The influence of dietary sugars and acute exercise on postprandial lipemia in premenopausal women

Postprandial lipemia (PPL) is elevation in triglyceride (TG) concentration within the blood in the hours following the ingestion of a meal and is a risk factor for cardiovascular disease (CVD) and may be a greater risk in women compared to men. Women completing aerobic exercise prior to ingesting a high-fat meal have reported a lower postprandial TG concentration. It is unclear if prior aerobic exercise would lower the postprandial TG concentration in women following the ingestion of a high-carbohydrate meal comprised of high amounts of glucose and fructose sugars. This investigation examined the effect of prior exercise on postprandial (PP) triglyceride concentration following a mixed meal (MM) made with either glucose or fructose. Sedentary premenopausal women (n=16; age=28.2 ± 6.1yrs; VO2max= 30.8 ± 4.2 ml -1˙kg-1˙min) completed four trials in random order: 1) Rest-Fructose: RF, 2) Rest-Glucose: RG, 3) Exercise-Fructose: EF, 4) Exercise-Glucose: EG. Exercise was treadmill walking at 70%VO2max expending 500 kcal. Rest was 1 hr of supine rest. The morning after each trial, a fasting (12 hr) blood sample was collected followed by consumption of the MM with a macronutrient composition of 55% carbohydrate (CHO), 15% protein, and 30% fat. The MM was blended with whole food items plus a glucose or fructose powder that accounted for half of the total carbohydrate content within the MM. Blood was collected again at 0.5, 1, 1.5, 2, 3, 4, 5, and 6 hr post-MM and analyzed for triglyceride concentration. Postprandial responses were quantified via the area under the curve (AUC) using the trapezoidal method. Significant differences (p < .05) between trials were determined using a repeated measures ANOVA and Bonferroni post hoc test. The PPTG AUC (mg˙dl -1˙6hr-1) following the EG trial (346.8±178.1) was significantly lower (p < .028) compared to the RF (476.2 ± 279.5) and RG (485.0 ± 309.7) trials, but not compared to the EF trial. Postprandial TG concentration was reduced only in the EG trial. The RG, RF, and EF trials had a similar postprandial TG concentration. The lack of difference in the TG concentration between the RG, RF, and EF trails is unclear.