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Original Research: PULMONARY FUNCTION |

Comparison of Pulmonary Function in Immigrant vs US-Born Asian Indians FREE TO VIEW

Ashok Fulambarker, MD, FCCP; Ahmet Sinan Copur, MD; Mark E. Cohen, PhD; Monali Patel, MD; Sanjay Gill, MD; Stephen T. Schultz, PhD; Philip H. Quanjer, MD, PhD
Author and Funding Information

From the Pulmonary Division (Drs Fulambarker, Copur, Patel, and Gill), Rosalind Franklin University of Medicine and Science/ The Chicago Medical School, Chicago, IL; the Naval Institute for Dental and Biomedical Research (Drs Cohen and Schultz), Great Lakes, IL; and the Departments of Pulmonary Diseases and Pediatrics (Dr Ouanjer), Erasmus Medical Centre, Sophia Children’s Hospital, Erasmus University, Rotterdam, The Netherlands.

Correspondence to: Ashok Fulambarker, MD, FCCP, Pulmonary Division, Rosalind Franklin University of Medicine and Science/ The Chicago Medical School, 3001 Green Bay Rd, North Chicago, IL 60064; e-mail: ashok.fulambarker@va.gov


Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestpubs.org/site/misc/reprints.xhtml).


© 2010 American College of Chest Physicians


Chest. 2010;137(6):1398-1404. doi:10.1378/chest.09-1911
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Objective:  This study investigated whether there is a difference in pulmonary function between healthy adult US-born Asian Indians and immigrant Asian Indians attributable to country of birth, environmental, and socioeconomic factors.

Design:  FEV1, FVC, and forced mid-expiratory flow between 25% and 75% of vital capacity (FEF25-75) were measured in India-born and US-born subjects residing in the Chicago metropolitan area. Hollingshead Index of Social Position was used to evaluate socioeconomic factors.

Results:  There were 262 India-born (61.8% male), and 200 US-born (50% male) subjects who were healthy lifelong nonsmokers; their age range was 16 to 36 years. US-born Asian Indian men and women were taller and had higher pulmonary function values for height and age compared with immigrant Asian Indian men and women. The differences were most pronounced in women: about 7% for FVC, 9% for FEV1, and 17% for FEF25-75. Immigrant and US-born subjects did not differ in socioeconomic position.

Conclusion:  We conclude that US-born Asian Indian men and women have higher pulmonary function values for age and height compared with immigrant Asian Indian men and women. This probably reflects the effect of differing environmental conditions, which cause year-of-birth trends in lung volumes.

Figures in this Article

Our previous study showed that immigrant Asian Indians have lower pulmonary function values compared with whites in the United States.1 US census data of 2000 show that the Asian Indian population currently living in the United States is increasing, and the US-born Asian Indian population is increasing as a consequence.2 There are no studies in the medical literature regarding lung function in US-born Asian Indians. Although race is a well-known determinant of pulmonary function, environmental and socioeconomic factors are also known to affect lung function.3

There are few studies that compare pulmonary function in the same ethnic population living in two different environments. Japanese Americans were shown to produce larger flow-volume curves and to be taller compared with Japanese from Japan.4 Asian Indians who were born in African Guyana had smaller lung volumes compared with Africans.5 Independent of smoking and respiratory disease, Nigerians had lower age and height-adjusted FVC and FEV1 than African Americans of both genders; however, relative lung function was better among Nigerians.6 On the other hand, no significant differences were reported in whites living in Europe, Australia, and North America.7-9

We performed this study to determine if there is a difference in pulmonary function between US-born and immigrant Asian Indians. We hypothesized that if the lung function in US-born Asian Indians was different from that of immigrant Asian Indians, this might be because of differences in environmental and socioeconomic conditions or to differences in lung development in early childhood.

Recruitment

This study included 462 subjects recruited over a period of 10 years, 1995 to 2005. Healthy adult subjects of both sexes were recruited from a population of nonsmoking Asian Indians residing in the Chicago metropolitan area. The subjects were divided into India-born immigrants and US-born Asian Indians. Immigrant Asian Indians were defined as subjects migrating to the United States from the Asian India continent. Their ages ranged from 16 to 36 years. US-born Asian Indians were born to Asian Indian parents and grew up in the United States. Spirometry was performed in the pulmonary function laboratory at North Chicago Veterans Affairs (VA) Medical Center or at festivals, picnics, and ceremonies where subjects could be conveniently recruited. Some subjects were VA Medical Center medical residents and nursing staff. The research protocol was reviewed and approved by the Institutional Review Board of the VA Medical Center, which consists of the Research and Development Committee and The Human Studies Subcommittee. The protocol was also approved by the Institutional Review Board Committee of the Rosalind Franklin University of Medicine and Science, North Chicago, IL.

