Global Alliance for the Promotion of Physical Activity: the Hamburg Declaration.

Non-communicable diseases (NCDs), including coronary heart disease, stroke, hypertension, type 2 diabetes, dementia, depression and cancers, are on the rise worldwide and are often associated with a lack of physical activity (PA). Globally, the levels of PA among individuals are below WHO recommendations. A lack of PA can increase morbidity and mortality, worsen the quality of life and increase the economic burden on individuals and society. In response to this trend, numerous organisations came together under one umbrella in Hamburg, Germany, in April 2021 and signed the 'Hamburg Declaration'. This represented an international commitment to take all necessary actions to increase PA and improve the health of individuals to entire communities. Individuals and organisations are working together as the 'Global Alliance for the Promotion of Physical Activity' to drive long-term individual and population-wide behaviour change by collaborating with all stakeholders in the community: active hospitals, physical activity specialists, community services and healthcare providers, all achieving sustainable health goals for their patients/clients. The 'Hamburg Declaration' calls on national and international policymakers to take concrete action to promote daily PA and exercise at a population level and in healthcare settings.

Dissociated coupling between cerebral oxygen metabolism and perfusion in the prefrontal cortex during exercise: a NIRS study.

Purpose: The present study used near-infrared spectroscopy to investigate the relationships between cerebral oxygen metabolism and perfusion in the prefrontal cortex (PFC) during exercises of different intensities. Methods: A total of 12 recreationally active men (age 24 ± 6 years) were enrolled. They performed 17 min of low-intensity exercise (ExL), followed by 3 min of moderate-intensity exercise (ExM) at constant loads. Exercise intensities for ExL and ExM corresponded to 30% and 45% of the participants' heart rate reserve, respectively. Cardiovascular and respiratory parameters were measured. We used near-infrared time-resolved spectroscopy (TRS) to measure the cerebral hemoglobin oxygen saturation (ScO2) and total hemoglobin concentration ([HbT]), which can indicate the cerebral blood volume (CBV). As the cerebral metabolic rate for oxygen (CMRO2) is calculated using cerebral blood flow (CBF) and ScO2, we assumed a constant power law relationship between CBF and CBV based on investigations by positron emission tomography (PET). We estimated the relative changes in CMRO2 (rCMRO2) and CBV (rCBV) from the baseline. During ExL and ExM, the rate of perceived exertion was monitored, and alterations in the subjects' mood induced by exercise were evaluated using the Profile of Moods Scale-Brief. Results: Three minutes after exercise initiation, ScO2 decreased and rCMRO2 surpassed rCBV in the left PFC. When ExL changed to ExM, cardiovascular variables and the sense of effort increased concomitantly with an increase in [HbT] but not in ScO2, and the relationship between rCMRO2 and rCBV was dissociated in both sides of the PFC. Immediately after ExM, [HbT], and ScO2 increased, and the disassociation between rCMRO2 and rCBV was prominent in both sides of the PFC. While blood pressure decreased and a negative mood state was less prominent following ExM compared with that at rest, ScO2 decreased 15 min after exercise and rCMRO2 surpassed rCBV in the left PFC. Conclusion: Dissociated coupling between cerebral oxidative metabolism and perfusion in the PFC was consistent with the effort required for increased exercise intensity and associated with post-exercise hypotension and altered mood status after exercise. Our result demonstrates the first preliminary results dealing with the coupling between cerebral oxidative metabolism and perfusion in the PFC using TRS.

Estimation of Cerebral Hemodynamics and Oxygenation During Various Intensities of Rowing Exercise: An NIRS Study.

