Proton nuclear magnetic resonance methyl and methylene linewidths from plasma decrease during postprandial lipemia.

Narrow proton nuclear magnetic resonance (1H-NMR) linewidths from plasma have been associated with the presence of malignancy (Fossel et al., New Engl. J. Med. (1986) 315, 1369-1376). In that study, subjects and controls were not fasted. In the present study, 1H-NMR methyl and methylene linewidths were measured in plasma from normolipemic individuals without cancer both during fasting and every 90 min after eating a fat meal. Plasma lipoprotein levels were measured in order to relate results to postprandial lipemia. Methyl, methylene, and average 1H-NMR linewidths were strongly positively correlated with high-density lipoprotein levels and inversely correlated with triacylglycerol-rich lipoprotein levels in both the fasting and postprandial states. Linewidths decreased postprandially, reaching a nadir at the peak of plasma triacylglycerol levels. This study demonstrated that postprandial lipemia can lead to narrowing of plasma methyl and methylene resonances comparable to that reported for subjects with cancer.