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Pulmonary Function Test in Normal Healthy School Children Kundan Mittal, Tanu Satija, Jyoti Yadav, K B Gupta, Anupama Mittal Abstract

Pulmonary function tests were studied in 1000 (500 boys and 500 girls) healthy school going children of Rohtak (Haryana) of 10-14 age years. Recording was done by portable Spirolab
1spirometer. Forced Vital Capacity (FVC), Forced Expiratory Volume (FEV1 ), Forced Expiratory Flow (FEF25-75%) showed a significant correlation with age, weight, height, body surface area and body mass index in both sex except for correlation of FEF25-75% with BMI in females. In males, FVC and FEV1 had the best correlation with body surface area followed by weight and age in both males and females. The correlation of FEV1 /FVC% with age, weight, height, body surface area and body mass index was not significant. The mean values of all pulmonary function measurements were higher in boys as compared to girls but statistically significant difference (p<0.001) was found for FVC and FEV1.
Key-words: FEV1, FVC, FEV1 /FVC, FEF25-75%.
Address for correspondence: Kundan Mittal, 227- B, Medical More Rohtak (Haryana)

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Introduction

Respiratory illnesses are leading cause of morbidity and mortality in children. In some pulmonary disorders pulmonary function testing plays an important role in diagnosis, assessment of severity and response to medications1. With great advances in pulmonary physiology and medical instrumentation, pulmonary function testing has come to assume a central place in the practice of pulmonary medicine. During the last few decades, pulmonary function tests have evolved from tools for physiologic study
to clinical investigations and are widely used in assessing the respiratory status in children. These have become a part of routine health examination in respiratory, occupational, sports medicine and as public health screening tool2. Enough data regarding pulmonary function tests in children is available for Caucasian, Negroid, Aboriginal and Chinese children3. Though data on pulmonary function tests of Indian children is available but very few studies in North Indian healthy children are available, especially in healthy children of Haryana4-9. Various factors including age, sex, body build, Body Mass Index are known to affect the pulmonary function tests. Keeping in view all these factors which may affect the normal values, present study was done to have normogram of pulmonary function tests and its correlation with age, sex, weight and body surface area of children aged 10-14 years studying in schools.

Material and methods

Present study was conducted in 1000 healthy school going children aged 10-14 years (500 boys & 500 girls). Simple randomization was carried out for selecting schools and children in various age groups. Children having history of smoking, respiratory infections in preceding three weeks, chronic pulmonary diseases including bronchial asthma, thoracic surgery, systemic diseases which can affect respiratory system and smokers were excluded.
Children and school authorities were explained the aim and objectives of the study and consent was taken from children. Detailed history and clinical examination was performed in all the subjects before doing their pulmonary function tests and the informations were recorded on a predetermined performa. Anthropometric measurements of every child were recorded (Weight in Kg, height in cm, body surface area and body mass index).
Pulmonary function tests were done by using portable spirometer (Spirolab I) from Medical International Research Instrument. Standard methodology for assessment of lung functions as recommended by American Thoracic Society were applied. Student was asked to sit comfortably and nose clipped. Then child was asked to inhale and exhale maximally in one go via mouthpiece with lips tightly sealed around mouth piece. Three acceptable readings were taken and largest of them was recorded for study purpose. Following parameters were recorded in each case; forced vital capacity (FVC), forced expiratory volume in one second
(FEV1 ), FEV1 /FVC % and FEV25-75%.

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Results

One thousand healthy school children divided into four groups had the following observations regarding different pulmonary function tests.
1. FVC, FEV1 , FEF25-75% increased with increase in age and most of the values were found higher in boys than girls of the same age group (table 1).