Purpose: This study aimed to investigate changes in cerebral hemodynamics and oxygenation at moderate, heavy, maximal and supramaximal intensities of rowing exercise. It also examined whether these changes reflect alterations in sensation of effort and mood. We also aimed to examine the effects of peak pulmonary oxygen consumption ( V . O2peak ) on cerebral oxygenation. Methods: Eleven rowers, consisting out of six athletes and five recreational rowers [two female; age, 27 ± 9 years; height, 171 ± 7 cm, body mass, 67 ± 9 kg; V . O2peak , 53.5 ± 6.5 mL min-1 kg-1] rowed a 13-min session separated by 10 and 3 min, at 70 (Ex70%) and 80% of V . O2peak (Ex80%), respectively, on a rowing ergometer, followed by three sessions of 1-min supramaximal exercise (ExSp). After a warm-up at 60% of V . O2peak (ExM), seven male rowers performed a 2,000 m all-out test (Ex2000). Cardiovascular and respiratory variables were measured. Cerebral oxygenation was investigated by near-infrared time-resolved spectroscopy (TRS) to measure cerebral hemoglobin oxygen saturation (ScO2) and total hemoglobin concentration ([HbT]) in the prefrontal cortex (PFC) quantitatively. We estimated the relative changes from rest in cerebral metabolic rate for oxygen (rCMRO2) using TRS at all intensities. During Ex70% and Ex80%, ratings of perceived exertion (RPE) were monitored, and alteration of the subject's mood was evaluated using a questionnaire of Positive-and-Negative-Affect-Schedule after Ex70% and Ex80%. Results: When exercise intensity changed from Ex70% to Ex80%, the sense of effort increased while ScO2 decreased. [HbT] remained unchanged. After Ex70% and Ex80%, a negative mood state was less prominent compared to rest and was accompanied by increases in both ScO2 and [HbT]. At termination of Ex2000, ScO2 decreased by 23% compared to rest. Changes in ScO2 correlated with V . O2peak only during Ex2000 (r = -0.86; p = 0.01). rCMRO2 did not decrease at any intensities. Conclusion: Our results suggest that alterations in the sense of effort are associated with oxygenation in the PFC, while positive changes in mood status are associated with cerebral perfusion and oxygen metabolism estimated by TRS. At exhaustion, the cerebral metabolic rate for oxygen is maintained despite a decrease in ScO2.

Dynamic Exercise Elicits Dissociated Changes Between Tissue Oxygenation and Cerebral Blood Flow in the Prefrontal Cortex: A Study Using NIRS and PET.

Neuronal activity causes changes in both cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF). Since the relationship between tissue oxygenation and regional CBF (rCBF) during exercise has not been elucidated, we compared the data obtained using near-infrared spectroscopy (NIRS) and rCBF examined using positron emission tomography (PET). Participants in this study comprised 26 healthy young men. Changes in concentration of oxygenated hemoglobin (ΔO2Hb) and deoxygenated hemoglobin (ΔHHb) in the prefrontal cortex (PFC) were measured using NIRS continuously during a 15-min bout of the constant-load low-intensity cycling exercise (n = 14). Under the same protocol as the NIRS study, rCBF was measured using H215O and PET by the autoradiographic method at baseline (Rest) and at 3 min (Ex1) and 13 min (Ex2) after starting exercise (n = 12). As systematic factors influenced by exercise, heart rate, end-tidal pressure of carbon dioxide (PETCO2) and blood pressure (BP) were monitored. For each region investigated by NIRS, rCBF was analyzed quantitatively using PET-MRI co-registered standardized images. Despite inter-individual differences, changing patterns of ΔO2Hb and ΔHHb in the PFC were similar between channels. Significant main effects for time point were identified in ΔO2Hb, ΔHHb and changes in rCBF. While rCBF increased from rest, ΔO2Hb was not changed at Ex1. Conversely, rCBF was unchanged from rest but ΔO2Hb was significantly increased at Ex2. Fluctuations of PETCO2 and BP evoked by exercise were not in accordance with changes in ΔO2Hb, ΔHHb and rCBF, while BP may affect the forehead skin blood flow. Given that NIRS data are a mixture of skin and brain effects, our results suggest that CMRO2 may differ between the phases in a bout of dynamic exercise. The present study indicates the utility of NIRS to examine the relationship between CMRO2 and rCBF during exercise.

Response of Cerebral Blood Flow and Blood Pressure to Dynamic Exercise: A Study Using PET.

