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Manferdelli G, Narang BJ, Bourdillon N, Giardini G, Debevec T, Millet GP. Impaired cerebrovascular CO 2 reactivity at high altitude in prematurely born adults. J Physiol 2023. [PMID: 38116893 DOI: 10.1113/jp285048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023] Open
Abstract
Premature birth impairs cardiac and ventilatory responses to both hypoxia and hypercapnia, but little is known about cerebrovascular responses. Both at sea level and after 2 days at high altitude (3375 m), 16 young preterm-born (gestational age, 29 ± 1 weeks) and 15 age-matched term-born (40 ± 0 weeks) adults were exposed to two consecutive 4 min bouts of hyperoxic hypercapnic conditions (3% CO2 -97% O2 ; 6% CO2 -94% O2 ), followed by two periods of voluntary hyperventilation-induced hypocapnia. We measured middle cerebral artery blood velocity, end-tidal CO2 , pulmonary ventilation, beat-by-beat mean arterial pressure and arterialized capillary blood gases. Baseline middle cerebral artery blood velocity increased at high altitude compared with sea level in term-born (+24 ± 39%, P = 0.036), but not in preterm-born (-4 ± 27%, P = 0.278) adults. The end-tidal CO2 , pulmonary ventilation and mean arterial pressure were similar between groups at sea level and high altitude. Hypocapnic cerebrovascular reactivity was higher at high altitude compared with sea level in term-born adults (+173 ± 326%, P = 0.026) but not in preterm-born adults (-21 ± 107%, P = 0.572). Hypercapnic reactivity was altered at altitude only in preterm-born adults (+125 ± 144%, P < 0.001). Collectively, at high altitude, term-born participants showed higher hypocapnic (P = 0.012) and lower hypercapnic (P = 0.020) CO2 reactivity compared with their preterm-born peers. In conclusion, exposure to high altitude revealed different cerebrovascular responses in preterm- compared with term-born adults, despite similar ventilatory responses. These findings suggest a blunted cerebrovascular response at high altitude in preterm-born adults, which might predispose these individuals to an increased risk of high-altitude illnesses. KEY POINTS: Cerebral haemodynamics and cerebrovascular reactivity in normoxia are known to be similar between term-born and prematurely born adults. In contrast, acute exposure to high altitude unveiled different cerebrovascular responses to hypoxia, hypercapnia and hypocapnia. In particular, cerebral vasodilatation was impaired in prematurely born adults, leading to an exaggerated cerebral vasoconstriction. Cardiovascular and ventilatory responses to both hypo- and hypercapnia at sea level and at high altitude were similar between control subjects and prematurely born adults. Other mechanisms might therefore underlie the observed blunted cerebral vasodilatory responses in preterm-born adults at high altitude.
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Affiliation(s)
| | - Benjamin J Narang
- Department of Automatics, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Nicolas Bourdillon
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Guido Giardini
- Mountain Medicine and Neurology Centre, Valle D'Aosta Regional Hospital, Aosta, Italy
| | - Tadej Debevec
- Department of Automatics, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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Page L, Younge N, Freemark M. Hormonal Determinants of Growth and Weight Gain in the Human Fetus and Preterm Infant. Nutrients 2023; 15:4041. [PMID: 37764824 PMCID: PMC10537367 DOI: 10.3390/nu15184041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/13/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
The factors controlling linear growth and weight gain in the human fetus and newborn infant are poorly understood. We review here the changes in linear growth, weight gain, lean body mass, and fat mass during mid- and late gestation and the early postnatal period in the context of changes in the secretion and action of maternal, placental, fetal, and neonatal hormones, growth factors, and adipocytokines. We assess the effects of hormonal determinants on placental nutrient delivery and the impact of preterm delivery on hormone expression and postnatal growth and metabolic function. We then discuss the effects of various maternal disorders and nutritional and pharmacologic interventions on fetal and perinatal hormone and growth factor production, growth, and fat deposition and consider important unresolved questions in the field.
