Postprandial inflammation across the aging spectrum

OBJECTIVES: Postprandial inflammation post-high-fat meals may be linked to cardiovascular disease (CVD). CVD incidence increases with age; however, whether older adults experience greater postprandial inflammation remains unclear. We examined whether analyzing age categorically versus continuously influenced relationships between age and postprandial inflammatory measures. DESIGN: Cross-sectional. SETTING: Laboratory for Applied Nutrition and Exercise Science at Oklahoma State University (Stillwater, OK, USA). PARTICIPANTS: 56 apparently healthy adults ages 20-69 years. MEASUREMENTS: We measured interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α at baseline, 2-, 4-, and 6 -hs post-high-fat meal (9 kcal/kg; 70% fat). Data were examined in the full sample with paired t-tests (baseline to peak), by pre-defined age groups (i.e., 18-35, 36-49, 50-59, 60-69) using ANCOVA, and continuously using linear regression. RESULTS: Across the full sample, IL-1β, IL-6, and IL-8 increased after the high-fat meal (p's≤0.018). Cytokine differences post-high-fat meal by age category were generally not observed. However, age was positively associated with IL-6 incremental AUC when examined continuously (b = 0.029; p = 0.010). CONCLUSION: These data suggest increasing age is linked to a greater IL-6 response to a high-fat meal. Further, examining age continuously may have greater utility when studying aging and postprandial inflammation. REGISTRATION: N/A (secondary analysis).