RT Journal Article SR Electronic T1 Late-breaking abstract: Daytime motor activity and emphysema on CT: The multi-ethnic study of atherosclerosis (MESA) lung and sleep studies JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1391 VO 44 IS Suppl 58 A1 Christian M. Lo Cascio A1 Carrie P. Aaron A1 John H.M. Austin A1 Mark V. Avdalovic A1 Alan G. Bertoni A1 Vincent S. Fan A1 Eric A. Hoffman A1 Steven M. Kawut A1 Gina Lovasi A1 Mirja Quante A1 Susan Redline A1 Joseph E. Schwartz A1 R. Graham Barr YR 2014 UL http://erj.ersjournals.com/content/44/Suppl_58/1391.abstract AB Rationale: Emphysema is characterized by decrease in activity. Little is known about daytime activity and emphysema on computed tomography (CT) independent of COPD on spirometry. We hypothesize that greater percent emphysema is associated with lower daytime activity among participants with and without COPD.Methods: MESA enrolled participants aged 45-84 years, without clinical cardiovascular disease in 2000-02. MESA Lung measured percent emphysema, defined as % voxels with an attenuation < -950 HU, on full-lung CT scans for 3202 participants in 2010-12. MESA Sleep measured actimetry in 1466 participants. Daily activity was examined using the total activity counts/24h over 7 days. Multivariate linear regression was used to adjust for age, sex, race/ethnicity, education, height, weight, smoking, FEV1/FVC, scanner, hypertension and cholesterol.Results: Among 1513 participants (age 69±9 years, 52% ever-smokers, 8% with COPD), the mean maximal daily activity counts were 276000±106000. An increase of 1 log% emphysema was associated with an 7643 count decrease in activity (P=0.03) in the fully adjusted model (∼50 kcal active energy expenditure / 1 SD difference in log% emphysema1). Findings among participants without COPD were similar (-8651 / log% emphysema; P=0.01). Results were not modified by smoking status (Pint =0.6) or obesity (Pint =0.3).Conclusions: Percent emphysema on CT was independently associated with reduced daytime activity measured by actimetry in this multiethnic general-population sample including in participants without COPD.Funding: NIH/NHLBI, R01-HL077612, R01-HL093081, N01-HC95159-HC95169, UL1-TR000040, EPA RD831697011Rabinovich. ERJ. Nov 2013;42(5).