Sex-specific Equations Research Articles

Sex and stature estimations from dry femurs of Northeastern Thais: Using a logistic and linear regression approach

BackgroundSex determination and stature estimation from skeletal remains are still crucial components in creating biological profiles in forensic anthropology. The femur is particularly valuable due to its high sexual dimorphism and correlation with stature. This study aimed to develop sex estimation models and stature reconstruction equations using femoral measurements in a Northeastern Thai population. Materials and methodThe 400 dry femora were measured for its six parameters including femur maximum length (FL), femoral shaft length (FSL), femur epicondylar breadth (FEB), femur maximum head diameter (FHD), femur midshaft circumference (FMC) and femur weight (FW). Then all parameters were analyzed by using logistic regression for sex estimation and linear regression for stature reconstruction. ResultsResults showed significant sexual dimorphism across all measured parameters, with FHD being the best predictor of sex (correction rate, 88.5 %). The optimized multivariate model achieved the highest accuracy (91.0 %). For stature estimation, sex-specific equations demonstrated superior accuracy compared to combined-sex models. The FL and FSL showed the strongest correlations with stature. ConclusionThis study demonstrated the importance of population-specific standards in forensic anthropology of the femur's reliability as a valuable tool for both sex determination and stature estimation. These results contribute significantly to forensic practice in Thailand, enhancing the accuracy of biological profile reconstruction in medicolegal investigations.

Evaluating the accuracy of population-specific versus generic stature estimation regression equations in a South African sample.

Accurate estimates of stature play an important role in the personal identification of unknown decedents, however a drawback in the application of many stature estimation equations is the need for known sex and population, the assignment of which can be challenging. Researchers have formulated equations for stature estimation that are neither population- nor sex-specific and thereof the aim of this study was to assess the applicability of these stature estimation equations proposed by Albanese et al.. (2016) (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). The physiological length of the femur, condylar malleolar length of the tibia and a combination of these measurements, collected from Magnetic Resonance Imaging Scanograms of adult (20-60 years) White South African males (n = 30) and females (n = 44) were used to assess the accuracy of the Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). sex-specific and generic stature estimation equations. The stature estimates were compared with measured living stature (LSM), using paired t-tests. Results indicated that the Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). equations underestimated living stature by between 1.1 and 5.0cm. These underestimations were significantly different between the LSM and the sex-specific estimates for females and the LSM and the generic estimates for males and the tibia for sex-specific equation. All stature estimates however fell in between two standard error of estimates for the sex-specific equations for males and the generic equations for the females. Although, the equations by Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). can be used to estimate stature in White South Africans in certain cases, the use of sex/population-specific equations remains the method of choice.

Independent association of metabolic syndrome severity score and risk of diabetes: findings from 18 years of follow-up in the Tehran Lipid and Glucose Study

ObjectivesThis study aimed to investigate the association between age-specific and sex-specific continuous metabolic syndrome severity score (cMetS-S) and the risk of developing type 2 diabetes mellitus (T2DM). Additionally, the study...

Secular change in heights of rural adults in west-central poland between 1986 and 2016: The transition from pre- to post-communism

Secular change in the heights of adult men and women resident in ten rural communities in west-central Poland in four decennial surveys between 1986 and 2016 is considered. The adults were parents of children attending schools in rural communities in the province of Poznań. During each survey, parents of school children were asked to complete a questionnaire which requested their ages, heights and completed levels of education. Ages were reported in whole years. The self-reported heights were adjusted for the tendency of individuals to overestimate height. Height loss among of individuals 35+ years was estimated with sex-specific equations and was added to the adjusted heights. Secular gains in heights of adult males across the 30 year interval, and across the 1986–1996 and 2006–2016 surveys were, on average, larger than corresponding gains in heights of adult females; the sex difference between 1996 and 2006 surveys was negligible. When heights were regressed on year of birth, heights of males and females born before 1950 (prior to World War II and shortly after) showed minimal and non-significant secular changes, while heights of those born post-1950 showed larger and significant secular gains, more so in males than in females. The results highlight significant secular trends in the heights of rural adults over a 30-year interval. Consistent with other studies in Poland, the positive trends likely reflected political, educational and socio-economic changes and by inference improved nutritional and health conditions across generations.

