Cerebral oxygenation and metabolism during exercise following three months of endurance training in healthy overweight males

2009 ◽  
Vol 297 (3) ◽  
pp. R867-R876 ◽  
Author(s):  
T. Seifert ◽  
P. Rasmussen ◽  
P. Brassard ◽  
P. H. Homann ◽  
M. Wissenberg ◽  
...  
Keyword(s):  
Endurance Training ◽  
Cerebral Oxygenation ◽  
Metabolic Response ◽  
Cardiovascular Fitness ◽  
Submaximal Exercise ◽  
Controlled Study ◽  
Venous Catheterization ◽  
The Brain ◽  
Epinephrine Concentration

Endurance training improves muscular and cardiovascular fitness, but the effect on cerebral oxygenation and metabolism remains unknown. We hypothesized that 3 mo of endurance training would reduce cerebral carbohydrate uptake with maintained cerebral oxygenation during submaximal exercise. Healthy overweight males were included in a randomized, controlled study (training: n = 10; control: n = 7). Arterial and internal jugular venous catheterization was used to determine concentration differences for oxygen, glucose, and lactate across the brain and the oxygen-carbohydrate index [molar uptake of oxygen/(glucose + ½ lactate); OCI], changes in mitochondrial oxygen tension (ΔPMitoO2) and the cerebral metabolic rate of oxygen (CMRO2) were calculated. For all subjects, resting OCI was higher at the 3-mo follow-up (6.3 ± 1.3 compared with 4.7 ± 0.9 at baseline, mean ± SD; P < 0.05) and coincided with a lower plasma epinephrine concentration ( P < 0.05). Cerebral adaptations to endurance training manifested when exercising at 70% of maximal oxygen uptake (∼211 W). Before training, both OCI (3.9 ± 0.9) and ΔPMitoO2 (−22 mmHg) decreased ( P < 0.05), whereas CMRO2 increased by 79 ± 53 micromol·100·g−1 min−1 ( P < 0.05). At the 3-mo follow-up, OCI (4.9 ± 1.0) and ΔPMitoO2 (−7 ± 13 mmHg) did not decrease significantly from rest and when compared with values before training ( P < 0.05), CMRO2 did not increase. This study demonstrates that endurance training attenuates the cerebral metabolic response to submaximal exercise, as reflected in a lower carbohydrate uptake and maintaind cerebral oxygenation.

Cerebral blood flow and metabolism during exercise: implications for fatigue

2008 ◽  
Vol 104 (1) ◽  
pp. 306-314 ◽  
Author(s):  
Neils H. Secher ◽  
Thomas Seifert ◽  
Johannes J. Van Lieshout
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Perceived Exertion ◽  
Cerebral Oxygenation ◽  
Metabolic Response ◽  
Work Of Breathing ◽  
Whole Body ◽  
Strenuous Exercise ◽  
Glycogen Depletion ◽  
The Brain

During exercise: the Kety-Schmidt-determined cerebral blood flow (CBF) does not change because the jugular vein is collapsed in the upright position. In contrast, when CBF is evaluated by 133Xe clearance, by flow in the internal carotid artery, or by flow velocity in basal cerebral arteries, a ∼25% increase is detected with a parallel increase in metabolism. During activation, an increase in cerebral O2 supply is required because there is no capillary recruitment within the brain and increased metabolism becomes dependent on an enhanced gradient for oxygen diffusion. During maximal whole body exercise, however, cerebral oxygenation decreases because of eventual arterial desaturation and marked hyperventilation-related hypocapnia of consequence for CBF. Reduced cerebral oxygenation affects recruitment of motor units, and supplemental O2 enhances cerebral oxygenation and work capacity without effects on muscle oxygenation. Also, the work of breathing and the increasing temperature of the brain during exercise are of importance for the development of so-called central fatigue. During prolonged exercise, the perceived exertion is related to accumulation of ammonia in the brain, and data support the theory that glycogen depletion in astrocytes limits the ability of the brain to accelerate its metabolism during activation. The release of interleukin-6 from the brain when exercise is prolonged may represent a signaling pathway in matching the metabolic response of the brain. Preliminary data suggest a coupling between the circulatory and metabolic perturbations in the brain during strenuous exercise and the ability of the brain to access slow-twitch muscle fiber populations.