Table 1. Pulmonary Function Tests in relation to Age and Sex

Age

(Years)

Sex

Number

FVC

(Liter)

FEV1

(Liter)

FEV1 /FVC

(%)

FEF25-75%

(Liter/second)

Male

Female

100

1.89 ± 0.17

1.70 ± 0.14

1.60 ± 0.15

1.45 ± 0.13

85.15 ± 1.39

85.32 ± 1.64

2.30 ± 0.39

2.15 ± 0.19

Male

Female

100

2.00 ± 0.15

1.79 ± 0.15

1.72 ± 0.13

1.53 ± 0.13

85.46 ± 1.35

85.30 ± 1.49

2.62 ± 0.33

2.49 ± 0.63

Male

Female

100

2.04 ± 0.19

2.24 ± 0.17

1.74 ± 0.16

1.90 ± 0.14

85.22 ± 1.38

84.78 ± 1.25

2.50 ± 0.33

2.61 ± 0.27

Male

Female

100

2.57 ± 0.22

2.28 ± 0.23

2.19 ± 0.19

2.15 ± 0.20

85.05 ± 1.59

85.07 ± 1.27

2.91 ± 0.22

3.17 ± 0.20

Male

Female

100

2.63 ± 0.20

2.54 ± 0.27

2.26 ± 0.21

2.18 ± 0.24

85.43 ± 1.91

85.29 ± 1.45

3.36 ± 0.23

3.17 ± 0.60

2. FVC, FEV1 , FEF25-75% increased with increase in weight and were higher in males
than females (table 2).

Table 2. Pulmonary Function Tests in relation to Weight and Sex.

Weight

(kg)

Sex

Number

FVC(Liter)

FEV1 (Liter)

FEV1 /FVC%

FEF25-75%

(Liter/sec)

21-25

Male

Female

1.75 ± 0.08

1.66 ± 0.12

1.50 ± 0.08

1.44 ±0.09

85.36 ± 1.12

86.18 ± 1.57

2.35 ± 0.36

2.15 ± 0.23

26-30

Male

Female

1.84 ± 0.15

1.68 ± 0.15

1.56 ± 0.14

1.43 ± 0.13

85.42 ± 1.31

85.30 ± 1.58

2.29 ± 0.39

2.24 ± 0.75

31-35

Male

Female

1.99 ± 0.21

1.88 ± 0.29

1.70 ± 0.19

1.60 ± 0.25

85.15 ± 1.48

85.14 ± 1.51

2.48 ± 0.41

2.50 ± 0.34

36-40

Male

Female

132

2.06 ± 0.20

2.18 ± 0.25

1.76 ± 0.17

1.85 ± 0.21

85.29 ± 1.42

84.99 ± 1.41

2.52 ± 0.30

2.87 ± 0.41

41-45

Male

Female

138

2.25 ± 0.29

2.28 ± 0.32

1.93 ± 0.29

1.95 ± 0.27

85.06 ± 1.51

85.17 ±1.33

2.78 ± 0.38

2.95 ± 0.61

46-50

Male

Female

119

2.51 ± 0.23

2.35 ± 0.28

2.14 ± 0.20

2.00 ± 0.26

85.25 ± 1.58

85.01 ± 1.53

3.05 ± 0.32

2.85 ± 0.29

51-55

Male

Female

2.63 ± 0.19

2.49 ± 0.33

2.26± 0.18

2.12 ± 0.29

85.41 ± 1.99

85.17 ± 1.13

3.25 ± 0.32

2.90 ± 0.41

56-60

Male

Female

3.02 ± 0.22

2.86 ± 0.15

2.57 ± 0.21

2.47 ± 0.18

84.97 ± 2.14

85.00 ± 0.86

3.40 ± 0.30

3.32 ± 0.49

61-65

Male

Female

2.59 ± 0.00

2.19 ± 0.00

84.50 ± 0.00

3.29 ± 0.00

66-70

Male

Female

3.04 ± 0.15

2.65 ± 0.21

87.10 ± 2.54

3.36 ± 0.78

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3. FVC, FEV1 and FEF25-75% increased with increase in height and were often higher in boys than girls (table 3).

Table 3. Pulmonary Function Tests in relation to Height and Sex.

