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1.
J Neurophysiol ; 131(4): 607-618, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38381536

RESUMO

The benefits of cold have long been recognized in sport and medicine. However, it also brings costs, which have more rarely been investigated, notably in terms of sensorimotor control. We hypothesized that, in addition to peripheral effects, cold slows down the processing of proprioceptive cues, which has an impact on both feedback and feedforward control. We therefore compared the performances of participants whose right arm had been immersed in either cold water (arm temperature: 14°C) or lukewarm water (arm temperature: 34°C). In experiment 1, we administered a Fitts's pointing task and performed a kinematic analysis to determine whether sensorimotor control processes were affected by the cold. Results revealed 1) modifications in late kinematic parameters, suggesting changes in the use of proprioceptive feedback, and 2) modifications in early kinematic parameters, suggesting changes in action representations and/or feedforward processes. To explore our hypothesis further, we ran a second experiment in which no physical movement was involved, and thus no peripheral effects. Participants were administrated a hand laterality task, known to involve implicit motor imagery and assess the internal representation of the hand. They were shown left- and right-hand images randomly displayed in different orientations in the picture plane and had to identify as quickly and as accurately as possible whether each image was of the left hand or the right hand. Results revealed slower responses and more errors when participants had to mentally rotate the cooled hand in the extreme orientation of 160°, further suggesting the impact of cold on action representations.NEW & NOTEWORTHY We investigated how arm cooling modulates sensorimotor representations and sensorimotor control. Arm cooling induced changes in early kinematic parameters of pointing, suggesting an impact on feedforward processes or hand representation. Arm cooling induced changes in late kinematic parameters of pointing, suggesting an impact on feedback processes. Arm cooling also affected performance on a hand laterality task, suggesting that action representations were modified.


Assuntos
Braço , Lateralidade Funcional , Humanos , Lateralidade Funcional/fisiologia , Movimento/fisiologia , Mãos/fisiologia , Propriocepção , Água , Desempenho Psicomotor/fisiologia
2.
J Therm Biol ; 121: 103857, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38663342

RESUMO

BACKGROUND: Cryostimulation and cold-water immersion (CWI) have recently gained widespread attention due to their association with changes in cardiovascular and cardiac autonomic control responses. Therefore, the aim of the present systematic review and meta-analysis was to identify the global impact of such cold exposures on cardiovascular and cardiac autonomic activity. METHODS: Three databases (PubMed, Embase, Web-of-Science) were used. Studies were eligible for inclusion if they were conducted on healthy participants using cryostimulation and/or CWI. The outcomes included measurements of blood pressure (BP), heart rate (HR), and heart rate variability (HRV) indices: RR interval (RR), Root mean square of successive RR interval differences (RMSSD), low frequency band (LF), high frequency band (HF), and LF/HF ratio. RESULTS: Among the 27 articles included in our systematic literature review, only 24 were incorporated into the meta-analysis. Our results reveal a significant increase in HRV indices: RMSSD (Standardized mean difference (SMD) = 0.61, p < 0.001), RR (SMD = 0.77, p < 0.001), and HF (SMD = 0.46, p < 0.001), as well as significantly reduced LF (SMD = -0.41, p < 0.001) and LF/HF ratio (SMD = -0.25, p < 0.01), which persisted up to 15 min following cold exposure. Significantly decreased heart rate (SMD = -0.16, p < 0.05), accompanied by slightly increased mean BP (SMD = 0.28, p < 0.001), was also observed. These results seem to depend on individual characteristics and the cooling techniques. CONCLUSION: Our meta-analysis suggests that cryostimulation and/or CWI exposure enhance parasympathetic nervous activity. There is scarce scientific literature regarding the effect of individual characteristics on cold-induced physiological responses.


