Effect of altitude on the lung function of high altitude residents of European ancestry

Greksa, Lawrence P.; Spielvogel, Hilde; Paz-Zamora, Mario; Caceres, Esperanza; Paredes-Fernández, Luis

doi:10.1002/ajpa.1330750109

Cited by 52 publications

(50 citation statements)

References 15 publications

(26 reference statements)

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“…The FVC and FEV 1 of high altitude populations have frequently been compared to low altitude standards in order to gauge the general increase associated with either genetic adaptation or developmental adjustments to high altitude hypoxia (Frisancho, 1969;Frisancho et al, 1973;Malik and Singh, 1979;Beall, 1984;Greksa et al, 1987Greksa et al, , 1988Havryk et al, 2002;Kiyamu et al, 2012). The results of this study indicate that the inclusion of stunted children in high altitude populations compromises the validity of such comparisons.…”

Section: Discussionmentioning

confidence: 97%

Stunting and the Prediction of Lung Volumes Among Tibetan Children and Adolescents at High Altitude

Weitz

Garruto

2015

High Altitude Medicine & Biology

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Weitz, Charles A., and Ralph M. Garruto. Stunting and the prediction of lung volumes among Tibetan children and adolescents at high altitude. High Alt Biol Med 16: [306][307][308][309][310][311][312][313][314][315][316][317] 2015.-This study examines the extent to which stunting (height-for-age Z-scores £ -2) compromises the use of low altitude prediction equations to gauge the general increase in lung volumes during growth among high altitude populations. The forced vital capacity (FVC) and forced expiratory volume (FEV 1 ) of 208 stunted and 365 non-stunted high-altitude Tibetan children and adolescents between the ages of 6 and 20 years are predicted using the Third National Health and Nutrition Examination Survey (NHANESIII) and the Global Lung Function Initiative (GLF) equations, and compared to observed lung volumes. Stunted Tibetan children show smaller positive deviations from both NHANESIII and GLF prediction equations at most ages than non-stunted children. Deviations from predictions do not correspond to differences in body proportions (sitting heights and chest circumferences relative to stature) between stunted and non-stunted children; but appear compatible with the effects of retarded growth and lung maturation that are likely to exist among stunted children. These results indicate that, before low altitude standards can be used to evaluate the effects of hypoxia, or before high altitude populations can be compared to any other group, it is necessary to assess the relative proportion of stunted children in the samples. If the proportion of stunted children in a high altitude population differs significantly from the proportion in the comparison group, lung function comparisons are unlikely to yield an accurate assessment of the hypoxia effect. The best solution to this problem is to (1) use stature and lung function standards based on the same low altitude population; and (2) assess the hypoxic effect by comparing observed and predicted values among high altitude children whose statures are most like those of children on whom the low altitude spirometric standard is based-preferably high altitude children with HAZ-scores ‡ -1.

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Section: Discussionmentioning

confidence: 97%

Stunting and the Prediction of Lung Volumes Among Tibetan Children and Adolescents at High Altitude

Weitz

Garruto

2015

High Altitude Medicine & Biology

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“…As in the study of STANOJEVIC et al [5], with the exception of English children, Caucasian children from different centres produced a higher FEV1 and FVC than their American counterparts (table 3). Mexican children produced relatively large volumes (table 3), possibly because they were born and raised at an altitude of 2,240 m [52]. In spite of a comparable TLC for Ht and age between children from Hong Kong, Australia, the Netherlands and England, the RV/TLC ratio was appreciably smaller in Australian youths, who had a larger vital capacity, for which we have no explanation.…”

Section: Anthropometry and Ethnicitymentioning

confidence: 90%

Changes in the FEV1/FVC ratio during childhood and adolescence: an intercontinental study