Association of Visceral Obesity Indices With Incident Diabetic Retinopathy in Patients With Diabetes: Prospective Cohort Study.

Visceral adipose tissue plays an active role in the pathogenesis of type 2 diabetes and vascular dysfunction. The lipid accumulation product (LAP), visceral adiposity index (VAI), and Chinese VAI (CVAI) have been proposed as simple and validated surrogate indices for measuring visceral adipose tissue. However, the evidence from prospective studies on the associations between these novel indices of visceral obesity and diabetic retinopathy (DR) remains scant. This study aimed to investigate the longitudinal associations of LAP, VAI, and CVAI with incident DR in Chinese patients with diabetes. This was a prospective cohort study conducted in Guangzhou in southern China. We collected baseline data between November 2017 and July 2020, while on-site follow-up visits were conducted annually until January 2022. The study participants consisted of 1403 patients with a clinical diagnosis of diabetes, referred from primary care, who were free of DR at baseline. The LAP, VAI, and CVAI levels were calculated by sex-specific equations based on anthropometric and biochemical parameters. DR was assessed using 7-field color stereoscopic fundus photographs and graded according to the modified Airlie House Classification scheme. Time-dependent Cox proportional hazard models were constructed to estimate the hazard ratios with 95% CIs. Restricted cubic spline curves were fitted to examine the dose-response relationship between the 3 indices of visceral obesity and new-onset DR. Subgroup analyses were performed to investigate the potential effect modifiers. The mean age of study participants was 64.5 (SD 7.6) years, and over half (816/1403, 58.2%) were female. During a median follow-up of 2.13 years, 406 DR events were observed. A 1-SD increment in LAP, VAI, or CVAI was consistently associated with increased risk for new-onset DR, with a multivariable‑adjusted hazard ratio of 1.24 (95% CI 1.09-1.41; P=.001), 1.22 (95% CI 1.09-1.36; P<.001), and 1.48 (95% CI 1.19-1.85; P=.001), respectively. Similar patterns were observed across tertiles in LAP (P for trend=.001), VAI (P for trend<.001), and CVAI (P for trend=.009). Patients in the highest tertile of LAP, VAI, and CVAI had an 84%, 86%, and 82% higher hazard of DR, respectively, compared to those in the lowest tertile. A nonlinear dose-response relationship with incident DR was noted for LAP and VAI (both P for nonlinearity<.05), but not for CVAI (P for nonlinearity=.51). We did not detect the presence of effect modification by age, sex, duration of diabetes, BMI, or comorbidity (all P for interaction>.10). Visceral obesity, as measured by LAP, VAI, or CVAI, is independently associated with increased risk for new-onset DR in Chinese patients with diabetes. Our findings may suggest the necessity of incorporating regular monitoring of visceral obesity indices into routine clinical practice to enhance population-based prevention for DR.

The association of aerobic and muscular fitness with cognitive impairment: Findings from a nationally representative survey

This study aimed to characterize the combined association between cardiorespiratory fitness (CRF), muscular strength, and cognitive outcomes in middle-aged and older adults from low and middle-income countries (LMICs). We analyzed cross-sectional, population-based data from adults aged 50 years or older from six LMICs. Mild cognitive impairment (MCI) was defined according to the National Institute on Aging‐Alzheimer's Association criteria. Estimated CRF (eCRF) was calculated using previously validated, sex-specific equations. Handgrip strength (HS) was used as an indicator of muscular strength. We used linear and robust Poisson regression models to examine the associations between eCRF, HS, and MCI. Data from 28,339 adults (63.1 [9.5] years) were analyzed. Participants with low eCRF (PR: 1.45; 95%CI: 1.11, 1.90) and HS (PR: 1.92; 95%CI: 1.79, 2.04) were more prone to have MCI. Participants with low HS showed higher likelihood of MCI than those with preserved HS through the CRF range; however, this difference was not seen among highly fit individuals (10 METs or higher). Each 1-MET (PR: 0.77; 95%CI: 0.67, 0.86) and 5-kgf (PR: 0.63; 95%CI: 0.48, 0.79) increase was associated with a reduction in the likelihood of MCI. eCRF and HS were strongly and independently associated with MCI in middle-aged and older adults.

