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1.
Artigo em Inglês | MEDLINE | ID: mdl-38572540

RESUMO

Cold exposure increases blood pressure (BP) and salivary flow rate (SFR). Increased cold-induced SFR would be hypothesised to enhance oral nitrate delivery for reduction to nitrite by oral anaerobes and to subsequently elevate plasma [nitrite] and nitric oxide bioavailability. We tested the hypothesis that dietary nitrate supplementation would increase plasma [nitrite] and lower BP to a greater extent in cool compared to normothermic conditions. Twelve males attended the laboratory on four occasions. Baseline measurements were completed at 28°C. Subsequently, participants ingested 140 mL of concentrated nitrate-rich (BR; ~13 mmol nitrate) or nitrate-depleted (PL) beetroot juice. Measurements were repeated over 3 h at either 28°C (Norm) or 20°C (Cool). Mean skin temperature was lowered compared to baseline in PL-Cool and BR-Cool. SFR was greater in BR-Norm, PL-Cool and BR-Cool than PL-Norm. Plasma [nitrite] at 3 h was higher in BR-Cool (592 ± 239 nM) vs. BR-Norm (410 ± 195 nM). Systolic BP (SBP) at 3 h was not different between PL-Norm (117 ± 6 mmHg) and BR-Norm (113 ± 9 mmHg). SBP increased above baseline at 1, 2 and 3 h in PL-Cool but not BR-Cool. These results suggest that BR consumption is more effective at increasing plasma [nitrite] in cool compared to normothermic conditions and blunts the rise in BP following acute cool air exposure, which might have implications for attenuating the increased cardiovascular strain in the cold.

2.
J Am Heart Assoc ; 13(6): e033154, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38497482

RESUMO

BACKGROUND: Exercise-associated secondary amenorrhea results in estrogen deficiency, which may lead to dysfunction in estrogen's normal cardioprotective pathways. Estrogen may be essential in a woman's endothelial adaptations to exercise. The objective of this review was to assess the association between secondary amenorrhea in physically active women and cardiovascular disease (CVD) risk. METHODS AND RESULTS: A literature search was performed in January 2023 and updated in August 2023 of the Cumulative Index to Nursing and Allied Health Literature (EBSCOhost), Cochrane Library, Embase (Ovid), MEDLINE (Ovid), SPORTDiscus (EBSCOhost), and Scopus from inception to present with no date or language limitations. Citation chaining was done to screen for additional studies. Eight sources were searched for gray literature. Studies that compared physically active women with amenorrhea to physically active women with eumenorrhea aged 18 to 35 years with evidence of CVD, alterations to cardiovascular physiology, or CVD risks were included. Eighteen observational studies from 3 countries were included. Overall, the quality of evidence was good. A meta-analysis was performed. Physically active women with secondary amenorrhea had significantly lower estradiol, flow-mediated dilation, resting heart rate, systolic blood pressure, and diastolic blood pressure and higher total cholesterol, triglycerides, high-density lipoprotein, and low-density lipoprotein cholesterol. CONCLUSIONS: Estrogen deficiency resulting from exercise-associated secondary amenorrhea in physically active women may impact cardiovascular physiology and certain CVD risk factors. The research in this area is observational; therefore, findings should be interpreted cautiously. However, as exercise-associated secondary amenorrhea is reversible and the primary prevention of CVD is important for public health, it may be important to treat secondary amenorrhea and restore estrogen levels.


Assuntos
Doenças Cardiovasculares , Humanos , Feminino , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Amenorreia/etiologia , Triglicerídeos , LDL-Colesterol , Estrogênios
3.
Br Dent J ; 236(1): 30-34, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38225310

RESUMO

Cardiac transplantation replaces a severely damaged non-functioning heart with a healthy heart from a donor. Within the UK, the number of cardiac transplants being performed each year is increasing, with significant improvements in longer-term survival. Dental professionals are therefore more likely to see and manage these patients in the pre- and post-transplant periods. This paper proposes a protocol for the dental management of these patients, reinforced by a case series from Scotland and London.