Assuntos
Sistema Nervoso Autônomo , Crioterapia , Humanos , Sistema Nervoso Autônomo/fisiologia , Pressão Sanguínea , Temperatura Baixa , Crioterapia/métodos , Coração/fisiologia , Frequência Cardíaca , Imersão
3.
Cryobiology ; 112: 104561, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37499963

RESUMO

This study aimed to investigate the effect of partial-body cryostimulation (PBC) on microvascular responsiveness and muscular metabolic O2 consumption rate (mV˙O2). Twenty healthy young adults (ten males and ten females) underwent a post-occlusive reactive hyperemia (PORH) test at the flexor digitorum superficialis area before and after a 3-min PBC session and a 3-min control session. Using near-infrared spectroscopy, occlusion and reperfusion slopes were calculated: oxyhemoglobin ([HbO2]) decrease rate ([HbO2] slope 1), deoxyhaemoglobin ([HHb]) increase rate ([HHb] slope 1), [HbO2] increase rate ([HbO2] slope 2), and [HHb] increase rate ([HHb] slope 2. Using HbO2 kinetics during the occlusion, mV˙O2 was also calculated to characterize myocytes' metabolic O2 consumption. HbO2 slope 1 value was lower after PBC than before PBC (-0.15 ± 0.08 vs -0.24 ± 0.11 s-1; respectively; P < 0.05) in male participants only. A lower [HHb] slope 1 was also observed after PBC compared to before PBC (0.18 ± 0.10 vs 0.24 ± 0.16 s-1; P < 0.05) with no interaction for sex categories. mV˙O2 was significantly lower after PBC than before (pre values 14.75 ± 3.94 vs 18.47 ± 5.73 µMO2Hb.s-1; respectively; P < 0.01) with no interaction between sex categories. No changes in the calculated slope 2 were observed. These findings suggest that a single session of PBC reduces the muscular metabolic O2 needs at rest; however, it does not alter the vascular ability to provide O2 to the myocytes.


Assuntos
Criopreservação , Músculo Esquelético , Adulto Jovem , Feminino , Humanos , Masculino , Criopreservação/métodos , Músculo Esquelético/metabolismo , Oxigênio/metabolismo
4.
Diabetologia ; 64(4): 778-794, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33599800

RESUMO

AIMS/HYPOTHESIS: This is an update of the results from the previous report of the CORONADO (Coronavirus SARS-CoV-2 and Diabetes Outcomes) study, which aims to describe the outcomes and prognostic factors in patients with diabetes hospitalised for coronavirus disease-2019 (COVID-19). METHODS: The CORONADO initiative is a French nationwide multicentre study of patients with diabetes hospitalised for COVID-19 with a 28-day follow-up. The patients were screened after hospital admission from 10 March to 10 April 2020. We mainly focused on hospital discharge and death within 28 days. RESULTS: We included 2796 participants: 63.7% men, mean age 69.7 ± 13.2 years, median BMI (25th-75th percentile) 28.4 (25.0-32.4) kg/m2. Microvascular and macrovascular diabetic complications were found in 44.2% and 38.6% of participants, respectively. Within 28 days, 1404 (50.2%; 95% CI 48.3%, 52.1%) were discharged from hospital with a median duration of hospital stay of 9 (5-14) days, while 577 participants died (20.6%; 95% CI 19.2%, 22.2%). In multivariable models, younger age, routine metformin therapy and longer symptom duration on admission were positively associated with discharge. History of microvascular complications, anticoagulant routine therapy, dyspnoea on admission, and higher aspartate aminotransferase, white cell count and C-reactive protein levels were associated with a reduced chance of discharge. Factors associated with death within 28 days mirrored those associated with discharge, and also included routine treatment by insulin and statin as deleterious factors. CONCLUSIONS/INTERPRETATION: In patients with diabetes hospitalised for COVID-19, we established prognostic factors for hospital discharge and death that could help clinicians in this pandemic period. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT04324736.


