilty associates with hypertension in patients and elderly populations. With hypertension known to develop earlier in black populations, we compared both plasma and urinary NO-related markers and their associations with central systolic blood pressure (cSBP) and arterial stiffness in healthy young black and white adults. We included healthy black and white men and women (n = 1110; 20-30 years) and measured cSBP and pulse wave velocity (PWV), along with both plasma and urinary arginine, homoarginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), as well as urinary ornithine/citrulline, nitrite and nitrate. In addition, the urinary nitrate-to-nitrite ratio (UNOxR) was calculated. The black men and women had higher cSBP and higher plasma arginine and ADMA, but lower urinary nitrate and UNOxR (all p ≤ 0.003) than their white counterparts. In single and forward stepwise multiple regression analyses, we found an inverse association of cSBP (adj. R2 = 0.124; β = -0.134; p = 0.006) and plasma homoarginine in black men. Central SBP associated inversely with UNOxR in black women only (adj. R2 = 0.171; β = -0.130; p = 0.029). In the white women, cSBP associated positively with urinary ADMA (adj. R2 = 0.372; β = 0.162; p = 0.015). PWV associated inversely with plasma ADMA (adj. R2 = 0.253; β = -0.163; p = 0.024) in the white women only. The lower NO synthesis and the higher cSBP in our black cohort support the notion of a potential increased risk for future large artery stiffness and hypertension development in later life.

Under the radar: Everyday sadism predicts both passive-aggressive harms and beneficial actions after accounting for prosocial tendencies

Two studies examined the predictive value of everyday sadism in determining participants' choices to cause frustration to a hypothetical other, controlling for prosocial characteristics (cognitive and affective empathy, helpfulness). In Study 1 (n = 154), forward-stepwise multiple regression analyses indicated direct physical sadism levels predicted participants' assignment of easy and difficult math items after levels of prosocial characteristics were statistically controlled. In Study 2 (n = 110), forward-stepwise multiple regression analyses indicated participants' levels of direct physical sadism predicted the assignment of easy and difficult math items across two math tasks (a replication of study one and a second math task related to the first). Study 2 analyses also revealed both direct verbal and physical sadism predicted the assignment of moderately difficult math items. Additional analyses further suggest direct verbal sadism predicted choosing to frustrate others in a more common, everyday experience. These findings suggest levels of direct physical and verbal sadism are important independent predictors of individuals' decisions to inflict non-physical forms of frustration on others.

The Relationship between CrossFit® Performance and Laboratory-Based Measurements of Fitness.

To date, research has examined the physiological determinants of performance in standardized CrossFit® (CF) workouts but not without the influence of CF familiarity. Therefore, the purpose of this present study was to examine the predictive value of aerobic fitness, body composition, and total body strength on performance of two standardized CF workouts in CF-naïve participants. Twenty-two recreationally trained individuals (males = 13, females = 9) underwent assessments of peak oxygen consumption (VO2 peak), ventilatory thresholds, body composition, and one repetition maximum tests for the back squat, deadlift, and overhead press in which the sum equaled the CF Total. Participants also performed two CF workouts: a scaled version of the CF Open workout 19.1 and a modified version of the CF Benchmark workout Fran to determine scores based on total repetitions completed and time-to-completion, respectively. Simple Pearson’s r correlations were used to determine the relationships between CF performance variables (19.1 and modified Fran) and the independent variables. A forward stepwise multiple linear regression analysis was performed and significant variables that survived the regression analysis were used to create a predictive model of CF performance. Absolute VO2 peak was a significant predictor of 19.1 performance, explaining 39% of its variance (adjusted R2 = 0.39, p = 0.002). For modified Fran, CF Total was a significant predictor and explained 33% of the variance in performance (adjusted R2 = 0.33, p = 0.005). These results suggest, without any influence of CF familiarity or experience, that performance in these two CF workouts could be predicted by distinct laboratory-based measurements of fitness.