Estimating the relative load from movement velocity in the seated chest press exercise in older adults.

This study aimed to i) determine the load-velocity relationship in the seated chest press in older adults, ii) compare the magnitude of the relationship between peak and mean velocity with the relative load, and iii) analyze the differences between sexes in movement velocity for each relative load in the chest press. Thirty-two older adults (17 women and 15 men; 79.6±7.7 years) performed a chest press progressive loading test up to the one-repetition maximum (1RM). The fastest peak and mean velocity reached with each weight were analyzed. Quadratic equations were developed for both sexes and the effectiveness of the regression model was analyzed through a residual analysis. The equations were cross-validated, considering the holdout method. The independent samples t-test analyzed i) the differences in the magnitude of the relationship between peak and mean velocity with the relative load and ii) the differences between sexes in the peak and mean velocity for each relative load. It was possible to observe very strong quadratic load-velocity relationships in the seated chest press in women (peak velocity: r2 = 0.97, standard error of the estimate (SEE) = 4.5% 1RM; mean velocity: r2 = 0.96, SEE = 5.3% 1RM) and men (peak velocity: r2 = 0.98, SEE = 3.8% 1RM; mean velocity: r2 = 0.98, SEE = 3.8% 1RM) without differences (p>0.05) in the magnitude of the relationship between peak and mean velocity with the relative load. Furthermore, there was no overfitting in the regression models due to the high and positive correlation coefficients (r = 0.98-0.99). Finally, men presented higher (p<0.001) lifting velocities than women in almost all relative loads, except for 95-100% 1RM (p>0.05). Measuring repetition velocity during the seated chest press is an objective approach to estimating the relative load in older adults. Furthermore, given the velocity differences between older women and men at submaximal loads, it is recommended to use sex-specific equations to estimate and prescribe the relative loads in older adults.

Should We Use the Men Load–Velocity Profile for Women in Deadlift and Hip Thrust?

Injuries are common in team sports and can impact both team and individual performance. In particular, hamstring strain injuries are some of the most common injuries. Furthermore, hamstring injury ratios, in number of injuries and total absence days, have doubled in the last 21 seasons in professional soccer. Weakness in hip extensor strength has been identified as a risk factor in elite-level sprinters. In addition, strength imbalances of the hamstring muscle group seem to be a common cause of hamstring strain injuries. In this regard, velocity-based training has been proposed to analyze deficits in the force-velocity profile. Previous studies have shown differences between men and women, since there are biomechanical and neuromuscular differences in the lower limbs between sexes. Therefore, the aim of this study was to compare the load-velocity profile between males and females during two of the most important hip extension exercises: the hip thrust and the deadlift. Sixteen men and sixteen women were measured in an incremental loading test following standard procedures for the hip thrust and deadlift exercises. Pearson's correlation (r) was used to measure the strength of the correlation between movement velocity and load (%1RM). The differences in the load-velocity relationship between the men and the women were assessed using a 2 (sex) × 15 (load) repeated-measures ANOVA. The main findings revealed that: (I) the load-velocity relationship was always strong and linear in both exercises (R2 range: 0.88-0.94), (II) men showed higher velocities for light loads (30-50%1RM; effect size: 0.9-0.96) than women for the deadlift, but no significant differences were found for the hip thrust. Based on the results of this study, the load-velocity equations seem to be sex-specific. Therefore, we suggest that using sex-specific equations to analyze deficits in the force-velocity profile would be more effective to control intensity in the deadlift exercise.