Assuntos
COVID-19/diagnóstico , COVID-19/mortalidade , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/mortalidade , Alta do Paciente , Idoso , Idoso de 80 Anos ou mais , COVID-19/complicações , COVID-19/terapia , Complicações do Diabetes/diagnóstico , Complicações do Diabetes/mortalidade , Complicações do Diabetes/terapia , Diabetes Mellitus/terapia , Feminino , Seguimentos , França/epidemiologia , Mortalidade Hospitalar , Hospitalização/estatística & dados numéricos , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Alta do Paciente/estatística & dados numéricos , Prognóstico , Respiração Artificial/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , SARS-CoV-2/fisiologia
5.
Diabetes Obes Metab ; 23(2): 434-443, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33118250

RESUMO

AIMS: To assess the prevalence, type and clinical factors associated with left ventricular (LV) dysfunction in patients with type 2 diabetes mellitus (T2DM) by performing a comprehensive echocardiographic Doppler assessment including speckle tracking. METHODS: Two hundred T2DM patients without overt cardiovascular disease were prospectively enrolled in a single-centre cohort study between 2018 and 2019. RESULTS: Left ventricular mass was increased in 24 patients (12%) and relative wall thickness (h/r) was increased in 46 patients (23%). Left atrial (LA) enlargement was observed in 27 patients (13.6%) and global longitudinal strain (GLS) was reduced in 38 patients (20.3%). In univariate analysis, LV hypertrophy (LVH) or increased h/r were associated with age, renal function, hypertension and B-type natriuretic peptide (BNP) plasma level. LA dilation was associated with age, history of hypertension, diabetes duration and complications, insulin treatment, BNP level and renal function. GLS was associated with body mass index (BMI) and, in a borderline manner, with diabetes duration. In multivariate analysis, hypertension was associated with LVH and with h/r and a borderline relationship was observed for female gender (LVH), age and insulin treatment (h/r). Age, hypertension and, in a borderline manner, insulin treatment were associated with LA dilation. BMI and shorter diabetes duration were associated with reduced GLS. CONCLUSION: A high prevalence of asymptomatic cardiac dysfunction/structural abnormalities was observed in patients with T2DM without overt cardiac disease and was associated with either age, diabetes duration or treatment and with comorbidities including hypertension and obesity. Whether these preclinical abnormalities are associated with poor outcomes warrants further study.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Disfunção Ventricular Esquerda , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Humanos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/epidemiologia , Disfunção Ventricular Esquerda/etiologia , Função Ventricular Esquerda
6.
Diabetes Obes Metab ; 23(5): 1162-1172, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33528920

RESUMO

AIM: To investigate the association between routine use of dipeptidyl peptidase-4 (DPP-4) inhibitors and the severity of coronavirus disease 2019 (COVID-19) infection in patient with type 2 diabetes in a large multicentric study. MATERIALS AND METHODS: This study was a secondary analysis of the CORONADO study on 2449 patients with type 2 diabetes (T2D) hospitalized for COVID-19 in 68 French centres. The composite primary endpoint combined tracheal intubation for mechanical ventilation and death within 7 days of admission. Stabilized weights were computed for patients based on propensity score (DPP-4 inhibitors users vs. non-users) and were used in multivariable logistic regression models to estimate the average treatment effect in the treated as inverse probability of treatment weighting (IPTW). RESULTS: Five hundred and ninety-six participants were under DPP-4 inhibitors before admission to hospital (24.3%). The primary outcome occurred at similar rates in users and non-users of DPP-4 inhibitors (27.7% vs. 28.6%; p = .68). In propensity analysis, the IPTW-adjusted models showed no significant association between the use of DPP-4 inhibitors and the primary outcome by Day 7 (OR [95% CI]: 0.95 [0.77-1.17]) or Day 28 (OR [95% CI]: 0.96 [0.78-1.17]). Similar neutral findings were found between use of DPP-4 inhibitors and the risk of tracheal intubation and death. CONCLUSIONS: These data support the safety of DPP-4 inhibitors for diabetes management during the COVID-19 pandemic and they should not be discontinued.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Idoso , Idoso de 80 Anos ou mais , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , COVID-19/complicações , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Prognóstico , Pontuação de Propensão
7.
Int J Sports Med ; 42(2): 122-131, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32920802

