Influence of Aerobic Exercise on Appetite-Regulating Hormones, Ghrelin-o-Acyltransferase and Perceived Hunger in Normal Weight and Obese Adults

Background: Obesity is a major public health issue in the United States (U.S.), affecting an estimated 78 million US adults. Aerobic exercise (AE) is recommended by the American College of Sports Medicine to prevent and treat obesity, yet the effects of AE on circulating hunger hormones including acylated ghrelin and its biological catalyst, ghrelin o-acyltransferase (GOAT) are less known. Objectives: We investigated the effects of AE on circulating concentrations of appetite regulating hormones and GOAT in a pilot sample of adults classified with normal weight (NW) and obese (OB) body weight status. Methods: Using a quasi-experimental design, nine adults with NW (n=4, body mass index [BMI] = 21.3±1.2 kg/m2 ) and OB (n=5, BMI = 38.9±6.2 kg/m2 ) body weight status completed a preliminary health/fitness assessment. Participants returned to the laboratory on three separate occasions, separated by ≥ 48 hours to perform cycle exercise at 30% and 60% oxygen uptake reserve (VO2 R) or a seated control session with no exercise for 40 min. Fifteen mL of blood was taken pre-and-post exercise and control and were assayed in duplicate. Nonparametric procedures determined whether mean rank differences existed between NW and OB for acylated ghrelin, leptin, insulin, and GOAT in response to exercise and control. Alpha levels were set a priori to p \u3c0.05. Results: Significant mean rank reductions were found in GOAT after compared to before AE and control for NW and OB (p\u3c.05). Significant mean rank differences were found in acylated ghrelin after compared to before performing AE at 60% VO2 R in NW and OB (p\u3c.05); however, differences were not observed between NW and OB (p\u3e.05). Conclusions: Our findings reveal the first available data regarding the effects of AE on GOAT, with NW and OB experiencing equivocal changes pre-to-post AE at 60% VO2 R, and in response to a seated control session

eXtraembryonic ENdoderm (XEN) Stem Cells Produce Factors that Activate Heart Formation

Initial specification of cardiomyocytes in the mouse results from interactions between the extraembryonic anterior visceral endoderm (AVE) and the nascent mesoderm. However the mechanism by which AVE activates cardiogenesis is not well understood, and the identity of specific cardiogenic factors in the endoderm remains elusive. Most mammalian studies of the cardiogenic potential of the endoderm have relied on the use of cell lines that are similar to the heart-inducing AVE. These include the embryonal-carcinoma-derived cell lines, END2 and PYS2. The recent development of protocols to isolate eXtraembryonic ENdoderm (XEN) stem cells, representing the extraembryonic endoderm lineage, from blastocyst stage mouse embryos offers new tools for the genetic dissection of cardiogenesis.Here, we demonstrate that XEN cell-conditioned media (CM) enhances cardiogenesis during Embryoid Body (EB) differentiation of mouse embryonic stem (ES) cells in a manner comparable to PYS2-CM and END2-CM. Addition of CM from each of these three cell lines enhanced the percentage of EBs that formed beating areas, but ultimately, only XEN-CM and PYS2-CM increased the total number of cardiomyocytes that formed. Furthermore, our observations revealed that both contact-independent and contact-dependent factors are required to mediate the full cardiogenic potential of the endoderm. Finally, we used gene array comparison to identify factors in these cell lines that could mediate their cardiogenic potential.These studies represent the first step in the use of XEN cells as a molecular genetic tool to study cardiomyocyte differentiation. Not only are XEN cells functionally similar to the heart-inducing AVE, but also can be used for the genetic dissection of the cardiogenic potential of AVE, since they can be isolated from both wild type and mutant blastocysts. These studies further demonstrate the importance of both contact-dependent and contact-independent factors in cardiogenesis and identify potential heart-inducing proteins in the endoderm

A Meta-Analysis of Candidate Gene Association Studies on the Blood Pressure Response to Aerobic Exercise