Sex-specific equations to estimate body composition: Derivation and validation of diagnostic prediction models using UK Biobank

Body mass index and waist circumference are simple measures of obesity. However, they do not distinguish between visceral and subcutaneous fat, or muscle, potentially leading to biased relationships between individual body composition parameters and adverse health outcomes. The purpose of this study was to develop and validate prediction models for volumetric adipose and muscle. Based on cross-sectional data of 18,457, 18,260, and 17,052 White adults from the UK Biobank, we developed sex-specific equations to estimate visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (ASAT), and total thigh fat-free muscle (FFM) volumes, respectively. Volumetric magnetic resonance imaging served as the reference. We used the least absolute shrinkage and selection operator and the extreme gradient boosting methods separately to fit three sequential models, the inputs of which included demographics and anthropometrics and, in some, bioelectrical impedance analysis parameters. We applied comprehensive metrics to assess model performance in the temporal validation set. The equations that included more predictors generally performed better. Accuracy of the equations was moderate for VAT (percentage of estimates that differed <30% from the measured values, 70 to 78 in males, 64 to 69 in females) and good for ASAT (85 to 91 in males, 90 to 95 in females) and FFM (99 to 100 in both sexes). All the equations appeared precise (interquartile range of the difference, 0.89 to 1.76L for VAT, 1.16 to 1.61L for ASAT, 0.81 to 1.39L for FFM). Bias of all the equations was negligible (-0.17 to 0.05L for VAT,-0.10 to 0.12L for ASAT,-0.07 to 0.09L for FFM). The equations achieved superior cardiometabolic correlations compared with body mass index and waist circumference. The developed equations to estimate VAT, ASAT, and FFM volumes achieved moderate to good performance. They may be cost-effective tools to revisit the implications of diverse body components.

Prediction of fat-free mass in a multi-ethnic cohort of infants using bioelectrical impedance: Validation against the PEA POD.

BackgroundBioelectrical impedance analysis (BIA) is widely used to measure body composition but has not been adequately evaluated in infancy. Prior studies have largely been of poor quality, and few included healthy term-born offspring, so it is unclear if BIA can accurately predict body composition at this age.AimThis study evaluated impedance technology to predict fat-free mass (FFM) among a large multi-ethnic cohort of infants from the United Kingdom, Singapore, and New Zealand at ages 6 weeks and 6 months (n = 292 and 212, respectively).Materials and methodsUsing air displacement plethysmography (PEA POD) as the reference, two impedance approaches were evaluated: (1) empirical prediction equations; (2) Cole modeling and mixture theory prediction. Sex-specific equations were developed among ∼70% of the cohort. Equations were validated in the remaining ∼30% and in an independent University of Queensland cohort. Mixture theory estimates of FFM were validated using the entire cohort at both ages.ResultsSex-specific equations based on weight and length explained 75–81% of FFM variance at 6 weeks but only 48–57% at 6 months. At both ages, the margin of error for these equations was 5–6% of mean FFM, as assessed by the root mean squared errors (RMSE). The stepwise addition of clinically-relevant covariates (i.e., gestational age, birthweight SDS, subscapular skinfold thickness, abdominal circumference) improved model accuracy (i.e., lowered RMSE). However, improvements in model accuracy were not consistently observed when impedance parameters (as the impedance index) were incorporated instead of length. The bioimpedance equations had mean absolute percentage errors (MAPE) < 5% when validated. Limits of agreement analyses showed that biases were low (< 100 g) and limits of agreement were narrower for bioimpedance-based than anthropometry-based equations, with no clear benefit following the addition of clinically-relevant variables. Estimates of FFM from BIS mixture theory prediction were inaccurate (MAPE 11–12%).ConclusionThe addition of the impedance index improved the accuracy of empirical FFM predictions. However, improvements were modest, so the benefits of using bioimpedance in the field remain unclear and require further investigation. Mixture theory prediction of FFM from BIS is inaccurate in infancy and cannot be recommended.