scholarly journals Cerebral metabolic response to submaximal exercise

1999 ◽  
Vol 87 (5) ◽  
pp. 1604-1608 ◽  
Author(s):  
Kojiro Ide ◽  
Allan Horn ◽  
Niels H. Secher
Keyword(s):  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Metabolic Response ◽  
Molar Ratio ◽  
Moderate Exercise ◽  
Lactate Metabolism ◽  
Low Intensity ◽  
Norepinephrine Spillover ◽  
Low Intensity Exercise ◽  
The Brain

We studied cerebral oxygenation and metabolism during submaximal cycling in 12 subjects. At two work rates, middle cerebral artery blood velocity increased from 62 ± 3 to 63 ± 3 and 70 ± 5 cm/s as did cerebral oxygenation determined by near-infrared spectroscopy. Oxyhemoglobin increased by 10 ± 3 and 25 ± 3 μmol/l ( P < 0.01), and there was no significant change in brain norepinephrine spillover. The arterial-to-internal-jugular-venous (a-v) difference for O2 decreased at low-intensity exercise (from 3.1 ± 0.1 to 2.9 ± 0.1 mmol/l; P < 0.05) and recovered at moderate exercise (to 3.3 ± 0.1 mmol/l). The profile for glucose was similar: its a-v difference tended to decrease at low-intensity exercise (from 0.55 ± 0.05 to 0.50 ± 0.02 mmol/l) and increased during moderate exercise (to 0.64 ± 0.04 mmol/l; P < 0.05). Thus the molar ratio (a-v difference, O2 to glucose) did not change significantly. However, when the a-v difference for lactate (0.02 ± 0.03 to 0.18 ± 0.04 mmol/l) was taken into account, the O2-to-carbohydrate ratio decreased (from 6.1 ± 0.4 to 4.7 ± 0.3; P < 0.05). The enhanced cerebral oxygenation suggests that, during exercise, cerebral blood flow increases in excess of the O2demand. Yet it seems that during exercise not all carbohydrate taken up by the brain is oxidized, as brain lactate metabolism appears to lower the balance of O2-to-carbohydrate uptake.

scholarly journals Childhood Leukemia Survivors and Metabolic Response to Exercise: A Pilot Controlled Study

2020 ◽  
Vol 9 (2) ◽  
pp. 562 ◽  
Author(s):  
Charline Pegon ◽  
Emmanuelle Rochette ◽  
Nadège Rouel ◽  
Bruno Pereira ◽  
Eric Doré ◽  
...  
Keyword(s):  
Heart Rate ◽  
Childhood Leukemia ◽  
Metabolic Response ◽  
Tanner Stage ◽  
Fat Oxidation ◽  
Submaximal Exercise ◽  
Controlled Study ◽  
Healthy Children ◽  
Oxidation Rates ◽  
Response To Exercise

Background: Leukemia is the most common cancer in pediatrics, with many late effects such as higher risk of dyslipidemia, insulin resistance, obesity, and metabolic syndrome. The objective of this work was to investigate substrate oxidation during submaximal exercise in survivors of childhood acute leukemia. Methods: A total of 20 leukemia survivors and 20 healthy children were matched by sex, age, and Tanner stage. They all took a submaximal incremental exercise test to determine fat and carbohydrate oxidation rates. Results: Cardiorespiratory fitness was significantly lower in leukemia survivors, with lower relative VO2 peaks (p < 0.001), lower heart rate values (p = 0.02), and lower exercise power (p = 0.012), whereas rest metabolism and body mass index did not differ between the two groups. During exercise, upward of heart rate relative to VO2 peak was significantly higher (p < 0.001) in childhood leukemia survivors. We found lower carbohydrate and fat oxidation rates (p = 0.07) in leukemia survivors compared with healthy children, and also a significantly lower relative maximal fat oxidation rate (p = 0.014). Conclusion: Despite impaired physical fitness and metabolic response to exercise, childhood leukemia survivors remained sensitive to physical activity interventions, and could readily adapt to submaximal exercise intensity.