Height(cm)

Sex

Number

FVC (Liter)

FEV1 (Liter)

FEV1 /FVC%

FEF25-75%

121-125

Male

Female

1.63 ± 0.03

1.51 ± 0.22

1.41 ± 0.06

1.29 ± 0.18

84.83 ± 1.58

85.34 ± 1.30

2.15 ± 0.51

2.30 ± 0.63

126-130

Male

Female

1.75 ± 0.12

1.61 ± 0.09

1.49 ± 0.10

1.39 ± 0.09

85.04 ± 1.60

85.49 ± 1.71

2.32 ± 0.36

2.19 ± 0.26

131-135

Male

Female

1.86 ± 0.14

1.69 ± 0.10

1.58 ± 0.13

1.44 ± 0.08

85.36 ± 1.44

85.11 ± 1.41

2.30 ± 0.37

2.22 ± 0.24

136-140

Male

Female

109

1.97 ± 0.12

1.88 ± 0.17

1.69 ± 0.11

1.60 ± 0.15

85.39 ± 1.34

85.29 ± 1.61

2.46 ± 0.33

2.61 ± 0.87

141-145

Male

Female

2.12 ± 0.14

2.09 ± 0.16

1.81 ± 0.11

1.78 ± 0.13

85.26 ± 1.41

85.20 ± 1.44

2.63 ± 0.36

2.69 ± 0.35

146-150

Male

Female

129

150

2.44 ± 0.23

2.30 ± 0.16

2.10 ± 0.23

1.96 ± 0.15

85.33 ± 1.60

84.99 ± 1.30

3.02 ± 0.40

3.08 ± 0.37

151-155

Male

Female

2.63 ± 0.16

2.55 ± 0.21

2.25 ± 0.15

2.17 ± 0.20

84.95 ± 1.53

84.99 ± 1.50

3.11 ± 0.28

3.18 ± 0.80

156-160

Male

Female

2.72 ± 0.22

2.68 ± 0.27

2.32 ± 0.21

2.29 ± 0.24

85.67 ± 2. 85

85.60 ± 0.99

3.24 ± 0.34

3.18 ± 0.11

161-165

Male

Female

3.04 ± 0.10

3.35 ± 0.29

2.58 ± 0.13

2.72 ± 0.09

84.91 ± 1.72

83.00 ± 2.40

3.34 ± 0.24

3.47 ± 0.58

166-170

Male

Female

3.16 ± 0

2.72 ± 0

86.00 ± 0

2.99 ± 0

4. FVC, FEV1 and FEF25-75% increased with increase in body surface area and were most of the times higher in boys than girls (table 4).

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Table 4. Values of various function tests in relation to BSA and Sex.

BSA(m2)

Sex

Number

FVC (Liter)

FEV1 (Liter)

FEV1 /FVC %

FEF25-75%

(Liter/sec)

