LUNG FUNCTION TESTS IN RAJASTHANI SUBJECTS PRATIB'HA GUPTA*. SOM'NATH GUPTA AND R. L. AJMERA

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1 LUNG FUNCTION TESTS IN RAJASTHANI SUBJECTS PRATIB'HA GUPTA*. SOM'NATH GUPTA AND R. L. AJMERA Department of Physiology, S.M.S. Medical Co/lege. Jaipur Summary: Various lung volumes and ventilatory tests (TV. ERV. IC. MV. MVV. VC. FEV 1 MMFER and PEFR) were determined and BR. 01 and AVI (Air velocity Index) calculated in 241 Rajasthani subjects of either sex ranging from 17 to 40 years of age. Most of the values ( ) are higher in males than in females. and also higher in the younger age groups (17 to 27 years) than in the older age groups (28 to 40 years) for the same sex. Key words: lung function tests peak expiratory flew rate air velocity index INTRODUCTION Literature survey reveals considerable amount of data on pulmonary function norms in western subjects (2.19). This is, however. singularly lacking for our country where socio-economic. cultural and ethnic groups present a rather wide spectrum and are likely to influence the physiological norms. Data on pulmonary functions in population samples from West Bengal (6). Madhya Pradesh (1\I..P.) (5). Tamil Nadu (14.15) and Gujarat (18) are available but the sample size and the investigation have been restrictive. In order to mitigate this lacuna at least partly. the present study was undertaken to assess the pulmonary functions by a battery of tests in homogenous population samples of Rajasthani residents. MATERIALS AND METHODS The study was conducted on 241 healthy volunteers drawn from the students and staff of the S.M.S. Medical College. Jaipur and belonged to Rajasthan. The subjects were arranged in four groups according to the age arid/or sex. Group I consists of males (17 to 27 years); group II (males. 28 to 40 years); group III (females. 17 to 27 years); and group IV (females, 28 to 40 years). Each subject underwent a clinical examination including screening and only those subjects who were found clinically normal were alone assessed for the lung function tests. As a routine. habitual smokers were not included in this series of 'Present address: Department of Physiology. University College of Medical Sciences. Ring Road. New Delhi

2 Volume 23 Number 1 Lung Functions in Rajasthani Subjects 9 studies. Body height (cm) and weight (kg) were taken and body surface area determined according to the Du-Bois formula. A = WO 42sxHo 72sx71.84 Where W = Weight in kg H = Height in cm The various pulmonary function tests performed consisted of : (i) TV. (ii) IC. (iii) ERV. (iv) MV. (v) MVV. (vi) BR. (vii) 01. (viii) VC. (ix) FEV t (x) MMFER. (xi) PEFR. and (xii) AVI. The readings were taken in standing posture and values corrected to BTPS (body temperature and ambient pressure and saturated water vapour). Except for PEFR which was determined by Wright's Peak Flow meter. all other tests were conducted by INCO's Spirometer. The AVI was calculated by applying Bass (3) formula. AVI = Percent of predicted MVV Percent of predicated VC RESULTS Table 1 shows the details of physical features and Table 11. the lung function tests in all the four groups of the subjects investigated. Most of the values in males are higher than TABLE I : Physical characteristics of the subjects investigated Males Females Group I Group 11 Group 1/1 Group IV (127)* (50) (54) (10) Mean + Mean + Mean + Mean + Height (cm) ± 0.76 ± 1.02 ± 0.80 ±.0.28 Wt. (kg) ± 0.12 ± 1.16 ± 0.85 ± 1.78 SA (Sq.m) ± ± ± ± 0.02 'Note : = Number of subjects in the groups (n). in females for the same age group. However. FEV 1 is higher in females as compared to males (group III & I). The 0.1. also has higher values in group II1 as compared to group l.

3 o, Group I TV(L) ±0.008 ERV (L) ±0.020 IC(L) ±0.130 VC(L) ±0.050 MV (L/min) 9.72 ±0.11 MVV (L/min) ±0.17 MMFER (L/min) ± ±5.66 PEFR (L/min) ±4.18 BR (L/min) ± (%) ±029 Males TABLE11: Details of lung function tests investigated. Group ± ± ± ± ± ± ± ± ±2.43 Group III ± ± ± ± ± ± ±4.53 Females Gr I vs Group W ± ± ± ± ± ± ~ AVI 1.21 ±O ± ± ± ± ± ± ± ± ± ±0.09 Gr " Gr I vs Gr III Gr fi vs GrlV Gr III vs P<0.001 P<0.001 Gr IV P<O.OO1 P<0.001 P<0.001 P<0.001 P<0.001 P<0.001 P<O.OO1 P<0.001 P<0.001 P<O 001 P<0.001 P<0001 P<0.001 P<0.001 P<0.001 P<O.001 P<0.001 Not Significant (P > 0.05).