RESUMO

The aim of this study was to evaluate the impact of using a cooling vest during physical exercise (per-cooling) in humid and temperate conditions (≈22°C, ≈80% relative humidity) on perceptual and physiological responses (tissue oxygenation and heart rate). 20 physically active men performed twice a 30-min cycling exercise at 70% of their theoretical maximum heart rate while using an activated (experimental condition) and a deactivated (control condition) cooling system in a randomized crossover study. Heart rate and tissue (cerebral and muscular) oxygenation were continuously measured during exercise and recovery, and skin temperature was measured every 10 min. Perception of temperature, humidity and comfort were assessed at the end of the recovery period. Results showed a decrease in trunk skin temperature (p<0.05), a faster heart rate recovery and an increase in the concentration of total hemoglobin at the brain level (p<0.05) compared with control condition. Moreover, an improved subjective rating of thermal sensations, wetness and comfort compared to control values (p<0.05) was noted. In conclusion, wearing a cooling vest during submaximal exercise improves perceptual and physiological responses in humid temperate conditions, which may be due to a better blood perfusion at the brain level and a better parasympathetic reactivation.


Assuntos
Encéfalo/fisiologia , Crioterapia/métodos , Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Consumo de Oxigênio/fisiologia , Temperatura Cutânea/fisiologia , Adulto , Vestuário , Estudos Cross-Over , Crioterapia/instrumentação , Humanos , Masculino , Adulto Jovem
8.
Eur J Appl Physiol ; 120(8): 1733-1743, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32474683

RESUMO

PURPOSE: A predominance of parasympathetic drive is observed following cold exposure. Such modulation of the autonomic nervous system (ANS) is associated with faster post-exercise recovery. Within this context, whole-body cryotherapy (WBC) has been spreading in sport medicine, though the optimal temperature and frequency are unclear. The aim of this study was to examine the effects of different cryotherapy conditions on the sympathovagal balance. METHODS: Forty healthy males were randomly assigned into five different groups (- 110 °C, - 60 °C, - 10 °C, control temperature [≃ 24 °C]) and undertook 5 WBC sessions over 5 consecutive days. Cardiac autonomic activity was assessed through heart rate variability (HRV) using power density of high frequency (HF), root-mean square difference of successive R-R intervals (RMSSD) and sympathovagal balance (LF/HF). Systemic sympathetic activity was assessed via circulating blood catecholamines. RESULTS: Mean weekly RMSSD (pre: 48 ± 22 ms, post: 68 ± 29 ms) and HF (pre: 607 ± 692 ms2, post: 1271 ± 1180 ms2) increased (p < 0.05) from pre to post WBC, only in the - 110 °C condition. A rise in plasma norepinephrine was found after the first - 110 °C WBC session only (pre: 173 ± 98, post: 352 ± 231 ng L-1, p < 0.01); whereas, it was not significant after the 5th session (pre: 161 ± 120, post: 293 ± 245 ng L-1, p = 0.15). CONCLUSION: These results suggest that one - 110 °C WBC exposure is required to stimulate the ANS. After five daily exposures, a lower autonomic response was recorded compared to day one, therefore suggesting the development of physiological habituation to WBC.


Assuntos
Catecolaminas/sangue , Crioterapia/efeitos adversos , Frequência Cardíaca , Adulto , Crioterapia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Nervo Vago/fisiologia
9.
J Aging Phys Act ; 28(3): 489-498, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31743086

RESUMO

Master athletes are often considered exemplars of successful aging, thanks to their capacity to maintain a high sports performance during their entire life. A high training capacity, regular participation in sporting competitions, and delayed alterations in body composition and physiological capacities have been listed among the main factors contributing to impressive master athletes' performances. However, there is a paucity of data on the metabolism and dietary habits of master athletes, and the question of whether they need to adapt their nutrition to the aging process remains open. Herein, the authors presented a contemporary overview of the metabolic challenges associated with aging, including the risk of low energy availability, anabolic resistance, and periods of metabolic crisis due to forced immobilization. After assembling scientific evidence to show that master athletes must adapt their dietary intake, the authors proposed a summary of nutritional recommendations for master athletes and suggested the next stage of research.

