Exaggerated postprandial lipaemia and lower post-heparin lipoprotein lipase activity in middle-aged men
Exaggerated postprandial lipaemia and lower post-heparin lipoprotein lipase activity in middle-aged men
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DOI：
10.1042/cs20030134
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发表时间：
2003-10-01
期刊：
影响因子：
6
通讯作者：
Williams, CM
中科院分区：
文献类型：
--
作者：
Jackson, KG;Knapper-Francis, JME;Williams, CM
餐后血脂反应过度被认为在致动脉粥样硬化脂蛋白表型的形成中发挥着核心作用，而致动脉粥样硬化脂蛋白表型是公认的冠心病脂质危险因素。少数有限的研究比较了不同年龄受试者的餐后脂血症，但尚未调查餐后脂血症与年龄相关的变化的机制。为了检验老年受试者血脂受损与胰岛素敏感性丧失相关的假设，本研究比较了血脂正常的健康年轻和中年男性在标准混合餐后 9 小时内的餐后血脂和激素反应。餐后 9 小时和空腹条件下测定肝素后血浆中的脂蛋白脂肪酶 (LPL) 和肝脂肪酶 (HL) 活性。餐后血浆葡萄糖 (P < 0.02)、视黄酯（乳糜微粒颗粒的间接标志物；P < 0.005）和富含三酰甘油 (TAG) 的脂蛋白（密度 < 1.006 g/ml 血浆分数）TAG (P < 0.05) 和视黄酯 (P < 0.005) 反应在中年男性中较高，而血浆胰岛素反应在该组中较低（P<0.001）。中年男性的空腹和餐后9小时LPL和HL活性也显着低于年轻男性（P < 0.006）。总之，中年男性的餐后 TAG 反应增量高于年轻男性，归因于饮食中富含 TAG 的脂蛋白（密度 < 1.006 g/ml 血浆分数）的积累，并且发生在两组之间空腹 TAG 水平没有显着差异的情况下。中年男性的空腹和餐后 LPL 和 HL 活性明显较低，但胰岛素反应测量值与肝素后脂肪酶活性之间以及胰岛素与餐后脂血症测量值之间缺乏统计关联，表明这种较低的活性不能归因于脂肪酶对胰岛素激活缺乏敏感性。或者，肝素后脂肪酶活性可能不是餐后激活的脂肪酶胰岛素敏感成分的良好标志。
An exaggerated postprandial lipaemic response is thought to play a central role in the development of an atherogenic lipoprotein phenotype, a recognized lipid risk factor for coronary heart disease. A small number of limited studies have compared postprandial lipaemia in subjects of varying age, but have not investigated mechanisms underlying age-associated changes in postprandial lipaemia. In order to test the hypothesis that impaired lipaemia in older subjects is associated with loss of insulin sensitivity, the present study compared the postprandial lipaemic and hormone responses for 9 h following a standard mixed meal in normolipidaemic healthy young and middle-aged men. Lipoprotein lipase (LPL) and hepatic lipase (HL) activities were determined in post-heparin plasma 9 h postprandially and on another occasion under fasting conditions. Postprandial plasma glucose (P < 0.02), retinyl ester (indirect marker for chylomicron particles; P < 0.005) and triacylglycerol (TAG)-rich lipoprotein (density < 1.006 g/ml fraction of plasma) TAG (P < 0.05) and retinyl ester (P < 0.005) responses were higher in middle-aged men, whereas plasma insulin responses were lower in this group (P < 0.001). Fasting and 9 h postprandial LPL and HL activities were also significantly lower in the middle-aged men compared with the young men (P < 0.006). In conclusion, the higher incremental postprandial TAG response in middle-aged men than young men was attributed to the accumulation of dietary-derived TAG-rich lipoproteins (density < 1.006 g/ml fraction of plasma) and occurred in the absence of marked differences in fasting TAG levels between the two groups. Fasting and postprandial LPL and HL activities were markedly lower in middle-aged men, but lack of statistical associations between measures of insulin response and post-heparin lipase activities, as well as between insulin and measures of postprandial lipaemia, suggest that this lower activity cannot be attributed to lack of sensitivity of lipases to activation by insulin. Alternatively, post-heparin lipase activities may not be good markers for the insulin-sensitive component of lipase that is activated postprandially.