C-18 Thematic Poster - Reduction of Metabolic Syndrome and Chronic Disease Thursday, May 29, 2014, 8:00 AM - 10:00 AM Room: 110 B
Postprandial dyslipidemia increases expression and circulating concentrations of adhesion molecules linked to oxidative stress and endothelial dysfunction. Aerobic exercise and niacin attenuate postprandial dyslipidemia following a high-fat meal (HFM); however, the combined effects on endothelial phenotype have not been reported.
PURPOSE: The purpose of this investigation was to examine the effects of a single session of aerobic exercise conducted before and after 6 wks of niacin on postprandial concentrations of soluble vascular adhesion molecules in men with metabolic syndrome.
METHODS: Twelve men (46 ± 2 yrs; BMI = 34.6 ± 0.8 kg·m2; % fat = 36 ± 2; VO2max = 27.5 ± 1.7 mL·min-1·kg-1; waist circumference = 109.5 ± 2.2 cm; HDL-C = 39 ± 8 mg·dL-1; triglycerides = 300 ± 44 mg·dL-1; HOMA score = 4.4 ± 0.8) completed each of four conditions prior to ingesting a HFM (1000 kcals, 100 g fat, 18g CHO, 3 g protein): No exercise Control; Exercise - treadmill walking (500 kcal energy expenditure at 65% VO2max) performed one hour prior to a HFM; Niacin - 6 weeks of niacin (1500 mg·d-1) and; Niacin + Exercise. Blood samples were obtained prior to and at two-hour intervals for eight hours following the HFM for each condition. Soluble vascular adhesion molecule 1 (sVCAM1) and intercellular adhesion molecule 1 (sICAM1) concentrations were measured and total (AUCT) and incremental (AUCI) areas under the curve were calculated.
RESULTS: Exercise decreased sVCAM1 AUCI by 2-fold compared to Control (from 1256.5 ± 146.7 to 629.1 ± 98.4 ng·mL-1 × 8 hr; p< 0.05); whereas, niacin produced a 25% reduction that did not meet statistical significance. Combining exercise with niacin reduced sVCAM1 AUCI by a similar extent to exercise alone (559.0 ± 108.5 versus 629.1 ± 98.4 ng·mL-1 × 8 hr). Postprandial sICAM1 was not affected by any of the conditions or the HFM.
CONCLUSIONS: Aerobic exercise reduces postprandial sVCAM1 concentrations with no further exercise-induced reductions observed after 6 weeks of niacin therapy. sICAM1 expression appears refractory to short-term niacin therapy and responses to single sessions of moderate-intensity exercise.