Interview and Clinical Examination

Positive smoking status was defined by any answer indicating prior or current history of smoking cigarettes, pipe, or cigars, or marijuana use. Smokers were excluded.3 All subjects were screened by means of a self-administered health questionnaire10 to exclude cardiopulmonary or other diseases that might affect pulmonary function. Specifically, subjects with a history of asthma, chronic bronchitis, chronic cough, exposure to any toxic chemicals, or surgery involving the chest wall were not eligible. Subjects who were unable to perform spirometry according to American Thoracic Society (ATS) guidelines were excluded. Spirometry was postponed if the subjects had any flulike illness or cold. Age was recorded to the nearest year; height was entered to the nearest inch and converted to centimeters, and body weight was recorded in each case. Hollingshead Socioeconomic Index (HSI)11 was introduced later in the study and was obtained in only 203 subjects (96 US-born and 107 immigrant subjects).

Participant Preparation, Equipment, and Quality Assurance

All subjects signed an informed consent document. After the purpose of the tests and the methods to be used were explained to the subjects, spirometric testing was performed by trained personnel using a Winspiro Spirotech spirometer. The same spirometer was used both in and out of the laboratory. The ATS guidelines for spirometry were strictly followed.3,12

Spirometry was performed in a sitting position. Acceptability criteria also included spirograms free from artifacts, having good starts with extrapolated volume less than 5% of FVC or 0.15 L, whichever was greater, and satisfactory exhalation of 6 s or a plateau in the volume-time curve. Three acceptable spirograms were obtained; the two largest FEV1 and FVC values had to agree within 0.2 L of each other. The largest values were used in the analyses. Forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) was derived from the FVC maneuver with the highest sum of FVC plus FEV1.

Statistical Analysis

Results from 13 participants whose spirometry test sessions did not meet the ATS standards for acceptability and reproducibility were excluded from all analyses.We needed to modeled lung function indices as a function of age, height, and sex. In addition, the model needed to allow for smooth changes across the age range. We therefore used generalized additive modeling of location, scale, and shape (GAMLSS).13 This technique offers a choice of error distributions, uses the Box-Cox power transform to obtain near-normal data distributions, and allows the user to model the median and the coefficient of variation using cubic smoothing splines. In addition it allows modeling of additive and multiplicative relationships. All models were fitted using the package GAMLSS14 in R (version 2.9.2) (R Foundation for Statistical Computing; Vienna, Austria).15

We used the normal and the Box-Cox-Cole-Green distributions, and the Box-Cox power exponential distribution to test for nonnormal kurtosis. Given the wide range of models that may be tested we adopted the stepwise approach advocated by Cole and colleagues16 (in all analyses first establish whether age and height are both required in modeling the median and whether any height-age relationship is additive or multiplicative); subsequently we fitted cubic splines. The process was then repeated for the coefficient of variation, subsequently for skewness. Finally we tested for differences between centers in the predicted median and in the variability. The model with the smallest Schwarz Bayesian criterion within a family of models was selected. The final choice of the most appropriate and parsimonious model was based on inspection of worm plots,17 QQ-plots, and the distribution of residuals.

Multiple linear regression analysis was applied to observed lung function values as a function of standing height, age, and country of birth. The FEV1, FVC, FEV1/FVC, and FEF25-75 were dependent variables, whereas height and age were independent variables. To facilitate inspection of the magnitude of differences in predicted values, these were determined for each dependent variable for a subject age 25 years and of average height: 175 cm for men and 165 cm for women. Explained variances (R2), and residual standard deviations were also reported. P values ≤ 0.05 were considered to be significant. Statistical analysis was done using R version 2.9.2 statistical software.15

Two hundred sixty-two India-born (162 men and 100 women), and 200 US-born (100 men and 100 women) subjects met the inclusion criteria. Subject characteristics are displayed in Table 1. Age ranged between 16 and 36 years in all groups. Age distribution for each group is shown in Table 2. Heights ranged from 152 to 188 cm (mean 175.8 ± 6.2) for men and 150 to 174 cm (mean 161.8 ± 6.1) for women in the US-born group. In the immigrant group, heights ranged from 157 to 193 cm (173.8 ± 6.3 cm) for men and 127 to 183 cm (159.7 ± 6.7 cm) for women. Height as a spline function of age revealed a slight difference between groups (P = .0544) in men, but not in women (P = .091). Weight did not differ significantly between the groups. The HSI yielded a high score with no differences between groups by using χ2 test (P > .05).

Table Graphic Jump Location
Table 1 —Characteristics of Immigrant and US-Born Asian Indians

Values are given as mean ± SD or number of subjects for each category for the HSI. Height as a spline function of age revealed a slight difference between groups (P = .0544) in men but not in women (P = .091). Weight did not differ significantly between the groups. The HSI yielded a high score with no differences between groups by using χ2 test (P > .05). FEF25-75 = forced expiratory flow between 25% and 75% of vital capacity; HSI = Hollingshead Socioeconomic Index.