0.90-0.98

Male

Female

1.77 ± 0.10

1.63 ± 0.11

1.52 ± 0.08

1.40 ± 0.09

85.42 ± 1.34

85.44 ± 1.84

2.25 ± 0.34

2.10 ± 0.16

0.99-1.07

Male

Female

1.85 ± 0.18

1.69 ± 0.15

1.57 ± 0.17

1.44 ± 0.13

85.08 ± 1.55

85.29 ± 1.45

2.33 ± 0.39

2.30 ± 0.74

1.08-1.16

Male

Female

1.94 ± 0.13

1.76 ± 0.20

1.66 ± 0.11

1.50 ± 0.17

85.43 ± 1.35

85.27 ± 1.62

2.40 ± 0.35

2.34 ± 0.22

1.17-1.25

Male

Female

102

111

2.06 ± 0.19

2.14 ± 0.22

1.76 ± 0.17

1.82 ± 0.18

85.27 ± 1.36

85.05 ± 1.37

2.53 ± 0.35

2.84 ± 0.39

1.26-1.34

Male

Female

143

2.22 ± 0.24

2.24 ± 0.25

1.89 ± 0.20

1.91 ± 0.21

85.07 ± 1.46

85.11 ± 1.40

2.74 ± 0.30

2.90 ± 0.34

1.35-1.42

Male

Female

2.46 ± 0.25

2.42 ± 0.30

2.13 ± 0.27

2.07 ± 0.27

85.37 ± 1.63

84.96 ± 1.45

3.01 ± 0.37

3.03 ± 0.75

1.43-1.50

Male

Female

106

2.62 ± 0.16

2.56 ± 0.36

2.23 ± 0.14

2.19 ± 0.33

85.22 ± 1.57

85.29 ± 1.13

3.18 ± 0.30

2.88 ± 0.32

1.51-1.58

Male

Female

2.86 ± 0.27

2.69 ± 0.16

2.40 ± 0.27

2.31± 0.18

85.63 ± 4.33

85.18 ± 0.52

3.46 ± 0.24

3.32 ± 0.33

1.59-1.66

Male

Female

2.93 ± 0.24

2.83 ± 0.20

2.46 ± 0.25

2.40 ± 0.20

83.63 ± 1.86

84.75 ± 1.06

3.32 ± 0.40

3.03 ± 0.07

1.67-1.74

Male

Female

2.65 ± 0.09

2.29 ± 0.14

86.35 ± 2.61

3.15 ± 0.19

1.75-1.82

Male

Female

3.21 ± 0.00

2.77 ± 0.00

86.2 ± 0.00

3.13 ± 0.00

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5. FVC, FEV1 and FEF25-75% increased with increase in body mass index (BMI) and males mostly had higher values than females (table 5).

Table 5. Pulmonary function tests values in relation to BMI and Sex.

BMI (kg/m2)

Sex

Number

FVC (Liter)

FEV1

(Liter)

FEV1 /FVC

FEF25-75%

(Liter/sec)