Assuntos
Transplante de Coração , Humanos , Doadores de Tecidos , Escócia , Assistência Odontológica , Londres
4.
Eur J Appl Physiol ; 2023 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-38040982

RESUMO

PURPOSE: Dietary nitrate (NO3-) supplementation can lower systolic blood pressure (SBP) and improve exercise performance. Salivary flow rate (SFR) and pH are key determinants of oral NO3- reduction and purported to peak in the afternoon. We tested the hypotheses that NO3--rich beetroot juice (BR) would increase plasma [nitrite] ([NO2-]), lower SBP and improve exercise performance to a greater extent in the afternoon (AFT) compared to the morning (MORN) and evening (EVE). METHOD: Twelve males completed six experimental visits in a repeated-measures, crossover design. NO3--depleted beetroot juice (PL) or BR (~ 13 mmol NO3-) were ingested in the MORN, AFT and EVE. SFR and pH, salivary and plasma [NO3-] and [NO2-], brachial SBP and central SBP were measured pre and post supplementation. A severe-intensity exercise tolerance test was completed to determine cycling time to exhaustion (TTE). RESULTS: There were no between-condition differences in mean SFR or salivary pH. The elevation in plasma [NO2-] after BR ingestion was not different between BR-MORN, BR-AFT and BR-EVE. Brachial SBP was unchanged following BR supplementation in all conditions. Central SBP was reduced in BR-MORN (- 3 ± 4 mmHg), BR-AFT (- 4 ± 3 mmHg), and BR-EVE (- 2 ± 3 mmHg), with no differences between timepoints. TTE was not different between BR and PL at any timepoint. CONCLUSION: Acute BR supplementation was ineffective at improving TTE and brachial SBP and similarly effective at increasing plasma [NO2-] and lowering central SBP across the day, which may have implications for informing NO3- supplementation strategies.

5.
Scand J Med Sci Sports ; 33(9): 1690-1702, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37365858

RESUMO

Low energy availability (LEA) is prevalent in active individuals and negatively impacts bone turnover in young females. High-impact exercise can promote bone health in an energy efficient manner and may benefit bone during periods of LEA. Nineteen regularly menstruating females (aged 18-31 years) participated in two three-day conditions providing 15 (LEA) and 45 kcals kg fat-free mass-1 day-1 (BAL) of energy availability, each beginning 3 ± 1 days following the self-reported onset of menses. Participants either did (LEA+J, n = 10) or did not (LEA, n = 9) perform 20 high-impact jumps twice per day during LEA, with P1NP, ß-CTx (circulating biomarkers of bone formation and resorption, respectively) and other markers of LEA measured pre and post in a resting and fasted state. Data are presented as estimated marginal mean ± 95% CI. P1NP was significantly reduced in LEA (71.8 ± 6.1-60.4 ± 6.2 ng mL-1 , p < 0.001, d = 2.36) and LEA+J (93.9 ± 13.4-85.2 ± 12.3 ng mL-1 , p < 0.001, d = 1.66), and these effects were not significantly different (time by condition interaction: p = 0.269). ß-CTx was significantly increased in LEA (0.39 ± 0.09-0.46 ± 0.10 ng mL-1 , p = 0.002, d = 1.11) but not in LEA+J (0.65 ± 0.08-0.65 ± 0.08 ng mL-1 , p > 0.999, d = 0.19), and these effects were significantly different (time by condition interaction: p = 0.007). Morning basal bone formation rate is reduced following 3 days LEA, induced via dietary restriction, with or without high-impact jumping in regularly menstruating young females. However, high-impact jumping can prevent an increase in morning basal bone resorption rate and may benefit long-term bone health in individuals repeatedly exposed to such bouts.


Assuntos
Reabsorção Óssea , Menstruação , Humanos , Feminino , Metabolismo Energético , Reabsorção Óssea/prevenção & controle , Remodelação Óssea , Exercício Físico , Colágeno , Biomarcadores
6.
Psychoneuroendocrinology ; 152: 106079, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36947969

RESUMO

Disordered eating-related attitudes are a leading cause of energy deficiency and menstrual disturbances in exercising women. Although treatment recommendations include psychological counseling with increases in dietary intake, a key concern is whether increased dietary intake may exacerbate negative eating behaviors. OBJECTIVE: To determine the effects of a 12-month nutritional intervention on eating-related attitudes and psychological characteristics in exercising women with oligomenorrhea/amenorrhea (Oligo/Amen). METHODS: Intent-to-treat analysis of the REFUEL randomized controlled trial (#NCT00392873) in 113 exercising women (age [mean±SEM]:] 21.9 ± 0.4 yrs; BMI: 20.9 ± 0.2 kg/m2). Women were randomized to increase energy intake 20-40% above baseline energy needs (Oligo/Amen+Cal, n = 40) or maintain energy intake (Oligo/Amen Control, n = 36) while maintaining their exercise behaviors. A reference group of ovulatory women (OVref, n = 37) maintained diet and exercise behaviors. Body composition, eating attitudes, stress, and depressive symptoms were assessed at baseline and every 3 months. RESULTS: At baseline, the Oligo/Amen groups had higher drive for thinness, cognitive restraint, and eating disorder risk than OVref group (p < 0.001). Increased energy intake led to increases in percent body fat and fat mass (p < 0.010), but not psychobehavioral outcomes, in the Oligo/Amen+Cal compared to Oligo/Amen Control group. Independent of group, cognitive restraint decreased (p < 0.001) and resilient coping increased (p < 0.007) over 12-months, while perceived stress (p = 0.143) and depressive symptoms (p = 0.344) were unchanged. DISCUSSION: Long-term nutritional intervention consisting of modest increases in dietary intake with guidance from a registered dietician and a psychologist increases body and fat mass without increasing disordered eating-related attitudes, stress, or depressive symptoms in exercising women with Oligo/Amen.


