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To examine measures of total and regional body composition using dual X-ray absorptiometry (DXA) in NCAA Division I collegiate equestrian athletes, 31 female collegiate equestrian athletes were matched to a population of normal controls by age and body mass index. Total and regional fat tissue mass (FM), lean tissue mass (LM), bone mineral density (BMD), and abdominal visceral adipose tissue (VAT) were measured by DXA. Equestrian athletes had a significantly (p=0.03) lower total body fat percentage (%fat) than controls. There were no significant differences in total LM and VAT between equestrian athletes and controls. However, equestrian athletes, when compared to the controls, had significantly lower leg %fat, leg FM and higher leg LM. The greater leg LM in equestrian riders resulted in a smaller upper to lower body LM ratio compared to controls. There was no difference in leg BMD between equestrian athletes and controls. There were no significant differences between the 2 styles of riding (i. e., hunt seat and western style) in regards to body composition. The lower total %fat in equestrian athletes seems to be influenced by differences in leg composition, with equestrian athletes having significantly more LM and less FM.

Objective Anastrozole, an aromatase inhibitor, has been used off-label in males with short stature to delay bone maturation. No studies have examined anastrozole's effect on bone mineral density (BMD) or body composition in children with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. Our objective was to evaluate anastrozole's effect on BMD and visceral adipose tissue (VAT) in children with CAH. Design Total body BMD (TBMD) and L2-L4 BMD Z-scores were adjusted for height-for-age Z-scores (TBMDHAZ and L2-L4HAZ ). Hydrocortisone doses (mg/m2 /d) were averaged over the previous year. Comparison of treated vs not treated with anastrozole used linear regression adjusting for age, pubertal status, sex, CAH type, years on hydrocortisone, BMI Z-scores and bone age Z-scores. Patients We compared 25 children with CAH treated with anastrozole (mean age 11.3 [SD 3.0] years, 56% males) vs 31 children with CAH not treated with anastrozole (13.5 [SD 4.6], 29%). Participants underwent a pubertal exam, bone age X-ray and dual X-ray absorptiometry (DXA) scan. Results Average bone age Z-score of 4.3 SDs on beginning anastrozole decreased to 1.9 SDs at time of DXA exam (P = 0.0004) 5.2 (SD 2.2) years later. TBMD Z-scores (P = 0.51), L2-L4 BMD Z-scores (P = 0.66), VAT (P = 0.38), TBMDHAZ Z-scores (P = 0.66) and L2-L4HAZ Z-scores (P = 0.41) did not differ between children treated vs not treated with anastrozole. Conclusion Anastrozole significantly reduced bone age advancement in children with CAH and advanced bone age (>2SDs) without adverse effects on BMD or VAT. Longitudinal studies of anastrozole in children with CAH are needed to validate these findings.

Background: In adolescents with severe obesity, long-term weight loss maintenance using lifestyle therapy alone is hampered by numerous biological adaptations favoring weight regain such as increased appetite and sense of food palatability and decreased satiety and resting energy expenditure. Anti-obesity pharmacotherapy may have a role in mitigating some of these physiological adaptations, thereby enhancing weight loss maintenance. We conducted a randomized, double-blind, placebo-controlled clinical trial to evaluate the effect of the glucagon-like peptide-1 receptor agonist (GLP-1RA) exenatide extended release (XR) on the maintenance of BMI reduction and improvements in cardiometabolic risk factors induced by short-term meal replacement therapy (MRT) among adolescents with severe obesity. Methods: One-hundred adolescents ages 12 to

Previously, we have demonstrated that high-flow-mediated constriction (H-FMC) of the brachial artery has been shown to negatively affect flow-mediated dilation (FMD). However, the reproducibility of an H-FMC response is unknown.The aim of this study was to determine the intra- and interday reproducibility of H-FMC in young adults.Thirty young adults (15 male, 15 female; 24 ± 3 years) were assessed for H-FMC reproducibility via high-resolution ultrasound imaging of the brachial artery during and after forearm occlusion of a normal FMD procedure. Two vascular assessments were conducted for all participants during two separate visits with a minimum of 7 days in between. H-FMC was characterized as the greatest 10-s average constriction occurring after 3-s postocclusion compared to baseline brachial artery diameter and considered present if the percent change was-0·1%.Of the 120 total vascular assessments performed in this study, 98 of the assessments (80·3%) displayed an H-FMC. H-FMC diameter was not statistically different for intraday comparisons for visit 1 (P = 0·39) or visit 2 (P = 0·55) or interday comparisons between the first (P = 0·61) or second (P = 0·10) assessments. H-FMC percentage was also not statistically different for intra-day comparison for visit 1 (P = 0·94) or visit 2 (P = 0·15) or interday comparisons between the first (P = 0·63) or second (P = 0·16) assessments.These data are supportive of H-FMC being reproducible in young adults and included in future FMD studies. The impact of H-FMC on future CVD risk and development warrants evaluation.

Purpose During reactive hyperemia, the brachial artery in some individuals constricts prior to dilation. Our aim was to describe the frequency of high-flow-mediated constriction (H-FMC) in adults, and its relationship to body composition and biomarkers of cardiovascular and metabolic risk. Methods Two hundred forty-six adults (124 male, 122 female; 36 ± 7 years old) were assessed for H-FMC via sonographic imaging of the brachial artery. Blood pressure, glucose, insulin, lipids, and body composition assessed via dual energy X-ray absorptiometry were collected. H-FMC was characterized as a 10-second average of maximal postocclusion constriction. Independent t test was used to compare H-FMC versus non-H-FMC individuals. Results H-FMC was observed in approximately 69% of adult participants (54 obese, 57 overweight, and 59 normal weight). Total body mass (82.3 ± 17.5 versus 76.3 ± 16.3 kg, p = 0.012), fat mass (27.7 ± 11.5 versus 23.8 ± 10.5 kg, p = 0.012), body mass index (27.7 ± 4.9 versus 26.1 ± 5.0 kg/m2, p = 0.018), and low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio (2.41 ± 1.03 versus 2.09 ± 0.72, p = 0.007) were higher in H-FMC than in non-H-FMC individuals. Flow-mediated dilatation (FMD) (6.12 ± 3.48 versus 8.09 ± 3.02%, p

Objective: Skipping breakfast and consuming fast food are related to the risk of obesity and are common adolescent behaviors. The relationship between these behaviors and biomarkers related to diabetes and CVD is understudied in this population. Methods: Data are from a study of the etiologic factors related to obesity risk in adolescents. Breakfast and fast food consumption were assessed using a self-report survey. Anthropometrics, fasting lipids, glucose, insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were assessed. Multivariate analyses were used to examine the relationship between dietary behaviors and selected biomarkers, controlling for calories consumed, body mass index (BMI), and demographic covariates. Results: 367 adolescents (11 to 18-years; mean 14.7 ± 1.8 years) were assessed at the University of Minnesota-Twin Cities from 2006–2008. Breakfast consumption was significantly associated with lower BMI, body fat, insulin, HOMA-IR, and metabolic syndrome (MetS) cluster score, while fast food consumption was associated with higher BMI, body fat, low-density lipoprotein cholesterol, triglycerides, glucose, insulin, HOMA-IR, and MetS cluster score. Some gender differences were observed. Conclusion: Breakfast and fast food consumption appear to be related to important metabolic syndrome biomarkers for chronic disease in a sample of healthy adolescents. The importance of this finding needs to be validated by examining the stability of this pattern over time and to assess the pattern in other populations., Highlights • Risk factor clustering may create metabolic dysfunction. • Eating breakfast is related to decrease metabolic risk in adolescents. • Eating fast food is related to increased metabolic risk in adolescents.