Breeding Phenology and Nestling Morphology of Bald Eagles in the Upper Midwestern United States1

Abstract We report on egg-laying and hatching dates (n = 656), and morphological characteristics (n = 642) of nestling Bald Eagles (Haliaeetus leucocephalus) from six study areas in Minnesota and Wisconsin, USA, from 2006 to 2011, 2014, and 2015. Nestling age was estimated from length of the eighth primary feather using sex-specific equations from the literature. Egg-laying advanced from south to north beginning in late January and continuing through mid-April; hatching began in late February and ended in mid-May. Mean annual hatching dates were correlated with the average dates of ice break-up each spring at two ice-monitoring sites (n = 8 yr, r2 = 0.90). We found no significant long-term trend or shift in hatching dates over the 10 yr. Male and female nestlings overlapped in weight, footpad length, bill depth, and culmen and hallux claw chord length; however, by 35 d these features had diverged sufficiently to allow estimation of the sex of nestlings due to the larger size of females (P &amp;lt; 0.05 all contrasts). Our models suggest that most of the nestling traits we measured continued to grow beyond the 70 d for which we had measurements, except for footpad, which reached predicted full size by about 46 d after hatching. Footpad length and bill depth were important traits for determining the sex of nestlings ≥35 d old. We provide a classification tree that uses footpad length and bill depth to estimate the sex of nestlings. Overall accuracy of this classification tree was 91%. Individuals with footpad length ≥132 mm and bill depth ≥29 mm (46% of our sample) had a 0.95 probability of being female and individuals with footpad length &amp;lt;132 mm and bill depth &amp;lt;30 mm (41% of our sample) had a 0.92 probability of being male, making our classification tree unbiased and robust for assigning sex for most nestlings ≥35 d old.

Non-linear Associations Between Visceral Adiposity Index and Cardiovascular and Cerebrovascular Diseases: Results From the NHANES (1999-2018).

ObjectiveTo investigate associations between visceral adiposity index (VAI) and cardiovascular and cerebrovascular diseases (CCDs) in the American population from 1999 to 2018.MethodsData from the National Health and Nutrition Examination Survey (1998–2018) were analyzed in this study. Specifically, VAI scores were calculated using sex-specific equations that incorporate body mass index, waist circumference (WC), high-density lipoprotein (HDL), triglycerides (TG), and cholesterol. Weighted logistic regression analysis was conducted to assess the relationship between VAI tertile and increased risk of CCDs. Restricted cubic splines were used to evaluate the non-linear relationship between VAI and CCDs, such as heart failure, angina, heart attack, stroke, hypertension, and coronary heart disease. Sensitivity analysis was conducted, using VAI quartiles as independent variables.ResultsA total of 22,622 subjects aged over 20 years were included. In the fully adjusted model after controlling for covariates, the third VAI tertile was more strongly associated with CCDs than the first VAI tertile, with odds ratio (OR) and 95% confidence interval (95% CI) values for angina of 2.86, 1.68–4.85; heart attack, 1.75, 1.14–2.69; stroke, 2.01, 1.23–3.26; hypertension, 2.28, 1.86–2.78; and coronary heart disease, 1.78, 1.32–2.41; but there was no significant association with heart failure (p > 0.05). Restricted cubic splines revealed parabolic relationships between VAI score and angina (p for non-linear = 0.03), coronary heart disease (p for non-linear = 0.01), and hypertension (p for non-linear < 0.001). Sensitivity analysis indicated that the fourth VAI quartile was more strongly associated with an increased risk of angina (OR = 2.92, 95% CI, 1.49–5.69), hypertension (OR = 2.37, 95% CI, 1.90–2.97), heart attack (OR = 1.77, 95% CI, 1.09–2.88), and coronary heart disease (OR = 1.89, 95% CI, 1.24–2.86) than the first VAI quartile. VAI had superior predictive power for prevalent CCDs than other independent indicators (p < 0.05).ConclusionVisceral adiposity index score is positively correlated with angina, heart attack, stroke, hypertension, and coronary heart disease, but not heart failure, and the relationships between VAI score and angina, hypertension, and coronary heart disease are non-linear.