12.5-14.19

Male

Female

1.92 ± 0.20

1.78 ± 0.05

1.56 ± 0.19

1.55 ± 0.04

85.58 ± 1.29

86.92 ± 1.45

2.28 ± 0.40

2.36 ± 0.29

14.2-15.89

Male

Female

1.92 ± 0.23

1.96 ± 0.36

1.63 ± 0.20

1.67± 0.30

85.24 ± 1.42

85.51 ± 1.55

2.38 ± 0.43

2.45 ± 0.47

15.90-

17.59

Male

Female

2.06 ± 0.32

2.03 ± 0.38

1.78 ± 0.32

1.72 ± 0.32

85.29 ± 1.22

85.02 ± 1.43

2.53 ± 0.46

2.64 ± 0.53

17.6-19.29

Male

Female

166

2.09 ± 0.34

2.17 ± 0.38

1.78 ± 0.29

1.85 ± 0.23

85.17 ± 1.56

85.05 ± 1.46

2.56 ± 0.40

2.83 ± 0.62

19.3-20.99

Male

Female

2.14 ± 0.24

2.17 ± 0.38

1.83 ± 0.23

1.86 ± 0.27

85.09 ± 1.45

85.38 ± 1.39

2.67 ± 0.41

2.86 ± 0.37

21.0-22.69

Male

Female

159

2.47 ± 0.27

2.18± 0.32

2.11± 0.23

1.86 ± 0.28

85.34 ± 1.76

84.88 ± 1.29

3.00 ± 0.36

2.89 ± 0.40

22.7-24.39

Male

Female

2.49 ± 0.35

2.20 ± 0.20

2.14 ± 0.32

1.87 ± 0.17

85.44 ± 1.57

84.67 ± 1.14

3.19 ± 0.47

2.68 ± 0.30

24.4-26.09

Male

Female

2.31 ± 0.50

2.52 ± 0.57

1.96 ± 0.39

2.14 ± 0.49

84.92 ± 1.43

84.88 ± 1.10

2.96 ± 0.51

2.72 ± 0.53

26.1-27.79

Male

Female

1.8 ± 0

1.6 ± 0

85.1 ± 0

2.83 ± 0

27.8-29.49

Male

Female

2.23± 0.74

1.98 ± 0

2.02 ± 0.66

1.65± 0

85.77 ± 1.87

83.3 ± 0

2.49 ± 0.66

2.13± 0

6. FVC, FEV1 and FEF25-75% showed a significant correlation with age, weight, height, body surface area (BSA) and body mass index (BMI) in both males and females, except for the correlation of FEF25-75% with BMI in females (table 6). In males, FVC and FEV1 had the best correlation with BSA followed by weight and age. FEF25-75% had highest correlation with age in both males and females. The correlation of
FEV1 /FVC% with age, weight, height, BSA and BMI was not significant (table 6).

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Table 6. Correlation coefficients PFTs and Anthropometry

Age/Anthropometric

measurements

Sex

FVC

(Liter)

FEV1

(Liter)

FEV1 /FVC

FEF25-75%

(Liter/second)

Age (Years)

Male

Female

0.798*

0.796*

0.789*

0.797*

0.012

- 0.038

0.706*

0.657*

Weight (Kg)

Male

Female

0.798*

0.673*

0.778*

0.669*

0.020

- 0.084

0.662*

0.416*

Height (Cm)

Male

Female

0.709*

0.899*

0.686*

0.889*

- 0.053

- 0.076

0.551*

0.597*

BSA (m2)

Male

Female

0.836*

0.773*

0.815*

0.768*

0.005

- 0.094

0.682*

0.492*

BMI (Kg/m2)

Male

Female

0.458*

0.165*

0.435*

0.159*

0.003

- 0.102

0.419*

0.076

*p<0.001
7. The mean values of all pulmonary function measurements were higher in boys as compared to girls but statistically significant difference (p<0.001) was found for FVC and FEV1 (table 7).

Table 7. PFTs and its relation with Sex

PFT	Male (Mean ± SD)	Female (Mean ± SD)	p value
FVC (Liter)	2.22 ± 0.36	2.09 ± 0.36	0.000*
FEV1 (Liter)	1.90 ± 0.32	1.78 ± 0.31	0.000*
FEF25-75% (Liter/sec)	2.74 ± 0.48	2.72 ± 0.58	0.551

*p< 0.001

Discussion

Pulmonary function tests play an important role in diagnosis, assessment of severity and response to medications. They are important in children not only for clinical reasons but also due to considerable growth and development of respiratory system which occurs with age. Besides diseases other factors which affect pulmonary functions are genetic, age, sex, height, weight , surface area, race, environment, birth weight, socioeconomic status, duration of breast feeding & history of childhood respiratory tract infections10,11.Pulmonary function tests can identify abnormalities of lung volumes, airflow, diffusion, respiratory endurance and respiratory muscle strength. They permit an accurate and reproducible assessment of the
respiratory system and allow quantification of the severity of disease, thereby enabling assessment of the natural history and response to therapy12.
In the present study, FVC, FEV1, FEF25-75% increases with increasing age in both sex while FEV1 /FVC% remained almost constant in all the groups. Values of FVC and FEV1 were higher in boys in all the age groups. However, FEF25-75% was also found to be higher in boys as compared to girls in all the age groups except in 12-13 years and 13-14 years age groups where girls had higher FEF25-75% values than boys. Values of FEV1 /FVC % were