Dynamic exercise elicits fluctuations in blood pressure (BP) and cerebral blood flow (CBF). This study investigated responses in BP and CBF during cycling exercise and post-exercise hypotension (PEH) using positron emission tomography (PET). CBF was measured using oxygen-15-labeled water (H215O) and PET in 11 human subjects at rest (Rest), at the onset of exercise (Ex1), later in the exercise (Ex2), and during PEH. Global CBF significantly increased by 13% at Ex1 compared with Rest, but was unchanged at Ex2 and during PEH. Compared with at Rest, regional CBF (rCBF) increased at Ex1 (20~42%) in the cerebellar vermis, sensorimotor cortex for the bilateral legs (M1Leg and S1Leg), insular cortex and brain stem, but increased at Ex2 (28~31%) only in the vermis and M1Leg and S1Leg. During PEH, rCBF decreased compared with Rest (8~13%) in the cerebellum, temporal gyrus, piriform lobe, thalamus and pons. The areas showing correlations between rCBF and mean BP during exercise and PEH were consistent with the central autonomic network, including the brain stem, cerebellum, and hypothalamus (R2=0.25-0.64). The present study suggests that higher brain regions are coordinated through reflex centers in the brain stem in order to regulate the cardiovascular response to exercise.

Central µ-Opioidergic System Activation Evoked by Heavy and Severe-Intensity Cycling Exercise in Humans: a Pilot Study Using Positron Emission Tomography with 11C-Carfentanil.

The central opioid receptor system likely contributes to the mechanism underlying the changes in affect elicited by exercise. Our aim was to use positron emission tomography (PET) to test whether exercise intensity influences activation of the µ-opioid receptor system in the brain, and whether changes in opioid receptor activation correlate with exercise-induced changes in affect. 7 healthy young male subjects (23±2 years) performed 20-min constant-load cycling exercises at heavy (ExH) and severe-intensity (ExS), and PET was performed using [11C]carfentanil as a tracer before and after each exercise. Exercise elicited the µ-opioidergic system activation in the large areas of the limbic system, particularly in the insular cortex, and cerebellum. Of note, deactivation of the µ-opioidergic system in the pituitary gland was identified as a specific finding in ExS, which evoked a distinctive sensation of fatigue. Within these brain areas, µ-opioid receptor activation correlated positively with increased positive affect (R2=0.67-0.95) in ExH and negative affect (R2=0.63-0.77) in ExS. These findings suggest that central µ-opioidergic neurotransmission evoked by continuous exercise is discriminated by work intensity. Notably, we also observed a possible contribution of the central µ-opioidergic system to the development of the sensation of fatigue during exhaustive exercise.

Test-retest variability of adenosine A2A binding in the human brain with (11)C-TMSX and PET.

BACKGROUND: The goal of the present study was to evaluate the reproducibility of cerebral adenosine A2A receptor (A2AR) quantification using (11)C-TMSX and PET in a test-retest study. METHODS: Five healthy volunteers were studied twice. The test-retest variability was assessed for distribution volume (V T) and binding potential relative to non-displaceable uptake (BPND) based on either metabolite-corrected arterial blood sampling or a reference region. The cerebral cortex and centrum semiovale were used as candidate reference regions. RESULTS: Test-retest variability of V T was good in all regions (6% to 13%). In the putamen, BPND using the centrum semiovale displayed a lower test-retest variability (3%) than that of BPND using the cerebral cortex as a reference region (5%). The noninvasive method showed a higher or similar level of test-retest reproducibility compared to the invasive method. CONCLUSIONS: Binding reproducibility is sufficient to use (11)C-TMSX as a tool to measure the change in A2AR in the human brain.

Changes in cerebral blood flow during steady-state cycling exercise: a study using oxygen-15-labeled water with PET.