Summary Hypercapnia has been utilized as a stimulus to elicit changes in cerebral blood flow (CBF). However, in many instances it has been delivered in a non-controlled method that is often difficult to reproduce. The purpose of this study was to examine the within- and between-visit reproducibility of blood oxygen level-dependent (BOLD) signal changes to an iso-oxic square wave alteration in end-tidal carbon dioxide partial pressure (PetCO2). Two 3-Tesla (3T) MRI scans were performed on the same visit, with two square wave alterations administered per scan. The protocol was repeated on a separate visit with minimum of 3 days between scanning sessions. PetCO2 was altered to stimulate changes in cerebral vascular reactivity (CVR), while PetO2 was held constant. Eleven subjects (six females; mean age 26·5 ± 5·7 years) completed the full testing protocol. Excellent within-visit square wave reproducibility (ICC > 0·75) was observed. Similarly, square waves were reproducible between scanning sessions (ICC > 0·7). This study demonstrates BOLD signal changes in response to alterations in PetCO2 are reproducible both within- and between-visit MRI scans.

Flow-mediated dilation (FMD) relies on reactive hyperemia to stimulate the endothelium to release nitric oxide, causing smooth muscle relaxation. Hypercapnia also produces vasodilation, which is thought to be nitric oxide-independent. The purpose of this study was to compare and contrast the effects of hypercapnia and reactive hyperemia as stimuli for brachial artery dilation. On separate days, twenty-five participants underwent vasodilation studies via reactive hyperemia or hypercapnia (i.e. 10 mmHg increase in end-tidal carbon dioxide [PetCO2)]). During both studies changes in brachial artery diameter were recorded using continuous ultrasound imaging. Heart rate (HR) was measured throughout both tests. Resting HR (63 ± 11 versus 68 ± 14 beats min(-1), p = 0.0027) and baseline brachial artery diameter measurements (4.57 ± 1.51 versus 5.28 ± 1.86 mm, p = 0.022) were significantly different between reactive hyperemia and hypercapnia, respectively. HR at peak dilation (65 ± 11 versus 76 ± 14 beats min(-1), p

Though individual differences in arterial carbon dioxide and oxygen levels inherently exist, the degree of their influence on cerebral vascular reactivity (CVR) is less clear. We examined the reproducibility of BOLD signal changes to an iso-oxic ramping P(et)CO(2) protocol. CVR changes were induced by altering P(et)CO(2) while holding P(et)O(2) constant using a computer-controlled sequential gas delivery (SGD) device. Two MRI scans, each including a linear change in P(et)CO(2), were performed using a 3-Tesla (3T) scanner. This ramp sequence consisted of 1 minute at 30 mmHg followed by 4 minute period during where P(et)CO(2) was linearly increased from 30 mmHg to 50 mmHg, 1 minute at 51 mmHg, and concluded with 4 minutes at baseline. The protocol was repeated at a separate visit with 3 days between visits (minimum). Intraclass correlation coefficients (ICC) and coefficients of variation (CV) were used to verify reproducibility. Eleven subjects (6 females; mean age 26.5 ± 5.7 years) completed the full testing protocol. Good reproducibility was observed for the within-visit ramp sequence (Visit 1: ICC = 0.82, CV = 6.5%; Visit 2: ICC = 0.74, CV = 6.4%). Similarly, ramp sequence were reproducible between-visits (Scan 1: ICC = 0.74, CV = 6.5%; Scan 2: ICC = 0.66, CV = 6.1%). Establishing reproducible methodologies for measuring BOLD signal changes in response to P(et)CO(2) alterations using a ramp protocol will allow researchers to study CVR functionality. Finally, adding a ramping protocol to CVR studies could provide information about changes in CVR over a broad range of P(et)CO(2).

BACKGROUND The relationship between pediatric severe obesity (SO) and central aortic blood pressure (BP) has yet to be established. METHODS We conducted a cross-sectional study of 348 youth (48.5% male, age 12.7 ± 0.1 years) with a wide range of body mass index (BMI) values: normal weight (NW; ≥5th and RESULTS After adjustment for covariates, no significant sex differences were observed for radial−aortic systolic blood pressure (SBP) (P = 0.39), carotid−aortic SBP (P = 0.99), radial−aortic diastolic blood pressure (DBP) (P = 0.44), and carotid−aortic DBP (P = 0.53). Compared to youth with NW, youth with SO exhibited higher radial−aortic SBP (SO vs. NW: 102 ± 1 mm Hg vs. 90 ± 1 mm Hg, P CONCLUSIONS In a cohort of youth with a wide range of adiposity levels, central aortic BP was elevated among individuals with SO and associated with BMI but not body fatness.

Intramyocellular lipid (IMCL) is generally associated with insulin resistance and lipotoxicity. However, the “athlete’s paradox” is well documented, where IMCL levels are similar between athletes and patients with type 2 diabetes despite discrepant levels of insulin sensitivity. Differences in muscle lipid metabolites between aerobically trained, lean, insulin-sensitive (LT) vs. sedentary, overweight/obese, insulin-resistant (OIR) individuals remain insufficiently characterized and may help to explain the “athlete’s paradox.” LT [n=14: 50% females, 28.5±1.6 years (Mean±SE)] and OIR [n=24: 79% females, 29.8±1.6 years] subjects each provided 2 muscle biopsies from the vastus lateralis (bilateral, 6 hours apart, ≥48 hours after last exercise, ≥8 fasting, overnight admission prior to biopsy) for mass spectrometry analysis. At a separate visit, insulin sensitivity was quantified by a hyperinsulinemic-euglycemic clamp (mg glucose/kg FFM/min). As the sequential biopsy results were not significantly different, the results were averaged for each subject. Compared with the OIR group, the LT group had lower BMI (22.3±0.5 vs. 36.2±1.2 kg/m2:p Disclosure L.S. Chow: Research Support; Self; Eli Lilly and Company, National Institute of Diabetes and Digestive and Kidney Diseases. D.G. Mashek: None. T. Bosch: None. A. Bantle: None. M. Petterson: None. D.R. Dengel: None. M.D. Jensen: Other Relationship; Self; Novo Nordisk A/S. Consultant; Self; Novo Nordisk A/S.

