Background/Aims: Postprandial inflammation, endotoxaemia, and oxidative stress are determinants of cardiovascular and metabolic disease risk and are amplified after high fat meals. We aimed to examine determinants of postprandial inflammation and endotoxaemia in older and younger adults following a high fat mixed meal.
Methods: In a randomised cross-over trial, healthy participants aged 20-25 and 60-75 years (n=15/group) consumed separately a high fat and a low fat breakfast. Plasma taken at baseline and post-meal for 5 hours was analysed for circulating endotoxin, cytokines (monocyte chemotactic protein (MCP)-1, IL-1β, IL-6, and tumour necrosis factor (TNF)-α), lipopolysaccharide binding protein (LBP), and expression of inflammatory genes in peripheral blood mononuclear cells (PBMC).
Results: Older subjects had 16% lower baseline PBMC expression of glutathione peroxidase (GPX)-1 (P<0.05), but 2.7-fold greater baseline expression of insulin-like growth factor-binding protein (IGFBP)-3 (P<0.001) and 11% greater circulating MCP-1 compared to younger subjects (P<0.05). After either meal, there were no age differences in plasma or chylomicron endotoxin or plasma LBP concentrations, nor in inflammatory cytokine gene and protein expression (MCP-1, IL-1β, and TNF-α). Unlike younger participants, the older group had a 35% decrease in SOD-2 expression after the meals (P<0.001).
Conclusions: After a high fat meal, older adults had no increased inflammatory or endotoxin response, but an altered oxidative stress response. Healthy older adults, without apparent metabolic dysfunction, have a comparable postprandial inflammatory and endotoxaemia response to younger adults.
Funding Sources: Liggins Institute Trust, AgResearch Ltd.