Table Graphic Jump Location
Table 2 —Age Distribution for Immigrant and US-Born Asian Indians

In view of the age differences between groups, pulmonary function might be on the rise in the youngest subjects and on the decline in the older adults. However, analysis with cubic splines (GAMLSS) did not reveal such a pattern; in fact, a conventional linear regression equation (using SPSS) (SPSS Inc; Chicago, IL) best described the relationships, log transformation leading to the best results. Conventional multiple linear regression analysis of pooled data with adjustment of the intercept for country of birth showed a highly significant difference between spirometric indices in men and women, and consistent interaction with country of birth in women. Regression equations were then obtained for FEV1, FVC, FEV1/FVC, and FEF25-75 (Table 3) for sexes separately, using country of birth as a categorical variable. In women, country of birth contributed significantly to all predicted values; in men born in the United States there was a consistent tendency for values to be higher, which was statistically significant for the FVC (Table 3). These equations were used to generate predicted values for FEV1, FVC, FEV1/FVC, and FEF25-75 for age 25 years at an average height 175 cm (165 cm for women) (Table 4). In US-born women the FVC was on average 7%, the FEV1 9%, and FEF25-75 17% higher (Table 4) than in immigrant women. Figures 1 and 21,18-24 illustrate predicted values for FEV1 and FVC for US-born and immigrant Asian Indian men and women, predicted values based on published equations from the Indian subcontinent, and for white Americans.

Table Graphic Jump Location
Table 3 —Prediction Equations for US-Born and Immigrant Asian Indian Men and Women

Volumes and flows are in L and L/s, respectively. A = age (y); CoB = country of birth, where India-born = 0, and USA-born = 1; H = height (cm); ln = natural logarithm; R2 = explained variance; RSD = residual standard deviation. See Table 1 for expansion of other abbreviation.

a 

P > .05.

Table Graphic Jump Location
Table 4 —Predicted Pulmonary Function Values for a 25-y-Old Asian Indian Man and Woman of About Average Height (175 cm in men, 165 cm in women)

See Table 1 for expansion of abbreviation.

Figure Jump LinkFigure 1. Predicted values for FEV1 in men (175 cm) and women (165 cm) for white Americans (S) and people of Indian extraction. Dashed lines represent results from the present study. C = Chatterjee et al18,19; F = Fulambarker et al1, J = Jindal and Wahi20; M = Memon et al21; S = Stanojevic et al22; U = Udupihille23; V = Vijayan et al24.Grahic Jump Location
Figure Jump LinkFigure 2. Predicted values for FVC in men (175 cm) and women (165 cm) for white Americans (S) and persons of Indian extraction. Dashed lines represent results from the present study. C = Chatterjee et al18,19; F = Fulambarker et al1, J = Jindal and Wahi20; M = Memon et al21; S = Stanojevic et al22; U = Udupihille23; V = Vijayan et al24.Grahic Jump Location

We found that for the same age and height US-born Asian Indian men and women have higher pulmonary function values compared with immigrant Asian Indian men and women. The differences are significant for FEV1, FVC, FEV1/FVC, and FEF25-75 in women. White American men aged 16 to 36 years who participated in the National Health and Nutrition Examination Survey III study25 were significantly taller than US-born and India-born Indians by 2.0 and 4.4 cm, respectively; the same applied to women (2.1 and 4.7 cm difference).

Pulmonary function values in immigrant Asian Indians are grossly comparable with published data from the Indian subcontinent (Figs 1, 2). We anticipated some growth in the youngest subjects and limited decline in the eldest ones, but appropriate statistical techniques did not reveal any dependence of pulmonary function on age. This is because of the relatively small age range in this study, which is associated with a transitional plateau in function from the end of the adolescent growth to a decrease with advancing age. This explains the difference with our previous prediction equation.1 Vijayan and colleagues,24 who also investigated Asian Indians with a limited age range (15-40 years), similarly found a plateau. In the same age range Stanojevic et al22 also found a near plateau in American whites (Figs 1, 2) in the National Health and Nutrition Examination Survey III data.

The lower pulmonary function, adjusted for differences in age and height, in immigrant than in US-born Asian Indians is unlikely to be genetically determined, but might be related to environmental, socioeconomic, and nutritional factors. We used the HSI questionnaire for socioeconomic factors between groups. Both groups showed high educational and income levels. US-born Asian Indians as well as immigrant Asian Indians were mainly college or university students. As a result no significant socioeconomic educational differences were observed between these two groups. However, India and the United States are dissimilar in terms of health care, socioeconomic level and life standards.26 Many studies, including that of Asian Indian children,27,28 demonstrated that lower socioeconomic status was associated with lower pulmonary function in both children and adults.29-32 Lower educational attainment was a predictor of rapid FEV1 decline.33 The Copenhagen Heart Study demonstrated that education and income were independently and positively associated with FEV1 and FVC.32

Factors such as social class, income, education, family size, urban or rural location, housing, overcrowding, and nutrition have all been implicated in the differences in height between successive cohorts.34,35 In both sexes, US-born subjects were taller than the immigrant group. In similar studies Japanese Americans were taller compared with those living in Japan,4 and also had larger lung volumes4,36 for the same age and height. This is in agreement with the finding that Asian Indian adolescents born in the United Kingdom had longer legs than immigrant children.28 In the developing world poor growth in infancy (ie, in the first 1-2 years of life), leads to reduced height for age.34 As conditions improve individuals grow taller, more so because of an increase in leg length than in trunk size. Thus the sitting height/height ratio changes,37 coming closer to that for American whites. Indeed, ethnic differences in lung volumes are often found to be considerably smaller when related to sitting than to standing height28,38; differences in body proportions may also underlie the differences in lung volumes between groups. This is in keeping with the impact of differences in socioeconomic status on lung function in Asian Indian children over and above an effect on anthropometric indices, attributable to different living conditions and dietary habits.27 Thus it is most likely that differences in living conditions and dietary habits in early childhood are responsible for the fact that American-born Asian Indians develop larger lungs for age and height than those born in India. This represents the cohort-related differences in height and lung volumes previously reported within countries.34,37,39-43 Levels of indoor or outdoor particulate air pollution during early life or later vary greatly within Indian cities and urban areas, and greatly exceed levels in Chicago.26