Ventilation/carbon dioxide production (VE/VCO2slope) is used clinically to determine cardiorespiratory fitness and morbidity in heart failure (HF). Previously, we demonstrated that lower lean leg mass is associated with high VE/VCO2slope during exercise in HF. In healthy individuals, we evaluated 1) whether VE/VCO2slope differed between lean and overweight women and 2) the relationship between lean leg mass and VE/VCO2slope in overweight sedentary (OWS), overweight trained (OWTR) and lean, trained (LTR) women. Methods Gas exchange and ventilation were collected during a treadmill peak oxygen uptake test (VO2peak) in 40 women [26 OWS (29 ± 7 yrs., mean ± SD), 7 OWTR (33 ± 5 yrs) and 7 LTR (26 ± 6 yrs)]. Body composition was measured by dual X-ray absorptiometry. Results VO2peak was highest in LTR (46.6 ± 8 ml/kg/min) compared with OWTR (38.1 ± 4.9 ml/kg/min) and OWS women (25.3 ± 4.8 ml/kg/min, p 0.05). Higher lean leg mass was associated with lower VE/VCO2slope in overweight women (OWS + OWTR: r = −0.55, p

OBJECTIVE: To evaluate the relationships of depression and anxiety symptoms with CVD risk factors and measures of vascular health in youth. Major Depressive Disorder and Bipolar Disorder are considered cardiovascular disease (CVD) risk factors in youth. STUDY DESIGN: Participants (n=202) were 8-18-year-olds from a cross-sectional study evaluating cardiovascular health across a wide range of BMI values (normal weight to severe obesity). CVD risk measurement included blood pressure, fasting lipids, glucose, insulin, carotid artery intima-media thickness, compliance and distensibility, brachial artery flow-mediated dilation, carotid-radial artery pulse wave velocity, body fat percentage, and a metabolic syndrome cluster score. Anxiety and depression symptoms were self-reported on the Screen for Child Anxiety Related Disorders and Center of Epidemiological Studies Depression Scale for Children. Two sets of adjustment variables were used in evaluation of differences between those with and without anxiety or depression symptomatology for the CVD risk factor and vascular outcomes. The first set included adjustment for Tanner stage, sex, and race; the second additionally adjusted for percent body fat. RESULTS: Anxiety was not significantly associated with CVD risk factors or vascular health in either model. Depression was associated with HDL cholesterol, triglycerides, and metabolic syndrome cluster score; these relationships were attenuated when accounting for percent body fat. CONCLUSIONS: When accounting for body fat, we found no clear relationship of self-reported depression or anxiety symptoms with CVD risk factors or vascular health in youth.

Background: Measures of carotid intima media thickness (cIMT) in adults are correlated with adiposity and the metabolic syndrome (MetS) and predict cardiovascular (CV) events. Relations in children are not as well studied. Our objective was to determine the relations of cIMT with body mass index (BMI) and CV risk score in children. Methods: The study included 291 children (158 M/133 F) 6–18 years of age (140 aged 6–11/151 aged 12–18) with measurements of height, weight, waist circumference; fasting lipids, glucose, insulin, and cIMT. A CV risk cluster score was developed from sum of the z-scores of the five MetS components (waist circumference, blood pressure, serum triglycerides, high-density lipoprotein cholesterol, and insulin). Partial Pearson correlation coefficients were adjusted for age, sex, and race. Results: There was no significant age difference in cIMT from 6 to 18 years of age. BMI and CV risk score were significantly correlated (P

To determine the associations of adiposity and insulin resistance with measures of vascular structure and function in children.A cross-sectional study included 252 children (age 15.1 ± 2.4 years; body mass index percentile 68.2 ± 26.5%; Tanner 2-5). Measurements of body fat percentage were obtained with dual-energy X-ray absorptiometry and visceral adipose tissue (VAT) with computed tomography. Insulin resistance was measured with hyperinsulinemic euglycemic clamp. Vascular measurements for endothelial function (brachial artery flow-mediated dilation [FMD]), vascular structure (carotid intima-media thickness [cIMT]), vascular stiffness (carotid incremental elastic modulus), and pulse wave velocity were analyzed by tertiles of adiposity and insulin resistance. Additional analyses with ANCOVA and linear regression were adjusted for Tanner, sex, race, and family relationship; FMD was also adjusted for baseline artery diameter.FMD was positively associated with high adiposity (body mass index, body fat percentage, and VAT) (P.01 all). Insulin resistance was not associated with FMD. cIMT was significantly, positively related to obesity, VAT, and insulin resistance (P.05 all). No differences in carotid incremental elastic modulus and pulse wave velocity were observed in relation to adiposity or insulin resistance.The findings suggest that adiposity is associated with higher FMD, and insulin resistance and VAT are associated with higher cIMT in children. Further research is needed to clarify the progression of these relations.

University of Minnesota M.S. thesis. May 2014. Major: Kinesiology. Advisor: Donald R. Dengel, Ph.D. 1 computer file (PDF); v, 43 pages.

Currently, there are few studies on the repeatability of a time series analysis of respiratory exchange ratio (RER) under the same conditions. This repeated-measures study compared 2 trials completed under the same conditions. After an 8-hour fast, subjects (7 male and 5 female) (mean ± SD) of age 27.3 ± 3.7 years, body weight of 71.8 ± 8.4 kg, percent body fat of 16.4 ± 8.1%, and peak oxygen uptake (V[Combining Dot Above]O2peak) of 46.0 ± 5.3 ml·kg·min completed a V[Combining Dot Above]O2peak test followed 7 days later by a cycle ergometer test at 30% of ventilatory threshold (VT) and 60% of VT for 15 minutes each. These tests were repeated again 7 days later. Paired t-tests revealed no significant differences between the tests for mean RER or sample entropy (SampEn) score at both intensities. The coefficients of variance were generally similar for the mean and SampEn of the RER. The intraclass correlation coefficient (ICC) values for the mean RER at 30% of VT were 1.00 and at 60% of VT were 0.92. The ICC values for the SampEn RER at 30% of VT were 0.81 and at 60% of VT were the lowest at 0.25. Bland-Altman plots demonstrated a measure of agreement between both methods. We demonstrated that RER measurements at 30 and 60% of VT are repeatable during steady-state cycle ergometery. Future research should determine if this finding is consistent with a larger sample size and different exercise intensities.

