Postprandial metabolism and vascular function: Impact of aging and physical activity level

Abstract

The consumption of a high-fat meal can induce acute postprandial lipemia (PPL) and endothelial dysfunction. We assessed the impact of age and physical activity on metabolic and vascular outcomes following meal consumption in healthy men and women. We recruited 4 groups of individuals: younger active (YA; age 22.1 ± 1.4 y; n = 9), younger inactive (YI; age 22.6 ± 3.7 y; n = 8), older active (OA; age 68.4 ± 7.7 y; n = 8), and older inactive (OI; age 67.7 ± 7.2 y; n = 7). Following a 10-hour overnight fast and 2 days of exercise avoidance, metabolic outcomes were measured at baseline and hourly for 6 hours after consumption of a high-fat meal (12 kcal/kg; 63% fat, 34% carbohydrate). Flow-mediated dilation (FMD) was measured at baseline, 2-hours, and 4-hours post-meal. Total area under the curve (tAUC) for TG was significantly lower in the more active individuals but did not differ based on age (YA = 578.3 ± 120.5 mg/dL x 6 hour, YI = 1032.0 ± 424.1, OA = 599.9 ± 235.3, OI = 1071.0 ± 149.5; p = 0.0004). FMD differed (p = 0.002) between groups at baseline (YA = 6.36 ± 1.70%; YI = 3.98 ± 1.67%, OA = 4.82 ± 1.27%, OI = 3.27 ± 1.33%), and decreased significantly in all groups 4 hours after the meal (Mean diff: 1.19%; 95% CI: 0.27 to 2.11%). These findings highlight the beneficial effect of regular physical activity on PPL, independent of age.