10.
J Sport Exerc Psychol ; 42(4): 336-343, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32570213

RESUMO

Research shows that negative or threatening emotional stimuli can foster movement velocity and force. However, less is known about how evaluative threat may influence movement parameters in endurance exercise. Based on social self-preservation theory, the authors predicted that evaluative threat would facilitate effort expenditure in physical exercise. In an exploratory study, 27 young men completed a bogus intelligence test and received either low-intelligence-quotient feedback (evaluative threat) or no feedback (control). Next, they were asked to pedal on a stationary bicycle for 30 min at a constant cadence. After 10 min (calibration period), the cadence display was hidden. Findings show that participants under evaluative threat increased cadence more than control participants during the subsequent 20-min critical period. These findings underline the potential importance of unrelated evaluative threat on physical performance.

11.
Scand J Med Sci Sports ; 29(11): 1660-1676, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31340407

RESUMO

INTRODUCTION: Hyperthermia during exercise induces central and peripheral fatigue and impairs physical performance. To facilitate heat loss and optimize performance, athletes can hasten body cooling prior (pre-cooling) or during (per-cooling) exercise. However, it is unclear whether per-cooling effect is the same on 'aerobic' and 'anaerobic' types of exercise (duration <75 and >76 seconds, respectively, according to Gastin [Sports Med 2001;31:725-741]) and whether the body area that is cooled makes a difference. METHODS: A literature search led to the identification of 1582 potential studies. Included studies had to include physical exercise with sufficient details on the type, duration, intensity, and provide valid performance measures and a cooling intervention administered during exercise with sufficient details on the type and site of application. RESULTS: Forty-five studies were included. Per-cooling provides a performance benefit during 'aerobic' (standardized mean difference (SMD) of 0.60, P < .001) and 'anaerobic' exercises (SMD = 0.27, P < .02). The effects were greater during aerobic compared to anaerobic exercises (P < .01). Internal cooling (cold fluid ingestion such as cold water and ice slurry/menthol beverage) and external cooling (face, neck, and torso) provide the greatest performance benefit for 'aerobic' performance with a moderate to large effect (0.46 < SMD < 1.24). For 'anaerobic' exercises, wearing a whole-body cooling garment is the best way to enhance exercise performance (SMD = 0.39, P < .01). CONCLUSION: Per-cooling improves 'aerobic' and 'anaerobic' exercise performance with a greater benefit for 'aerobic' exercise. The magnitude of the effect depends on the type and site of the cooling application.


Assuntos
Desempenho Atlético , Regulação da Temperatura Corporal , Temperatura Baixa , Exercício Físico , Administração Tópica , Bebidas , Ingestão de Líquidos , Humanos
13.
Int J Sports Med ; 40(6): 376-384, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30900226

RESUMO

Ten highly-trained Jiu-Jitsu fighters performed 2 repeated-sprint sessions, each including 2 sets of 8 x ~6 s back-and-forth running sprints on a tatami. One session was carried out with normal breathing (RSN) and the other with voluntary hypoventilation at low lung volume (RSH-VHL). Prefrontal and vastus lateralis muscle oxyhemoglobin ([O2Hb]) and deoxyhemoglobin ([HHb]) were monitored by near-infrared spectroscopy. Arterial oxygen saturation (SpO2), heart rate (HR), gas exchange and maximal blood lactate concentration ([La]max) were also assessed. SpO2 was significantly lower in RSH-VHL than in RSN whereas there was no difference in HR. Muscle oxygenation was not different between conditions during the entire exercise. On the other hand, in RSH-VHL, cerebral oxygenation was significantly lower than in RSN (-6.1±5.4 vs-1.5±6.6 µm). Oxygen uptake was also higher during the recovery periods whereas [La]max tended to be lower in RSH-VHL. The time of the sprints was not different between conditions. This study shows that repeated shuttle-run sprints with VHL has a limited impact on muscle deoxygenation but induces a greater fall in cerebral oxygenation compared with normal breathing conditions. Despite this phenomenon, performance is not impaired, probably because of a higher oxygen uptake during the recovery periods following sprints.


