Plasma sphingomyelin and longitudinal change in percent emphysema on CT. The MESA Lung study

Context: Ceramide causes endothelial apoptosis and emphysema-like changes in animal models. Objectives: Test if plasma sphingomyelin, a major precursor of ceramide, would predict longitudinal increase in the percentage of emphysema-like lung on computed tomography (CT). Materials and methods: 3840 participants had their plasma sphingomyelin measured at baseline examination and their pulmonary emphysema measured on cardiac CT scans at baseline and on follow-up visits. Mixed effects models were used to adjust for potential confounders. Results: One standard deviation increase in sphingomyelin predicted a 0.12% per year (95% CI: 0.02-0.22; p=0.019) greater increase of percent emphysema. Discussion and conclusion: Higher plasma levels of sphingomyelin predicted greater annual increase in quantitatively measured percent emphysema.