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Affiliation(s)
- Laura Page
- Division of Pediatric Endocrinology, Duke University Medical Center, Durham, NC 27710, USA;
| | - Noelle Younge
- Neonatology, Duke University Medical Center, Durham, NC 27710, USA;
| | - Michael Freemark
- Division of Pediatric Endocrinology, Duke University Medical Center, Durham, NC 27710, USA;
- The Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27710, USA
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Engan B, Omdal TR, Greve G, Vollsaeter M, Leirgul E. Myocardial function including estimates of myocardial work in young adults born very preterm or with extremely low birthweight - a cohort study. BMC Cardiovasc Disord 2023; 23:222. [PMID: 37120542 PMCID: PMC10149027 DOI: 10.1186/s12872-023-03253-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/20/2023] [Indexed: 05/01/2023] Open
Abstract
BACKGROUND Preterm birth and low birthweight have been associated with increased risk of heart failure and cardiovascular disease in young adulthood. However, results from clinical studies of myocardial function are not consistent. Echocardiographic strain analyses allow detection of early stages of cardiac dysfunction, and non-invasive estimates of myocardial work can provide additional information on cardiac function. We aimed to evaluate left ventricular (LV) myocardial function including measures of myocardial work in young adults born very preterm (gestational age < 29 weeks) or with extremely low birthweight (< 1000 g) (PB/ELBW), compared with term-born age- and sex matched controls. METHODS 63 PB/ELBW and 64 controls born in Norway in the periods 1982-1985, 1991-1992, and 1999-2000 were examined with echocardiography. LV ejection fraction (EF) and LV global longitudinal strain (GLS) were measured. Myocardial work was estimated from LV pressure-strain loops after determination of GLS and construction of a LV pressure curve. Diastolic function was evaluated by determination of the presence or absence of elevated LV filling pressure, including measures of left atrial longitudinal strain. RESULTS The PB/ELBW with mean birthweight 945 (standard deviation (SD) 217) grams, mean gestational age 27 (SD 2) weeks, and mean age 27 (SD 6) years had LV systolic function mainly within normal range. Only 6% had EF < 50% or impaired GLS >-16%, but 22% had borderline impaired GLS between - 16% and - 18%. Mean GLS in PB/ELBW (-19.4% (95% confidence interval (CI) -20.0, -18.9)) was impaired compared to controls (-20.6% (95% CI -21.1, -20.1)), p = 0.003. Lower birthweight was associated to more impaired GLS (Pearson correlation coefficient - 0.2). Means of EF, measures of diastolic function including left atrial reservoir strain, global constructive and wasted work, global work index and global work efficiency was similar in PB/ELBW and controls. CONCLUSION The young adults born very preterm or with extremely low birthweight had impaired LV-GLS compared to controls, although systolic function mainly within normal range. Lower birthweight was associated with more impaired LV-GLS. These findings could indicate an elevated lifetime risk of developing heart failure in preterm born individuals. Measures of diastolic function and myocardial work were similar compared to controls.
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Affiliation(s)
- Britt Engan
- Department of Clinical Science, University of Bergen, Bergen, Norway.
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway.
| | - Tom R Omdal
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Gottfried Greve
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Maria Vollsaeter
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Paediatric and Adolescent Medicine, Haukeland University Hospital, Bergen, Norway
| | - Elisabeth Leirgul
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
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Manferdelli G, Narang BJ, Pialoux V, Giardini G, Debevec T, Millet GP. Microvascular and oxidative stress responses to acute high-altitude exposure in prematurely born adults. Sci Rep 2023; 13:6860. [PMID: 37100885 PMCID: PMC10133287 DOI: 10.1038/s41598-023-34038-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/23/2023] [Indexed: 04/28/2023] Open
Abstract
Premature birth is associated with endothelial and mitochondrial dysfunction, and chronic oxidative stress, which might impair the physiological responses to acute altitude exposure. We assessed peripheral and oxidative stress responses to acute high-altitude exposure in preterm adults compared to term born controls. Post-occlusive skeletal muscle microvascular reactivity and oxidative capacity from the muscle oxygen consumption recovery rate constant (k) were determined by Near-Infrared Spectroscopy in the vastus lateralis of seventeen preterm and seventeen term born adults. Measurements were performed at sea-level and within 1 h of arrival at high-altitude (3375 m). Plasma markers of pro/antioxidant balance were assessed in both conditions. Upon acute altitude exposure, compared to sea-level, preterm participants exhibited a lower reperfusion rate (7 ± 31% vs. 30 ± 30%, p = 0.046) at microvascular level, but higher k (6 ± 32% vs. -15 ± 21%, p = 0.039), than their term born peers. The altitude-induced increases in plasma advanced oxidation protein products and catalase were higher (35 ± 61% vs. -13 ± 48% and 67 ± 64% vs. 15 ± 61%, p = 0.034 and p = 0.010, respectively) and in xanthine oxidase were lower (29 ± 82% vs. 159 ± 162%, p = 0.030) in preterm compared to term born adults. In conclusion, the blunted microvascular responsiveness, larger increases in oxidative stress and skeletal muscle oxidative capacity may compromise altitude acclimatization in healthy adults born preterm.