Assuntos
Desempenho Atlético/fisiologia , Encéfalo/metabolismo , Músculo Esquelético/metabolismo , Respiração , Corrida/fisiologia , Frequência Cardíaca , Hemoglobinas/metabolismo , Humanos , Hipoventilação , Ácido Láctico/sangue , Oxigênio/sangue , Consumo de Oxigênio/fisiologia , Oxiemoglobinas/metabolismo , Percepção , Esforço Físico , Troca Gasosa Pulmonar , Espectroscopia de Luz Próxima ao Infravermelho
14.
Brain Cogn ; 125: 127-134, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29990702

RESUMO

INTRODUCTION/PURPOSE: This study compared cognitive performances and cardiac autonomic measures of higher fit and lower fit middle-aged and older highly active adults. The working hypotheses were that higher fit (master athletes) would show cognitive benefits in executive control conditions due to a high level of fitness compared to lower fit people and that this effect would be mediated by better cardiac autonomic adaptations in athletes. METHODS: We recruited 39 highly active middle aged and older adults from Master Athletes' organizations. All participants performed a Rockport walking test and a computerized dual-task. Cardiac autonomic control was assessed with a measure of heart rate variability. Based on the V̇O2max estimated by the Rockport test, a median split was performed to assess the influence of fitness level on cognitive performance and the link with heart rate variability. Those with the highest fitness level were considered Master Athletes. RESULTS: Master Athletes showed better dual-task performances than lower fit individuals. A positive relationship between the V̇O2max and dual-task performances was also observed. Master Athletes demonstrated a lower resting HR and higher RR interval than lower fit individuals, and this index was specifically related to the executive conditions of the dual task. CONCLUSION: Our results highlight the role of fitness level on executive function in highly active middle aged and older adults and suggest that the better performances observed in highly fit individuals is mediated by cardiac autonomic control.


Assuntos
Atletas/psicologia , Sistema Nervoso Autônomo/fisiologia , Aptidão Cardiorrespiratória/psicologia , Cognição/fisiologia , Função Executiva/fisiologia , Análise e Desempenho de Tarefas , Idoso , Exercício Físico/psicologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade
16.
PLoS One ; 19(5): e0303748, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38809828

RESUMO

BACKGROUND: Overreaching is often linked to a deterioration in sleep quality, yet a comprehensive review is lacking. The aim of this systemic review and meta-analysis was to synthesise the literature and quantify the effect of overreaching from endurance-based training on sleep quality. METHOD: The review was conducted following the PRISMA guidelines. The final search was conducted in May 2023 using four electronic databases (Web of Science Core Collection, MEDLINE, Cochrane Central Database, SPORTDiscus). Studies were included for a qualitative review, while random-effects meta-analyses were conducted for objective and subjective sleep. RESULTS AND DISCUSSION: The search returned 805 articles. Fourteen studies were included in the systematic review; Three and eight articles were eligible for the meta-analyses (objective and subjective, respectively). On average, the overreaching protocols were sixteen days in length (6 to 28 days) and included exercise modalities such as cycling (number of studies [k] = 5), rowing (k = 4), triathlon (k = 3), running (k = 2), and swimming (k = 1). Actigraphy was the only form of objective sleep measurement used across all studies (k = 3), while various instruments were used to capture subjective sleep quality (k = 13). When comparing objective sleep quality following the overreaching intervention to baseline (or a control), there was a significant reduction in sleep efficiency (mean difference = -2.0%; 95% CI -3.2, -0.8%; Glass' Δ = -0.83; p < 0.01). In contrast, when comparing subjective sleep quality following the overreaching intervention to baseline (or a control), there was no effect on subjective sleep quality (Glass' Δ = -0.27; 95% CI -0.79, 0.25; p = 0.08). Importantly, none of the included studies were judged to have a low risk of bias. While acknowledging the need for more high-quality studies, it appears that overreaching from endurance-based training can deteriorate objective sleep without influencing the perception of sleep quality. PROTOCOL REGISTRATION: This protocol was registered in The International Prospective Register of Systematic Reviews (PROSPERO) on 21st November 2022, with the registration number CRD42022373204.


