内皮功能受损——高脂饮食摄入导致动脉粥样硬化的一种可能机制。

Ng C K, Chan A P, Cheng A

Department of Cardiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.

Ann Acad Med Singap. 2001 Sep;30(5):499-502.

INTRODUCTION

Endothelial dysfunction is known to occur in patients with coronary artery disease. Flow-mediated dilation of the brachial artery using Doppler ultrasound is a non-invasive technique for the assessment of endothelial function. The objective of the study was to use the above method to evaluate the pathophysiology of high-fat (HF) intake on endothelial function in a local population. A popular local dish "nasi-lemak", a source of high saturated fat content from coconut milk, was chosen to represent a local high-fat meal (LHF). In addition, the effects of a Western high-fat (WHF) ("McDonald's") meal and a low-fat (LF) meal control on endothelial function were studied.

MATERIALS AND METHODS

The study population consisted of 10 healthy male non-smoker (mean age 22 +/- 2 years) with normal body mass index, normal fasting sugar and lipid profiles. Nitric oxide dependent flow-mediated dilation and nitric oxide independent (GTN) dilation was assessed by Doppler flow in the brachial artery before and 4 hours after each meal on separate occasions by 2 experienced sonographers blinded to the type of meals.

RESULTS

The baseline brachial artery size, baseline vessel flow and increase in flow after cuff deflation were similar for each of the six arterial studies. In response to reactive hyperaemia after cuff deflation, the endothelium-dependent dilation was significantly different between the meals. There was a marked decrease in endothelium-dependent dilation after the WHF meal compared to the LF meal (8.6 +/- 2.2% vs. -0.8 +/- 1.1%, P < 0.006). There was also a marked decrease in endothelium-dependent dilation after the LHF meal compared to the LF meal (7.7 +/- 2.1% vs. -0.8 +/- 1.1%, P < 0.001). When comparing between the two HF meals, the change in endothelium-dependent dilation was not significant (7.7 vs. 8.6%, P = 0.678). GTN-induced dilation was not significantly different before and after the LF, WHF or LHF (0.1 +/- 0.5% vs. 0.2 +/- 0.9% vs. 1.3 +/- 0.5%, P = 0.094).

CONCLUSION

The results suggest that in a local population, impairment of endothelial function is a possible mechanism in the pathophysiology of atherosclerosis from HF intake, beyond just affecting lipid levels. This effect is observed after both a LHF and a WHF meal intake. This technique to study endothelial function may be a useful non-invasive screening tool in the study of other HF diet choices and provides further information for the education of the influence of dietary choices on atherosclerosis.

引言

已知冠状动脉疾病患者会出现内皮功能障碍。使用多普勒超声评估肱动脉血流介导的舒张功能是一种用于评估内皮功能的非侵入性技术。本研究的目的是使用上述方法评估当地人群中高脂（HF）饮食对内皮功能的病理生理学影响。选择当地一种受欢迎的菜肴“椰浆饭”，其富含来自椰奶的高饱和脂肪，作为当地高脂餐（LHF）的代表。此外，还研究了西式高脂（WHF）餐（“麦当劳”餐）和低脂（LF）餐对照对内皮功能的影响。

材料与方法

研究人群包括10名健康的非吸烟男性（平均年龄22±2岁），体重指数正常，空腹血糖和血脂谱正常。由2名对餐食类型不知情的经验丰富的超声检查人员，在每次用餐前和用餐后4小时，通过多普勒血流分别评估肱动脉中一氧化氮依赖性血流介导的舒张功能和一氧化氮非依赖性（GTN）舒张功能。

结果

六项动脉研究中，每项研究的肱动脉基线大小、基线血管血流以及袖带放气后的血流增加情况相似。在袖带放气后的反应性充血过程中，不同餐食后的内皮依赖性舒张功能存在显著差异。与低脂餐相比，西式高脂餐用餐后内皮依赖性舒张功能显著降低（8.6±2.2%对-0.8±1.1%，P<0.006）。与低脂餐相比，当地高脂餐用餐后内皮依赖性舒张功能也显著降低（7.7±2.1%对-0.8±1.1%，P<0.001）。比较两种高脂餐时，内皮依赖性舒张功能的变化不显著（7.7%对8.6%，P = 0.678）。GTN诱导的舒张功能在低脂餐、西式高脂餐或当地高脂餐前后无显著差异（0.1±0.5%对0.2±0.9%对1.3±0.5%，P = 0.094）。