Quanjer

Stanojevic

Stocks

et al. 2010

European Respiratory Journal

118

114

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In children, the ratio of forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) is reportedly constant or falls linearly with age, whereas the ratio of residual volume (RV) to total lung capacity (TLC) remains constant. This seems counter-intuitive given the changes in airway properties, body proportions, thoracic shape and respiratory muscle function that occur during growth. The age dependence of lung volumes, FEV1/FVC and RV/TLC were studied in children worldwide.Spirometric data were available for 22,412 healthy youths (51.4% male) aged 4-20 yrs from 15 centres, and RV and TLC data for 2,253 youths (56.7% male) from four centres; three sets included sitting height (SH). Data were fitted as a function of age, height and SH.In childhood, FVC outgrows TLC and FEV1, leading to falls in FEV1/FVC and RV/TLC; these trends are reversed in adolescence. Taking into account SH materially reduces differences in pulmonary function within and between ethnic groups. The highest FEV1/FVC ratios occur in those shortest for their age.When interpreting lung function test results, the changing pattern in FEV1/FVC and RV/TLC should be considered. Prediction equations for children and adolescents should take into account sex, height, age, ethnic group, and, ideally, also SH.

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“…Although this same issue has been raised, nutrition versus hypoxia per se, it is becoming clear that (i) there is growth retardation, including at birth, of children born at high altitude; and (ii) when controlled for nutrition, socio-economic class and other factors, studies have concluded that growth and development at high altitude result in a moderate delay in linear growth of wellnourished children, and that these patterns are established very early in life. 46,47 One very interesting observation that has bearing on this issue is related to hypoxia in invertebrates. 48,49 Fruit flies (Drosophila) decrease their body size as a function of severity of the hypoxic stress.…”

Section: Discussionmentioning

confidence: 99%

Differential effects of chronic intermittent and chronic constant hypoxia on postnatal growth and development

Farahani

Kanaan

Gavrialov

et al. 2007

Pediatric Pulmonology

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Summary. Exposure to chronic constant or intermittent hypoxia (CCH or CIH) may have different effects on growth and development in early life. In this work, we exposed postnatal day 2 (P2) CD1 mice to CCH or CIH (11% O 2 ) for 4 weeks and examined the effect of hypoxia on body and organ growth until P30. Regression analysis showed that weight increased in control, CCH and CIH cohorts with age with r 2 values of 0.99, 0.97, and 0.94, respectively. Between days 2 and 30, slopes were 0.93 AE 0.057, 0.76 AE 0.108, and 0.63 AE 0.061 (g/day, means AE SEM) for control, CIH, and CCH, respectively and significantly different from each other (P < 0.001). The slopes between P2 and P16 were 0.78 AE 0.012, 0.46 AE 0.002, and 0.47 AE 0.019 for control, CCH and CIH, respectively. From P16 to 30, slopes were 1.12 AE 0.033, 1.09 AE 0.143, and 0.82 AE 0.08 for control, CIH, and CCH, respectively with no significant difference from each other, suggesting a catch-up growth in the latter part of the hypoxic period. Slower weight gain resulted in a 12% and 23% lower body weight in CIH and CCH mice (P < 0.001) by P30. Lung/body ratios were 0.010, 0.015, 0.015 for control, CIH, and CCH at P30, respectively. The decrease in liver, kidney, and brain weight were greater in CCH than CIH. Smaller liver weight was shown to be due to a reduction in cell size and cell number. Liver in CIH and CCH mice showed a 5% and 10% reduction in cell size (P < 0.05) and a reduction of 28% in cell number (P < 0.001) at P30. In contrast, CCH and CIH heart weight was 13% and 33% greater than control at P30 (P < 0.05), respectively. This increase in the heart weight was due to an increase in the size of cardiomyocytes which showed an increase of 12% and 14% (P < 0.001) for CIH and CCH, respectively as compared to control. Brain weight was 0.48 and 0.46 g for CIH and CCH, respectively (95% and 92% of normal). We concluded that (a) CIH and CCH follow different body and organ growth patterns; (b) mostly with CCH, the liver and kidneys are reduced in size in a proportionate way to body size but heart, lung, and brain are either spared or increased in size compared to body weight; and (c) the decrease in liver is secondary mostly to a decrease in cell number.

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Effect of altitude on the lung function of high altitude residents of European ancestry

Cited by 52 publications

References 15 publications

Stunting and the Prediction of Lung Volumes Among Tibetan Children and Adolescents at High Altitude

Stunting and the Prediction of Lung Volumes Among Tibetan Children and Adolescents at High Altitude

Changes in the FEV1/FVC ratio during childhood and adolescence: an intercontinental study

Differential effects of chronic intermittent and chronic constant hypoxia on postnatal growth and development

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