Significant outdoor air pollution in Indian cities as well as indoor air pollution caused by using biomass fuel for heating and cooking may affect lung function.44 Another factor could be childhood respiratory diseases. Better access to the health system and better vaccination coverage in the United States may decrease the prevalence of respiratory disease and preserve lung function. Swimming and living at altitude, especially high altitude (> 3,000 m), may increase lung volumes,45 but these are unlikely to have contributed to our findings.

Although US-born Asian Indians had higher pulmonary function compared with the immigrant group, these were significantly lower compared with whites in the United States (Figs 1, 2). This reflects true ethnic differences in physiology between Asian Indians and whites that remain after taking into account anthropometric variables.28,38,46

Our study has some limitations. The first one is the limited age range. We could not recruit US-born Asian Indians older than age 36 because most of the Asian Indians are immigrant in this country, and US-born Asian Indians as a first generation still make a very young population. This precluded investigating whether the time-related trend in growth of body dimensions and lung volumes equally affected older birth cohorts. Because most, if not all, of the differences between cohorts are believed to develop in the first 2 years of life,34,35 including children and adolescents in the study would have allowed us to shed light on the temporal development of differences between cohorts born in the United States and in India. Another limitation is that we did not include factors other than socioeconomic index and age of immigration as explanatory variables for differences in pulmonary function. Such data might have helped to explain the finding that pulmonary function in Indian women differed much more from their American counterparts than men. Finally, because the study subjects were not a random sample of the Asian Indian population, we cannot exclude that some selection bias may have occurred. However, the Asian Indian community living in the United States generally comes together during these kinds of events, so that any selection bias will be quite limited. In both groups we had a significant contribution from medical workers of Asian Indian origin. Also, most Asian Indians coming to the United States originate from well-educated middle working class. Accordingly, we could not find any lower index individuals, the small range precluding firm conclusions about the relationship between socioeconomic index and pulmonary function.

In conclusion, US-born Asian Indians show higher pulmonary function compared with immigrant Asian Indians. These differences most likely reflect differing environmental and socioeconomic conditions in the country of birth leading to birth cohort-related trends in lung development and growth; such differences should be taken into account when interpreting pulmonary function in these groups.

Author contributions:Dr Fulambarker: contributed to conception and design of the original idea, data analysis, and draft of the manuscript.

Dr Copur: contributed to data collection, conception and design of the original idea, data analysis, and draft of the manuscript.

Dr Cohen: contributed to data collection, conception and design of the original idea, data analysis, and draft of the manuscript.

Dr Patel: contributed to data collection, conception and design of the original idea, data analysis, and draft of the manuscript.

Dr Gill: contributed to data collection, conception and design of the original idea, data analysis, and draft of the manuscript.

Dr Schultz: contributed to conception and design of the original idea, data analysis, and draft of the manuscript.

Dr Quanjer: contributed to data analysis and draft of the manuscript.

Financial/nonfinancial disclosures: The authors have reported to CHEST that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

ATS

American Thoracic Society

FEF2-7

forced expiratory flow between 2% and 7% of vital capacity

GAMLSS

generalized additive modeling of location, scale, and shape

HSI

Hollingshead socioeconomic index

VA

Veterans Affairs

Fulambarker A, Copur AS, Javeri A, Jere S, Cohen ME. Reference values for pulmonary function in Asian Indians living in the United States. Chest. 2004;1264:1225-1233. [CrossRef] [PubMed]
 
US Bureau of the CensusUS Bureau of the Census Census of Population and Housing. Summary Population and Housing Characteristics. 2000; Washington, DC United States CPH
 
American Thoracic SocietyAmerican Thoracic Society Standardization of spirometry, 1994 update. Am J Respir Crit Care Med. 1995;1523:1107-1136. [PubMed]
 
Massey DG, Fournier-Massey G. Japanese-American pulmonary reference values: influence of environment on anthropology and physiology. Environ Res. 1986;392:418-433. [CrossRef] [PubMed]
 
Miller GJ, Ashcroft MT, Swan AV, Beadnell HMSG. Ethnic variation in forced expiratory volume and forced vital capacity of African and Indian adults in Guyana. Am Rev Respir Dis. 1970;1026:979-981. [PubMed]
 
Gathuru IM, Bunker CH, Ukoli FA, Egbagbe EE. Differences in rates of obstructive lung disease between Africans and African Americans. Ethn Dis. 2002;124S3:107-113
 
Gore CJ, Crockett AJ, Pederson DG, Booth ML, Bauman A, Owen N. Spirometric standards for healthy adult lifetime nonsmokers in Australia. Eur Respir J. 1995;85:773-782. [PubMed]
 