Age and Growth of the Spot-Tail Shark, Carcharhinus sorrah, in the Taiwan Strait

The age and growth of the spot-tail shark, Carcharhinus sorrah, were estimated based on 327 specimens (171 females and 156 males) captured by the coastal/offshore longline or drift net fishery in the waters of the Taiwan Strait from October 2010 to December 2011 and July 2019 to August 2021. Sex-specific whole weight (W)—curved total length (TL) relationships were estimated as follows: W = 7.0 × 10−6 TL2.9313 (n = 171, and p &lt; 0.05) for females, and W = 4.0 × 10−6 TL3.0516 (n = 156, and p &lt; 0.05) for males. The periodicity of growth band pair (including translucent and opaque bands) deposition in precaudal vertebrae was assumed to be 1 year based on centrum edge analysis and verified by a statistical analysis. The band pairs after the birth mark were counted as 0–5 and 0–8 for females and males, respectively. The Gompertz and von Bertalanffy growth function best described the observed length-at-age data for females and males, respectively. The parameters for sex-specific growth equations were estimated as: L∞ = 158.6 ± 9.09 cm TL, kG = 0.2347 ± 0.0245 year−1, and c = −0.3233 ± 0.2043 (n = 171, and p &lt; 0.01) for females, and L∞ = 170.2 ± 9.51 cm TL, k = 0.1461 ± 0.0182 year−1, and t0 = −3.1586 ± 0.2065 (n = 156, and p &lt; 0.01) for males.

Estimation of neonatal body fat percentage predicts neonatal hypothermia better than birthweight centile

Introduction PEA POD™ air displacement plethysmography quickly and noninvasively estimates neonatal body fat percentage (BF%). Low PEA POD™ BF% predicts morbidity better than classification as small-for-gestational-age (SGA; <10th centile), but PEA PODs are not widely available. We examined whether skinfold measurements could effectively identify neonates at risk; comparing skinfold BF%, PEA POD™ BF% and birthweight centiles’ prediction of hypothermia – a marker of reduced in utero nutrition. Methods Neonates had customized birthweight centiles calculated, and BF% prospectively estimated by: (i) triceps and subscapular skinfolds using sex-specific equations; and (ii) PEA POD™. Medical record review identified hypothermic (<36.5 °C) episodes. Results 42/149 (28%) neonates had hypothermia. Skinfold BF%, with an area under the curve (AUC) of 0.66, predicted hypothermia as well as PEA POD™ BF% (AUC = 0.62) and birthweight centile (AUC = 0.61). Birthweight <10th centile demonstrated 11.9% sensitivity, 38.5% positive predictive value (PPV) and 92.5% specificity for hypothermia. At equal specificity, skinfold and PEA POD™ BF% more than doubled sensitivity (26.2%) and PPV increased to 57.9%. Conclusion Neonatal BF% performs better to predict neonatal hypothermia than birthweight centile, and may be a better measure of true fetal growth restriction. Estimation of neonatal BF% by skinfold measurements is an inexpensive alternative to PEA POD™.

Estimation of stature from lower limb measurements by regression analysis in north-west Indian population

The aim of the study was to estimate the stature from lower limb parameters in the north-west population of India and to know whether a significant correlation exists between the stature and various lower limb dimensions and to further derive regression formulae for estimation of stature from various lower limb segments. Materials and methods: the study was conducted on medical students age ranged between 18 to 28 years, which comes chiefly from north-west part of India. Only the subjects willing to participate in the study and given their written informed consent were included in the study group. The students having any obvious physical deformity were excluded from the study. Correlations between various lower limb parameters and stature were determined by using the Pearson’s correlation test. Sex-specific linear regression equations for stature estimation were developed using the lower limb measurements. The multiple regressions equations were produced based on various combinations of the parameters by stepwise regression analysis. Results: the Pearson’s correlation in combined group showed good correlations between lower limb parameters and stature. There was no statistically significant difference between known stature and estimated stature by using paired T-test for both right and left side in a group consisting of both sexes and in males (p&gt;0.05). Conclusion: from the parameters, lower limb length and foot length had shown strong positive correlations with stature in the north-west Indian population

Validation of the SMH Equations for the Estimation of the Total Body Water Volume in Hemodialysis Patients.

