Papers by mauro Marzorati
Research Square (Research Square), Apr 1, 2020
Background Late onset Pompe disease (LOPD) is a lysosomal neuromuscular disorder which can progre... more Background Late onset Pompe disease (LOPD) is a lysosomal neuromuscular disorder which can progressively impair the patients' exercise tolerance, motor and respiratory functions, and quality of life. The available enzyme replacement therapy (ERT) does not completely counteract disease progression. We investigated the effect of exercise training alone, or associated with a high-protein diet, on the exercise tolerance, muscle and pulmonary functions, and quality of life of LOPD patients on long term ERT. Methods The patients were asked to participate to a crossover randomized study comprehending a control period (free diet, no exercise) followed by 2 intervention periods: exercise or exercise+ diet , each lasting 26 weeks and separated by 13 weeks washout periods. Exercise training included moderate-intensity aerobic exercise on a cycle ergometer, stretching and balance exercises, strength training. The diet was composed by 25-30% protein, 30-35% carbohydrate and 35-40% fat. Before and after each period patients were assessed for: exercise tolerance test on a cycle-ergometer, serum muscle enzymes, pulmonary function tests and SF36 questionnaire for quality of life. Compliance was evaluated by training and dietary diaries. Patients were contacted weekly by researchers to optimize adherence to treatments. Results Thirteen LOPD patients, median age 49 ± 11 years, under chronic ERT (median 6.0± 4.0 years) were recruited. Peak aerobic power (peak pulmonary O 2 uptake) decreased after control , whereas it increased after exercise, and more markedly after exercise+diet. Serum levels of lactate dehydrogenase (LDH) significantly decreased after exercise+diet; both creatine kinase (CK) and LDH levels were significantly reduced after exercise+diet compared to exercise. Pulmonary function showed no changes after control and exercise , whereas a significant improvement of forced expiratory volume in one second (FEV1) was observed after exercise+diet. SF36 showed a slight improvement in the "mental component" scale after exercise , and a significant improvement in "general health" and "vitality" after exercise+diet. The compliance to prescriptions was higher than70% for both diet and exercise. Conclusions Exercise tolerance (as evaluated by peak aerobic power) showed a tendency to decrease 4 in LOPD patients on long term ERT. Exercise training, particularly if combined with high-protein diet, could reverse this decrease and result in an improvement, which was accompanied by improved quality of life. The association of the two lifestyle interventions resulted also in a reduction of muscle enzyme levels and improved pulmonary function.
Frontiers in Physiology, Jun 7, 2023
Editorial on the Research Topic Strategies to fight exercise intolerance in neuromuscular disorde... more Editorial on the Research Topic Strategies to fight exercise intolerance in neuromuscular disorders, volume II We are delighted to be Editors of the second volume of this Research Topic. In the first Research Topic, our conclusion focused on the need for a new cultural approach among clinicians and researchers to the use of exercise and diet as a safe and appropriate ways to fight neuromuscular diseases (NMD), in order to provide suitable care for children and adults (Lanfranconi et al., 2020). We can again raise our voice to other researchers who want to fill the knowledge gap, from cellular mechanisms to system disorders, and find concrete caretaking solutions for patients with NMD, in a strategy of constant close crosstalk between clinicians and exercise physiologists. Overall, although some progress has been made in recent years, people with NMD continue to die earlier, have poorer health and experience more limitations in everyday functioning than others. These outcomes are also due to inequities faced by people with disabilities in all aspects of life, including the health system itself and access to physical activity programmes. Indeed, the lack of equity for people with motor disabilities is a matter of concern for authorities as stated by the World Health Organization (2022) Global report on health equity for persons with disability," and a source of great frustration for the individual and their family. As is well known, the aetiology of NMD can be inherited or acquired, acute and transient or chronic, degenerative or non-degenerative. The spectrum of clinical manifestations is very broad, but inevitably results in reduced exercise tolerance (Lanfranconi et al., 2020), impaired skeletal muscle oxidative metabolism (McDonald et al., 1995) and weakness (van der Kooi et al., 2005). The ultimate tragic outcome is an extraordinary challenge to the resilience of those affected, from childhood to adulthood and into the last part of their lives.