Castellsagué J, Burgos F, Sunyer J, Barberà JA, Roca J. Prediction equations for forced spirometry from European origin populations. Barcelona Collaborative Group on Reference Values for Pulmonary Function Testing and the Spanish Group of the European Community Respiratory Health Survey. Respir Med. 1998;923:401-407. [CrossRef] [PubMed]
 
Roca J, Burgos F, Sunyer J, et al. References values for forced spirometry. Group of the European Community Respiratory Health Survey. Eur Respir J. 1998;116:1354-1362. [CrossRef] [PubMed]
 
Ferris BG. Epidemiology standardization project (American Thoracic Society). Am Rev Respir Dis. 1978;1186 pt 2:1-120. [PubMed]
 
Hollingshead AB. Two Factor Index of Social Position. 1957; New Haven, CT A.B. Hollingshead
 
American Thoracic SocietyAmerican Thoracic Society Lung function testing: selection of reference values and interpretative strategies. Am Rev Respir Dis. 1991;1445:1202-1218. [CrossRef] [PubMed]
 
Rigby RA, Stasinopoulos DM. Generalized additive models for location, scale and shape (with Discussion). Appl Stat. 2005;543:507-544
 
Stasinopoulos M, Rigby B, Akantziliotou C. GAMLSS: Generalized Additive Models for Location Scale and Shape. R package version 1.9-4. 2008;Accessed November 15,2009 Vienna, Austria R Foundation for Statistical Computing http://www.gamlss.com/.
 
R Development Core TeamR Development Core Team R: A Language and Environment for Statistical Computing. 2008; Vienna, Austria R Foundation for Statistical Computing
 
Cole TJ, Stanojevic S, Stocks J, Coates AL, Hankinson JL, Wade AM. Age- and size-related reference ranges: a case study of spirometry through childhood and adulthood. Stat Med. 2009;285:880-898. [CrossRef] [PubMed]
 
van Buuren S, Fredriks M. Worm plot: a simple diagnostic device for modelling growth reference curves. Stat Med. 2001;208:1259-1277. [CrossRef] [PubMed]
 
Chatterjee S, Nag SK, Dey SK. Spirometric standards for non-smokers and smokers of India (eastern region). Jpn J Physiol. 1988;383:283-298. [CrossRef] [PubMed]
 
Chatterjee S, Saha D. Pulmonary function studies in healthy non-smoking women of Calcutta. Ann Hum Biol. 1993;201:31-38. [CrossRef] [PubMed]
 
Jindal SK, Wahi PL.Sharma OP. Pulmonary function laboratory in the tropics: needs, problems and solutions. Lung Disease in the Tropics. 1991; New York, NY Marcel Dekker:523-542
 
Memon MA, Sandila MP, Ahmed ST. Spirometric reference values in healthy, non-smoking, urban Pakistani population. J Pak Med Assoc. 2007;574:193-195. [PubMed]
 
Stanojevic S, Wade A, Stocks J, et al. Reference ranges for spirometry across all ages: a new approach. Am J Respir Crit Care Med. 2008;1773:253-260. [CrossRef] [PubMed]
 
Udupihille M. Spirometric and flow standards for healthy adult non-smoking Sri Lankans belonging to the Sinhalese ethnic group. Ann Hum Biol. 1995;224:321-336. [CrossRef] [PubMed]
 
Vijayan VK, Kuppurao KV, Venkatesan P, Sankaran K, Prabhakar R. Pulmonary function in healthy young adult Indians in Madras. Thorax. 1990;458:611-615. [CrossRef] [PubMed]
 
National Center for Health StatisticsNational Center for Health Statistics Third National Health and Nutrition Examination Survey, 1988–1994, NHANES III Household Adult Data File and Examination Data File (CD-ROM, series 11, No.1). 1997; Hyattsville, MD Centers for Disease Control and Prevention Public Use Data File Documentation Number 76200.
 
World Bank WebsiteWorld Bank WebsiteAccessed October 20, 2008 http://web.worldbank.org/WBSITE/EXTERNAL/Countries/dataand statistics.
 
Raju PS, Prasad KVV, Ramana YV, Balakrishna N, Murthy KJR. Influence of socioeconomic status on lung function and prediction equations in Indian children. Pediatr Pulmonol. 2005;396:528-536. [CrossRef] [PubMed]
 
Whitrow MJ, Harding S. Ethnic differences in adolescent lung function: anthropometric, socioeconomic, and psychosocial factors. Am J Respir Crit Care Med. 2008;17711:1262-1267. [CrossRef] [PubMed]
 
Demissie K, Ernst P, Hanley JA, Locher U, Menzies D, Becklake MR. Socioeconomic status and lung function among primary school children in CanadaAm J Respir Crit Care Med. 1996;1532:719-723. [PubMed]
 
Vedal S, Schenker MB, Samet JM, Speizer FE. Risk factors for childhood respiratory disease. Analysis of pulmonary function. Am Rev Respir Dis. 1984;1302:187-192. [PubMed]
 
Steinberg M, Becklake MR. Socio-environmental factors and lung function. S Afr Med J. 1986;705:270-274. [PubMed]
 