Online dialysis clearance monitors typically provide an accurate value for Kt. A value for V (total body water [TBW]) is required to calculate Kt/V, the measure of the adequacy of the delivered dialysis in hemodialysis (HD) patients. Using bioimpedance spectroscopy (BIS), we previously developed 2 sex-specific equations for the estimation of the TBW, which we have chosen to name the St Michael's Hospital (SMH) equations. The objective of this study was to validate the SMH equations in a second distinct population of patients. Cross-sectional study. Single center hemodialysis unit at St Michael's Hospital, a tertiary care teaching hospital, in Toronto, Canada. Eighty-one adult HD patients who had been receiving conventional maintenance HD for at least 3 months. Anthropometric measurements including weight, height, and waist circumference were collected. TBW was measured by BIS using the Body Composition Monitor (Fresenius Medical Care, Bad Homburg, Germany). The Bland-Altman method to calculate the bias and limits of agreement and the difference plot analysis were used to evaluate the difference between the BIS-TBW and the TBW derived from our equations (SMH equation) in this validation cohort. The TBW values based on our equations had a high correlation with BIS-TBW (correlation coefficients = 0.93, P values < .01, bias = 1.8 [95% CI: 1-2.6] liter). Application of SMH equations closely predicted Kt/V, based on BIS value, in all categories of waist circumference. Small sample size, single-center, not including peritoneal dialysis patients. A larger and more heterogeneous sample with more patients at the extremes of body mass index would allow for more detailed sub-group analyses in different races and different anthropometric categories to better understand the performance of these equations in discrete sub-groups of patients. In maintenance HD patients, our previously derived equations to estimate the TBW using weight and waist circumference appear to be valid in a distinct patient population. Given the centrality of TBW to the calculation of small molecule clearance, the SMH equations may enhance the measurement of dialysis adequacy and inform practice.

Visceral adiposity index is associated with arterial stiffness in hypertensive adults with normal-weight: the china H-type hypertension registry study

BackgroundLimited information is available on arterial stiffness risk among hypertensive patients with metabolically abnormal but normal weight. Visceral adiposity index (VAI) is a novel indicator for visceral fat mass and metabolism, however, whether can be used to assessed arterial stiffness in a normal-weight population remains unclear. The goal of this study was to examine the independent association of VAI with arterial stiffness in normal-weight hypertensive patients.Methods3258 participants recruited from the China H-type Hypertension Registry Study. VAI value was calculated using sex-specific equations. High arterial stiffness was defined as baPWV ≥ 18 m/s. Multivariable regression analysis was used to identify the association of VAI with baPWV and high arterial stiffness.ResultsOf participants, 50.5% (1644) were males, the mean age was 65.5 (SD, 9.1) years. Mean VAI and baPWV were 2.0 (SD, 2.3) and 18.2 (SD, 3.9) m/s, respectively. For each unit increase of lg VAI in multivariable regression analysis, there was a 1.05 m/s increase in baPWV (95% CI 0.67, 1.43) and a 2.13-fold increase in the risk of high arterial stiffness (95% CI 1.59, 2.86). In all models, the VAI was consistently and significantly associated with baPWV after adjustment for different confounders. High VAI levels were stably associated with baPWV in all subgroups.ConclusionsWe found positive association of VAI with baPWV and high arterial stiffness in normal-weight adults with hypertension. The establishment of this association could help the arterial stiffness risk stratification in normal-weight hypertensive populations, who are frequently overlooked in preventing cardiovascular disease.

Modeling the Recommended Age for Initiating Coronary Artery Calcium Testing Among At-Risk Young Adults

BackgroundThere are currently no recommendations guiding when best to perform coronary artery calcium (CAC) scanning among young adults to identify those susceptible for developing premature atherosclerosis. ObjectivesThe purpose of this study was to determine the ideal age at which a first CAC scan has the highest utility according to atherosclerotic cardiovascular disease (ASCVD) risk factor profile. MethodsWe included 22,346 CAC Consortium participants aged 30-50 years who underwent noncontrast computed tomography. Sex-specific equations were derived from multivariable logistic modeling to estimate the expected probability of CAC >0 according to age and the presence of ASCVD risk factors. ResultsParticipants were on average 43.5 years of age, 25% were women, and 34% had CAC >0, in whom the median CAC score was 20. Compared with individuals without risk factors, those with diabetes developed CAC 6.4 years earlier on average, whereas smoking, hypertension, dyslipidemia, and a family history of coronary heart disease were individually associated with developing CAC 3.3-4.3 years earlier. Using a testing yield of 25% for detecting CAC >0, the optimal age for a potential first scan would be at 36.8 years (95% CI: 35.5-38.4 years) in men and 50.3 years (95% CI: 48.7-52.1 years) in women with diabetes, and 42.3 years (95% CI: 41.0-43.9 years) in men and 57.6 years (95% CI: 56.0-59.5 years) in women without risk factors. ConclusionsOur derived risk equations among health-seeking young adults enriched in ASCVD risk factors inform the expected prevalence of CAC >0 and can be used to determine an appropriate age to initiate clinical CAC testing to identify individuals most susceptible for early/premature atherosclerosis.