Assuntos
Depressão , Transtornos da Alimentação e da Ingestão de Alimentos , Feminino , Humanos , Adulto Jovem , Adulto , Distúrbios Menstruais , Ingestão de Alimentos , Exercício Físico/psicologia , Ingestão de Energia
7.
Med Sci Sports Exerc ; 55(5): 794-802, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36729923

RESUMO

INTRODUCTION: South Asians (SAs) have an elevated risk of cardiovascular disease (CVD) compared with White Europeans (WEs). Postprandial endothelial function (flow-mediated dilatation (FMD%)) in SA women and SA men with central obesity has not been investigated. Research in other populations has highlighted that a 1% higher FMD% is associated with a ~13% lower risk of future CVD events. We investigated whether FMD% and lipemia, two markers for CVD risk, were higher in SAs versus WEs, whether walking improved FMD% and lipemia, and if there were ethnic differences in the response. METHODS: Lean premenopausal women (study 1; 12 SA, 12 WE) and men with central obesity (study 2; 15 SA, 15 WE) completed two 2-d trials. On day 1, participants walked for 60 min at 60% of their peak oxygen uptake or rested. On day 2, participants rested and consumed two high-fat meals over 8 h. Repeated ultrasound assessments of endothelial function and venous blood samples for CVD risk markers were taken. RESULTS: Compared with WEs, SAs had lower postprandial FMD% (study 1, -1.32%; study 2, -0.54%) and higher postprandial triacylglycerol concentrations (study 1, 0.31 mmol·L -1 ·h -1 ; study 2, 0.55 mmol·L -1 ·h -1 ). Walking improved postprandial FMD% (study 1, 1.12%; study 2, 0.94%) and resulted in no significant change or small reductions in postprandial triacylglycerol concentrations (study 1, -0.01 mmol·L -1 ·h -1 ; study 2, -0.25 mmol·L -1 ·h -1 ). Exercise-induced changes in FMD% and triacylglycerol were consistent between ethnic groups. CONCLUSIONS: Walking mitigated the adverse postprandial effect of a high-fat diet on FMD% to a similar extent in SA and WE women and men, even with no/small improvements in triacylglycerol. This study highlights the importance of exercise to clinically improve FMD% in SAs and WEs.


Assuntos
Doenças Cardiovasculares , Hiperlipidemias , Masculino , Humanos , Feminino , População Europeia , Obesidade Abdominal , População do Sul da Ásia , Triglicerídeos , Caminhada/fisiologia , Período Pós-Prandial/fisiologia , Estudos Cross-Over , Gorduras na Dieta , População Branca
8.
Scand J Med Sci Sports ; 33(6): 882-893, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36785894