4 Volume 23 Lung Functions in Rajasthani Subjects 11 Number 1 TABLE III : Values of lung function tests reported by various workers. ~ S.No. Name of TV(L) ERV(L) IC(L) VC(L) MV(L) MVV FEV 1 % MMFER PEFR AVI the workers min. (L) min..ltmtn. l.tmtn: 1. Baldvin(2) M4.780 M126.0 F F Needham(19) M3.450 M Reddy(21) M De & De(7) M Mazumdar(18) M3.050 F F Kasliwal(13) MO.578 M3.881 M M80.3 M F F79.3 F Singh & Prabhakaran(24) M3.725 M Mathur et af(17) M3.856 M16-25yrs yrs. 9. Gupta(9) M1.40 M4.000 M M193.4 M537.7 FO.947 F90.99 M848 F133.2 F Jain S.K.(11 ) M2.534 M3.945 M210j 11. Comroe(12) 500 MO FO Bhargava(5) MO.996 M Chakraborty(6) M1.344 F Jain.S.K.(10) Ml.391 F1.759 f84.2 M152.5 FO Shephard(23) M Lockhart(16) M Rao et af(21) M Bajaj V.R. & V.D. Mullick(1) M Bhargava(4)I M Thompson Wells(27) M Gaensler (8) F 414 f 380 Fl.3 Number in brackets indicates reference number.

5 12 Guota et al. January-March 1979 Ind. J. Physiol. Pharmac. The various values decline in higher age groups particularly ERV, VC, MVV and BR which are significantly higher in younger males (P <0.001). DISCUSSION The results indicate that the individual variations are rather large and may be attributed, among other factors to the differences in body ht. wt and BSA. Similar conclusions have been drawn by Baldvin (2) and Needham (19). Informal observations in the present study suggested that motivation and attitude of the subjects also contributed to a considerable extent to these variations. In spite of these individual variations, the group trends indicate higher values in males as compared to females. Similarly. the values obtained in younger age groups are higher as compared to the values obtained in olde: age groups. Kasliwal (13), Mathur et al. (17) and Bharqava (5) noted similar trends in the subjects of Rajasthan, Uttar Pradesh and Madhya Pradesh respectively. V.C.: Our results on V.C. in males are in agreement with the findings of Reddy (22) but are higher than the values reported by De and De (7) and Mazumdar et al. (18) and lower than that obtained by Kasliwal (13), Singh and Prabhakaran (24), Mathur et al. (17) and others (9,11) (see Table Ill). In heterogenous population sample of South India, Krishnan et al. (14) observed lower values of 2.9 L as compared to our males, but are similar to their values of 3.05L (15) obtained in homogenous population sample from the same area. It would seem that these variations are linked not only to the methodology and use of different apparata but perhaps also to the wide range of population samples with differing socioeconomic and cultural background, and the variability in postures. environmental conditions under which the data have been collected. It should be pointed out that the condition be strictly defined for collecting the data of this type before formulating the physiological norms. This caution is as much applicable to VC as to the other pulmonary functions discussed below: TV, le and ERV: The'TV values obtained in the present study are quite comparable to the values reported by Kasliwal (13) for the Rajasthani subjects. Also, group I values are in agreement with that reported by Comroe(12) for the western subjects. Though ERV is characteristically subjected to considerable Variability among members of a homogenous group and even in the same individual (12) the present ERV values are similar to those OT Bhargava (5) but are si ig htly lower tha n those reported by others (6,9,10) for India n subjects of either sex (seetable Ill). Comroe(12) hasreportedthattheervis25%ofthevc. In our study the ERV in group I is 34.9 % of VC while in group 11, it is 21.2 %. In females (group III and IV), it was found to be 25.4 % and 29.2 % of VC respectively. Our studies thus indicate that the ratio of ERV to VC is somewhat higher in group I, III and IV. Reporting on IC, Comroe (12) showed that IC is 75 % of the VC. In our study IC in group I and group 11 was found to be 63.4 % and 6,.3% respectively, while in group III and IV, it was 59% and 62.3%. These ratios appear to be lower than those reported by Gupta and Jain et al. (9,10,11) (see Table Ill). Since our ERV values are generally comparable to that of Comroe (12) and since

6 Volume 23 Lung Functions in Rajasthani Subjects 13 Number 1 the value of VC in our subjects is lower as compared to others ( ) (see Table Ill), itwould seem that IC and particularly I RV is lower in these subjects. I RV reflects the balance between lung and chsst-elasticitv. muscle strength and thoracic mobility. and between mid-position (resting endexpiratorv position) and TV. (20). It would be of interest to further investigate the deviation in these balancing' factors. EV). MMFER. PEFR.- ~ FEV) shows a gradual rise with increasing age and then decreases in higher age groups of the population sample studied. A similar age dependent trend has been reported by Mathur et al (17) in the population sample from U.P. Our results are also comparable to that reported by other Indian workers ( ) (see Table Ill). The values of MMFER ranged fro'm L/min to L/min in different groups and the values are slightly lower than those reported by other Indian workers ( ) (seetable Ill). It is known that for a parameter li ke M M FER utmost cooperation and motivation of the subject is needed. It is difficultto say whether the subjects ofthe present study were less motivated. or the values are lower per se. Very little work has been done regarding the PEFR in our country. Gupta et al (9) in Indians. and Lockhart et al. (16) and Shephard (23) in western population have reported highervalues than those observed by us. The physical features like height and weight of the subjects of Gupta et a/. (9) were higher and comparable in many ways to western figures. If this is substantiated it would indicate that PEFR is 'more directly related to physical features than the other respiratory MV, MVV. BR & 01 : parameters. The mean MV ranged from 7.41 L/min to 9.72L/rnin in the various groups and the values are within normal range of the western figures (12). The values in Indian subjects reported by Bhargava (5) (see Table Ill) have shown large variations. Similarly. the mean value of BR ranged from 64.17L/min to 98.25L/min and the 01 from to 84.18% in al.the age groups. and the values are within normal limits. The present MVVvalues for males andfemales are hiqher than those reported by Rao et a/. (21) but lower than those reported by others( ) (see Table Ill). The variation in results is difficult to explain and might be due to the variation in the muscular forces available. the compliance of the thoracic wall and lungs. air way resistance and may be other factors. A. V'/'.- So far. only Thompson Wells (27) has reported AVI in Indian population. 'His values of AVI are higher than those of ours in either sex. The western figures obtained by Gaensler (8) (see Table ill). appear lower than the present values. May be. the relatively low