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slightly lower in girls in all the age groups except in 10-11 years and 13-14 years age groups where the values were slightly higher in boys (table 1). Bhattacharya and Banerjee in Jaipur also observed that vital capacity increases with increase in age in both the sexes and they also found that females have lower vital capacities than males13. Chowgule et al in Bombay also found that boys have higher values of FVC than girls8. Sharma et al in Delhi also observed that FVC values were significantly (p<0.05) greater for boys than girls4. Vijayan et al found that in south Indian children, the mean FVC values were 2.43±0.07 liter in boys and 1.86 ±
0.05 liter in girls, which was significantly high in boys7. The mean values of FVC in our
study were 2.22±0.36 liter for boys and 2.09±0.36 liter for girls and values were significantly higher in boys (table 7). Though the mean values of FVC of boys aged 10-14 years in our study were slightly higher than those obtained by Sharma et al and Raju et al4,5. This could be explained as a multitude of factors affect FVC apart from anthropometry to environment, socioeconomic factors and race which need further evaluation.
FVC, FEV1 , and FEF25-75% were found higher for boys as compared to girls. But the difference was statistically highly significant (p<0.001) for FVC and FEV1, while FEF25-75% did not vary significantly (table 7). We also correlated the mean values of FEV1 in different age groups in both males and females of 10-14 years of age and observed that the correlation of FEV1 increases with increase in age, weight, height, BSA and BMI as shown in (table 1 to
5). The correlation of FEV1 with these variables was statistically significant (p<0.001). This
was similar to the observations made earlier by Sharma et al, Raju et al, Vijayan et al. and Chowgule et al., in various parts of India4,6-8. The mean values of FEV1 were similar to the mean values obtained by Sharma et al and Raju et al. in boys of same age4,6. We also observed that FEV1 increases with increase in BMI as shown in table 5. The increase was
more marked till a BMI of 21.0-22.69 kg/m2 in males and 19.3-20.99 kg/m2 in females. The
correlation coefficients for FEV1 with BMI were 0.435 for males and 0.159 for females (table
6). Correlation coefficients for FVC, FEV1, FEV1 /FVC % and FEF25-75% with age, weight, height, BSA and BMI for both males and females are shown which is reflecting a good correlation. The correlation was found to be statistically highly significant (p<0.001) for all the variables except for BMI with FEF25-75% in females (table 6).
From table 1-5, it was also analyzed that there is no relationship of FEV1 /FVC% with age, weight, height, BSA and BMI in children of 10-14 years of age in both the sexes. We also computed correlation coefficients of FEV1 /FVC% with age and anthropometric measurements (p>0.05). Correlation coefficient values of FEV1 /FVC% with age (0.012- males, 0.038-females), weight (0.020-males, -0.084-females), height (-0.053-males, -0.076- females), BSA (0.005-males, -0.094-females) and BMI (0.003-males, -0.102 females) were observed (table 6). Vijayan et al. did not find significant correlation of FEV1 /FVC% with
age, height and weight7. Sharma et al observed that FEV1 /FVC% was more than 80% in age
and sex categories and the difference being insignificant between the two sexes4. The mean
values of FEV1 /FVC% for boys in our study were lower than the mean values reported by
Raju et al for all age groups6.
In our study, Forced expiratory flow (FEF25-75%) showed increase with increase in age, weight, height, BSA and BMI in both sexes (table 1-5). The correlation of FEF25-75% was

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significant (p<0.001) with all anthropometric measures except with BMI in females (table 6). Vijayan et al. found correlation between FEF25-75% and age, weight and height to be significant (p<0.01)7. Coefficient of correlation was highest with height and was higher in
boys than girls. We found maximum correlation of FEF25-75% with age in both boys and girls (table 6). We found that FEF25-75% was significantly correlated with age and height (table 3 and 6). Sharma et al also observed significant (p<0.001) increase in FEF25-75% with age and height in both sexes4. We found slightly higher values of FEF25-75% in girls than boys when the boys and girls of similar heights were compared (table 3). Raj Kapoor et al observed
higher FVC, FEV1 , FEF25% , in boys while FEF50%, FEF75% and FEF75-85% were higher in girls but this study was done in only 186 students14. After correlation for body size, girls have higher expiratory flow rates than boys whereas adult men have larger volumes and flow rates than women15,16. In our study (table 7), mean values of FEF25-75% of males is higher than females but the difference was not statistically significant (p=0.551).