Associations of Percent Body Fat and Motor Skill Development in Preschool-Aged Children: National Youth Fitness Survey.

Background: Body composition and motor skill development are important for the engagement in physical activity and healthy development of children. This study examined the associations between body composition and motor skill development in 3- to 5-year-old children. Methods: Data from preschool-aged children (N = 342, 51% males) who participated in the 2012 National Youth Fitness Survey were analyzed. Skinfold measurements (subscapular, calf, and triceps) were taken and percent body fat (%BF) was calculated using sex-specific equations. Lean muscle mass and fat mass were also calculated. Motor skill development was determined by the Test of Gross Motor Development-2nd Edition. Regression analyses were performed to determine the associations among %BF and locomotor skills, object control skills, and overall gross motor quotient (GMQ), controlling for sex, race, and poverty index ratio. Results: Most children were classified as with underweight/healthy weight (69%) and 31% were either with overweight or obesity. Average %BF was 17.02% ± 0.27%. The standard scores for locomotor skills, object control skills, and GMQ were 9.99 ± 0.16, 8.52 ± 0.14, and 95.57 ± 0.68, respectively. These scores were considered average. Regression analyses indicated that neither the %BF nor sum of skinfolds was associated with locomotor skills (β = -0.07 ± 0.05, p = 0.63; β = -0.03 ± 0.03, p = 0.22), object control skills (β = 0.03 ± 0.04, p = 0.55; β = 0.00 ± 0.02, p = 0.87), or GMQ (β = -0.13 ± 0.28, p = 0.63; β = -0.09 ± 0.14, p = 0.52). Furthermore, neither lean muscle mass nor fat mass was related with any motor skill measure (p > 0.05). Conclusions: Using different measures of body composition may provide additional insight into associations between obesity and motor skill development in preschool-aged children. Given the inconsistent findings in the literature, additional research is needed to elucidate these associations.

Predicting height from ulna length for the determination of weight status in New Zealand adolescents: A cross-sectional study.

The measurement of height is crucial for weight status assessment. When standing height is difficult to measure, ulna length may offer a convenient and accurate surrogate of height measure. Adolescence is a period of accelerated linear growth; hence, the validation of age-specific equations that predict height from ulna length in adolescents is warranted. The present study aimed to develop and validate age- and sex-specific equations for predicting height from ulna length in New Zealand adolescents. Height, weight and ulna length were measured in 364 adolescents (n=110males, n=254 females) aged 15.0-18.8years, who were enrolled in the SuNDiAL (Survey of Nutrition Dietary Assessment and Lifestyle) project, a cross-sectional survey performed in 2019 and 2020. Regression models were used to determine equations to predict height from ulna length. Agreement between measured and predicted height, body mass index (BMI) and BMI z-score was assessed with intra-class correlation coefficients (ICC) and Bland-Altman plots. Sensitivity and specificity were calculated for classifying obesity. Strong agreement was found between predicted and measured height (ICC=0.78; mean difference=0; 95% confidence interval=-0.5 to 0.5cm) and BMI (ICC=0.95; mean difference=0; 95% confidence interval=-0.1 to 0.1kgm-2 ). Predicted height was 88.1% accurate when classifiying weight status, showing high sensitivity (93.8%) and specificity (99.4%) for classifying obesity. Ulna length measurement can accurately estimate height and subsequently weight status in New Zealand adolescents aged 15-18years.