7 14 Gupta et 81. January-March ljl79 Ind. J. Physiol. Pharmac. figures of VC in the present population sample as compared to MVV values. might be responsible for this higher index as compared to the values in western population samples. REFERENCES 1. Bajaj. V.R. and V.D. Mullick. Pulmonary function tests. Proc. Se. Conqr. Pt IV : P Baldvin. E. A. Cowrnard, and D.W. Richard. Pulmonary Insufficiency. M1!dicine. 27 : Bass. B.H. The lung function tests. H.K. Lewic & Co. Ltd. London Bhargava. R.P. and Somnath. Maximum breathing capacity in normal Indian subjects as studied in Rajasthan. Ind. J. Physiol. and Allied Sci. 10 : Bhargava. R.P.. S.M. Misra and N.K. Gupta. Ventilatory tests and lung volumes studied in Madhya Pradesh Physiological Norms. lnd. J. Physiol. Pharmac. 17 : Chakrabortv, M.K M.S. Islam and P.K. Dutta. Pulmonary function tests. Lung volumes and capacities of Indians in health. Ind. J. Physiol. and Allied Sci. No : De. P. and B.N. De. The V.C. of Bengalees. Indian Med. Gazette. 711 : Gaensler. E.A. Analyses of the ventilatory defect by time capacity measurements. Amer. Rev. Tuberc. 64 : Gupta, S. M.B. Puri and S.1. Singh. Pulmonary Function tests in health. Jr. Assoc. Physiol. lnd., 23 : April Jain, S.K. and T.J. Ramiah. Spirometric studies in Healthy women years of age. Ind. J. of Chest Disease. 9 : Jain. S.K. and T.J. Ramiah. Normal standards of pulmonary function tests for healthy Indian men years old. Ind. J. Med. Res. 57 : Julius. H. Comroe Jr. Interpretation of commonly used pulmonary function tests. Am. Jour. Med. 10: Kasliwal. R.M.. V.S. Baldwa and P.H. Sharma. Ventilatory tests and lung volumes studies in health. Jour. I.M.A.. 43 : Krishna. B.T. and C. Vareed. The vital capacity of 103 male Medical Students in South India. Ind. J. Med. Res. 19 : Krishna. B.T. and C. Vareed. A further, study of the vital capacity of South Indians. Ind. J. Med. Res. 21 : Lockhart. W.. A. Main. D.H. Smith and W.A. Wilson. Practical experience with the peak flow meter. Brit. Med. Jour.. 1 : Mathur. K.S. D.K. Nigam and R.K. Garg. Pulmonary function studies in normal healthy persons. Ind. J. Chest Dis., 10 : Mazumdar. B.N. C.A. Desai and N.C. Saha. A comparative study of a few tests of Dynamic lung function. Ind. J. Physiol. Pharmac. 20 : Needham. C.D.. C.R. Mary and M.C. Donald. I Normal standards for lung volumes. Intrapulmonary gas and maximum breathing capacity. Thorax. 9 : N. Balpur Solnim and Lyle H. Hamilton. Respiratory Physiology. The C.V. Mosby Co. America Rao. M.N.. A. Sengupta. P.B. Saha and A. Sitadevi. Physiological norms in Indians. Pulmonary capacities in health. Indian Council of Medical Research. Special Report Series No., Reddy. D.V.S. Quoted by Reddyand Sastry. Studies in vital capacity. Ind. J. Med. Res. 32 : Shepherd. R.J. Some observation on Peak expiratory flow. Thorax. 17 : Singh. H.D. and S. Prabhakaran. Pul. function studies. A preliminary note. Jour. I.M.A Singh. H.D. Pulmonary function tests. A further study. Jour. I.M.A.. 31 : Singh. H.D.' Ventilatory function tests. Normal standards in male adults. J. Ind. Med. Prot., 5 : Thornpson Wells. J.A. Simple methods for assessing pulmonary function; effects. of pulmonary T.B. on ventilation. Ind. J. Tub. 1 :