RESUMO

INTRODUCTION: Menopause is associated with vascular dysfunction and increased risk of developing metabolic syndrome. Associations between vascular and metabolic health, and interactions with aerobic exercise training, are unknown in postmenopausal women (PMW). METHODS: In habitually aerobically trained PMW (PMWtr; n = 10; 57 ± 1 years; 40 ± 1 mL/kg/min), strain-gauge plethysmography was used to compare resting and peak calf blood flow (CBFr and CBFpk, respectively) and vascular resistance (CVRr; CVRpk) versus untrained PMW (PMWun; n = 13; 56 ± 1 years; 29 ± 1 mL/kg/min) and premenopausal women (PreM; n = 14; 26 ± 1 years; 40 ± 1 mL/kg/min). Vascular measures were taken before and 1 hour after 45 minutes of aerobic exercise (60% V̇ O2peak ), a known nitric oxide stimulus. Blood analyses included low- (LDLc) and high-density lipoprotein cholesterol (HDLc), insulin, and glucose. RESULTS: Pre-exercise, CBFr and CVRr did not differ (p > 0.05) between PMW groups, nor between PreM and PMWtr. CBFpk was highest (p < 0.05) and CVRpk was lowest (p < 0.05) in PMWtr. Blood markers were similar (p > 0.05) in PMW groups. However, in PMWtr, CBFpk was associated inversely (p < 0.05) with insulin (r = -0.725). Conversely, in PMWun, CBFpk correlated (p < 0.05) inversely with glucose (r = -0.717), positively with HDLc (r = 0.633), and CVRpk positively (p < 0.05) with LDLc (r = 0.568). Post-exercise, CBF increased and CVR decreased (p < 0.05) in all groups, yet CBFpk remained higher and CVRpk lower (p < 0.05) in PMWtr. CONCLUSION: In untrained PMW, peak CBF is associated inversely with circulating pro-atherogenic lipids and glucose. In contrast, peak CBF is associated inversely with insulin levels only in trained PMW. Habitual aerobic exercise may favorably modulate vasculo-metabolic interactions in PMW.


Assuntos
Pletismografia , Pós-Menopausa , Humanos , Feminino , Pós-Menopausa/fisiologia , Insulina , HDL-Colesterol , Glucose
9.
Curr Top Behav Neurosci ; 62: 309-331, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36697895

RESUMO

BackgroundWomen in many cohorts have a higher risk for Alzheimer's disease (AD), the most common form of dementia. Sex is a biological construct whereby differences in disease manifestation and prevalence are rooted in genetic differences between XX and XY combinations of chromosomes. This chapter focuses specifically on sex-driven differences in dementia, as opposed to differences driven by gender - a social construct referring to the societal norms that influence people's roles, relationships, and positional power throughout their lifetime.MethodsUsing a narrative review, this chapter explored the characteristics and risk factors for the dementias, alongside a discussion of sex differences including loss of sex steroid hormones in middle-aged women, differences in the prevalence of cardiovascular diseases and engagement in lifestyle protective factors for dementia.ResultsThe sex difference in AD prevalence may exist because of systematic and historic differences in risk and protective factors for dementia, including level of education obtained and socioeconomic status differences, which can impact on health and dementia risk.Levels of sex steroids decline significantly after menopause in women, whereas this is more gradual in men with age. Animal and cell culture studies show strong biological plausibility for sex steroids to protect the ageing brain against dementia. Sex steroid hormone replacement therapy has in some observational studies shown to protect against AD, but treatment studies in humans have mainly shown disappointing results. Cardiovascular disease (CVD) shares midlife medical risk (e.g. hypertension, hyperlipidaemia, obesity etc.) factors with AD and other forms of dementia, but also with related lifestyle risk - and protective factors (e.g. exercise, not smoking etc.). Men tend to die earlier of CVD, so fewer survive to develop AD at an older age. Those who do survive may have healthier lifestyles and fewer risk factors for both CVD and AD. An earlier age at menopause also confers great risk for both without hormone treatment.DiscussionIt could be the case that the decline in sex steroids around the menopause make women more susceptible to lifestyle-related risk factors associated with dementia and CVD, but this remains to be further investigated. Combining hormone treatment with lifestyle changes in midlife (e.g. exercise) could be an important preventative treatment for dementia and CVD in later life, but this also requires further research.


Assuntos
Doença de Alzheimer , Doenças Cardiovasculares , Pessoa de Meia-Idade , Humanos , Feminino , Masculino , Caracteres Sexuais , Fatores de Risco , Doenças Cardiovasculares/epidemiologia , Hormônios Esteroides Gonadais , Esteroides , Fatores Sexuais
10.
CJC Open ; 5(1): 54-71, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36700183

RESUMO

A growing body of literature has examined the role of physical activity (PA) in modifying the effects of estrogen withdrawal on cardiovascular health in postmenopausal women, but the impact of PA on androgens is less clear. Changes in androgen concentrations following regular PA may improve cardiovascular health. This narrative review summarizes the literature assessing the impact of PA interventions on androgens in postmenopausal women. The association between changes in androgen concentrations and cardiovascular health following PA programs is also examined. Randomized controlled trials were included if they (i) implemented a PA program of any type and duration in postmenopausal women and (ii) measured changes in androgen concentrations. Following PA interventions, no changes in androstenedione, conflicting changes in dehydroepiandrosterone/dehydroepiandrosterone-sulfate, and increases in sex hormone-binding globulin concentrations were found. Total testosterone decreased following aerobic PA but increased after resistance training. Most aerobic PA interventions led to reductions in free testosterone. A combination of caloric restriction and/or fat loss enhanced the influence of PA on most androgens. Evidence exploring the relationship between changes in androgens and cardiovascular health indicators was scarce and inconsistent. PA has shown promise in modifying the concentrations of some androgens (free and total testosterone, sex hormone-binding globulin), and remains a well-known beneficial adjuvant option for postmenopausal women to manage their cardiovascular health. Fat loss influences the effect of PA on androgens, but the synergistic role of PA and androgens on cardiovascular health merits further examination. Many research gaps remain regarding the relationship between PA, androgens, and cardiovascular disease in postmenopausal women.