European Journal of Applied Physiology, Oct 15, 2020
Purpose High altitude results in lower barometric pressure and hence partial pressure of O 2 decr... more Purpose High altitude results in lower barometric pressure and hence partial pressure of O 2 decrease can lead to several molecular and cellular changes, such as generation of reactive oxygen species (ROS). Electron Paramagnetic Resonance technique was adopted in the field, to evaluate the effects of acute and sub-acute hypobaric hypoxia (HH) on ROS production by micro-invasive method. Biological biomarkers, indicators of oxidative stress, renal function and inflammation were investigated too. Methods Fourteen lowlander subjects (mean age 27.3 ± 5.9 years) were exposed to HH at 3269 m s.l. ROS production, related oxidative damage to cellular components, systemic inflammatory response and renal function were determined through blood and urine profile performed at 1st, 2nd, 4th, 7th, and 14th days during sojourn. Results Kinetics of changes during HH exposition showed out significant (range p < 0.05-0.0001) increases that at max corresponds to 38% for ROS production rate, 140% for protein carbonyl, 44% for lipid peroxidation, 42% for DNA damage, 200% for inflammatory cytokines and modifications in renal function (assessed by neopterin concentration: 48%). Conversely, antioxidant capacity significantly (p < 0.0001) decreased − 17% at max. Conclusion This 14 days in-field study describes changes of oxidative-stress biomarkers during HH exposure in lowlanders. The results show an overproduction of ROS and consequent oxidative damage to protein, lipids and DNA with a decrease in antioxidant capacity and the involvement of inflammatory status and a transient renal dysfunction. Exposure at high altitude induces a hypoxic condition during acute and sub-acute phases accompanied by molecular adaptation mechanism indicating acclimatization.
Cerebral palsy (CP), one of the most common neurological disorders in childhood, features affecte... more Cerebral palsy (CP), one of the most common neurological disorders in childhood, features affected individual's motor skills and muscle actions. This results in elevated heart rate and rate of oxygen uptake during sub-maximal exercise, thus indicating a mean energy expenditure higher than healthy subjects. Rehabilitation, currently involving also robot-based devices, may have an impact also on these aspects. In this study, an ecological setting has been proposed to evaluate the energy expenditure of 4 children with CP before and after a robot-assisted gait training. Even if the small sample size makes it difficult to give general indications, results presented here are promising. Indeed, children showed an increasing trend of the energy expenditure per minute and a decreasing trend of the energy expenditure per step, in accordance to the control group. These data suggest a metabolic benefit of the treatment that may increase the locomotion efficiency of disabled children.
European Journal of Applied Physiology, Jan 18, 2000
Medicine and Science in Sports and Exercise, May 1, 2017
International Journal of Molecular Sciences, Feb 16, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Oxidative Medicine and Cellular Longevity, Apr 30, 2022
Concordia Station is the permanent, research station on the Antarctic Plateau at 3230 m. During t... more Concordia Station is the permanent, research station on the Antarctic Plateau at 3230 m. During the eleventh winter-over campaign (DC11-2015; February 2015 to November 2015) at Antarctic Concordia Station, 13 healthy team members were studied and blood samples were collected at six different time points: baseline measurements (T0), performed at sea level before the departure, and during the campaign at 3, 7, 20, 90, and 300 days after arrival at Concordia Station. Reducing the partial pressure of O 2 as barometric pressure falls, hypobaric hypoxia (HH) triggers several physiological adaptations. Among the others, increased oxidative stress and enhanced generation of reactive oxygen/nitrogen species (ROS/RNS), resulting in severe oxidative damage, were observed, which can share potential physiopathological mechanisms associated with many diseases. This study characterized the extent and time-course changes after acute and chronic HH exposure, elucidating possible fundamental mechanisms of adaptation. ROS, oxidative stress biomarkers, nitric oxide, and proinflammatory cytokines significantly increased (range 24-135%) during acute and chronic hypoxia exposure (peak 20 th day) with a decrease in antioxidant capacity (peak 90 th day:-52%). Results suggest that the adaptive response of oxidative stress balance to HH requires a relatively long time, more than 300 th days, as all the observed variables do not return to the preexposition level. These findings may also be relevant to patients in whom oxygen availability is limited through disease (i.e., chronic heart and lung and/or kidney disease) and/or during long-duration space missions.
