Decline in respiratory performance of Varanasi population in 22 years: a cross-sectional study

Lung function tests were performed on apparently healthy, non-smoking male volunteers aged 16-50 years normally staying in Varanasi city area. The volunteers were divided into five groups according to their age (16-19 yr, 20-25 yr, 26-30 yr, 31-35 yr, 40-50 yr). Anthropometric determinants (height and weight) and respiratory performance (vital capacity and peak expiratory flow rate) were recorded in the year 1982 and 2004. No significant (P>0.05) difference in height, weight and body mass index was detected between the age matched groups in the year 1982 and 2004. The Vital capacity (VC) was measured in 483 and 387 volunteers in the year 1982 and 2004 respectively; peak expiratory flow rate (PEFR) was measured in 200 and 388 subjects in the year 1982 and 2004 respectively. Both VC and PEFR were found to be reduced in the year 2004 as compared to those measured in 1982 from the similar population matched for age groups. They were significantly (P<0.001) lower (20-23% less for VC and 4-14% less for PEFR) in the 20-30 years age group. There was also significant (P<0.05) decrease in PEFR for the population of 16-19 years age group studied in 2004 compared to that of 1982. Significant (P<0.001) deterioration in VC per meter of height was observed in the population above 20 years of age. The mean values of VC (ml/m height) ranging from 2119.27 +/- 316.64 (20-25 years age group) to 1923.29 +/- 225.43 (40-50 years age group) in 1982 have dropped to 1896.54 +/- 289.50 and 1593.64 +/- 419.36 for the respective age groups in 2004. Similarly, mean value of PEFR (L/ min) was found to be reduced from 523.67 +/- 64.69 in 1982 to 471.44 +/- 85.25 in 2004 for the same age groups of 20-25 years. Similar reduction was also recorded for 16-19 yr group and 26-30 yr group of population. Air-pollution and sedentary lifestyles in the population of this city may be probable reasons for the decline in respiratory performance.