Log per cent low-attenuation area (%LAA) by sex and race
| Male | Female | β±se | p-value | |
| All subjects | 1.97±1.4 | 1.69±1.6 | 0.32±0.04 | <0.001# |
| Non-Hispanic whites | 2.06±1.3 | 1.79±1.5 | 0.34±0.05 | <0.001¶ |
| African-Americans | 1.63±1.5 | 1.31±1.7 | 0.31±0.1 | 0.002+ |
Data are presented as mean±sd, unless otherwise stated. Including all subjects with Global Initiative for Chronic Obstructive Lung Disease grade II–IV chronic obstructive pulmonary disease. Adjusted for age, pack-years, current smoking status, body mass index and computed tomography scanner. Log %LAA: emphysema (%LAA) log-transformed for normality; β: difference for male subjects compared with female subjects. Interaction between current smoking and sex on log %LAA: #: all subjects, p=0.004; ¶: non-Hispanic white subjects, p=0.01; +: African-American subjects, p=0.06.