Assuntos
Treino Aeróbico , Humanos , Treino Aeróbico/métodos , Sono/fisiologia , Qualidade do Sono , Resistência Física/fisiologia
17.
Geroscience ; 46(1): 597-607, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37880489

RESUMO

Frailty is characterized by an increased vulnerability to adverse health events. Executive function impairment is an early sign of progression towards cognitive impairments. Whether frailty is associated with executive function and the associated mechanisms are unclear. We test the hypothesis that higher frailty is associated with worse executive function (Trail Making Test) and if aerobic fitness, prefrontal cortex oxygenation (ΔO2Hb), or middle-cerebral artery velocity (MCAv) impact this association. Forty-one (38 females) cognitively health older adults (70.1 ± 6.3 years) completed a Trail task and 6-min walk test. Prefrontal cortex oxygenation was measured during the Trail task (via functional near-infrared spectroscopy) and MCAv in a sub-sample (n=26, via transcranial Doppler). A 35-item frailty index was used. Frailty was independently, non-linearly related to trail B performance (Frailty2: ß=1927 [95% CI: 321-3533], p = 0.02), with the model explaining 22% of the variance of trail B time (p = 0.02). Aerobic fitness was an independent predictor of trail B (ß=-0.05 [95% CI: -0.10-0.004], p = 0.04), but age and ΔO2Hb were not (both, p > 0.78). Frailty was positively associated with the difference between trails B and A (ß=105 [95% CI: 24-186], p = 0.01). Frailty was also associated with a higher peak MCAv (ρ = 0.40, p = 0.04), but lower ΔO2Hb-peakMCAv ratio (ρ = -0.44, p = 0.02). Higher frailty levels are associated to worse Trail times after controlling for age, aerobic fitness, and prefrontal oxygenation. High frailty level may disproportionately predispose older adults to challenges performing executive function tasks that may manifest early as a compensatory higher MCAv despite worse executive function, and indicate a greater risk of progressing to cognitive impairment.


Assuntos
Função Executiva , Fragilidade , Feminino , Humanos , Idoso , Estudos Transversais , Teste de Sequência Alfanumérica , Córtex Pré-Frontal
18.
Front Endocrinol (Lausanne) ; 15: 1408003, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952388