Interactions among obesity and age-related effects on the gait pattern and muscle activity across the ankle joint

The purposes of this study were to investigate the combined effects of age and obesity on gait and to analyze the relationship between age and obesity on ankle muscle activities during walking. 4 groups; the young non-obese control group (CG, n=50, age=31.8±4.5years; BMI=21.4±2.2kg/m2), the young obese group (OB, n=30, age=35.4±4.1years; BMI=38.6±3.5kg/m2), the non-obese older adults group (OA, n=20, age=76.1±3.5years; BMI=24.4±1.1kg/m2) and the obese older adults group (OBOA, n=20, age=79.6±5.7years; BMI=35.5±2.7kg/m2) walked on an instrumented gait analysis treadmill at their preferred walking speed. Spatiotemporal parameters, walking cycle phases, Vertical ground reaction force (GRFv) and center of pressure (CoP) velocity were sampled from the treadmill software. Electromyography (EMG) activity of the gastrocnemius medialis (GM), the soleus (SOL) and tibialis anterior (TA) were also collected during the walking test. A forward stepwise multiple regression analysis was performed to determine if body weight or age could predict ankle muscle activities during the different walking cycle phases. Compared to OB, OBOA walked with higher CoP velocity, shorter stride, spending more time in support phase (p<.05). These manifestations were associated with higher TA and SOL activities during the 1st double support (1st DS) and higher TA activity during the single support (SS) (p<.05). Compared to OA, OBOA walked with lower GRFv, shorter and wider stride and spend more time in SU (p<.05). Moreover, SOL, TA and GM activities of OBOA were higher compared to OAG during 1st DS, SS and 2nd Double support (2nd DS), respectively (p<.05). During the 1ST DS, the stepwise multiple regression revealed that age accounted for 87% of the variance of TA activity. The addition of age contributed a further 16% to explain the variance TA activity. During the SS, age accounted for 64% and 46% of the variance of SOL and TA activity respectively. The addition of the body weight added further 15% and 66% of the variation of SOL and TA activity respectively. During the 2nd DS, body weight accounted for 86% of the variance and the addition of the body weight added a further 17% to explain the high level of GM. Age in obese adults and obesity in older adults should be considered separately to evaluate neuromuscular responses during walking and, subsequently, optimize the modality of treatment and rehabilitation processes in obese individuals in order to reduce and/or prevent the risk of falls.

3-Dimensional objective aesthetic evaluation to replace panel assessment after breast-conserving treatment

BackgroundTwo-thirds of patients with early breast cancer undergo breast-conserving treatment (BCT). Aesthetic outcome is important and has long term implications for psychosocial wellbeing. The aesthetic goal of BCT is symmetry for which there is no gold-standard measure. Panel scoring is the most widely adopted assessment but has well-described limitations. This paper describes a model to objectively report aesthetic outcome using measures derived from 3-dimensional surface images (3D-SI).MethodObjective measures and panel assessment were undertaken independently for 3D-SI of women who underwent BCT 1–5 years previously. Univariate analysis was used to test for association between measures and panel score. A forward stepwise multiple linear regression model was fitted to identify 3D measurements that jointly predicted the mean panel score. The fitted model coefficients were used to predict mean panel scores for an independent validation set then compared to the mean observed panel score.ResultsVery good intra-panel reliability was observed for the training and validation sets (wκ = 0.87, wκ = 0.84). Six 3D-measures were used in the multivariate model. There was a good correlation between the predicted and mean observed panel score in the training (n = 190) and validation (n = 100) sets (r = 0.68, r = 0.65). The 3D model tended to predict scores towards the median. The model was calibrated which improved the distribution of predicted scores.ConclusionA six-variable objective aesthetic outcome model for BCT has been described and validated. This can predict and could replace panel assessment, facilitating the independent and unbiased evaluation of aesthetic outcome to communicate and compare results, benchmark practice, and raise standards.

In vivo measures of anterior scleral resistance in humans with rebound tonometry.