Un nombre croissant de publications ont examiné le rôle de l'activité physique (AP) pour contrer les effets de la privation en œstrogènes sur la santé cardiovasculaire des femmes ménopausées, mais les effets de l'AP sur les androgènes sont moins évidents. Les variations des taux d'androgènes associées à l'AP régulière pourraient améliorer la santé cardiovasculaire. Cette revue narrative résume des articles ayant évalué les répercussions des interventions fondées sur l'AP sur les taux d'androgènes chez les femmes ménopausées. Le lien entre la santé cardiovasculaire et les variations des taux d'androgènes consécutives à des programmes d'AP a également été examiné. Des essais contrôlés randomisés étaient inclus s'ils comprenaient (i) la mise en œuvre d'un programme d'AP quel qu'en soit le type ou la durée chez des femmes ménopausées et (ii) la mesure des variations des taux d'androgènes. Aucune variation des taux d'androstènedione n'a été observée après des interventions fondées sur l'AP. Toutefois, des variations conflictuelles des taux de déhydroépiandrostérone et de sulfate de déhydroépiandrostérone et des hausses des taux de la globuline liant les hormones sexuelles ont été observés. Le taux de testostérone totale a diminué après l'AP en aérobie, mais a augmenté après l'entraînement contre résistance. La plupart des interventions fondées sur l'AP en aérobie ont entraîné des réductions du taux de testostérone libre. En association avec la restriction calorique et/ou une perte de graisse corporelle, l'AP exerce une influence accrue sur la plupart des androgènes. Les données probantes explorant le lien entre les variations des taux d'androgènes et les indicateurs de santé cardiovasculaire étaient rares et contradictoires. L'AP s'est révélée prometteuse pour ce qui est de modifier les taux de certains androgènes (testostérone libre et testostérone totale, globuline liant les hormones sexuelles); elle demeure une option adjuvante bénéfique bien connue pour aider les femmes ménopausées à prendre en charge leur santé cardiovasculaire. La perte de graisse corporelle influe sur les effets de l'AP sur les androgènes, mais le rôle synergique de l'AP et des androgènes sur la santé cardiovasculaire mérite un examen plus approfondi. De nombreuses lacunes subsistent quant à la recherche d'un lien entre l'AP, les androgènes et les maladies cardiovasculaires chez les femmes ménopausées.

11.
Am J Physiol Heart Circ Physiol ; 323(5): H934-H940, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36206052

RESUMO

We examined the influence of sex and age on the relationship between aerobic fitness and muscle sympathetic nerve activity (MSNA) in healthy adults. Data were assessed from 224 volunteers (88 females), aged 18-76 yr, in whom resting MSNA (microneurography) and peak oxygen uptake (V̇o2peak; incremental exercise test) were evaluated. When separated into younger (<50 yr) and older (≥50 yr) subgroups, there were inverse relationships between relative V̇o2peak (mL·kg-1·min-1) and MSNA burst frequency in younger males (R2 = 0.21, P < 0.0001) and older females (R2 = 0.36, P < 0.01), but not older males (R2 = 0.05, P = 0.08) or younger females (R2 = 0.03, P = 0.14). Similar patterns were observed with absolute V̇o2peak (L·min-1) and percent-predicted (based on age, sex, weight, height, and modality), and with burst incidence. Sex and age influence the relationship between aerobic fitness and resting MSNA, and, thus, must be considered as key variables when studying these potential associations; inverse relationships are strongest in younger males and older females.NEW & NOTEWORTHY Our data reveal for the first time that associations between aerobic fitness and resting muscle sympathetic nerve activity are sex and age specific; inverse relationships are evident in younger males (<50 yr) and older females (≥50 yr), but absent in younger females (<50 yr) and older males (≥50 yr).


