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The purpose of this study was to determine the effect of circulating microvesicles isolated from chronic electronic (e‐)cigarette users on cultured human umbilical vein endothelial cell (HUVEC) expression of nuclear factor‐κB (NF‐κB), cellular cytokine release, phosphorylation of endothelial nitric oxide synthase (eNOS) and NO production. The HUVECs were treated with microvesicles isolated via flow cytometry from nine non‐tobacco users (five male and four female; 22 ± 2 years of age) and 10 e‐cigarette users (six male and four female; 22 ± 2 years of age). Microvesicles from e‐cigarette users induced significantly greater release of interleukin‐6 (183.4 ± 23.6 vs. 150.6 ± 15.4 pg/mL; P = 0.002) and interleukin‐8 (160.0 ± 31.6 vs. 129.4 ± 11.2 pg/mL; P = 0.01), in addition to expression of p‐NF‐κB p65 (Ser536) (18.8 ± 3.4 vs. 15.6 ± 1.5 a.u.; P = 0.02) from HUVECs compared with microvesicles from non‐tobacco users. Nuclear factor‐κB p65 was not significantly different between microvesicles from the non‐tobacco users and from the e‐cigarette users (87.6 ± 8.7 vs. 90.4 ± 24.6 a.u.; P = 0.701). Neither total eNOS (71.4 ± 21.8 vs. 80.4 ± 24.5 a.u.; P = 0.413) nor p‐eNOS (Thr495) (229.2 ± 26.5 vs. 222.1 ± 22.7 a.u.; P = 0.542) was significantly different between microvesicle‐treated HUVECs from non‐tobacco users and e‐cigarette users. However, p‐eNOS (Ser1177) (28.9 ± 6.2 vs. 45.8 ± 9.0 a.u.; P < 0.001) expression was significantly lower from e‐cigarette users compared with non‐tobacco users. Nitric oxide production was significantly lower (8.2 ± 0.6 vs. 9.7 ± 0.9 μmol/L; P = 0.001) in HUVECs treated with microvesicles from e‐cigarette users compared with microvesicles from non‐tobacco users. This study demonstrated increased NF‐κB activation and inflammatory cytokine production, in addition to diminished eNOS activity and NO production resulting from e‐cigarette use. Highlights: What is the central question of this study?Circulating microvesicles contribute to cardiovascular health and disease via their effects on the vascular endothelium. The impact of electronic (e‐)cigarette use on circulating microvesicle phenotype is not well understood.What is the main finding and its importance?Circulating microvesicles from e‐cigarette users increase endothelial cell inflammation and impair endothelial nitric oxide production. Endothelial inflammation and diminished nitric oxide bioavailability are central factors underlying endothelial dysfunction and, in turn, cardiovascular disease risk. Deleterious changes in the functional phenotype of circulating microvesicles might contribute to the reported adverse effects of e‐cigarette use on cardiovascular health. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the muscle-to-bone ratio (MBR) in National Collegiate Athletic Association Division I football players (collegiate football players [CFP]) to healthy, age-matched controls. In addition, we examined MBR in CFP by position. A total of 553 CFP and 261 controls had their total and regional lean mass (LM), fat mass (FM), and bone mineral content (BMC) determined by dual x-ray absorptiometry (DXA). College football players were categorized by positions defined as offensive linemen (OL), defensive linemen (DL), tight end, linebacker (LB), running back (RB), punter or kicker, quarterback (QB), defensive back (DB), and wide receiver (WR). There were significant differences between CFP and controls for total LM (80.1 ± 10.0 vs. 56.9 ± 7.8 kg), FM (22.2 ± 12.5 vs. 15.2 ± 7.1 kg), and BMC (4.3 ± 0.5 vs. 3.1 ± 0.5 kg). Although there were significant differences in body composition between CFP and controls, there was no significant differences in total MBR between CFP and controls (18.6 ± 1.4 vs. 18.8 ± 1.7). Regionally, CFP had significantly lower trunk MBR than controls (26.7 ± 2.7 vs. 28.7 ± 4.2), but no difference was seen in leg or arm MBR. Positional differences in CFP were noted as total MBR being significantly higher in DL (19.0 ± 1.4) than in DB (18.1 ± 1.3), WR (18.1 ± 1.3), and LB (18.2 ± 1.3). OL had a significantly higher total MBR (19.2 ± 1.3) than DB(18.1 ± 1.3), LB (18.2 ± 1.3), QB (18.1 ± 1.0), and WR (18.1 ± 1.3). In addition, RB had significantly higher total MBR (18.8 ± 1.3) than DB (18.1 ± 1.3) and WR (18.1 ± 1.3). This study may provide athletes and training staff with normative values when evaluating total and regional MBR with DXA. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to examine the muscle-to-bone ratio (MBR) in National Football League (NFL) players. Three hundred and forty-six NFL players had their total body lean, fat and bone masses determined using dual X-ray absorptiometry and were compared to 228 age-matched, healthy male controls. Compared to the control group, NFL players had a significantly lower percent total body fat (17.90±6.92 vs. 22.93±8.96%, p=0.053), but significantly greater total fat mass (19.76±11.29 vs. 17.84±12.11 kg, p<0.0001), lean mass (84.55±8.75 vs. 55.3±11.79 kg, p<0.0001), bone mineral content (4.58±0.45 vs. 2.91±0.67 kg, p<0.0001), and bone mineral density (1.61±0.11 vs. 1.26±0.21 g/cm2 , p<0.0001). NFL players had greater arm MBR (17.70±1.47 vs. 16.48±1.88, p<0.0001) than controls; however, both trunk (26.62±2.55 vs. 31.56±4.19, p<0.0001) and total (18.50±1.31 vs. 19.12±1.88, p<0.001) MBR were lower in NFL players. Leg MBR was not significantly different between NFL players and controls (16.72±1.53 vs. 16.85±1.87, p=0.34). When NFL players were categorized by their offensive or defensive position for comparison, no differences in total MBR were observed. However, leg MBR varied greatly among NFL players by position. It is possible that regional differences in MBR in the NFL players may be related to the demands of that position. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic has forced primary/grade schools and university closings as well as forced the suspension of a number of medical and laboratory testing procedures. Exercise science laboratories whether in clinical, research or educational locations were also forced to pause testing procedures. As the COVID-19 pandemic begins to subside in some areas of the world, exercise science laboratories are contemplating how to create a safe environment to resume some laboratory testing activities. In this article, we present suggestions for how exercise science laboratories can open and create a safe environment for subjects, laboratory personnel and equipment upon reopening. [ABSTRACT FROM AUTHOR]

Summary: Purpose: 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<0·001; visit 1 test 2: r = 0·706, P<0·001; visit 2 test 1: r = 0·836, P<0·001; visit 2 test 2: r = 0·857, P<0·001). The reproducibility of intra‐ and interday L‐FMC diameter was intraclass correlation coefficients (ICC) = 0·627, coefficient of variation (CV) = 54·4% and ICC = 0·734, CV = 43·5%, respectively. Conclusion: Vasoconstriction to low‐flow conditions influences the subsequent maximal dilation during reactive hyperaemia. However, L‐FMC is variable as evidenced by the weak intra‐ and interday reproducibility of the measure. Further research should study brachial L‐FMC reproducibility among varying populations and the implications L‐FMC has on the interpretation of FMD results. [ABSTRACT FROM AUTHOR]

Objective: Relationships between gonadotropins, sex hormones, and vascular structure and function in adolescents of varying weight statuses have not been fully investigated. In the present study, we examined associations among these in female and male adolescents with normal weight or obesity. Methods: We performed a cross-sectional analysis of adolescents ( n = 58; 12-<18 years) grouped according to BMI percentile (BMI%) into normal weight (5th-<85th BMI%; n = 25) and obesity (≥95th BMI%; n = 33) categories. Fasting blood samples were collected to measure follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and estradiol. Vascular function was measured via ultrasonography for measures of carotid artery diameter compliance (cDC), incremental elastic modulus (cIEM), and brachial artery flow mediated dilation (FMD). Results: Females with obesity had a significantly ( p = 0.009) greater mean FMD compared with those with normal weight. FSH, LH, testosterone, and estradiol did not differ between normal weight and obesity groups in either sex. After adjusting for age and multiple comparisons, higher testosterone was associated with decreased cDC ( R 2 = 0.189; p = 0.018) and increased cIEM ( R 2 = 0.346; p = 0.002) across all females. In all males, higher estradiol was associated with decreased cDC ( R 2 = 0.404; p = 0.006) and increased cIEM ( R 2 = 0.411; p = 0.003). Conclusion: We found that testosterone and estradiol were associated with vascular measures in female and male adolescents, respectively. Future studies are needed to confirm these relationships in larger cohorts and among those with BMIs in the overweight (85th-<95th BMI%) and severe obesity (BMI ≥120% of the 95th percentile and/or ≥35 kg/m 2 ) categories.