Obesity in older adults was associated with decreased pulmonary function, demonstrated by a significant negative correlation between functional residual capacity and total fat mass (r=-0.503, p<0.001).
Cross-Sectional (n=59)
Does obesity reduce pulmonary function in older adults, and are these effects sex-specific?
Obesity is associated with significant reductions in pulmonary function in older adults, independent of sex differences in fat distribution.
Effect estimate: r -0.503
p-value: p=<0.001
Introduction: Obesity is an epidemic problem in the U.S. and is a major clinical concern in older adults. First, because excess mass on the thorax predisposes individuals with obesity to decreased functional residual capacity, and second, because aging is associated with a decline in pulmonary function. Furthermore, the effects of obesity could be sex specific given potential differences in fat distribution and therefore, decreases in pulmonary function may be more dramatic in older women with obesity. To date, the influence of obesity and sex on pulmonary function in older adults remains poorly defined. Therefore, the purpose of this study was to determine the effects of obesity and sex on pulmonary function in older adults. Methods: We evaluated 59 older adults (70±3yrs). Of these, 27 participants were with obesity (9 men, BMI: 32±3 kg/m 2 ; and 18 women, BMI: 35±5 kg/m 2 ), and 32 participants without obesity (13 men, BMI: 25±2 kg/m 2 ; and 19 women BMI: 23±3 kg/m 2 ). Body composition was measured via DEXA. Pulmonary function was measured including spirometry and lung volumes by plethysmography. Results: Percent body fat was greater (p < 0.001) in those with obesity (M: 37±6, W: 49±4%) compared to those without obesity (M: 29±6, W: 38±7%) and women had greater (p < 0.001) values than men. Trunk fat as percent of total body fat was greater (p = 0.025) in those with obesity (M: 62±3, W: 53±8%) than those without obesity (M: 57±5, W: 49±8%) with men having greater (p < 0.001) values than women. Visceral fat as percent of total body fat was greater (p = 0.004) in those with obesity (M: 8±1, W: 4±2%) than without obesity (M: 6±2, W: 3±2%) with men having greater (p < 0.001) values than women. Total lung capacity (TLC) was lower (p < 0.001) in those with obesity (M: 89±9, W: 96±7 %predicted) than without obesity (M: 104±15, W: 107±12 %predicted); however, there was no difference (p = 0.121) between men and women. Functional residual capacity (%TLC) was lower (p < 0.001) in those with obesity (M: 44±5, W: 45±6%) than without obesity (M: 53±5, W: 53±6%), with no difference (p = 0.604) between men and women. Residual volume was lower (p < 0.001) in those with obesity (M: 84±10, W: 92±13 %predicted) than without obesity (M: 102±21, W: 110±19 %predicted) with no difference (p = 0.096) between men and women. Forced vital capacity (FVC) was lower (p = 0.001) in those with obesity (M: 101±16, W: 109±12 %predicted) than without obesity (M: 119±17, W: 118±13 %predicted), with no difference (p = 0.308) between men and women. Forced expiratory volume (FEV1) had no difference (p=0.096) between those with obesity (M: 105±19, W: 108±14 %predicted) than without obesity (M: 115±14, W: 110±9 %predicted), with no difference (p = 0.784) between men and women. The correlation coefficient between FRC as %TLC and total fat (kg) had a significant negative relationship (r: -0.503, p < 0.001). Conclusion: Our data demonstrate that obesity results in significant decreases in pulmonary function in older adults. We also show that these effects were not different between older men and women despite observed sex differences in fat distribution. These findings suggest that pulmonary function is reduced by obesity in older adults regardless of sex. Funding Source. This research was supported, in part, by the National Institutes of Health (R01AG070262 T.G.B and K99HL164957 [B.N.B), King Charitable Foundation, Atwell Gift for Pulmonary Research, Cain Foundation, and Texas Health Presbyterian Hospital Dallas This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.
Skillett et al. (Fri,) conducted a cross-sectional in Obesity (n=59). Obesity vs. Without obesity was evaluated on Correlation between functional residual capacity (%TLC) and total fat (kg) (r -0.503, p=<0.001). Obesity in older adults was associated with decreased pulmonary function, demonstrated by a significant negative correlation between functional residual capacity and total fat mass (r=-0.503, p<0.001).