Assuntos
Músculo Esquelético , Sistema Nervoso Simpático , Adulto , Masculino , Feminino , Humanos , Pressão Sanguínea/fisiologia , Músculo Esquelético/inervação , Sistema Nervoso Simpático/fisiologia , Exercício Físico/fisiologia , Oxigênio
12.
Nucleic Acids Res ; 50(20): 11401-11414, 2022 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-35944903

RESUMO

Current therapies for Duchenne muscular dystrophy (DMD) use phosphorodiamidate morpholino oligomers (PMO) to induce exon skipping in the dystrophin pre-mRNA, enabling the translation of a shortened but functional dystrophin protein. This strategy has been hampered by insufficient delivery of PMO to cardiac and skeletal muscle. To overcome these limitations, we developed the FORCETM platform consisting of an antigen-binding fragment, which binds the transferrin receptor 1, conjugated to an oligonucleotide. We demonstrate that a single dose of the mouse-specific FORCE-M23D conjugate enhances muscle delivery of exon skipping PMO (M23D) in mdx mice, achieving dose-dependent and robust exon skipping and durable dystrophin restoration. FORCE-M23D-induced dystrophin expression reached peaks of 51%, 72%, 62%, 90% and 77%, of wild-type levels in quadriceps, tibialis anterior, gastrocnemius, diaphragm, and heart, respectively, with a single 30 mg/kg PMO-equivalent dose. The shortened dystrophin localized to the sarcolemma, indicating expression of a functional protein. Conversely, a single 30 mg/kg dose of unconjugated M23D displayed poor muscle delivery resulting in marginal levels of exon skipping and dystrophin expression. Importantly, FORCE-M23D treatment resulted in improved functional outcomes compared with administration of unconjugated M23D. Our results suggest that FORCE conjugates are a potentially effective approach for the treatment of DMD.


The biggest problem confronting oligonucleotide therapeutics is a lack of compounds capable of targeting compounds to diseased tissues. This paper reports a major advance targeting the transferrin receptor to increase the delivery of morpholine oligomers to muscle cells in vivo. This work suggests the possibility for improved treatments of muscular dystrophy and other diseases.


Assuntos
Distrofina , Éxons , Morfolinos , Distrofia Muscular de Duchenne , Oligonucleotídeos Antissenso , Animais , Camundongos , Distrofina/genética , Éxons/genética , Camundongos Endogâmicos mdx , Morfolinos/farmacologia , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/terapia , Oligonucleotídeos Antissenso/farmacologia , Receptores da Transferrina/genética
13.
Menopause ; 29(6): 714-722, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35324537

RESUMO

OBJECTIVE: The aim of the present study was to examine the effects of habitual exercise training and metabolic health on basal cardiac autonomic function and cardiac autonomic recovery after exercise in healthy postmenopausal women (PMW). METHODS: Habitually aerobically trained PMW (PMW-tr; 56 ±â€Š1y; n = 11), and untrained PMW (PMW-un; 57 ±â€Š1y; n  = 13) and premenopausal women (PreM; ages 26 ±â€Š1y; n  = 14) were studied. Cardiac autonomic function, assessed using heart rate variability (HRV), was measured before and one hour after 45-minutes of moderate-intensity exercise (60% VO2peak). Fast Fourier frequency domain measures of high (HF; 0.15 Hz-0.4 Hz), low (LF; 0.04 Hz-0.15 Hz), very low (VLF; 0.01 Hz-0.04 Hz), and Total (VLF + LF + HF) HRV were assessed. Serum estradiol, insulin, and glucose were determined, and HOMA-IR, an index of insulin resistance, was calculated. RESULTS: In PMW groups, body composition and serum markers did not differ (P > 0.05). Pre-exercise, heart rate was lower (P < 0.05) in PMW-tr than PMW-un, yet HRV did not differ (P > 0.05). In PMW-tr only, HF was inversely associated (P < 0.05) with insulin (r = -0.738) and HOMA-IR (r = -0.758). In PreM, HRV was higher than PMW (P  < 0.05) and was positively correlated with estradiol (P  < 0.05). Postexercise, HRV was decreased within all groups (P  < 0.05) yet remained higher in PreM (P  < 0.05), and similar (P  > 0.05) between PMW. CONCLUSIONS: Basal and postexercise HRV does not differ between habitually aerobically trained and untrained PMW. However, greater insulin sensitivity was associated with higher cardiac parasympathetic tone in trained PMW only. Exercise training may favorably modulate cardiac autonomic-metabolic interactions in PMW.