ABSTRACT Purpose: Aerobic exercise (AE) lowers blood pressure (BP) 5-7 mmHg among those with hypertension, but there is considerable variability in the BP response to AE. Genetic predispositions account for 40-65% of this variability; however, identifying genetic variants that associate with the BP response to AE is a challenge. We performed a meta-analysis to integrate the small number of studies that examined the influence of candidate genes on the BP response to AE. Methods: Studies retrieved included an acute or chronic AE intervention; BP before and after AE by genotype; and candidate gene polymorphisms. Effect sizes were the standardized mean difference of BP post-vs. pre-exercise for AE training interventions, and post-vs. pre-exercise BP vs. control for acute AE interventions. Effect sizes were disaggregated for genotype and adjusted for baseline sample features. Analyses followed fixed‑effects assumptions. Results: 11 AE training (N=2646) and 4 acute AE (N=50) studies qualified. AE training interventions were performed at 62.3±7.5% (Mean+SD) maximum oxygen consumption for 43.8±11.6 min×session-1,3.6±1.2 d×wk-1 for 15.3±7.6 wk. Participants were mostly non-Hispanic white (N=1,736) men (N=1,278) and women (N=1,360), 44.2±10.7 yr with a BP of 134.4±11.9/78.6±9.3 mmHg and body mass index of 26.9±2.6 kg.m-2. The effect of exercise on the BP response to AE training was small but statistically significant for systolic BP (SBP) (d+ = -0.21 [95% CI = -0.247, -0.168], -3.1 mmHg, I2=77.8%) and diastolic BP (DBP) (d+ = ‑0.20 [95% CI = -0.235, -0.158], -1.9 mmHg, I2=62.2%). Sample features explained 59.1-71.5% of the variability in the BP response to AE training (P\u3c 0.001), and reductions were greater among samples that had a higher resting BP (SBP: β = -0.68, P\u3c 0.001; DBP: β=-0.56, P=0.01), that were younger (SBP: β=0.34, P\u3c0.01; DBP: NS, P\u3e0.05), and that included more women than men (SBP: β = 0.41, P\u3c0.001; DBP: β=0.52, PAGT) M235T (rs699) polymorphism showed a significant association with the DBP response to AE training (Multiple R=0.058, P=0.02), explaining 0.3% of the variability in the DBP response. Pairwise comparisons of AGT M235T genotypes showed those with the AGT MM genotype reduced DBP 2.9 mmHg more in response to AE training compared to those with the AGT TT genotype (Multiple R=0.076, P=0.02). Acute interventions were performed at 50.1±10.1% maximum oxygen consumption for 40 min·session-1. Participants were men, 44.1±1.0 yr with a BP of 145.7±1.7 / 85.8±0.9 mmHg and body mass index of 29.9±0.3 kg.m-2. BP responses to acute AE were large and heterogeneous for SBP (d+ = -0.62 [95% CI = ‑0.75, ‑0.50], ‑5.5 mmHg, I2 =48%), and small and homogeneous for DBP (d+ =-0.28 [95% CI = ‑0.40, ‑0.16], ‑1.7 mmHg, I2 =0%). Sample features explained 55.2-82.3% of the variability in the BP response to acute AE (P\u3c 0.001), while candidate gene polymorphisms explained a marginally significant 4.6-6.0% of the variability (P=0.08). Analyses of individual polymorphisms were not feasible due to the low numbers of interventions and observations. Conclusions: Despite our attempt to increase the sample size to detect polymorphism associations with the BP response to AE, sample features explained most of the variability across trials, although the AGT M235T polymorphism is promising. These findings reinforce the notion that most genetic variants explain only a small amount of variability in the response of health/fitness phenotypes to exercise, if any. Future research efforts seeking to explain the variability of health/fitness phenotypes to exercise such as BP should explore sample features known to influence the phenotype of interest, as well as the multiple levels of gene regulation using high throughput screening in larger, more ethnically diverse samples of men and women with HTN

Periphery-brain interactions and leptin in the regulation of whole-body energy metabolism

No abstract availabl

The Effects of a Six-Week Ketogenic Diet on CrossFit Performance Parameters: A Pilot Study

