Increased usual physical activity is associated with a blunting of the triglyceride response to a high-fat meal

Abstract

Postprandial lipemia (PPL), defined as a prolonged or elevated rise in triglycerides that accompanies fat feeding, is a significant risk factor for coronary heart disease and associated comorbidities. The impact of PPL on coronary heart disease risk is underscored by the preponderance of each day spent in the postprandial state. In this study, we evaluated cross-sectionally the association between usual (ie, noninterventional) physical activity and the 6-hour triglyceride response to a standardized high-fat meal. The high-fat meal intervention was carried out in 671 apparently healthy individuals as part of the Heredity and Phenotype Intervention Heart Study. Triglyceride levels were measured in the fasting state and during 6 hours after administration of a standardized fat challenge. We defined PPL response as the triglyceride area under the fat load curve (AUC) and measured physical activity using accelerometers that were worn continuously over a 7-day period. Physical activity levels decreased with increasing age and were higher in men than women (both P<.001). The triglyceride AUC increased with increasing age in both men and women (both P<.001) and was also higher in men than in women (age-adjusted P=9.2×10-12). Higher physical activity levels were associated with a lower triglyceride AUC (P=.003), adjusting for age, sex, body mass index, and fasting low-density lipoprotein. These results suggest that the protective benefits of physical activity on cardiovascular health may operate, at least in part, through reduction of the PPL triglyceride response.