Until recently cardiovascular disease is often thought of as a disease that manifests itself during middle age. Researchers and clinicians have begun to realize that the initial signs of cardiovascular disease begin early on in childhood with changes present in both vascular structure and function. This increased recognition has resulted in considerable effort to develop accurate and reliable methods to measure as well as track changes in vascular structure and function applicable to study this process in children and adolescents. Certain genetic abnormalities and chronic diseases, which present or emerge in childhood often result in meaningful changes to vascular structure and function, which aid in our understanding of the vascular disease process. In this review, we will discuss different methods of assessing vascular structure and function, the diseases in childhood associated with decrements and maladaptive changes in the vascular system, and whether modification of lifestyle (ie, weight loss, dietary and/or exercise changes) can affect vascular structure and function in children.

Objective: To determine visceral adipose tissue (VAT) volume (VATvol) by dual energy X-ray absorptiometry (DXA) in spinal cord injured (SCI) and able-bodied (AB) participants and to explore the relationships between VATvol and routine anthropometric measures. Methods: Sixty-three subjects with SCI and 126 healthy male AB controls were stratified as low risk [LR: waist circumference (WC)

Purpose When assessing vasomotor endothelial function by reactive hyperemia, the brachial artery, in some individuals, constricts immediately before beginning to dilate following cuff release. We call this response high-flow-mediated constriction (H-FMC). The aim of this study was to describe the rate of the H-FMC during reactive hyperemia in children and adolescents throughout a range of body mass index (BMI) values, and to investigate differences in flow-mediated dilation (FMD), cardiovascular, and anthropometric measures between subjects with and without H-FMC. Methods FMD was assessed in 136 children and adolescents (61 male, 75 female; 13 ± 3 years) by sonographic imaging of the brachial artery. H-FMC was characterized as the lowest point from the baseline brachial artery diameter immediately following reactive cuff release. Independent t tests were used to compare subjects with and without H-FMC. Results H-FMC was observed in 91 of the 136 participants (66.9%). No significant difference was found between H-FMC and non-H-FMC subjects for age (p = 0.602), gender (p = 0.767), height (p = 0.227), or weight (p = 0.171). BMI percentile was nonsignificantly higher (91.8 ± 14.9th versus 84.6 ± 22.8th percentile, p = 0.057) and FMD was significantly lower (5.43 ± 3.41% versus 8.05 ± 3.97%, p

Raymond, CJ, Dengel, DR, and Bosch, TA. Total and segmental body composition examination in collegiate football players using multifrequency bioelectrical impedance analysis and dual X-ray absorptiometry. J Strength Cond Res 32(3): 772-782, 2018-The current study examined the influence of player position on the agreement between multifrequency bioelectrical impedance analysis (MfBIA) and dual X-ray absorptiometry (DXA) when assessing total and segmental percent body fat (BF%), fat mass (FM), and fat-free mass (FFM) in National Collegiate Athletic Association Division I collegiate football athletes. Forty-four male collegiate athletes (age = 19 ± 1 year; height = 1.9 ± 1.0 m; and body mass = 106.4 ± 18.8 kg) participated. Player positions included: offensive linemen (OL; n = 7), tight ends (TE; n = 4), wide receivers (WR; n = 9), defensive linemen (DL; n = 6), defensive backs (DB; n = 8), linebackers (LB; n = 6), and running backs (RB; n = 4). Total and segmental body composition measured using MfBIA were compared with values obtained using DXA. Compared with DXA, MfBIA underestimated BF% (3.0 ± 3.8%), total FM (2.5 ± 4.3 kg), arm FM (0.4 ± 0.8 kg), arm FFM (1.4 ± 0.9 kg), leg FM (2.8 ± 2.0 kg), and leg FFM (5.4 ± 2.4 kg) (all p < 0.001; arm FM p = 0.002) and overestimated total FFM (-2.4 ± 4.5 kg) (p < 0.001). Limits of agreement (LOAs) were: ±7.39% (BF%), ±8.50 kg (total FM), ±1.50 kg (arm FM), ±1.83 kg (arm FFM), ±3.83 kg (leg FM), ±4.62 kg (leg FFM), and ±8.83 kg (total FFM). No significant differences were observed between devices for trunk FM (-0.3 ± 3.0 kg; p = 0.565) and trunk FFM (0.4 ± 2.4 kg; p = 0.278), with LOAs of ±5.92 and ±4.69 kg, respectively. Player position significantly affected all between-device mean body composition measurement differences (adjusted p ≤ 0.05), with OL demonstrating the greatest effect on each variable. Therefore, MfBIA does not seem accurate in examining between-player body composition in college football players.

Introduction: The relationship between different central BP measurements with hypertension status in youth is not well documented. We hypothesized that measures of central BP would be positively associated with hypertension status in youth independent of adiposity. Methods: We recruited 149 males and 160 females for this cross-sectional analysis (mean±SD: age = 12.8±2.7; BMI percentile (%) = 78.5±27.8). Body fat % was measured by dual energy X-ray absorptiometry (DXA) and brachial BP was measured using an automated cuff to calculate systolic BP (SBP) and diastolic BP (DBP). Determined by systolic percentile, there were 238 normotensive (th ), 29 pre-hypertensive (th - th ), and 42 hypertensive (th ) individuals enrolled. Central BP was determined using the SphygmoCor MM3 system to calculate carotid-aorta SBP (caSBP) carotid-aorta DBP (caDBP) radial-aorta SBP (raSBP) and radial-aorta DBP (raDBP). Central BP measures were compared across hypertension status groups using ANCOVA, with post-hoc Tukey HSD, adjusted for age, sex, and race. Pearson correlations (unadjusted) and multiple linear regression models, examining the relationship between central BP measures with brachial BP adjusted for age, sex, race, and height, were conducted with further adjustment for body fat % (shown as β±SE). Results: raSBP, caSBP, raDBP, and caDBP were significantly different between the normotensive and hypertensive groups (all p Conclusion: These data suggest that central BP, regardless of measurement site, is highly associated with brachial BP and hypertension status in youth independent of adiposity.

Purpose: When assessing vasomotor endothelial function of the brachial artery by reactive hyperemia, blood flow is stopped and creates a period of low-flow mediated constriction (L-FMC). Little is known about how this parameter influences flow-mediated vasodilation (FMD). The purpose of this study was to better understand this relationship and to determine the intra- and inter-day reproducibility of brachial L-FMC in healthy adults. Methods: Brachial L-FMC and FMD were measured on 26 healthy, young adults (13 males, 13 females; 24.6 ± 2.7 years). Each subject had two assessments conducted on two separate visits, separated by a minimum of seven days. Brachial artery pre-occlusion baseline diameter was imaged during rest and prior to cuff-occlusion. Continuous imaging of the artery was captured during the last 20 seconds of cuff-occlusion to 180 seconds post-cuff release. An L-FMC was considered present if the relative change from pre-occlusion baseline to L-FMC artery diameter was less than -0.1%. Peak FMD was measured as the greatest 10-second average in brachial artery diameter following occlusion compared to pre-occlusion baseline. Results: Overall, there was a strong, positive correlation between increased brachial L-FMC and blunted FMD (visit 1 test 1: r=0.758, p p p p Conclusion: The results of the present study suggest that the degree of vasoconstriction to low-flow conditions influences the subsequent maximal dilation during reactive hyperemia. However, L-FMC in young adults is variable as evidenced by the weak inter- and intra-day reproducibility of the measure. Further research is needed to study brachial L-FMC reproducibility among varying subject populations and the implications L-FMC has on the interpretation of FMD results.