Cerebral blood flow (CBF) during dynamic exercise has never been examined quantitatively using positron emission tomography (PET). This study investigated changes in CBF that occur over the course of a moderate, steady-state cycling exercise. Global and regional CBF (gCBF and rCBF, respectively) were measured using oxygen-15-labeled water (H(2)(15)O) and PET in 10 healthy human subjects at rest (Rest), at the onset of exercise (Ex1) and at a later phase in the exercise (Ex2). At Ex1, gCBF was significantly (P<0.01) higher (27.9%) than at Rest, and rCBF was significantly higher than at Rest in the sensorimotor cortex for the bilateral legs (M1(Leg) and S1(Leg)), supplementary motor area (SMA), cerebellar vermis, cerebellar hemispheres, and left insular cortex, with relative increases ranging from 37.6% to 70.5%. At Ex2, gCBF did not differ from Rest, and rCBF was significantly higher (25.9% to 39.7%) than at Rest in only the M1(Leg), S1(Leg), and vermis. The areas showing increased rCBF at Ex1 were consistent with the central command network and the anatomic pathway for interoceptive stimuli. Our results suggest that CBF increases at Ex1 in parallel with cardiovascular responses then recovers to the resting level as the steady-state exercise continues.

Initial human PET studies of metabotropic glutamate receptor type 1 ligand 11C-ITMM.

UNLABELLED: N-[4-[6-(isopropylamino)pyrimidin-4-yl]-1,3-thiazol-2-yl]-4-(11)C-methoxy-N-methylbenzamide ((11)C-ITMM) is a potential radioligand for mapping metabotropic glutamate receptor type 1 (mGluR1) in the brain by PET. The present study was performed to determine the safety, distribution, radiation dosimetry, and initial brain imaging of (11)C-ITMM in healthy human subjects. METHODS: The multiorgan biodistribution and radiation dosimetry of (11)C-ITMM were assessed in 3 healthy human subjects, who underwent 2-h whole-body PET scans. Radiation dosimetry was estimated from the normalized number of disintegrations of source organs using the OLINDA/EXM program. Five healthy human subjects underwent 90-min dynamic (11)C-ITMM scans of brain regions with arterial blood sampling. For anatomic coregistration, T1-weighted MR imaging was performed. Metabolites in plasma and urine samples were analyzed by high-performance liquid chromatography. (11)C-ITMM uptake was assessed quantitatively using a 2-tissue-compartment model. RESULTS: There were no serious adverse events in any of the subjects throughout the study period. (11)C-ITMM PET demonstrated high uptake in the urinary bladder and gallbladder, indicating both urinary and fecal excretion of radioactivity. The absorbed dose (µGy/MBq) was highest in the urinary bladder wall (13.2 ± 3.5), small intestine (9.8 ± 1.7), and liver (9.1 ± 2.0). The estimated effective dose for (11)C-ITMM was 4.6 ± 0.3 µSv/MBq. (11)C-ITMM showed a gradual increase of radioactivity in the cerebellar cortex. The total distribution volume in the brain regions ranged from 2.61 ± 0.30 (cerebellar cortex) to 0.52 ± 0.17 (pons), and the rank order of the corresponding total distribution volume of (11)C-ITMM was cerebellar cortex > thalamus > frontal cortex > striatum ≈ pons, which was consistent with the known distribution of mGluR1 in the primate brain. The rate of (11)C-ITMM metabolism in plasma was moderate: at 60 min after injection, 62.2% ± 8.2% of the radioactivity in plasma was intact parent compound. CONCLUSION: The initial findings of the present study indicated that (11)C-ITMM PET is feasible for imaging of mGluR1 in the brain. The low effective dose will permit serial examinations in the same subjects.

PET molecular imaging to investigate higher brain dysfunction in patients with neurotrauma.