We determined the oxygen uptake (V _ O 2), heart rate (HR), and blood lactate responses to 2 high... more We determined the oxygen uptake (V _ O 2), heart rate (HR), and blood lactate responses to 2 high-intensity interval exercise protocols differing in interval length. On separate days, 14 recreationally active males performed a 4 3 4 (four 4minute intervals at 90-95% HR peak , separated by 3-minute recovery at 50 W) and 16 3 1 (sixteen 1-minute intervals at 90-95% HR peak , separated by 1-minute recovery at 50 W) protocol on a cycle ergometer. The 4 3 4 elicited a higher mean V _ O 2 (2.44 6 0.4 vs. 2.36 6 0.4 L$min 21) and "peak" V _ O 2 (90-99% vs. 76-85% V _ O 2 peak) and HR (95-98% HR peak vs. 81-95% HR peak) during the high-intensity intervals. Average power maintained was higher for the 16 3 1 (241 6 45 vs. 204 6 37 W), and recovery interval V _ O 2 and HR were higher during the 16 3 1. No differences were observed for blood lactate concentrations at the midpoint (12.
Journal of Physiological Sciences, 2009
Sport Sciences for Health, Sep 1, 2015
Recent works have shown that metabolic power is the best estimator of the high-intensity demands ... more Recent works have shown that metabolic power is the best estimator of the high-intensity demands of soccer training. Moreover, Gaudino et al (2015) showed that high-intensity running distance and number of accelerations/decelerations are likely to be strong predictors of training load, estimated by rate of perceived exertion multiplied by session duration (RPE-TL), in elite soccer players. However, up to date absolute speed/power zones have been utilized to define high-intensity activities without accounting for individual physiological capacity. Aim. Aim of this study was to evaluate the relationship between RPE-TL and high-intensity distance (HID) determined by individual power thresholds in elite young soccer players. Methods. 18 U15 soccer players were investigated. All subjects performed a YO-YO IRT1 to determine maximal velocity (Vmax). HID was calculated utilizing: a) the most common power threshold used for young soccer players (ThP-st, 17.5W*kg-1); b) an individual threshold based on the equivalent metabolic power at Vmax (ThP-ind). During 16 training sessions 203 individual observations were recorded using a 10Hz GPS devise (K-Sport, Italy). RPE was collected 30 minutes after each training session using the CR-10 Borg scale. Linear regression analyses were made between RPE-TL and HID. Results. Training sessions lasted 112\ub121min. Mean total distance covered was 6532\ub11418m. HID was 1772\ub1637m and 1365\ub1493m by ThP-st and ThP-ind, respectively. HID was significantly related to RPE-TL (p&lt;0.001) and the best correlation was found when employing ThP-ind (r2=0.42). Conclusion. The present findings suggest that high-intensity distance determined by an individual power threshold seems to be an effective tool to predict training load of elite young soccer players. This observation may support coaches and sport scientists to better monitor and design training. References. Gaudino P, Iaia FM, Strudwick AJ, Hawkins RD, Alberti G, Atkinson G, Gregson W (2015). Factors influencing perception of effort (session-RPE) during elite soccer training. IJSPP (ahead of print)