Prescott E, Lange P, Vestbo J. Socioeconomic status, lung function and admission to hospital for COPD: results from the Copenhagen City Heart Study. Eur Respir J. 1999;135:1109-1114. [CrossRef] [PubMed]
 
Burchfiel CM, Marcus EB, Sharp DS, et al. Characteristics associated with rapid decline in forced expiratory volume. Ann Epidemiol. 1996;63:217-227. [CrossRef] [PubMed]
 
Cole TJ. Secular trends in growth. Proc Nutr Soc. 2000;592:317-324. [CrossRef] [PubMed]
 
Kuzawa CW. Developmental origins of life history: growth, productivity, and reproduction. Am J Hum Biol. 2007;195:654-661. [CrossRef] [PubMed]
 
Raven PB, Taguchi S, Drinkwater BL, Kaneko M, Horvath SM, Matsui H. Anthropometric, spirometric, and physiologic comparisons of migrant Japanese. Hum Biol. 1974;463:483-494. [PubMed]
 
Tanner JM, Hayashi T, Preece MA, Cameron N. Increase in length of leg relative to trunk in Japanese children and adults from 1957 to 1977: comparison with British and with Japanese Americans. Ann Hum Biol. 1982;95:411-423. [CrossRef] [PubMed]
 
Harik-Khan RI, Fleg JL, Muller DC, Wise RA. The effect of anthropometric and socioeconomic factors on the racial difference in lung function. Am J Respir Crit Care Med. 2001;1649:1647-1654. [PubMed]
 
Glindmeyer HW, Diem JE, Jones RN, Weill H. Noncomparability of longitudinally and cross-sectionally determined annual change in spirometry. Am Rev Respir Dis. 1982;1255:544-548. [PubMed]
 
van Pelt W, Borsboom GJJM, Rijcken B, Schouten JP, van Zomeren BC, Quanjer PH. Discrepancies between longitudinal and cross-sectional change in ventilatory function in 12 years of follow-up. Am J Respir Crit Care Med. 1994;1495:1218-1226. [PubMed]
 
Xu X, Laird N, Dockery DW, Schouten JP, Rijcken B, Weiss ST. Age, period, and cohort effects on pulmonary function in a 24-year longitudinal study. Am J Epidemiol. 1995;1416:554-566. [PubMed]
 
Kerstjens HA, Rijcken B, Schouten JP, Postma DS. Decline of FEV1 by age and smoking status: facts, figures, and fallacies. Thorax. 1997;529:820-827. [CrossRef] [PubMed]
 
Ip MSM, Karlberg EM, Karlberg JPE, Luk KDK, Leong JCY. Lung function reference values in Chinese children and adolescents in Hong Kong. I. Spirometric values and comparison with other populations. Am J Respir Crit Care Med. 2000;1622 Pt 1:424-429. [PubMed]
 
Smith KR. Inaugural article: national burden of disease in India from indoor air pollution. Proc Natl Acad Sci U S A. 2000;9724:13286-13293. [CrossRef] [PubMed]
 
Gaultier C, Crapo R. Effects of nutrition, growth hormone disturbances, training, altitude and sleep on lung volumes. Eur Respir J. 1997;1012:2913-2919. [CrossRef] [PubMed]
 
Korotzer B, Ong S, Hansen JE. Ethnic differences in pulmonary function in healthy nonsmoking Asian-Americans and European-Americans. Am J Respir Crit Care Med. 2000;1614 Pt 1:1101-1108. [PubMed]
 

Figures

Figure Jump LinkFigure 1. Predicted values for FEV1 in men (175 cm) and women (165 cm) for white Americans (S) and people of Indian extraction. Dashed lines represent results from the present study. C = Chatterjee et al18,19; F = Fulambarker et al1, J = Jindal and Wahi20; M = Memon et al21; S = Stanojevic et al22; U = Udupihille23; V = Vijayan et al24.Grahic Jump Location
Figure Jump LinkFigure 2. Predicted values for FVC in men (175 cm) and women (165 cm) for white Americans (S) and persons of Indian extraction. Dashed lines represent results from the present study. C = Chatterjee et al18,19; F = Fulambarker et al1, J = Jindal and Wahi20; M = Memon et al21; S = Stanojevic et al22; U = Udupihille23; V = Vijayan et al24.Grahic Jump Location

Tables

Table Graphic Jump Location
Table 1 —Characteristics of Immigrant and US-Born Asian Indians

Values are given as mean ± SD or number of subjects for each category for the HSI. Height as a spline function of age revealed a slight difference between groups (P = .0544) in men but not in women (P = .091). Weight did not differ significantly between the groups. The HSI yielded a high score with no differences between groups by using χ2 test (P > .05). FEF25-75 = forced expiratory flow between 25% and 75% of vital capacity; HSI = Hollingshead Socioeconomic Index.

Table Graphic Jump Location
Table 2 —Age Distribution for Immigrant and US-Born Asian Indians
Table Graphic Jump Location
Table 3 —Prediction Equations for US-Born and Immigrant Asian Indian Men and Women

Volumes and flows are in L and L/s, respectively. A = age (y); CoB = country of birth, where India-born = 0, and USA-born = 1; H = height (cm); ln = natural logarithm; R2 = explained variance; RSD = residual standard deviation. See Table 1 for expansion of other abbreviation.

a 

P > .05.