INTRODUCTION: Many neurotrauma patients suffer from higher brain dysfunction even when focal brain damage is not detected with MRI. We performed functional imaging with positron emission tomography (PET) to clarify the relationship between the functional deficit and symptoms of such patients. METHODS: Patients who complain of higher brain dysfunction without apparent morphological cortical damage were recruited. Thirteen patients underwent PET study to image glucose metabolism by (18)F-FDG, and central benzodiazepine receptor (cBZD-R) by (11)C-flumazenil, together with measurement of cognition. RESULTS: Diffuse axonal injury (DAI) patients have a significant decrease in glucose metabolism and cBZD-R distribution in the cingulated cortex than normal controls. Score of cognition test was variable among patients. The degree of decreased glucose metabolism and cBZD-R in the dominant hemisphere corresponded well to the severity of cognitive disturbance. Patients with a milder type of diffuse brain injury (i.e., cerebral concussion) also showed abnormal glucose metabolism and cBZD-R distribution when they suffered from cognitive deficit. CONCLUSION: PET molecular imaging was useful for depicting the cortical dysfunction of neurotrauma patients even when morphological change was not apparent. This method may be promising in clarifying the pathophysiology of higher brain dysfunction of patients with neurotrauma, but without morphological abnormality.

[Carotid plaque assessment using inversion recovery T1 weighted-3 dimensions variable refocus flip angle turbo spin echo sampling perfection with application optimized contrast using different angle evolutions black blood imaging].

Vulnerable plaque can be attributed to induction of ischemic symptoms and magnetic resonance imaging of carotid artery is valuable to detect the plaque. Magnetization prepared rapid acquisition with gradient echo (MPRAGE) method could detect hemorrhagic vulnerable plaque as high intensity signal; however, blood flow is not sufficiently masked by this method. The contrast for plaque in T1 weighted image (T1WI) could not be obtained sufficiently with black blood image (BBI) by sampling perfection with application optimized contrast using different angle evolutions (SPACE) method as turbo spin echo (TSE). In addition, an appearance of artifact by slow flow is a problem. Considering these controversial situations in plaque imaging, we examined the modified BBI inversion recovery (IR)-SPACE in which IR was added for SPACE method so that the contrast for plaque in T1WI was optimized. We investigated the application of this method in plaque imaging. As a result of phantom imaging, the contrast for plaque in T1WI was definitely obtained by choosing an appropriate inversion time (TI) for the corresponding repetition time. In clinical cases, blood flow was sufficiently masked by IR-SPACE method and the plaque imaging was clearly obtained in clinical cases to the same extent as MPRAGE method. Since BBI with IR-SPACE method was derived from both IR pulse and flow void effect, this method could obtain the blood flow masking effect definitely. The present study suggested that SPACE method might be applicable to estimate properties of carotid artery plaque.

Memory deficits due to brain injury: unique PET findings and dream alterations.

The authors herein report the case of a young male with memory deficits due to a traumatic head injury, who presented with sleep-related symptoms such as hypersomnia and dream alterations. Although MRI and polysomnography showed no abnormalities, (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) and (11)C flumazenil (FMZ)-PET revealed findings consistent with cerebral damage to the affected temporal region. The memory deficit of the patient gradually improved in parallel with the relief of the sleep-related symptoms. FDG-PET showed considerable improvement in glucose metabolism when he had recovered, however, evidence of neural loss remained in the FMZ-PET findings.

Cerebral oxygenation in the frontal lobe cortex during incremental exercise tests: the regional changes influenced by volitional exhaustion.

The present study examined the regional differences of cortical oxygenation in the frontal lobe by near-infrared spectroscopy (NIRS) during incremental exercise tests and the precise location of NIRS was examined by brain magnetic resonance imaging (MRI). Pulmonary gas exchange and NIRS measurement during incremental cycling ergometry tests were investigated in 14 men. In 7 of these subjects, the right middle cerebral artery mean velocity (MCA Vmean) was simultaneously measured by transcranial Doppler (TCD). In the right medial of the frontal lobe cortex, Tissue Oxygenation Index (TOI) increased by 8.8% with its peak value at respiratory compensation threshold (RCT) and Normalized Tissue Hemoglobin Index (nTHI) increased until endpoint by 16.2%. During incremental exercise tests, the changing pattern of TOI was different according to the distribution of the probes. Volitional exhaustion by exercise induced the deteriorated TOI and MCA Vmean, whereas nTHI increased.