Background: CrossFit is a popular high-intensity functional training method. Despite the importance of muscle glycogen in fueling such high-intensity efforts, research exploring the use of a ketogenic diet in CrossFit practitioners is limited. Objectives: To conduct an experimental trial examining the effects of a 6-week ketogenic diet on CrossFit performance parameters. Methods: Eight men and seven women (N = 15; 30.2 ± 4.11 years) were recruited for this experimental study design and were randomly assigned to either the ketogenic diet (KD; n = 8) or the control group (CON; n = 7) for 6 weeks. Several measures of anaerobic performance were assessed at baseline and after 6 weeks utilizing the following series of standardized exercise tests: timed 500 m row, Wingate Anaerobic Test, and 3-repetition maximum (3-RM) deadlift. Aerobic capacity was also assessed by measuring VO2peak. In addition, body composition was assessed via BodPod. Results: Multiple 2 X 2 mixed factorial analyses of variance were performed for measures of body composition and aerobic and anaerobic performance variables. No significant differences in body composition (p 0.05), anaerobic performance (p 0.05), or aerobic performance (p 0.05) were observed between groups. Conclusion: A 6-week ad libitum KD had no effect on exercise performance or body composition in CrossFit practitioners. Our findings demonstrate that a KD does not impair CrossFit performance, which may be of interest to those considering a KD when participating in CrossFit

The Influence of Quiet Kits on Reducing Night Noise and Improving the Patient Experience

https://scholarlycommons.libraryinfo.bhs.org/nursing_artof_answering/1011/thumbnail.jp

Sport-Specific Crossover Point Differences during a Maximal Oxygen Consumption Test

Introduction/Purpose: The crossover point occurs during exercise when one transitions energy substrates from fat to carbohydrate predominance. The crossover point varies in an intensity-dependent manner; however, less is known about its specificity in sports with varying metabolic demands. The purpose of our study was to determine if various sports yield differences in the time to crossover and heart rate and percentage of maximal oxygen consumption (V O2max) at crossover during a standardized exercise protocol. Methods: A total of 77 athletes (39 women, 38 men; 39.1 + 10.4 yr of age) were measured for respiratory exchange ratio during a modified Taylor V O2max treadmill test. Sports included running (n = 20), triathlon (n = 20), rowing (n = 20), and CrossFit (n = 17). A one-way ANOVA determined differences in time to crossover. A Kruskal–Wallis test was applied to determine differences between sport types for percent V O2max and heart rate at crossover. Bonferroni correction procedures were used to control the family-wise error rate and maintain alpha levels at P \u3c 0.05. Results: Average time to crossover for all athletes was 3:43 + 1:12 min. Times to crossover for runners, triathletes, rowers, and CrossFit athletes were 4:16 + 0:58, 3:28 + 1:08, 4:00 + 1:23, and 3:01 + 0:58 min, respectively. Significant differences were observed between groups for time to crossover (P = 0.007) and percent V O2max at crossover (P = 0.01). Pairwise analyses revealed that runners had a significantly longer time to crossover compared with CrossFit athletes (P = 0.009). Triathletes’ percent V O2max at crossover was significantly lower than rowers (P = 0.04) and runners (P = 0.04). Conclusions: We found significant differences in time to crossover between runners and CrossFit athletes, which suggests that substrate use may be dependent on sport type

Individualization of leflunomide dosing in rheumatoid arthritis patients

Leflunomide is largely considered to be a second-line treatment option for rheumatoid arthritis (RA). Those who fail to respond, tend to progress to treatment with expensive biological agents, which can also be associated with serious toxicities. Optimizing leflunomide treatment to meet the needs of individuals would hence be beneficial in terms of patient outcomes and health care expenditure. In this respect, therapeutic drug monitoring (TDM) may be useful, as plasma concentrations of leflunomide’s active metabolite, teriflunomide, correlate with response to treatment, but are highly variable between patients. A number of pharmacogenetic markers have also been identified that influence response and toxicity. Incorporation of these findings into clinical practice could facilitate more efficient use of leflunomide.Ashley M Hopkins, Catherine E O'Doherty, David JR Foster, Richard N Upton, Susanna M Proudman, Michael D Wies