Purpose: This study aimed to investigate the accuracy and reliability of a novel dual-energy x-ray absorptiometry (DXA) scanning method in the frontal plane for total, fat, and lean mass quantification of the anterior and posterior upper leg compartments. Methods: Twenty-one (11 females; X¯age = 20.3 ± 1.3 yr) college athletes were assessed for total and regional body composition using DXA. The segmentation of anterior/posterior thigh compartments was measured with participants lying on their right and left sides and the scanned leg elevated with two foam pads. Custom regions of interest (ROIs) were created manually with enCoreTM software for each scan using bony landmarks to quantify lean, fat, and total masses. Paired t-tests assessed this novel positioning method's accuracy against standard positioning. Intraclass correlation coefficients and coefficients of variation examined inter- and intrarater reliability for lateral scan measures of total, fat, and lean masses from manually created ROIs. Results: All mean ± SD differences between frontal and lateral DXA scans of right (R) and left (L) leg total mass (R: 8.42 ± 195.57 g; L: 19.47 ± 131.80 g), fat mass (R: 61.26 ± 215.66 g; L: −5.89 ± 239.97 g), and lean mass (R: −103.00 ± 302.54 g; L: −27.58 ± 288.14 g) were nonsignificant (P value range = 0.15–0.91). Intraclass correlation coefficients were high for all composition measures between and within raters, ranging from 0.983 to 0.999 and from 0.954 to 0.999, respectively, with low variation across measures (all coefficients of variation ≤ 5%). Conclusion: The results of this study suggest that DXA measures using lateral subject positioning and custom ROIs to assess upper leg total, fat, and lean masses are accurate and reliable compared with total-body frontal subject positioning. Future studies are needed to determine the clinical usefulness of lateral view measures regarding prevention or rehabilitation of sports- or age-related injury.

Treatments for mucopolysaccharidoses (MPSs) have increased longevity, but cardiovascular disease causes mortality in a significant percentage of survivors. Markers must be developed to predict MPS cardiac risk and monitor efficacy of investigational therapies.MPS patients underwent carotid artery ultrasonography from which carotid intima-media thickness (cIMT) and three measures of arterial stiffness were calculated: carotid artery distensibility (cCSD), compliance (cCSC), and incremental elastic modulus (cIEM). MPS carotid measurements were compared to corresponding data from pediatric and adult healthy cohorts. 33 MPS patients (17 MPS I, 9 MPS II, 4 MPS IIIA, and 3 MPS VI; mean age 12.5 ± 4.7 years), 560 pediatric controls (age 13.1 ± 4.0 years), and 554 adult controls (age 39.2 ± 2.2 years) were studied. Age and sex-adjusted aggregate MPS cIMT (0.56 ± 0.05 mm) was significantly greater than both pediatric (+0.12 mm; 95% CI +0.10 to +0.14 mm) and adult (+0.10 mm; 95% CI +0.06 to +0.14 mm) control cohorts; similar findings were observed for all MPS subtypes. Mean MPS cIMT approximated the 80th percentile of the adult cohort cIMT. MPS patients also demonstrated significantly increased adjusted arterial stiffness measurements, evidenced by reduced cCSD, cCSC, and increased cIEM, compared to pediatric and adult control cohorts. Regardless of treatment, MPS patients demonstrate increased cIMT and arterial stiffness compared to healthy pediatric and adult controls. These data suggest that relatively young MPS patients demonstrate a “structural vascular age” of at least 40 years old.

Bosch, TA, Carbuhn, AF, Stanforth, PR, Oliver, JM, Keller, KA, and Dengel, DR. Body composition and bone mineral density of Division 1 collegiate football players: a consortium of college athlete research study. J Strength Cond Res 33(5): 1339-1346, 2019-The purpose of this study was to generate normative data for total and regional body composition in Division 1 collegiate football players using dual-energy x-ray absorptiometry (DXA) and examine positional differences in total and regional measurements. Data were used from the Consortium of College Athlete Research (C-CAR) group. Four hundred sixty-seven players were included in this study. Height, body mass, total and regional fat mass, lean mass, and bone mineral density were measured in each athlete in the preseason (June-August). Players were categorized by their offensive or defensive position for comparisons. Linemen tended to have the higher fat and lean mass measures (p ≤ 0.05 for all) compared with other positions. Positions that mirror each other (e.g. linemen) had similar body composition and body ratios. All positions were classified as overweight or obese based on body mass index (BMI) (>25 kg·m), yet other than offensive and defensive linemen, all positions had healthy percent body fat (13-20%) and low visceral fat mass (

SummaryPurpose When assessing brachial endothelial function by reactive hyperaemia, stopping blood flow creates a period of low-flow-mediated constriction (L-FMC). As little is known about how this parameter influences flow-mediated vasodilation (FMD), the purpose of this study was to better understand this relationship and to determine the intra- and interday reproducibility of brachial L-FMC. Methods Brachial L-FMC and FMD were measured on 26 healthy, young adults (13 males, 13 females; 24·6 ± 2·7 years). Each participant had two assessments conducted on two separate visits, separated by a minimum of seven days. Brachial artery baseline diameter was imaged during rest. Continuous imaging of the artery was performed during the last 20 s of cuff-occlusion to 180 s postcuff release. An L-FMC was considered present if the relative change from pre-occlusion baseline to L-FMC artery diameter was less than −0·1%. Results Overall, there was a strong, positive correlation between increased brachial L-FMC and blunted FMD (visit 1 test 1: r = 0·758, P

Background Understanding the heritable contribution of vascular measures, from parent to offspring, may aid in risk stratification and atherosclerosis prevention efforts. We hypothesized that measures of vascular structure and function would be heritable in this cohort of parents and their adolescent offspring. Methods and Results High‐resolution ultrasound scans of the brachial and carotid arteries were obtained in parents (n=558) and their offspring (n=369). Lumen diameter and flow‐mediated dilation were measured in the brachial artery. Intima‐media thickness, lumen diameter, incremental elastic modulus, diameter distensibility, and cross‐sectional distensibility were measured, and carotid cross‐sectional compliance was measured in the carotid artery. Carotid–radial pulse wave velocity was obtained using SphygmoCor ® . Heritability analysis (h 2 , expressed as %) using Sequential Oligogenic Linkage Analysis Routines was performed on the entire cohort and adjusted for age, sex, race, body–mass index, smoking, and mean arterial pressure. Data are presented as mean± SE . Measures of brachial artery diameter (h 2 =25±9%, P =0.001), lumen diameter (h 2 =55±9%, P 2 =29±13%, P =0.014), diameter distensibility (h 2 =28±7%, P 2 =27±7%, P 2 =26±9%, P Conclusions These data show that the majority of noninvasive measures of vascular structure and function are heritable, suggesting that measurement of these subclinical risk factors in parents may be helpful in assessing childhood risk for future cardiovascular disease.

