Changes in the Fev1/Fvc Ratio During Childhood and Adolescence: An Intercontinental Study Publisher Pubmed



Quanjer PH¹ ; Stanojevic S⁴ ; Stocks J¹ ; Hall GL⁷ ; Prasad KVV⁸ ; Cole TJ⁴ ; Rosenthal M⁶ ; Perezpadilla R⁹ ; Hankinson JL¹⁰ ; Falaschetti E⁵ ; Golshan M¹¹ ; Brunekreef B^{2, 3} ; Alrawas O¹² ; Kuhr J¹³ Show All Authors
Source: European Respiratory Journal Published:2010

Abstract

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. Copyright©ERS 2010.