Assuntos
Insulinas , Pós-Menopausa , Adulto , Sistema Nervoso Autônomo , Estradiol , Exercício Físico/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Pós-Menopausa/fisiologia
14.
Antioxidants (Basel) ; 12(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36670889

RESUMO

Short-term dietary nitrate (NO3−) supplementation has the potential to enhance performance during submaximal endurance, and short-duration, maximal-intensity exercise. However, it has yet to be determined whether NO3− supplementation before and during submaximal endurance exercise can improve performance during a short-duration, maximal-intensity end-sprint. In a randomised, double-blind, crossover study, 9 recreationally active men ingested NO3−-rich (BR: 8 mmol NO3−/day) and NO3−-depleted (PL: 0.75 mmol NO3−/day) beetroot powder for 7 days. On day 7, participants completed 2 h of moderate-intensity cycling, which immediately transitioned into a 60 s maximal-intensity end-sprint, with supplements ingested 2 h before and 1 h into the moderate-intensity exercise bout. Plasma [NO3−] and [NO2−] were higher in BR compared to PL pre- and post-exercise (p < 0.05). Post-exercise plasma [NO3−] was higher than pre-exercise (562 ± 89 µM vs. 300 ± 73 µM; p < 0.05) and plasma [NO2−] was not significantly different pre- (280 ± 58 nM) and post-exercise (228 ± 63 nM) in the BR condition (p > 0.05). Mean power output during the final 30 s of the end-sprint was greater after BR (390 ± 38 W) compared to PL (365 ± 41 W; p < 0.05). There were no differences between BR and PL in any muscle oxygenation variables during moderate-intensity cycling (p > 0.05), but muscle [deoxyhaemoglobin] kinetics was faster during the end-sprint in BR (6.5 ± 1.4 s) compared to PL (7.3 ± 1.4 s; p < 0.05). These findings suggest that NO3− supplementation has the potential to improve end-sprint performance in endurance events when ingested prior to and during exercise.

15.
Artigo em Inglês | MEDLINE | ID: mdl-34969617

RESUMO

Cognitive and mood changes are frequently mentioned as complaints before, during and after menopausal transition. There is substantial biological evidence for such associations to occur, as there are many mechanisms through which oestrogens can affect the brain: by regulating metabolism, increasing cerebral blood flow and dendritic outgrowth, by acting on nerve growth factors through the co-localisation of receptors via neurotransmitter synthesis and turnover and many more. However, the evidence for objective and longer-term changes in cognitive function and mental health over the menopausal transition and beyond is less clear. While hormone treatment (HT) including oestrogens could potentially reverse these psychological issues, the evidence of long-term benefit is also inconclusive. However, for women with severe menopausal complaints, and particularly for those who undergo early menopause, including women with premature ovarian insufficiency, personalised HT at least up to the natural age of menopause around 50 should be considered, which is probably safe up to 10 years of treatment, unless contraindicated. This paper reviews the evidence for changes in psychological health related to menopausal transition and HTs.


Assuntos
Terapia de Reposição de Estrogênios , Saúde Mental , Cognição/fisiologia , Terapia de Reposição de Estrogênios/psicologia , Estrogênios/uso terapêutico , Feminino , Humanos , Menopausa/fisiologia , Menopausa/psicologia
16.
J Sports Sci ; 39(22): 2558-2566, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34269142

RESUMO

Bone stress injury (BSI) is prevalent in female distance runners. Menstrual disturbances are associated with impaired bone health in endurance athletes. This study aimed to investigate the association between menstrual function and BSI and explore whether plyometric training may protect against BSI in individuals with menstrual disturbances. Competitive female distance runners (n = 183) aged 18-40 years were surveyed for training habits, menstrual function, and BSI, during the previous 12 months. Oligo/amenorrhoea during the previous 12 months (<9 menses) was deemed to indicate menstrual disturbance; hormonal contraceptive users and those previously diagnosed with a pathology that impacted menstrual function were excluded. BSI incidence rate was 2.25 (p = 0.02, 95% CI: 1.14-4.41) times greater in oligo/amenorrhoeic than eumenorrhoeic runners. BSI incidence rate was similar in oligo/amenorrhoeic and eumenorrhoeic runners that did plyometric training, but 3.78 (p = 0.001, 95% CI: 1.68-8.5) times greater in oligo/amenorrhoeic versus eumenorrhoeic runners that did not. However, the effect of plyometrics was non-significant (menstrual function × plyometric training interaction, p = 0.06; main effect, p = 0.89). Conventional plyometric training may not reduce BSI incidence in female distance runners, but menstrual disturbances and prolonged periods of low energy availability should be avoided.


