Changes in lung function in older people from the English Longitudinal Study of Ageing

Background: Decline in lung function with increasing age is common in older people. However, the rate of decline using the forced expiratory volume in 1 s (FEV1) in a longitudinal study in the elderly community dwellers is unknown. Methods: We analyzed data from the English Longitudinal Study of Ageing on people 50 years and older who had FEV1 measurement at Wave 2 and Wave 4 of 4 years of follow-up, respectively. A random coefficient model was employed to examine the changes in FEV1 and predict differences in the levels of FEV1 in older people. Results: A total of 4224 participants were included in the study. The mean (+/- standard deviation [SD]) rate of change in FEV1 was a decline of 32.92 +/- 0.96 ml/ year. The absolute difference in mean FEV1 level between female and male participants was 767.07 +/- 16.6 ml. It was 253.91 +/- 22.7 ml lower in current smokers than in nonsmokers, 73.67 +/- 18.67 ml lower in participants with a history of sputum in winter months than in participants without sputum, 63.32 +/- 7.07 ml lower in participants with a higher dyspnea score than in participants with a lower dyspnea score and 67.77 +/- 15.87 ml higher in participants with good health compared to participants with fair/ poor health status. One microgram increase in C-reactive protein level lowered FEV1 by 4.66 +/- 0.86 ml and one Hb of hemoglobin increased the FEV1 level by 4.78 +/- 0.77 ml. All were statistically significant at p < 0.001. Conclusions: The average rate of FEV1 decline in older people without respiratory diseases was found to be high. Lower level of FEV1 was also observed in current smokers, females, those with a history of sputum in winter months and in participants with higher dyspnea score or in those with poorer health status.