Introduction: Several studies have shown that short term (3-6 days) of either pharmacological (Na... more Introduction: Several studies have shown that short term (3-6 days) of either pharmacological (NaNO3- and KNO3-) or dietary nitrate (NO3-) supplementation reduces the whole body oxygen cost during continuous moderate-intensity exercise, improving eendurance exercise tolerance. Furthermore, The nitrate supplementation appears to be particularly effective in enhancing performance in hypoxia (Kenjale et al. 2011; Vanhatalo et al. 2011; Masschelein et al. 2012) and it may specifically improve O2 delivery and force production in type II muscle fibres (Hernandez et al.2012, Ferguson et al. 2013). During high-intensity intermittent exercise, type II muscle fibres are heavily recruited. Thus, an impaired O2delivery/O2uptake may result in the development of muscle hypoxia, as well as low muscle pH and disturbances of ionic balance. The aim of this study was to examine in vivo the effects of nitrate supplementation (by spinach juice) on intermittent high-intensity performance. Methods: Seven healthy male subjects (age: 25 \ub1 2 years) participated in a randomized double-blind placebo-controlled cross-over study. They were tested after 6 days of supplementation of either 0.5 l per day of spinach juice (5.5 mol/day nitrate) (SPINACH) or placebo (PLACEBO). Subjects performed a Repeated Sprint Ability test (RSA), which consisted in five \u201call out\u201d 6 seconds sprints on a cycloergometer (894E, Monark, Sweden) separated by 24 seconds of inactive recovery. Results: After PLACEBO, plasma [NO3-] and [NO2-] were 11 \ub1 2 \ub5M and 0.3 \ub1 0.04 \ub5M, respectively. After SPINACH, plasma [NO3-] significantly increased to 127 \ub1 24 \ub5M, whereas [NO2-] was not significantly different from PLACEBO (0.3 \ub1 0.04 \ub5M). As for RSA, there was no difference in absolute peak power output of the first two sprints between SPINACH (701.9 \ub1 8.1 and 703.9 \ub1 8.0 W) and PLACEBO (684.4 \ub1 6.7 and 690.3 \ub1 7.1 W). In contrast, the peak power output of the 3rd, 4th and 5th sprint were significantly higher in SPINACH (695.9 \ub1 8.3, 682.5 \ub1 7.6 and 666.1 \ub1 7.1 W, respectively) than in PLACEBO (663.9 \ub1 6.5, 641.2 \ub1 7.2 and 622.1 \ub1 7.2 W, respectively). Conclusion: This study has shown that short term dietary nitrate supplementation can improve repeated sprint performance in healthy subjects. This finding suggestconfirmed that NO3- may be an effective ergogenic aid not only for endurance-typeaerobic activitiesperformance but also for team sport or racquet players
Journal of Applied Physiology, Feb 1, 1996
Peak blood lactate ([Labl]peak) and blood lactate concentration ([Labl]) vs. workload (W) relatio... more Peak blood lactate ([Labl]peak) and blood lactate concentration ([Labl]) vs. workload (W) relationships during acclimatization to altitude and in the deacclimatization were evaluated in 10 Caucasian lowlanders at sea level (SL0); after approximately 1 wk (Alt1wk), 3 wk (Alt3wk), and 5 wk (Alt5wk) at 5,050 m; and weekly during the first 5 wk after return to sea level (SL1wk-SL5wk). Incremental bicycle ergometer exercises (30 W added every 4 