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Affiliation(s)
- Giorgio Manferdelli
- Institute of Sport Sciences (ISSUL), University of Lausanne, Synathlon, 1015, Lausanne, Switzerland.
| | - Benjamin J Narang
- Department of Automatics, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
- Institute of Biostatistics and Medical Informatics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Vincent Pialoux
- Laboratoire Interuniversitaire de Biologie de La Motricité UR 7424, Faculté de Médecine Rockefeller, Univ Lyon, Université Claude Bernard Lyon 1, 69008, Lyon, France
- Institut Universitaire de France, Paris, France
| | - Guido Giardini
- Mountain Medicine and Neurology Centre, Valle D'Aosta Regional Hospital, Aosta, Italy
| | - Tadej Debevec
- Department of Automatics, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Grégoire P Millet
- Institute of Sport Sciences (ISSUL), University of Lausanne, Synathlon, 1015, Lausanne, Switzerland
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Manferdelli G, Narang BJ, Bourdillon N, Debevec T, Millet GP. Physiological Responses to Exercise in Hypoxia in Preterm Adults: Convective and Diffusive Limitations in the O 2 Transport. Med Sci Sports Exerc 2023; 55:482-496. [PMID: 36459101 DOI: 10.1249/mss.0000000000003077] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
PURPOSE Premature birth induces long-term sequelae on the cardiopulmonary system, leading to reduced exercise capacity. However, the mechanisms of this functional impairment during incremental exercise remain unclear. Also, a blunted hypoxic ventilatory response was found in preterm adults, suggesting an increased risk for adverse effects of hypoxia in this population. This study aimed to investigate the oxygen cascade during incremental exercise to exhaustion in both normoxia and hypobaric hypoxia in prematurely born adults with normal lung function and their term born counterparts. METHODS Noninvasive measures of gas exchange, cardiac hemodynamics, and both muscle and cerebral oxygenation were continuously performed using metabolic cart, transthoracic impedance, and near-infrared spectroscopy, respectively, during an incremental exercise test to exhaustion performed at sea level and after 3 d of high-altitude exposure in healthy preterm ( n = 17; gestational age, 29 ± 1 wk; normal lung function) and term born ( n = 17) adults. RESULTS At peak, power output, oxygen uptake, stroke volume indexed for body surface area, and cardiac output were lower in preterm compared with term born in normoxia ( P = 0.042, P = 0.027, P = 0.030, and P = 0.018, respectively) but not in hypoxia, whereas pulmonary ventilation, peripheral oxygen saturation, and muscle and cerebral oxygenation were similar between groups. These later parameters were modified by hypoxia ( P < 0.001). Hypoxia increased muscle oxygen extraction at submaximal and maximal intensity in term born ( P < 0.05) but not in preterm participants. Hypoxia decreased cerebral oxygen saturation in term born but not in preterm adults at rest and during exercise ( P < 0.05). Convective oxygen delivery was decreased by hypoxia in term born ( P < 0.001) but not preterm adults, whereas diffusive oxygen transport decreased similarly in both groups ( P < 0.001 and P < 0.001, respectively). CONCLUSIONS These results suggest that exercise capacity in preterm is primarily reduced by impaired convective, rather than diffusive, oxygen transport. Moreover, healthy preterm adults may experience blunted hypoxia-induced impairments during maximal exercise compared with their term counterparts.
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Affiliation(s)
| | | | - Nicolas Bourdillon
- Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND
| | | | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND
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Parizotto GP, de Souza LV, Thomazini F, Prado MS, Agudelo JSH, de Almeida DC, do Carmo Franco M. Birth weight and its relationship with endothelial function and pattern of endothelium-derived microparticles during childhood: New insight about early vascular damage. Life Sci 2022; 298:120517. [DOI: 10.1016/j.lfs.2022.120517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/17/2022] [Accepted: 03/26/2022] [Indexed: 10/18/2022]
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Richter RP, Payne GA, Ambalavanan N, Gaggar A, Richter JR. The endothelial glycocalyx in critical illness: A pediatric perspective. Matrix Biol Plus 2022; 14:100106. [PMID: 35392182 PMCID: PMC8981764 DOI: 10.1016/j.mbplus.2022.100106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 12/18/2022] Open
Abstract
The endothelial glycocalyx thins with age and cardiovascular comorbidities. Endothelial glycocalyx is affected by and integral to severe pediatric illnesses. Mechanistic insight into cause/effect of endothelial glycocalyx injury is paramount. Vascular glycocalyx damage in pediatric critical illness warrants further study.