Objective The purpose of this study was to measure the linearity of visceral adipose tissue (VAT) accumulation with measures of total body adiposity to determine whether a threshold exists and to explore the association with cardiometabolic risk factors in adults. Methods Using a cross-sectional design, data were obtained from 723 adults (324 females) age 19-47 years. Body mass index ranged from 15 to 52 kg/m2. Segmented linear regression was used to identify sex-specific percent body fat thresholds at which VAT slope changes. Linear regression measured the association of VAT mass, total fat mass, and subcutaneous fat with cardiometabolic risk factors above and below each threshold. Results Adiposity thresholds were identified at 23.4% body fat in males and 38.3% body fat in females beyond which the slope of VAT per unit of percent body fat increased to strongly positive. Males and females above these adiposity thresholds had significant dyslipidemia (P

Background Childhood cancer survivors (CCS) are at high risk of developing treatment-related late effects, including cardiovascular disease and diabetes. Late effects can be exacerbated by low physical activity (PA) levels. Relationships between PA and cardiovascular risk factors during childhood have not been well described in CCS. Procedure PA and cardiovascular risk factors were measured cross-sectionally in 319 CCS and 208 sibling controls aged 9–18 years. Comparisons between CCS and controls and associations of outcomes with PA (dichotomized at 60 min/day or treated as continuous) were performed with linear regression. Results Among CCS, the high PA group had lower percent fat mass (24.4% vs. 29.8%, P

To compare markers of cardiovascular health in youth diagnosed with attention deficit hyperactivity disorder (ADHD) by the use of stimulant medication with healthy controls.Children and adolescents (n = 85; mean age 11.2 ± 2.8 years; 66 boys) diagnosed with ADHD using a stimulant and 53 siblings without ADHD (mean age 11.1 ± 3.8 years; 28 boys) were included in this cross-sectional study. Measured variables included blood pressure, heart rate (HR), HR variability: SD of the RR interval and low frequency to high frequency ratio, carotid-radial pulse wave velocity, carotid artery augmentation index (AIx), radial artery AIx, brachial artery flow-mediated dilation, and digital reactive hyperemic index.Compared with control patients, participants with ADHD had greater resting systolic blood pressure (3.9 mm Hg, 95% CI [1.2-6.7], P = .005), diastolic blood pressure (5.5 mm Hg, 95% CI [3.2-7.8], P .001), HR (9.2 beats/min, 95% CI [6.0-12.3], P .001), low frequency to high frequency ratio (0.55, 95% CI [0.22-0.89], P = .001), carotid AIx (7.2%, 95% CI [1.9-12.5], P = .008), and pulse wave velocity (0.36 m/s, 95% CI [-0.05, 0.78], P = .089), and lower SD of the RR interval (-33.7 milliseconds, 95% CI [-46.1, -21.3], P .001). Neither flow-mediated dilation nor reactive hyperemic index was significantly different.Children and adolescents being treated with a stimulant medication for ADHD exhibited signs of altered cardiac autonomic function, characterized by increased sympathetic tone, and showed evidence of arterial stiffening.

The use of digital reactive hyperemia as a measure of endothelial function among children and adolescents is becoming increasingly common. However, unexpected observations of low reactive hyperemic index values in younger children in our laboratory led us to conduct a study evaluating the influence of age, sex, height, weight, blood pressure, body mass index (BMI), and finger volume on RHI values.Endothelial function, measured by digital reactive hyperemia (reactive hyperemic index: RHI) was assessed in 113 children and adolescents (mean age 12.4 ± 3.8 years; 64 males), with 102 also assessed for brachial artery flow-mediated dilation (FMD) using ultrasound imaging. Associations with age, sex, height, weight, systolic and diastolic blood pressure (SBP, DBP), BMI, and finger volume were evaluated.Using GLM regression, age (β = 0.03, P = 0.014) and SBP (β = 0.015, P = 0.004) were significantly associated with RHI. No measures were associated with FMD. In the subset of individuals with measured finger volume, age (β = 0.025, P = 0.037) was the only measure significantly associated with log RHI. Similarly, no measures were associated with FMD.Younger age is associated with lower RHI but not lower FMD among children and adolescents. These findings call into question the validity and usefulness of digital reactive hyperemia as a method to quantify endothelial function among younger children.

Introduction: Accelerometers are used to quantify energy expenditure in field research. The ActiGraph™ GT1M (ActiGraph™) is a commonly used accelerometer for research. The FitBit ® Ultra (FitBit ® ) is a low-cost alternative to the ActiGraph™; however, there is limited research on the validity of this device. Purpose: The pilot study compares the FitBit ® against the ActiGraph™ and metabolic cart for measurement of energy expenditure and step counts during treadmill walking. Methods: Thirty-two (25 female) adults, mean age 22±2 years, performed two thirty-minute phases of walking (slow and brisk) on a treadmill while concurrently wearing the FitBit ® and the ActiGraph™. Energy expenditure estimates were compared against energy expenditure measured by a metabolic cart. The Pearson's correlation and t-tests determine the linear association and similarity between the accelerometers. Results: Energy expenditure estimate is moderately correlated between the two accelerometers during slow walking (r=0.584, p=0.011) and strongly correlated during brisk walking (r=0.910, p