min up to exhaustion) were performed. At Alt1wk and at Alt5wk, the experiments were repeated in hypobaric normoxia (Alt1wk-O2 and Alt5wk-O2). [Labl] was determined at rest and during the last approximately 30 s of each W. [Labl]peak was taken as the highest [Labl] during recovery. Acid-base status (pH and concentration of HCO-3 in arterialized capillary blood) was determined at rest. Mean [Labl]peak values were 11.5 (SL0), 8.0 (Alt1wk), 6.4 (Alt3wk), 6.3 (Alt5wk), 8.0 (SL1wk), 9.4 (SL2wk), 10.8 (SL3wk), 11.3 (SL4wk), and 11.6 (SL5wk) mM. At Alt1wk-O2 and Alt5wk-O2, peak W increased, compared with Alt1wk and Alt5wk, whereas no changes were observed for [Labl]peak. [Labl] vs. W was shifted to the left (i.e., higher [Labl] values were found for the same W) at Alt1wk compared with SL0 and partially shifted back to the right (i.e., lower [Labl] values were found for the same W) at Alt3wk and Alt5wk. At Alt1wk-O2 and Alt5wk-O2, [Labl] vs. W values were superimposed on that at SL0. At SL1wk-SL5wk, [Labl] vs. W values were shifted to the right compared with that at SL0. At Alt1wk, a condition of respiratory alkalosis was found, which was only partially compensated for during acclimatization. At SL1wk, the acid-base status was back to normal. We conclude that 1) the reduced [Labl]peak at altitude is still present for 2-3 wk after return from altitude; is not attributable to reduced peak W nor to hypoxia per se, nor to a reduced buffer capacity; alternatively, it could be related to some central determinants of fatigue. 2) The [Labl] vs. W leftward shift at altitude was due to hypoxia per se. 3) The factor(s) responsible for the [Labl] vs. W partial rightward shift during acclimatization could still be effective during the first weeks after return to sea level.
Medicine and Science in Sports and Exercise, May 1, 2018
METHODS: C57BL/6J mice at the age of 2 mo (young, Y; N=7) and 24 mo (old, O; N=7) were transfecte... more METHODS: C57BL/6J mice at the age of 2 mo (young, Y; N=7) and 24 mo (old, O; N=7) were transfected in vivo with either PGC-1α DNA or GFP into the tibialis anterior (TA) muscle. For electroporation, mice were anesthetized, and a small incision was made through the skin covering the TA muscle. A 27-gauge needle was used to inject plasmid DNA solution into the proximal and distal ends of the muscle belly. Electric pulses were applied to proximal and distal myotendinous junctions. The incision was closed with surgical glue. RESULTS: Aging increased SIRT1 level by 1.9, and 2.4-fold (P<.01) in O and O/OE, respectively; PGC-1α OE enhanced this effect (P<.05). SIRT3 and 6 level were decreased by 70 and 80% with aging (P<.01), whereas this effect was attenuated with PGC-1α OE. GCN5 level was elevated by ~10-fold with aging (P<.01), and PGC-1α OE showed no effect. Total cytoplasmic and mitochondrial protein acetylation level was 1.5-and 1.2-fold higher in O vs. Y (P<.05), whereas no effect of PGC-1α OE was seen. CONCLUSION: GCN5 and global and mitochondrial protein acetylation levels were increased with aging in mouse skeletal muscle. PGC-1α OE exerted no effect on this aging phenomenon. However, PGC-1α OE upregulated SIRT1 and ameliorated age-associated reduction of SIRT3 and 6 protein levels.