Longitudinal Changes in Individual BrainAGE in Healthy Aging, Mild Cognitive Impairment, and Alzheimer’s Disease

GeroPsych ◽  
2012 ◽  
Vol 25 (4) ◽  
pp. 235-245 ◽  
Author(s):  
Katja Franke ◽  
Christian Gaser
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Healthy Aging ◽  
Brain Aging ◽  
Elderly Subjects ◽  
Additional Increase ◽  
Longitudinal Changes ◽  
Novel Method ◽  
The Brain

We recently proposed a novel method that aggregates the multidimensional aging pattern across the brain to a single value. This method proved to provide stable and reliable estimates of brain aging – even across different scanners. While investigating longitudinal changes in BrainAGE in about 400 elderly subjects, we discovered that patients with Alzheimer’s disease and subjects who had converted to AD within 3 years showed accelerated brain atrophy by +6 years at baseline. An additional increase in BrainAGE accumulated to a score of about +9 years during follow-up. Accelerated brain aging was related to prospective cognitive decline and disease severity. In conclusion, the BrainAGE framework indicates discrepancies in brain aging and could thus serve as an indicator for cognitive functioning in the future.

Comparison of Fluorine(18)-fluorodeoxyglucose and Gallium(68)-citrate PET/CT in patients with tuberculosis

2019 ◽  
Vol 58 (05) ◽  
pp. 371-378
Author(s):  
Alfred O. Ankrah ◽  
Ismaheel O. Lawal ◽  
Tebatso M.G. Boshomane ◽  
Hans C. Klein ◽  
Thomas Ebenhan ◽  
...  
Keyword(s):  
Tracer Uptake ◽  
Pet Ct ◽  
The Mean ◽  
18F Fdg ◽  
Definition Of ◽  
Gallium 68 ◽  
Attending Physician ◽  
Pet Scans ◽  
The Brain

Abstract 18F-FDG and 68Ga-citrate PET/CT have both been shown to be useful in the management of tuberculosis (TB). We compared the abnormal PET findings of 18F-FDG- and 68Ga-citrate-PET/CT in patients with TB. Methods Patients with TB on anti-TB therapy were included. Patients had a set of PET scans consisting of both 18F-FDG and 68Ga-citrate. Abnormal lesions were identified, and the two sets of scans were compared. The scan findings were correlated to the clinical data as provided by the attending physician. Results 46 PET/CT scans were performed in 18 patients, 11 (61 %) were female, and the mean age was 35.7 ± 13.5 years. Five patients also had both studies for follow-up reasons during the use of anti-TB therapy. Thirteen patients were co-infected with HIV. 18F-FDG detected more lesions than 68Ga-citrate (261 vs. 166, p < 0.0001). 68Ga-citrate showed a better definition of intracerebral lesions due to the absence of tracer uptake in the brain. The mean SUVmax was higher for 18F-FDG compared to 68Ga-citrate (5.73 vs. 3.01, p < 0.0001). We found a significant correlation between the SUVmax of lesions that were determined by both tracers (r = 0.4968, p < 0.0001). Conclusion Preliminary data shows 18F-FDG-PET detects more abnormal lesions in TB compared to 68Ga-citrate. However, 68Ga-citrate has better lesion definition in the brain and is therefore especially useful when intracranial TB is suspected.

Brain FDG PET for the Etiological Diagnosis of Clinically Uncertain Cognitive Impairment During Delirium in Remission

2020 ◽  
Vol 77 (4) ◽  
pp. 1609-1622
Author(s):  
Franziska Mathies ◽  
Catharina Lange ◽  
Anja Mäurer ◽  
Ivayla Apostolova ◽  
Susanne Klutmann ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Fdg Pet ◽  
False Negative ◽  
Ground Truth ◽  
Etiological Diagnosis ◽  
Geriatric Unit ◽  
Positron Emission ◽  
The Brain ◽  
Hospitalized Geriatric Patients