RESUMO

We present the case of a 36-year-old female who was diagnosed at birth with CHI that caused severe hypoglycaemia unresponsive to Diazoxide. Subtotal pancreatectomy was performed at the age of three weeks. Later, histological analysis of her pancreas in a research setting revealed a focal form of CHI. Genetic testing was not available at that time. The patient developed pancreatic exocrine deficiency and insulin-dependent diabetes at the age of 9 years. In 2016, a genetic test revealed a missense heterozygous variant in the ABCC8 gene inherited from her father and classified as having a recessive inheritance. The geneticist concluded that the risk of CHI for her offspring would be low (1/600), making pregnancy favourable. As there was no consanguinity in the family, testing the future father was deemed unnecessary (carrier frequency 1/150 in the general population). The pregnancy occurred spontaneously in 2020 and at a gestational age of 28 weeks, the mother went into premature labour. An emergency C-section was performed in April 2021 resulting in the birth of bichorial bi-amniotic male twins. Following birth, both newborns experienced persistent severe hypoglycaemia which required glucagon treatment and intravenous glucose infusion initially, followed by Diazoxide from day 51 after birth, without satisfactory response. Continuous intravenous Octreotide treatment was introduced on day 72. Due to the recurrence of hypoglycaemia episodes despite reaching maximum doses of Octreotide, from day 92 the treatment was switched to Pasireotide. Genetic tests revealed the same genotypes for both infants: the exon 39 missense variant (c.4716C>A; p.Ser1572Arg) inherited from their mother and a truncating variant in exon 28 (c.3550del; p.Val1184*), inherited from their asymptomatic father. As a result of inheriting two recessive variants of the ABCC8 gene, the children were diagnosed with a diffuse form of CHI, consistent with the diazoxide-unresponsive presentation. This situation is very rare outside consanguinity. This case emphasises the significance of genetic counselling for individuals with a history of rare diseases outside the context of consanguinity, as there is a potential risk of recurrence. Prenatal diagnosis can lead to better outcomes for affected neonates, as well as help families make informed decisions about future pregnancies.


Assuntos
Hiperinsulinismo Congênito , Humanos , Feminino , Hiperinsulinismo Congênito/genética , Hiperinsulinismo Congênito/tratamento farmacológico , Gravidez , Adulto , Recém-Nascido , Receptores de Sulfonilureias/genética , Masculino , Gêmeos Dizigóticos/genética
19.
Geroscience ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38722469

RESUMO

Cardiovascular endurance and muscular fitness seem to impact specific cognitive components in older females. However, it remains uncertain whether these relate to executive functions or if these correlations are limited to specific physical fitness indicators. This study aimed to determine the association between specific physical fitness components and executive functions in community-dwelling older females. Thirty-five cognitively healthy community-dwelling older females (71.5 ± 5.7 years) underwent a series of physical fitness tests. These included the handgrip strength test (HGT), the 6-min walk test (6MWT), the 8-foot up-and-go test (8FUGT), and the chair stand test (CST). Participants also completed trail A and trail B of the cognitive trail making test. Results showed that trail B reaction time had a negative association with both HGT (r = - 0.502; p = 0.002) and 6MWT (r = - 0.543; p < 0.001). Together, the HGT and 6MWT results explained 39% of the variation in trail B reaction times: HGT accounted for 18% and 6MWT for 21%. Better scores on the 6MWT and HGT-but not on the 8FUGT and CST-correlated with enhanced executive function in cognitively healthy community-dwelling older females. The results of this study underscore the importance of specific physical assessments, like the 6MWT and HGT, as potential indicators of executive function, offering targeted strategies for maintaining cognitive health in aging females.

20.
Sci Rep ; 14(1): 8003, 2024 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-38580840

RESUMO

Advancing age is associated with declines in cognitive function. Although physical activity is thought to protect against this decline, it is unclear how a short-term uptake in daily steps or a decline in day-to-day step variability may contribute to cognition among older adults. We tested associations between changes in step counts, day-to-day step variability and executive cognitive functions among older adults taking part in a physical activity intervention. Thirty-seven older adults (33 females; 71.4 ± 6.3 years) completed a 10-week personalized physical activity intervention. Participants wore a Fitbit to measure daily step counts throughout the study. They also completed a computerized Stroop task before and after the intervention. Average step counts and step count variability via average-real-variability (ARV) were determined. Compared to pre-intervention, step counts increased (p < 0.001) and step variability decreased post-intervention (p = 0.04). Models describing the changes in step counts and ARV over the 10-weeks were cubic (both, p < 0.04). Reaction times during the simple (p = 0.002) and switching (p = 0.04) conditions were faster post-intervention. Change in step variability was positively associated with the change in reaction time for the switching condition (ß = 0.029, p = 0.002). On average, a reduction in day-to-day step variability was associated with improvements in cognitive flexibility.


Assuntos
Cognição , Exercício Físico , Feminino , Humanos , Idoso , Teste de Stroop
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