Table Graphic Jump Location
Table 4 —Predicted Pulmonary Function Values for a 25-y-Old Asian Indian Man and Woman of About Average Height (175 cm in men, 165 cm in women)

See Table 1 for expansion of abbreviation.

References

Fulambarker A, Copur AS, Javeri A, Jere S, Cohen ME. Reference values for pulmonary function in Asian Indians living in the United States. Chest. 2004;1264:1225-1233. [CrossRef] [PubMed]
 
US Bureau of the CensusUS Bureau of the Census Census of Population and Housing. Summary Population and Housing Characteristics. 2000; Washington, DC United States CPH
 
American Thoracic SocietyAmerican Thoracic Society Standardization of spirometry, 1994 update. Am J Respir Crit Care Med. 1995;1523:1107-1136. [PubMed]
 
Massey DG, Fournier-Massey G. Japanese-American pulmonary reference values: influence of environment on anthropology and physiology. Environ Res. 1986;392:418-433. [CrossRef] [PubMed]
 
Miller GJ, Ashcroft MT, Swan AV, Beadnell HMSG. Ethnic variation in forced expiratory volume and forced vital capacity of African and Indian adults in Guyana. Am Rev Respir Dis. 1970;1026:979-981. [PubMed]
 
Gathuru IM, Bunker CH, Ukoli FA, Egbagbe EE. Differences in rates of obstructive lung disease between Africans and African Americans. Ethn Dis. 2002;124S3:107-113
 
Gore CJ, Crockett AJ, Pederson DG, Booth ML, Bauman A, Owen N. Spirometric standards for healthy adult lifetime nonsmokers in Australia. Eur Respir J. 1995;85:773-782. [PubMed]
 
Castellsagué J, Burgos F, Sunyer J, Barberà JA, Roca J. Prediction equations for forced spirometry from European origin populations. Barcelona Collaborative Group on Reference Values for Pulmonary Function Testing and the Spanish Group of the European Community Respiratory Health Survey. Respir Med. 1998;923:401-407. [CrossRef] [PubMed]
 
Roca J, Burgos F, Sunyer J, et al. References values for forced spirometry. Group of the European Community Respiratory Health Survey. Eur Respir J. 1998;116:1354-1362. [CrossRef] [PubMed]
 
Ferris BG. Epidemiology standardization project (American Thoracic Society). Am Rev Respir Dis. 1978;1186 pt 2:1-120. [PubMed]
 
Hollingshead AB. Two Factor Index of Social Position. 1957; New Haven, CT A.B. Hollingshead
 
American Thoracic SocietyAmerican Thoracic Society Lung function testing: selection of reference values and interpretative strategies. Am Rev Respir Dis. 1991;1445:1202-1218. [CrossRef] [PubMed]
 
Rigby RA, Stasinopoulos DM. Generalized additive models for location, scale and shape (with Discussion). Appl Stat. 2005;543:507-544
 
Stasinopoulos M, Rigby B, Akantziliotou C. GAMLSS: Generalized Additive Models for Location Scale and Shape. R package version 1.9-4. 2008;Accessed November 15,2009 Vienna, Austria R Foundation for Statistical Computing http://www.gamlss.com/.
 
R Development Core TeamR Development Core Team R: A Language and Environment for Statistical Computing. 2008; Vienna, Austria R Foundation for Statistical Computing
 
Cole TJ, Stanojevic S, Stocks J, Coates AL, Hankinson JL, Wade AM. Age- and size-related reference ranges: a case study of spirometry through childhood and adulthood. Stat Med. 2009;285:880-898. [CrossRef] [PubMed]
 
van Buuren S, Fredriks M. Worm plot: a simple diagnostic device for modelling growth reference curves. Stat Med. 2001;208:1259-1277. [CrossRef] [PubMed]
 
Chatterjee S, Nag SK, Dey SK. Spirometric standards for non-smokers and smokers of India (eastern region). Jpn J Physiol. 1988;383:283-298. [CrossRef] [PubMed]
 
Chatterjee S, Saha D. Pulmonary function studies in healthy non-smoking women of Calcutta. Ann Hum Biol. 1993;201:31-38. [CrossRef] [PubMed]
 
Jindal SK, Wahi PL.Sharma OP. Pulmonary function laboratory in the tropics: needs, problems and solutions. Lung Disease in the Tropics. 1991; New York, NY Marcel Dekker:523-542
 
Memon MA, Sandila MP, Ahmed ST. Spirometric reference values in healthy, non-smoking, urban Pakistani population. J Pak Med Assoc. 2007;574:193-195. [PubMed]
 
Stanojevic S, Wade A, Stocks J, et al. Reference ranges for spirometry across all ages: a new approach. Am J Respir Crit Care Med. 2008;1773:253-260. [CrossRef] [PubMed]
 
Udupihille M. Spirometric and flow standards for healthy adult non-smoking Sri Lankans belonging to the Sinhalese ethnic group. Ann Hum Biol. 1995;224:321-336. [CrossRef] [PubMed]
 
Vijayan VK, Kuppurao KV, Venkatesan P, Sankaran K, Prabhakar R. Pulmonary function in healthy young adult Indians in Madras. Thorax. 1990;458:611-615. [CrossRef] [PubMed]
 
National Center for Health StatisticsNational Center for Health Statistics Third National Health and Nutrition Examination Survey, 1988–1994, NHANES III Household Adult Data File and Examination Data File (CD-ROM, series 11, No.1). 1997; Hyattsville, MD Centers for Disease Control and Prevention Public Use Data File Documentation Number 76200.
 
