Effect of a High Fat Meal on Blood Flow and Endothelial Function during Passive Leg Movement: 2246 Board #82 June 1 11 00 AM - 12 30 PM

Passive leg movement (PLM) leads to a significant increase in femoral artery blood flow (FABF). Recent studies suggest that the increase in FABF during PLM is mediated by the bioavailability of nitric oxide (NO) since inhibition of NO attenuates the FABF response. PLM has been gaining popularity as a simple, reliable method for assessing endothelial function. Since the consumption of a high fat meal (HFM) has been shown to induce endothelial dysfunction, investigators have used a HFM to demonstrate the therapeutic benefits of exercise, anti-inflammatories and anti-oxidants on endothelial function. Consumption of a HFM on the FABF response to PLM has not been previously examined but may prove useful in determining endothelial function in healthy and diseased populations. PURPOSE: To examine the effect of consuming a single HFM on FABF during PLM. It was hypothesized that consumption of a HFM would attenuate the FABF response compared to control, consistent with impaired endothelial function. METHODS: Eight healthy (31.8 ± 4.2 yrs, (±SEM)) men (n=5) and women (n=3) reported to the laboratory following a 12 h fast and no exercise. PLM was accomplished using an isokinetic (Biodex) machine which allowed the lower leg to move through 90° range of motion at 30 cycles/min. Femoral artery blood velocities (FABV) were measured continuously at baseline (60 s) and during PLM (120 s) using Doppler ultrasound. FABF was calculated using the arterial diameter measured at baseline. Each subject consumed a HFM consisting of 90 g total fat (63 g saturated fat), 364 mg cholesterol, 17 g carbohydrate, and 139 mg sodium and after 2 hrs of rest, subjects returned to the isokinetic machine and completed a second PLM trial. RESULTS: Consumption of a HFM did not lead to any differences in baseline FABF (Pre-HFM, 139.1 ± 21.0 ml/min; Post-HFM, 165.8 ± 44.3 ml/min; p>0.05). Similarly, the peak FABF responses were not different (p>0.05) between Pre-HFM (301.1 ± 40.8 ml/min) and Post-HFM (359.3 ± 73.3 ml/min). CONCLUSION: In contrast to our hypothesis and in comparison to previous studies demonstrating a decrease in endothelial function following consumption of a HFM, we did not observe blunted FABF during PLM. The reason(s) for this discrepancy is not readily apparent but warrants further investigation if PLM is to be used to assess endothelial health.