To measure regional variations in anterior scleral resistance (ASR) using a ballistic rebound tonometer (RBT) and examine whether the variations are significantly affected by ethnicity and refractive error (RE). ASR was measured using a RBT (iCare TA01) following calibration against the biomechanical properties of agarose biogels. Eight scleral regions (nasal, temporal, superior, inferior, inferior-nasal, inferior-temporal, superior-nasal and superior-temporal) were measured at locations 4mm from the limbus. Subjects were 130 young adults comprising three ethnic groups whose RE distributions [MSE (D) ± S.D.] incorporated individuals categorised as without-myopia (NM; MSE≥-0.50) and with-myopia (WM; MSE<-0.50); British-White (BW): 26 NM+0.52±1.15D; 22 WM -3.83±2.89D]; British-South-Asian (BSA): [9 NM+0.49±1.06D; 11 WM -5.07±3.76D; Hong-Kong-Chinese (HKC): [11 NM+0.39±0.66D; 49 WM -4.46±2.70D]. Biometric data were compiled using cycloplegic open-field autorefraction and the Zeiss IOLMaster. Two- and three-way repeated measures analysis of variances (anovas) tested regional differences for RBT values across both refractive status and ethnicity whilst stepwise forward multiple linear regression was used as an exploratory test. Significant regional variations in ASR were identified for the BW, BSA and HKC (p<0.001) individuals; superior-temporal region showed the lowest levels of resistance whilst the inferior-nasal region the highest. Compared to the BW and BSA groups, the HKC subjects displayed a significant increase in mean resistance for each respective region (p<0.001). With the exception of the inferior region, ethnicity was found to be the chief predictor for variation in the scleral RBT values for all other regions. Mean RE group differences were insignificant. The novel application of RBT to the anterior sclera confirm regional variation in ASR. Greater ASR amongst the HKC group than the BW and BSA individuals suggests that ethnic differences in anterior scleral biomechanics may exist.

An easy method for monitoring patients with pulmonary Hypertension: P-wave dispersion.

Pulmonary arterial hypertension (PAH) is a haemodynamic and pathophysiological condition with restricted flow through the pulmonary arterial circulation. In pulmonary hypertension, right ventricular hypertrophy and diastolic dysfunction can lead to an increase in atrial strain, fibrosis and dilation, which cause inhomogeneous atrial conduction. Interlead variation in P-wave duration is called P-wave dispersion (PwD), which is an electrocardiographic parameter that can be used to predict atrial arrhythmias. Our aim was to investigate the relationship between PwD, functional capacity, and invasive and non-invasive haemodynamic parameters of patients diagnosed with PAH. Between 2015 and 2017 we enrolled 33 patients admitted to our in-patient clinic and diagnosed with PAH, and 32 healthy individuals for the control group. Details of these patients at the time of diagnosis were analysed, including gender, age, physical examination, electrocardiogram (ECG), echocardiography, six-minute walk test distance (6MWD), haemodynamic parameters and blood tests for biochemical markers that are correlated with clinical severity. Statistical analyses were performed using SPSS version 20.0 (SPSS Inc, Chicago, Illinois, USA). Statistical significance was taken as p < 0.05. In the forward stepwise multiple linear regression analysis, PwD and mean pulmonary artery pressure determined by right heart catheterisation were independently related to the functional capacity tested by the 6MWD (p < 0.02 and p < 0.01, respectively). PwD can easily be calculated from a surface ECG to indirectly estimate the functional status and prognosis of the patient with PAH.

A novel mathematical model of true ovarian reserve assessment based on predicted probability of poor ovarian response: a retrospective cohort study.

To establish a mathematical model for assessing the true ovarian reserve based on the predicted probability of poor ovarian response (POR). In this retrospective cohort study, a total of 1523 GnRH-antagonist cycles in 2017 were firstly analyzed. The ovarian responses were calculated based on the number of retrieved oocytes. The continuous variables were converted into categorical variables according to cutoff values generated by the decision tree method. The optimal model was identified using forward stepwise multiple logistic regression with 5-fold cross-validation and further verified its performances using outer validation data. The predictors in our model were anti-Müllerian hormone (AMH), antral follicle counts (AFC), basal follicle-stimulating hormone (FSH), and age, in order of their significance, named AAFA model. The AUC, sensitivity, specificity, positive predictive value, and negative predictive value of AAFA model in inner validation and outer validation data were 0.861 and 0.850, 0.603 and 0.519, 0.917 and 0.930, 0.655 and 0.570, and 0.899 and 0.915. Ovarian reserve of 16 subgroups was further ranked according to the predicted probability of POR and further divided into 4 groups of A-D using clustering analysis. The incidence of POR in the four groups was 0.038 (0.030-0.046), 0.139 (0.101-0.177), 0.362 (0.308-0.415), and 0.571 (0.525-0.616), respectively. The order of ovarian reserve from adequate to poor followed the order of A to D. We have established an easy applicable AAFA model for assessing true ovarian reserve and may have important implications in both infertile women and general reproductive women in Chinese or Asian population.

Movement Demands and Injury Characteristics in Under-20-Years University Rugby Union Players.

