Conrado J Llapur1,2, Myriam R Martínez1, Pedro T Grassino3,4, Ana Stok5, Héctor H Altieri6,7, Federico Bonilla8, María M Caram9,10, Natasha M Krowchuk11, Miranda Kirby11, Harvey O Coxson11, Robert S Tepper12. 1. 1 Department of Pediatric Pulmonology and. 2. 2 Cátedra de Metodología de la Investigación. 3. 3 Department of Radiology, Hospital del Niño Jesús, Tucumán, Argentina. 4. 4 Cátedra de Diagnostico por Imágenes. 5. 5 Instituto de Patologías Respiratorias Tucumán, Tucumán, Argentina. 6. 7 Cátedra de Clínica Medica, and. 7. 6 Department of Pulmonology, Hospital Centro de Salud Zenón Santillán, Tucumán, Argentina. 8. 8 Instituto Superior de Investigaciones Biológicas, Universidad Nacional de Tucumán, Tucumán, Argentina. 9. 9 Cátedra de Histología, Facultad de Medicina, Universidad Nacional de Tucumán, Tucumán, Argentina. 10. 10 Hospital Eva Perón, Tucumán, Argentina. 11. 11 Centre for Heart Lung Innovation, St. Paul's Hospital and the University of British Columbia, Vancouver, British Columbia, Canada; and. 12. 12 Herman B. Wells Center for Pediatric Research, Section of Pulmonology, James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana.
Abstract
RATIONALE: Adults born and raised at high altitudes have larger lung volumes and greater pulmonary diffusion capacity compared with adults at low altitude; however, it remains unclear whether the air and tissue volumes have comparable increases and whether there is a difference in airway size. OBJECTIVES: To assess the effect of chronic hypoxia on lung growth using in vivo high-resolution computed tomography measurements. METHODS: Healthy adults born and raised at moderate altitude (2,000 m above sea level; n = 19) and at low altitude (400 m above sea level; n = 23) underwent high-resolution computed tomography. Differences in total lung, air, and tissue volume, mean lung density, as well as airway lumen and wall areas in anatomically matched airways were compared between groups. MEASUREMENTS AND MAIN RESULTS: No significant differences for age, sex, weight, or height were found between the two groups (P > 0.05). In a multivariate regression model, altitude was a significant contributor for total lung volume (P = 0.02), air volume (P = 0.03), and tissue volume (P = 0.03), whereby the volumes were greater for the moderate- versus the low-altitude group. However, altitude was not a significant contributor for mean lung density (P = 0.35) or lumen and wall areas in anatomically matched segmental, subsegmental, and subsubsegmental airways. CONCLUSIONS: Our findings suggest that the adult lung did not increase lung volume later in life by expansion of an existing number of alveoli, but rather from increased alveolarization early in life. In addition, chronic hypoxia accentuates dysanaptic lung growth by increasing the lung parenchyma but not the airways.
RATIONALE: Adults born and raised at high altitudes have larger lung volumes and greater pulmonary diffusion capacity compared with adults at low altitude; however, it remains unclear whether the air and tissue volumes have comparable increases and whether there is a difference in airway size. OBJECTIVES: To assess the effect of chronic hypoxia on lung growth using in vivo high-resolution computed tomography measurements. METHODS: Healthy adults born and raised at moderate altitude (2,000 m above sea level; n = 19) and at low altitude (400 m above sea level; n = 23) underwent high-resolution computed tomography. Differences in total lung, air, and tissue volume, mean lung density, as well as airway lumen and wall areas in anatomically matched airways were compared between groups. MEASUREMENTS AND MAIN RESULTS: No significant differences for age, sex, weight, or height were found between the two groups (P > 0.05). In a multivariate regression model, altitude was a significant contributor for total lung volume (P = 0.02), air volume (P = 0.03), and tissue volume (P = 0.03), whereby the volumes were greater for the moderate- versus the low-altitude group. However, altitude was not a significant contributor for mean lung density (P = 0.35) or lumen and wall areas in anatomically matched segmental, subsegmental, and subsubsegmental airways. CONCLUSIONS: Our findings suggest that the adult lung did not increase lung volume later in life by expansion of an existing number of alveoli, but rather from increased alveolarization early in life. In addition, chronic hypoxia accentuates dysanaptic lung growth by increasing the lung parenchyma but not the airways.
Authors: Sheila Krishnan; Robert S Stearman; Lily Zeng; Amanda Fisher; Elizabeth A Mickler; Brooke H Rodriguez; Edward R Simpson; Todd Cook; James E Slaven; Mircea Ivan; Mark W Geraci; Tim Lahm; Robert S Tepper Journal: Am J Physiol Lung Cell Mol Physiol Date: 2020-07-08 Impact factor: 5.464
Authors: Erick Forno; Daniel J Weiner; James Mullen; Gregory Sawicki; Geoffrey Kurland; Yueh Ying Han; Michelle M Cloutier; Glorisa Canino; Scott T Weiss; Augusto A Litonjua; Juan C Celedón Journal: Am J Respir Crit Care Med Date: 2017-02-01 Impact factor: 21.405
Authors: Marcus H Jones; Cristian Roncada; Morgana Thais Carollo Fernandes; João Paulo Heinzmann-Filho; Edgar Enrique Sarria Icaza; Rita Mattiello; Paulo Marcio C Pitrez; Leonardo A Pinto; Renato T Stein Journal: Front Pediatr Date: 2017-12-18 Impact factor: 3.418
Authors: Alexander M Kulminski; Amisha V Barochia; Yury Loika; Nalini Raghavachari; Konstantin G Arbeev; Mary K Wojczynski; Bharat Thyagarajan; Badri N Vardarajan; Kaare Christensen; Anatoliy I Yashin; Stewart J Levine Journal: PLoS One Date: 2018-11-09 Impact factor: 3.240