Conclusion

We found positive correlation of FVC, FEV1, and FEF25-75% with age, height, BSA and BMI. There were some differences in pulmonary function between the values obtained in our study and the studies done earlier on Indian children. This could possibly be due to multiple factors;
ethnic background, environmental, body build, socioeconomic status, and pollution.

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References

1. Shah MD, Lahin KR. Pulmonary function testing in office practice. Indian Pediatr
1992;29:387-93.
2. Lung function testing: Selection of reference values and interpretative strategies.
Official statement of American Thoracic Society adopted by ATS board of directors. Am Rev Respir Dis 1991;144:1202-18.
3. Cotes JE. Lung function throughout life: Determinants and reference values. In: Cotes JE, editor. Lung function: Assessment and application in medicine. 5th ed. London: Blackwell Scientific Publications 1993:445-513.
4. Sharma PP, Gupta P, Deshpande R, Gupta P. Lung function values in healthy children
(10-15 years). Indian J Pediatr 1997;64:85-91.
5. Raju PS, Prasad KVV, Ramana YV, Murthy KJR. Pulmonary function tests in Indian girls- Prediction equations. Indian J Pediatr 2004;71:893-7.
6. Raju PS, Prasad KVV, Ramana YV, Ahmed SK, Murthy KJR. Study on lung function tests and prediction equations in Indian male children. Indian Pediatr 2003;40:705-11.
7. Vijayan VK, Reetha AM, Kuppurao KV, Venkatesan P, Thilakavathy S. Pulmonary function in normal south Indian children aged 7 to 19 years. Indian J Chest Dis Allied Sci 2000;42:147-56.
8. Chowgule RV, Shetye VB, Parmar JR. Lung function tests in normal Indian children.
Indian Pediatr 1995;32:185-91.
9. Malik SK, Jindal SK. Pulmonary function tests in healthy children. Indian Pediatr
1985;22:677-81.
10. Warren MG. Pulmonary function testing. In: Murray JF, Nadel JA, Mason RJ, BoushnyHA,editors. Textbook of respiratory medicine. 3rd ed. Philadelphia: WB Saunders 2000:802-5.
11. Tennant PWG, Gibson GJ, Pearce MS. Life course predictors of adult respiratory function: results from Newcastle thousand families study. Thorax 2008;63:823-30.
12. Gold WM. Pulmonary function testing. In: Murray JF, Nadel JA, Mason RJ, Boushey HA, editors. Textbook of respiratory medicine (volume 1). 3rd ed. Pennsylvania: WB Saunders 2000:781-2.
13. Bhattacharya AK, Banerjee S. Vital capacity in children and young adults of India.
Indian Med Res 1966;54:62-71.
14. Kapoor R, Mahajan KK, Mahajan A. Ventilatory lung function tests in school children of 6-13 years. Indian J Chest Dis Allied Sci 1997;39:97-105.
15. Schwartz JD, Katz SA, Fegley RW. Sex and race differences in the neurodevelopment
of lung function. Am Rev Respir Dis 1988;138:1415-21.
16. Schwartz JD, Katz SA, Fegley RW. Analysis of spirometric data from a national sample of healthy 6 to 24 year olds (NHANESII). Am Rev Respir Dis
1988;138:1405-14.

International Journal of Scientific & Engineering Research, Volume 5, Issue 4, April-2014 1484

ISSN 2229-5518

Authors
1. Kundan Mittal: Professor in Pediatrics, Pt. B D Sharma, PGIMS Rohtak-India
2. Tanu Satija: Ex Resident Department of Pediatrics, Pt. B D Sharma, PGIMS Rohtak- India
3. Dr. Jyoti Yadav: Professor Physiology, Pt. B D Sharma, PGIMS Rohtak-India
4. Dr. K B Gupta: Professor & Head, Respiratory Diseases, Pt. B D Sharma, PGIMS Rohtak-India
5. Dr. Anupama Mittal: Resident Anatomy, Subharti Medical College, Meerut-India
Corresponding Author
Kundan Mittal: Professor in Pediatrics, Pt. B D Sharma, PGIMS Rohtak-India