Treatments for mucopolysaccharidoses (MPSs) have increased longevity, but coronary artery disease (CAD) and cardiovascular complications cause mortality in a high percentage of patients. Non-invasive measures of sub-clinical atherosclerosis, such as carotid intima-media thickness (cIMT) and arterial stiffness, may be useful for prediction of CAD outcomes in MPS patients.The aim of the study was to determine if cIMT and arterial stiffness are abnormal in MPS I and II patients compared to healthy controls.MPS patients underwent carotid artery ultrasonography, and electronic wall-tracking software was used to measure cIMT, carotid artery cross-sectional compliance (cCSC), cross-sectional distensibility (cCSD), and incremental elastic modulus (cIEM). Control data from healthy subjects were obtained from a different study that utilized identical testing within the same laboratory.A total of 406 healthy controls and 25 MPS patients (16 MPS I, 9 MPS II) were studied. All MPS patients had or were receiving treatment: 15 patients (6 MPS I, 9 MPS II) were receiving enzyme replacement therapy (ERT), 9 patients (all MPS I) had received hematopoietic stem cell transplant (HSCT), and 1 patient with MPS I had received HSCT and was receiving enzyme replacement therapy (ERT). MPS patients had significantly higher mean (± SD) cIMT (0.56 ± 0.05 mm) compared to controls (0.44 ± 0.04 mm; adjusted p0.001). MPS patients also had increased stiffness compared to controls, showing significantly lower cCSC (0.14 ± 0.09 mm(2)/mmHg versus 0.16 ± 0.05 mm(2)/mmHg; adjusted p=0.019), and higher cIEM (1362 ± 877 mmHg versus 942 ± 396 mmHg; adjusted p0.001). cCSD in MPS patients was lower than that of controls (29.7 ± 16.4% versus 32.0 ± 8.2%) but was not statistically significant; p=0.12. Among MPS patients, cCSD showed a significant association with cIMT (p=0.047), while the association between cIEM and cIMT approached significance (p=0.077). No significant differences were observed in cIMT, cCSD, cCSC, and cIEM between MPS I and MPS II patients.Despite treatment, MPS patients had higher cIMT compared to healthy controls, indicating this marker of sub-clinical atherosclerosis may be a useful predictor of CAD outcomes. The association of arterial stiffness measures with cIMT suggests that mechanical and structural changes may occur in concert among MPS patients. Although yet to be confirmed, increased cIMT and arterial stiffness in MPS I and II patients may be a consequence of inflammatory signaling pathways triggered by heparan or dermatan sulfate-derived oligosaccharides. Prospective, longitudinal studies will need to be performed in order to evaluate the usefulness of these carotid measurements as predictors of adverse CAD outcomes in MPS patients.

We sought to determine whether childhood wrist circumference predicts insulin resistance in adulthood. Measures were taken in prepubertal children and then approximately 30 years later in the same subjects as adults. Our findings suggest that wrist circumference in childhood is not a predictor of insulin resistance in adulthood.

Objective Evaluate the association of abdominal visceral and subcutaneous fat, independent of total body fat, with cardiometabolic risk factors and insulin resistance among youth.

To determine muscular strength differences in patients with MPS-I, II, and VI versus age- and sex-matched healthy controls.Dominant leg isokinetic knee extension strength was measured at 90 and 120 degrees per second (d/s) using a dynamometer in 30 subjects with MPS and 42 controls (5-16 yrs). MPS-I was further divided into MPS-IA (attenuated) and MPS-IH (severe). Strength measures analyzed were peak torque (PkT), peak torque per unit body weight (PkT/BW) and per unit lean body mass (PkT/LBM), and average power (AP).Following adjusting strength measures for age, MPS-IH and MPS-II had significantly lower strength measures for all variables at both angular velocities. MPS-VI had significantly lower PkT, PkT/LBM, and AP compared to controls at 90 and 120d/s. In contrast, MPS-IA was not significantly different from controls for any strength variable at either angular velocity.The results of this study suggest that decrements in skeletal muscle strength depend on MPS diagnosis and severity of disease. Children with MPS-IH demonstrate the greatest difference in muscular strength compared to healthy controls.

The purpose of the present study was to examine the body composition of National Football League (NFL) players before the start of the regular season. Four hundred eleven NFL players were measured for height, weight and lean, fat, and bone mass using dual-energy x-ray absorptiometry (DXA). Subjects were categorized by their offensive or defensive position for comparison. On average, positions that mirror each other (i.e., offensive lineman [OL] vs. defensive lineman [DL]) have very similar body composition. Although OL had more fat mass than DL, they were similar in total and upper and lower lean mass. Linebackers (LB) and running backs (RB) were similar for all measures of fat and lean mass. Tight ends were unique in that they were similar to RB and LB on measures of fat mass; however, they had greater lean mass than both RB and LB and upper-body lean mass that was similar to OL. Quarterbacks and punters/kickers were similar in fat and lean masses. All positions had normal levels of bone mineral density. The DXA allowed us to measure differences in lean mass between arms and legs for symmetry assessments. Although most individuals had similar totals of lean mass in each leg and or arms, there were outliers who may be at risk for injury. The data presented demonstrate not only differences in total body composition, but also show regional body composition differences that may provide positional templates.

Background Cancer is the leading cause of death by disease among U.S. children ages 1–14 years; however, over the last few decades there has been a dramatic increase in survival in these individuals. Although free of cancer, survivors are faced with a variety of chronic health problems including an increased risk of cardiovascular and metabolic abnormalities. The effect of cancer treatments on vascular structure and function in childhood cancer survivors (CCS) has not been examined. Procedure Measures of carotid artery stiffness (compliance and distensibility) and thickness (IMT), brachial artery endothelial-dependent dilation (EDD), and endothelial-independent dilation (EID) were obtained from ultrasound imaging in 319 CCS (age: 14.6 ± 0.1 years; male/female: 112/96) who were >5 years from diagnosis and 208 (age: 13.6 ± 0.2 years; male/female: 171/148) siblings who had never been diagnosed with cancer. Participants were 9–18 years of age at examination. Results Survivors of leukemia had lower carotid distensibility and compliance, indicating increased arterial stiffness, when compared to controls. There were no significant differences in measures of carotid stiffness or EDD in survivors of solid tumors and central nervous system (CNS) tumors compared to controls. EDD was lower in leukemia survivors than in controls, and EID was greater in survivors of CNS tumors than in controls. Conclusion These results demonstrate that early in life, CCS have arterial changes indicating increased risk for premature atherosclerosis and cardiovascular disease. Therefore, it is reasonable to advocate that efforts should be directed at monitoring and managing cardiovascular risk factors in CCS. Pediatr Blood Cancer 2014;61:532–537. © 2013 Wiley Periodicals, Inc.

Low bone mineral density (BMD) has been reported in recipients of pediatric hematopoietic cell transplantation (HCT), but it is unclear whether age at HCT has a role. The objective of this cross-sectional study was to determine if patients treated with HCT before the age of 10 years have long-term BMD deficits compared with patients transplanted at an older age and with sibling controls. The study included 151 HCT recipients (87 males), age at study 24.7±8.6 years treated with HCT for hematologic malignancies at age 10.9±6.4 years, and 92 healthy sibling controls (49 males), age at study 22.3±8.0 years. Dual-energy x-ray absorptiometry was performed to measure BMD Z-scores for total body BMD (TBMD), lumbar spine BMD (LBMD) and femoral neck BMD (FNBMD, for subjects 20 years at study visit). Patients10 years at HCT had significantly lower TBMD and FNBMD Z-scores (by 0.5 and 0.8 s.d., respectively) compared with controls (P=0.003 and P=0.0001, respectively) and patients18 years at HCT (P=0.04 and P=0.004, respectively) at an average of 14 years after HCT. In conclusion, this study identified young age at transplant as an important risk factor for bone deficits in young adulthood, suggesting that efforts to reduce bone loss should focus on this patient population.