Rugby union is a field-based collision sport with high injury rates. Associations between injury characteristics and global positioning system-derived movement demands in rugby union athletes are yet to be investigated. To investigate associations between match injuries and movement demands, anthropometrics, and physical performance in under-20-years university-level rugby union players. Descriptive epidemiology study. Competition season. Rugby union players (n = 34, age = 19.3 ± 0.6 years) from a university club were recruited. Acute medical attention non-time-loss (NTL), medical-attention time-loss (TL), and total medical-attention (MA) injuries sustained were recorded. Principal component (PC) analysis was performed on player-movement demand variables to identify independent-movement demand components. Pearson correlation and bivariate linear regression were used to test associations between match injuries and PCs. Anthropometric and physical performance measures were tested as predictors of match injuries using a forward stepwise multiple regression analysis. Backs had lower anthropometric and performance measures than forwards (P < .05), whereas forwards performed fewer weekly movement demands than backs (P < .05). Increases in body mass and skinfold thickness were associated with more injuries (P < .05). Principal component analysis revealed 3 PCs representing overall performance, high-intensity running (HIR) performance, and impacts. Increases in HIR were associated with decreases in NTL upper limb and trunk (r = -0.32, P = .03), NTL musculoskeletal (r = -0.36, P = .05), NTL total (r = -0.46, P < .01), TL musculoskeletal (r = -0.30, P = .05), MA musculoskeletal (r = -0.41, P < .01), and MA total (r = -0.48, P < .01) injuries. Increases in impacts were associated with increased TL (r = 0.32, P = .03) and MA (r = 0.33, P = .03) head or neck injuries. Backs experienced greater weekly movement demands than forwards. Increases in HIR demands were associated with decreased acute injuries in university rugby players. Increases in impacts were associated with more acute head or neck injuries. Positional differences in movement demands, anthropometrics, and physical performance highlight the need for position-specific training.

Does the child’s health influence the caregiver’s health using the EQ-5D instruments?

BackgroundHealth- related quality of life (HRQoL) is an important aid in medical decision making. The child’s health may influence the caregiver’s health due to their intimate relationship.ObjectivesThe aim of this study was to investigate the influence of the child’s health on the caregiver’s health as measured on the EuroQoL Youth and Adult instruments.MethodA sample of 50 caregivers and their acutely-ill children, aged 3–6 years, was recruited from a paediatric hospital. Each caregiver completed the EQ-5D-Y, a proxy rating of their child’s HRQoL, and the EQ-5D-3L, a self-report measure of their own HRQoL, at baseline, 24 and 48 hours. The correlation between the caregiver and the child’s health over time was established. Forward stepwise multiple regression analysis was performed to establish the relative contribution of the child’s VAS score to the caregiver’s VAS score.ResultsThe results indicated that the child’s and the caregiver’s VAS ratings were significantly correlated over time, with an improvement in HRQoL scores over 48 hours. The child’s proxy VAS rating accounted for 21% and 18% of the variance in the caregiver’s VAS score at baseline and 24 hours, respectively, which was higher than self-reported problems on the caregivers EQ-5D-3L dimensions.ConclusionThe health of the caregiver is reported to improve as the perceived health of the child improves. The proxy rating of the child’s health influences the caregiver’s self-reported health more than their reported problems on the EQ-5D-3L.Clinical implicationsImproving the HRQoL of the child will lead to improved HRQoL in the caregiver.

Predictors of long-distance race performance in master runners.

To determine predictors of temperature-converted VDOT in master runners training for a long-distance race (10-26.2 mi). Twenty-three master runners (age 57±9 years; eight females) performed treadmill marathon-intensity-effort (MIE) and V .O2peak tests within four weeks of their goal race. The MIE occurred at 88% of predicted maximum heart rate, which corresponds to estimated marathon intensity. Participants completed online training-history surveys. Forward stepwise multiple linear regression was used to find key predictors of VDOT. The alpha level for significance was .05. Converted VDOT was significantly associated with three-year peak weekly training distance (3YP) (r = 0.454, p = .039), V .O2peak (r = 0.845, p = .000), alloV .O2 (r = 0.623, p = .005), and EC (r = -0.528, p = .018). The best-fitting model included V .O2peak and 3YP (r = 0.898). Physiological and training factors are related to race performance in master runners. The best predictors of VDOT are V .O2peak and 3YP. Training to enhance these variables may improve distance-running performance in masters.