Nitric Oxide, Feb 1, 2021
Nitric oxide seems to be involved in the altitude acclimatization process due to its ability to r... more Nitric oxide seems to be involved in the altitude acclimatization process due to its ability to regulate pulmonary, cardiovascular and muscular responses to hypoxia. In this study, we investigated the plasma nitrate (NO3-) and nitrite (NO2-) response to hypobaric hypoxia in two groups of lowlanders exposed at different altitudes. For seven days, fourteen subjects were evaluated at Casati Hut (3269 m a.s.l. M.CEVEDALE) and eleven individuals were studied at Capanna Regina Margherita (4554 m a.s.l. M.ROSA). Before expeditions and at different time points during high-altitude sojourn, plasma NO3- and NO2- concentrations were measured by chemiluminescence. Resting peripheral arterial oxygen saturation (SpO2), heart rate (HR) and mean arterial blood pressure (MAP) were monitored during the experimental period. Possible confounding factors such as dietary NO3- intake, physical activity and altitude changes were controlled. Sea level plasma NO3- and NO2- concentrations significantly increased at altitude in both M.CEVEDALE group (+26.2 μM, p≤0.0001, 95% CI [+17.6, +34.8] and +559.2 nM, p≤0.0001, [+332.8, +785.6]) and M.ROSA group (+18.7 μM, p≤0.0001, [+10.8, +26.5] and +463.7 nM, p≤0.0001, [+314.3, +613.0]). Average peak value in NO metabolites concentration occurred earlier in M.CEVEDALE group vs M.ROSA group (NO3-, day 3 vs day 5, p=0.007; NO2-, day 3 vs day 5, p=0.019). In both groups, resting SpO2, HR and MAP values changed according to altitude levels. This study shows that exposure to hypobaric hypoxia affects nitric oxide metabolites, resulting in a significant increase in plasma NO3- and NO2- concentrations from sea level values. Interestingly, the higher the altitude reached, the longer the time taken to reach a peak in plasma concentrations of nitric oxide metabolites.
American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
Elbow flexors (EFs) and knee extensors (KEs) have shown differences in performance fatigability a... more Elbow flexors (EFs) and knee extensors (KEs) have shown differences in performance fatigability and recovery of neuromuscular function after isometric and isotonic single-joint fatiguing contractions. However, dynamic multi-joint movements are more representative of real-world activities. The aim of the study was to assess central and peripheral mechanisms of fatigability after either arm-cranking or cycling. Ten physically active men performed maximal incremental arm-cranking and cycling until task failure. Maximal voluntary isometric contraction (MVIC) and electrically evoked forces of both EF and KE were assessed before (PRE) and 1 (POST) and 20 (POST20) min after exercise. At POST, MVIC decreased similarly to 76 ± 8% and 81 ± 7% (both P < 0.001) of PRE for EF and KE, respectively. MVIC force remained lower than PRE at POST20 for both EF and KE (85 ± 8% vs. 95 ± 3% of PRE, P ≤ 0.033), having recovered less in EF than in KE ( P = 0.003). Electrically evoked forces decreased sim...
OTA International: The Open Access Journal of Orthopaedic Trauma, 2021
Abstract Background: The burden of musculoskeletal trauma is increasing in low- and middle-income... more Abstract Background: The burden of musculoskeletal trauma is increasing in low- and middle-income countries. Due to the low clinical follow-up rates in these regions, the Squat-and-Smile test (S&S) has previously been proposed as a proxy to assess bone healing (BH) capacity after surgery involving bone fractures. This study deals with various aspects of using S&S and bone radiography examination to obtain information about an individual's ability to recover after a trauma. In summary, we performed the S&S test to assess the possibility of recovering biomechanical function in lower limbs in a remote area of Kenya (Samburu County). Methods: Eighty-nine patients (17.9% F; 31.7 ± 18.9 yrs) who underwent intramedullary nail treatment for femur or tibia fractures were enrolled in this study. Both S&S [evaluated by a goal attainment scale (GAS)] and x-ray (evaluated by REBORNE, Bone Healing Score) were performed at 6 and 24 weeks, postoperatively. An acceptable margin for satisfactory S&S GAS scores was determined by assessing its validity, reliability, and sensitivity. Results: S&S GAS scores increased over time: 80.2% of patients performed a satisfactory S&S at the 24-weeks follow-up with a complete BH. A high correlation between S&S GAS and REBORNE at the 6- and 24- weeks’ timepoint was found. Facial expression correlated partially with BH. The S&S proved to be accurate at correctly depicting the BH process (75% area fell under the Receiver Operator Curve). Conclusion: The S&S provides a possible substitution for bone x-ray during BH assessment. The potential to remotely follow up the BH is certainly appealing in low- and middle-income countries, but also in high-income countries; as was recently observed with the Covid-19 pandemic when access to a hospital is not conceivable.
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Papers by mauro Marzorati