Background: Positron emission tomography (PET) of the brain with 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG) is widely used for the etiological diagnosis of clinically uncertain cognitive impairment (CUCI). Acute full-blown delirium can cause reversible alterations of FDG uptake that mimic neurodegenerative disease. Objective: This study tested whether delirium in remission affects the performance of FDG PET for differentiation between neurodegenerative and non-neurodegenerative etiology of CUCI. Methods: The study included 88 patients (82.0±5.7 y) with newly detected CUCI during hospitalization in a geriatric unit. Twenty-seven (31%) of the patients were diagnosed with delirium during their current hospital stay, which, however, at time of enrollment was in remission so that delirium was not considered the primary cause of the CUCI. Cases were categorized as neurodegenerative or non-neurodegenerative etiology based on visual inspection of FDG PET. The diagnosis at clinical follow-up after ≥12 months served as ground truth to evaluate the diagnostic performance of FDG PET. Results: FDG PET was categorized as neurodegenerative in 51 (58%) of the patients. Follow-up after 16±3 months was obtained in 68 (77%) of the patients. The clinical follow-up diagnosis confirmed the FDG PET-based categorization in 60 patients (88%, 4 false negative and 4 false positive cases with respect to detection of neurodegeneration). The fraction of correct PET-based categorization did not differ between patients with delirium in remission and patients without delirium (86% versus 89%, p = 0.666). Conclusion: Brain FDG PET is useful for the etiological diagnosis of CUCI in hospitalized geriatric patients, as well as in patients with delirium in remission.

Severe Head Injury linked to Subsequent Development of Malignant Brain Tumour within a Short Period- A Case Report

2018 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Head Injury ◽  
Brain Tumour ◽  
Severe Head Injury ◽  
Case Reports ◽  
Subsequent Development ◽  
Malignant Brain Tumour ◽  
Tumour Development ◽  
Short Period ◽  
The Brain

There have been a few case reports of head injury leading to brain tumour development in the same region as the brain injury. Here we report a case where the patient suffered a severe head injury with contusion. He recovered clinically with conservative management. Follow up Computed Tomography scan of the brain a month later showed complete resolution of the lesion. He subsequently developed malignant brain tumour in the same region as the original contusion within a very short period of 15 months. Head injury patients need close follow up especially when severe. The link between severity of head injury and malignant brain tumour development needs further evaluation. Role of anti-inflammatory agents for prevention of post traumatic brain tumours needs further exploration.

Topical Bimatoprost Insert for Primary Open-Angle Glaucoma and Ocular Hypertension Treatment - A Phase II Controlled Study

2021 ◽  
Vol 18 ◽  
Author(s):  
Francine Rubião ◽  
Alan Cezar Faria Araújo ◽  
João Bernardo Sancio ◽  
Bárbara Silva Nogueira ◽  
Juçara Ribeiro Franca ◽  
...  
Keyword(s):  
Ocular Hypertension ◽  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
T Test ◽  
Controlled Study ◽  
Therapeutic Drug ◽  
Eye Drops ◽  
Open Angle ◽  
Drug Concentrations

Background: The most common treatment for primary open-angle glaucoma (POAG) is the daily use of eye drops. Sustained-release drug delivery systems have been developed to improve patient adherence by achieving prolonged therapeutic drug concentrations in ocular target tissues while limiting systemic exposure. The purpose of this study is to compare the efficacy and safety of bimatoprost inserts with bimatoprost eye drops in patients with POAG and ocular hypertension (OH). Methods: We include OH and POAG patients aged between 40 and 75 years-old. Both OH and POAG patients had intraocular pressure (IOP) greater than 21 and ≤30 mmHg at 9:00 am without glaucoma medication and normal biomicroscopy. Five normal patients with IOP≤14 mmHg constitute the control group. A chitosan-based insert of bimatoprost was placed at the upper conjunctival fornix of the right eye. In the left eye, patients used one drop of LumiganTM daily at 10:00 pm. For statistical analysis, we used a two-way analysis of variance (ANOVA), Student t-test, and paired t-test. Results: Sixteen POAG and 13 OH patients with a mean age of 61 years were assessed. In both eyes, IOP reduction was similar during three weeks of follow-up (19.5±2.2 mmHg and 16.9±3.1 mmHg), insert, and eye drop, respectively; P=0.165). The percentage of IOP reduction in the third week was 30% for insert and 35% for eye drops (P=0.165). No intolerance or discomfort with the insert was reported. Among the research participants, 58% preferred the use of the insert while 25% preferred eye drops, and 17% reported no preference. Conclusions: Bimatoprost-loaded inserts showed similar efficacy to daily bimatoprost eye drops during three weeks of follow up, without major side effects. This might suggest a possible change in the daily therapeutic regimen for the treatment of POAG and OH.

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