The vascular endothelium is the interface between circulating blood and end organs and thus has a critical role in preserving organ function. The endothelium is lined by a glycan-rich glycocalyx that uniquely contributes to endothelial function through its regulation of leukocyte and platelet interactions with the vessel wall, vascular permeability, coagulation, and vasoreactivity. Degradation of the endothelial glycocalyx can thus promote vascular dysfunction, inflammation propagation, and organ injury. The endothelial glycocalyx and its role in vascular pathophysiology has gained increasing attention over the last decade. While studies characterizing vascular glycocalyx injury and its downstream consequences in a host of adult human diseases and in animal models has burgeoned, studies evaluating glycocalyx damage in pediatric diseases are relatively few. As children have unique physiology that differs from adults, significant knowledge gaps remain in our understanding of the causes and effects of endothelial glycocalyx disintegrity in pediatric critical illness. In this narrative literature overview, we offer a unique perspective on the role of the endothelial glycocalyx in pediatric critical illness, drawing from adult and preclinical data in addition to pediatric clinical experience to elucidate how marked derangement of the endothelial surface layer may contribute to aberrant vascular biology in children. By calling attention to this nascent field, we hope to increase research efforts to address important knowledge gaps in pediatric vascular biology that may inform the development of novel therapeutic strategies.
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Affiliation(s)
- Robert P. Richter
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA
- Program in Protease and Matrix Biology, University of Alabama at Birmingham, Birmingham, AL, USA
- Center for Injury Science, University of Alabama at Birmingham, Birmingham, AL, USA
- Corresponding author at: Department of Pediatrics, University of Alabama at Birmingham, 1600 5 Avenue South, CPPI Suite 102, Birmingham, Alabama 35233, USA.
| | - Gregory A. Payne
- Program in Protease and Matrix Biology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Namasivayam Ambalavanan
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
- Translational Research in Normal and Disordered Development Program, University of Alabama, Birmingham, AL, USA
| | - Amit Gaggar
- Program in Protease and Matrix Biology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jillian R. Richter
- Center for Injury Science, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
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Debevec T, Poussel M, Osredkar D, Willis SJ, Sartori C, Millet GP. Post-exercise accumulation of interstitial lung water is greater in hypobaric than normobaric hypoxia in adults born prematurely. Respir Physiol Neurobiol 2021; 297:103828. [PMID: 34890833 DOI: 10.1016/j.resp.2021.103828] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 11/24/2021] [Accepted: 12/05/2021] [Indexed: 10/19/2022]
Abstract
We aimed to gauge the interstitial lung water accumulation following moderate-intensity exercise under normobaric and hypobaric hypoxic conditions in a group of preterm born but otherwise healthy young adults. Sixteen pre-term-born individuals (age = 21±2yrs.; gestational age = 29±3wk.; birth weight = 1160±273 g) underwent two 8 -h hypoxic/altitude exposures in a cross-over manner: 1) Normobaric hypoxic exposure (NH; FIO2 = 0.142±0.001; PIO2 = 90.6±0.9 mmHg) 2) Hypobaric hypoxic exposure (HH; terrestrial high-altitude 3840 m; PIO2 = 90.2±0.5 mmHg). Interstitial lung water was assessed via quantification of B-Lines (using lung ultrasound) before (normoxia) and after 4-h and 8-h of respective exposures. At each time point, B-Lines were quantified before (Pre) and immediately after (Post) a 6-min moderate-intensity exercise. The baseline B-lines count were comparable between both conditions (P = 0.191). A higher B-lines count was noted at Pre-H4 in HH versus NH (P = 0.0420). At Post-H8 B-lines score was significantly higher in HH (4.6 ± 1.6) than in NH (3.1 ± 1.4; P = 0.0073). Furthermore, at this time point, a significantly higher number of individuals with B-line scores ≥5 was observed in HH (n = 7) than in NH (n = 3; P = 0.0420). These findings suggest that short moderate-intensity exercise provokes a significant increase in the interstitial lung water accumulation after 8 h of exposure to terrestrial but not simulated altitude (≈3840 m) in prematurely born adults. Further work is needed to elucidate the exact mechanisms of (moderate-intensity) exercise-induced interstitial lung water accumulation in this population and directly compare the obtained data to full-term born adults.
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Affiliation(s)
- Tadej Debevec
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia; Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.
| | - Mathias Poussel
- Department of Pulmonary Function Testing and Exercise Physiology, CHRU de Nancy, Nancy, France; Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Damjan Osredkar
- Department of Pediatric Neurology, University Children's Hospital Ljubljana, Ljubljana, Slovenia
| | - Sarah J Willis
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Claudio Sartori
- Department of Internal Medicine and the Botnar Center for Extreme Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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