World Bank WebsiteWorld Bank WebsiteAccessed October 20, 2008 http://web.worldbank.org/WBSITE/EXTERNAL/Countries/dataand statistics.
 
Raju PS, Prasad KVV, Ramana YV, Balakrishna N, Murthy KJR. Influence of socioeconomic status on lung function and prediction equations in Indian children. Pediatr Pulmonol. 2005;396:528-536. [CrossRef] [PubMed]
 
Whitrow MJ, Harding S. Ethnic differences in adolescent lung function: anthropometric, socioeconomic, and psychosocial factors. Am J Respir Crit Care Med. 2008;17711:1262-1267. [CrossRef] [PubMed]
 
Demissie K, Ernst P, Hanley JA, Locher U, Menzies D, Becklake MR. Socioeconomic status and lung function among primary school children in CanadaAm J Respir Crit Care Med. 1996;1532:719-723. [PubMed]
 
Vedal S, Schenker MB, Samet JM, Speizer FE. Risk factors for childhood respiratory disease. Analysis of pulmonary function. Am Rev Respir Dis. 1984;1302:187-192. [PubMed]
 
Steinberg M, Becklake MR. Socio-environmental factors and lung function. S Afr Med J. 1986;705:270-274. [PubMed]
 
Prescott E, Lange P, Vestbo J. Socioeconomic status, lung function and admission to hospital for COPD: results from the Copenhagen City Heart Study. Eur Respir J. 1999;135:1109-1114. [CrossRef] [PubMed]
 
Burchfiel CM, Marcus EB, Sharp DS, et al. Characteristics associated with rapid decline in forced expiratory volume. Ann Epidemiol. 1996;63:217-227. [CrossRef] [PubMed]
 
Cole TJ. Secular trends in growth. Proc Nutr Soc. 2000;592:317-324. [CrossRef] [PubMed]
 
Kuzawa CW. Developmental origins of life history: growth, productivity, and reproduction. Am J Hum Biol. 2007;195:654-661. [CrossRef] [PubMed]
 
Raven PB, Taguchi S, Drinkwater BL, Kaneko M, Horvath SM, Matsui H. Anthropometric, spirometric, and physiologic comparisons of migrant Japanese. Hum Biol. 1974;463:483-494. [PubMed]
 
Tanner JM, Hayashi T, Preece MA, Cameron N. Increase in length of leg relative to trunk in Japanese children and adults from 1957 to 1977: comparison with British and with Japanese Americans. Ann Hum Biol. 1982;95:411-423. [CrossRef] [PubMed]
 
Harik-Khan RI, Fleg JL, Muller DC, Wise RA. The effect of anthropometric and socioeconomic factors on the racial difference in lung function. Am J Respir Crit Care Med. 2001;1649:1647-1654. [PubMed]
 
Glindmeyer HW, Diem JE, Jones RN, Weill H. Noncomparability of longitudinally and cross-sectionally determined annual change in spirometry. Am Rev Respir Dis. 1982;1255:544-548. [PubMed]
 
van Pelt W, Borsboom GJJM, Rijcken B, Schouten JP, van Zomeren BC, Quanjer PH. Discrepancies between longitudinal and cross-sectional change in ventilatory function in 12 years of follow-up. Am J Respir Crit Care Med. 1994;1495:1218-1226. [PubMed]
 
Xu X, Laird N, Dockery DW, Schouten JP, Rijcken B, Weiss ST. Age, period, and cohort effects on pulmonary function in a 24-year longitudinal study. Am J Epidemiol. 1995;1416:554-566. [PubMed]
 
Kerstjens HA, Rijcken B, Schouten JP, Postma DS. Decline of FEV1 by age and smoking status: facts, figures, and fallacies. Thorax. 1997;529:820-827. [CrossRef] [PubMed]
 
Ip MSM, Karlberg EM, Karlberg JPE, Luk KDK, Leong JCY. Lung function reference values in Chinese children and adolescents in Hong Kong. I. Spirometric values and comparison with other populations. Am J Respir Crit Care Med. 2000;1622 Pt 1:424-429. [PubMed]
 
Smith KR. Inaugural article: national burden of disease in India from indoor air pollution. Proc Natl Acad Sci U S A. 2000;9724:13286-13293. [CrossRef] [PubMed]
 
Gaultier C, Crapo R. Effects of nutrition, growth hormone disturbances, training, altitude and sleep on lung volumes. Eur Respir J. 1997;1012:2913-2919. [CrossRef] [PubMed]
 
Korotzer B, Ong S, Hansen JE. Ethnic differences in pulmonary function in healthy nonsmoking Asian-Americans and European-Americans. Am J Respir Crit Care Med. 2000;1614 Pt 1:1101-1108. [PubMed]
 
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