Assuntos
Exercício Pliométrico , Corrida , Amenorreia/epidemiologia , Densidade Óssea , Feminino , Humanos , Incidência , Distúrbios Menstruais/epidemiologia
17.
Br J Sports Med ; 55(15): 865-872, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33648944

RESUMO

OBJECTIVES: We systemically reviewed the literature to assess how long-term testosterone suppressing gender-affirming hormone therapy influenced lean body mass (LBM), muscular area, muscular strength and haemoglobin (Hgb)/haematocrit (HCT). DESIGN: Systematic review. DATA SOURCES: Four databases (BioMed Central, PubMed, Scopus and Web of Science) were searched in April 2020 for papers from 1999 to 2020. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Eligible studies were those that measured at least one of the variables of interest, included transwomen and were written in English. RESULTS: Twenty-four studies were identified and reviewed. Transwomen experienced significant decreases in all parameters measured, with different time courses noted. After 4 months of hormone therapy, transwomen have Hgb/HCT levels equivalent to those of cisgender women. After 12 months of hormone therapy, significant decreases in measures of strength, LBM and muscle area are observed. The effects of longer duration therapy (36 months) in eliciting further decrements in these measures are unclear due to paucity of data. Notwithstanding, values for strength, LBM and muscle area in transwomen remain above those of cisgender women, even after 36 months of hormone therapy. CONCLUSION: In transwomen, hormone therapy rapidly reduces Hgb to levels seen in cisgender women. In contrast, hormone therapy decreases strength, LBM and muscle area, yet values remain above that observed in cisgender women, even after 36 months. These findings suggest that strength may be well preserved in transwomen during the first 3 years of hormone therapy.


Assuntos
Composição Corporal/efeitos dos fármacos , Hemoglobina A/efeitos dos fármacos , Força Muscular/efeitos dos fármacos , Esportes , Testosterona/antagonistas & inibidores , Pessoas Transgênero , Tecido Adiposo/efeitos dos fármacos , Antagonistas de Androgênios/farmacologia , Desempenho Atlético , Composição Corporal/fisiologia , Acetato de Ciproterona/farmacologia , Estradiol/farmacologia , Feminino , Hematócrito , Humanos , Masculino , Força Muscular/fisiologia , Músculo Esquelético/efeitos dos fármacos , Esportes/fisiologia , Fatores de Tempo , Transexualidade/sangue
19.
Appl Physiol Nutr Metab ; 46(1): 86-89, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32835490

RESUMO

This study tested the hypothesis that exposure to chlorine-sterilised pool water would impair oral nitrate reduction (ONR). ONR was assessed in elite swimmers before and after morning and afternoon pool-based training. Nonswimmers were only assessed in the morning. ONR was similar in swimmers and nonswimmers (P = 1.000) and unchanged before and after morning and afternoon training (P ≥ 0.341). Therefore, exposure to chlorinated pool water does not interfere with ONR. Novelty Exposure to chlorine-sterilised pool water does not impair oral nitrate reduction in elite swimmers.


Assuntos
Atletas/estatística & dados numéricos , Cloro/metabolismo , Boca/metabolismo , Nitratos/metabolismo , Piscinas , Natação , Adulto , Feminino , Humanos , Masculino , Reino Unido , Água/química , Adulto Jovem
20.
Sports Med ; 51(3): 391-403, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33346900

RESUMO

Endurance athletes expend large amounts of energy in prolonged high-intensity exercise and, due to the weight-sensitive nature of most endurance sports, often practice periods of dietary restriction. The Female Athlete Triad and Relative Energy Deficiency in Sport models consider endurance athletes at high-risk for suffering from low energy availability and associated health complications, including an increased chance of bone stress injury. Several studies have examined the effects of low energy availability on various parameters of bone structure and markers of bone (re)modelling; however, there are differences in findings and research methods and critical summaries are lacking. It is difficult for athletes to reduce energy expenditure or increase energy intake (to restore energy availability) in an environment where performance is a priority. Development of an alternative tool to help protect bone health would be beneficial. High-impact exercise can be highly osteogenic and energy efficient; however, at present, it is rarely utilized to promote bone health in endurance athletes. Therefore, with a view to reducing the prevalence of bone stress injury, the objectives of this review are to evaluate the effects of low energy availability on bone health in endurance athletes and explore whether a high-impact exercise intervention may help to prevent those effects from occurring.


Assuntos
Densidade Óssea , Síndrome da Tríade da Mulher Atleta , Atletas , Ingestão de Energia , Metabolismo Energético , Feminino , Humanos , Estado Nutricional
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