Katelyn E Uithoven,1 Justin R Ryder,2 Roland Z Brown,3 Kyle D Rudser,3 Nicholas G Evanoff,1 Donald R Dengel,1,2 Aaron S Kelly2,4 1School of Kinesiology, University of Minnesota, 2Department of Pediatrics, University of Minnesota Medical School, 3Division of Biostatistics, School of Public Health, University of Minnesota, 4Department of Medicine, University of Minnesota Medical School, Minneapolis, MN, USA Abstract: The carotid artery represents an ideal location for noninvasive assessment of subclinical atherosclerosis in youth. Examination of arterial structure and function is generally conducted in the left common carotid. However, if the left common carotid is inaccessible or provides a poor acoustic window, it is unknown if the right common carotid can provide comparable values. The symmetry of carotid arteries in youth with high-resolution ultrasound was compared. Participants (N=230 [121 females], 13.8±2.9 years old) were assessed for carotid intima media thickness (cIMT), carotid lumen diameter (cLD), carotid incremental elastic modulus (cIEM), carotid diameter compliance (cDC), carotid cross-sectional compliance (cCSC), carotid diameter distensibility (cDD), and carotid cross-sectional distensibility (cCSD). No significant differences (P>0.05 all) were found for cIMT (0.49±0.09 vs 0.49±0.08mm), cIEM (1095±382 vs 1116±346 mmHg), cDC (0.01±0.0 vs 0.01±0.0 mm/mmHg), cCSC (0.01±0.001/mmHg vs 0.01±0.001/mmHg), cDD (14.0%±3.16% vs 13.7%±3.18%), and cCSD (30.1%±7.37% vs 29.4%±7.36%). Significant differences were found for cLD (6.06±0.62 mm vs 6.33±0.64 mm, P

During reactive hyperemia, the brachial artery in some individuals constricts prior to dilation. Our aim was to describe the frequency of high-flow-mediated constriction (H-FMC) in adults, and its relationship to body composition and biomarkers of cardiovascular and metabolic risk.Two hundred forty-six adults (124 male, 122 female; 36 ± 7 years old) were assessed for H-FMC via sonographic imaging of the brachial artery. Blood pressure, glucose, insulin, lipids, and body composition assessed via dual energy X-ray absorptiometry were collected. H-FMC was characterized as a 10-second average of maximal postocclusion constriction. Independent t test was used to compare H-FMC versus non-H-FMC individuals.H-FMC was observed in approximately 69% of adult participants (54 obese, 57 overweight, and 59 normal weight). Total body mass (82.3 ± 17.5 versus 76.3 ± 16.3 kg, p = 0.012), fat mass (27.7 ± 11.5 versus 23.8 ± 10.5 kg, p = 0.012), body mass index (27.7 ± 4.9 versus 26.1 ± 5.0 kg/mIncreased body mass, fat mass, and body mass index were associated with a greater H-FMC. When H-FMC was present, the FMD response to reactive hyperemia was significantly lower. Because H-FMC has been observed to negatively affect FMD response to reactive hyperemia, we suggest that H-FMC should be noted when analyzing and interpreting FMD data. H-FMC may be an ancillary measure of endothelial health. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:35-42, 2017.

Purpose Given the role of arterial wall elasticity in the development of cardiovascular disease, carotid artery compliance and distensibility have been used commonly over the last decade as predictors of cardiovascular risk, although their gender differences remain unknown. The purpose of our study was to evaluate the impact of gender on carotid arterial elasticity in a large sample of children and adults. Methods Carotid artery compliance and distensibility were measured with ultrasonography in 294 children (157 boys, 137 girls; ages 6–18 years) and 604 adults (291 men, 311 women; ages 18–49 years) previously recruited for a study investigating cardiovascular risk factors. An independent sample t test was used to compare demographic and carotid artery elasticity values by age and gender. Results No significant gender difference in carotid arterial compliance and distensibility was observed in children. Women had significantly greater cross-sectional compliance than men (0.004 ± 0.000 versus 0.003 ± 0.000 1/mmHg, p = 0.041). Conclusions We found significant gender difference in carotid compliance in adults, but not in children, suggesting that gender differences in arterial stiffness are not present early in life but emerge later in adulthood. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound 41:340–346, 2013

We investigated the impact of continuous-flow left ventricular assist devices (LVAD) on the carotid elastic properties. Carotid artery parameters (diameter distensibility (DD), cross-sectional distensibility (CSD), diameter compliance (DC), cross-sectional compliance (CSC), and incremental elastic modulus (IEM)) were measured in a cross-sectional study using a standard ultrasound with a 10-MHz linear array probe. Measurements (mean ± SEM) were made in separate groups at various clinical time points: prior to LVAD surgery (baseline; 13 male/3 female; age 48 ± 3 years), 1 week following LVAD placement (acute; 12 male/2 female; age 47 ± 3 years), approximately 24 weeks following LVAD surgery (chronic; 13 male/2 female; age 52 ± 3 years), and in a group of healthy subjects (controls; 9 male/1 female; age 51 ± 4 years). Distensibility properties were lower (P0.05) in the acute (DD 2.3 % ± 0.4 %; CSD 4.7 % ± 0.8 %) and chronic (DD 2.2 % ± 0.4 %; CSD 4.5 ± 0.9 %) compared with the baseline (DD 5.9 % ± 0.7 %; CSD 12.2 % ± 1.5 %) and control (DD 5.8 % ± 0.6 %; CSD 11.9 % ± 1.3 %) groups. Compliance properties were lower (P0.05) in the chronic (DC 4.4 ± 0.7 mm/mmHg × 10(-3); CSC 1.2 ± 0.2 mmHg(-1) × 10(-3)) compared with acute (DC 9.0 ± 1.6 mm/mmHg × 10(-3); CSC 2.6 ± 0.4 mmHg(-1) × 10(-3)) and baseline (DC 11.1 ± 1.1 mm/mmHg × 10(-3); CSC 3.3 ± 0.4 mmHg(-1) × 10(-3)) groups. The compliance properties in the control (DC 8.3 ± 0.8 mm/mmHg × 10(-3); CSC 2.4 ± 0.2 mmHg(-1) × 10(-3)) group were not different from any of the patient groups. The IEM was higher (P0.05) in the chronic (6908 ± 1269 mmHg) compared with acute (2739 ± 412 mmHg), baseline (1849 ± 177 mmHg), and control (2349 ± 241 mmHg) groups. Chronic continuous-flow LVAD support is associated with lower carotid artery compliance and distensibility, which may place further strain on the left ventricle.