Effect of homocysteine-lowering nutrients on blood lipids: results from four randomised, placebo-controlled studies in healthy humans.
Effect of homocysteine-lowering nutrients on blood lipids: results from four randomised, placebo-controlled studies in healthy humans.
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同型半胱氨酸养分对血脂的影响：健康人类中的四个随机，安慰剂对照研究的结果。
DOI：
10.1371/journal.pmed.0020135
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发表时间：
2005-05
期刊：
影响因子：
15.8
通讯作者：
Katan, MB
中科院分区：
文献类型：
--
作者：
Olthof, MR;van Vliet, T;Verhoef, P;Zock, PL;Katan, MB
甜菜碱（三甲基甘氨酸）降低血浆同型半胱氨酸，一个可能的心血管疾病的危险因素。然而，对肾病患者和减肥饮食的肥胖者的研究表明，甜菜碱补充剂会提高血液胆固醇;缺乏健康个体的数据。这种对胆固醇的作用将抵消对同型半胱氨酸的任何有利作用。因此，我们研究了甜菜碱，其前体胆碱的磷脂酰胆碱的形式，和经典的同型半胱氨酸降低维生素叶酸对健康人的血脂浓度的影响。我们在四项安慰剂对照、随机干预研究中测量了血脂，这些研究检查了甜菜碱（三项研究，n = 151）、叶酸（两项研究，n = 75）和磷脂酰胆碱（一项研究，n = 26）对血浆同型半胱氨酸浓度的影响。我们结合了来自个体研究的血脂数据，并计算了相对于安慰剂的血脂浓度的加权平均变化。与安慰剂相比，补充甜菜碱（6 g/d）6周使血液LDL胆固醇浓度增加0.36 mmol/l（95%置信区间：0.25-0.46），甘油三酯浓度增加0.14 mmol/l（0.04-0.23）。总胆固醇与HDL胆固醇的比值增加了0.23（0.14-0.32）。HDL胆固醇浓度不受影响。甜菜碱剂量低于6 g/d也会升高LDL胆固醇，但这些变化在统计学上不显著。此外，甜菜碱对LDL胆固醇的影响在干预2周后已经很明显。补充磷脂酰胆碱（提供约2.6 g/d的胆碱）2周，三酰甘油浓度增加0.14 mmol/l（0.06-0.21），但不影响胆固醇浓度。叶酸补充剂（0.8毫克/天）对脂质浓度没有影响。甜菜碱补充剂增加了健康人血液中LDL胆固醇和三酰甘油的浓度，这与以前有限的数据一致。对血脂的不利影响可能会抵消甜菜碱补充剂通过降低同型半胱氨酸对心血管健康的潜在益处。在我们的研究中，补充磷脂酰胆碱略微增加了健康人的三酰甘油浓度。以前的研究表明，磷脂酰胆碱和血脂没有明确的影响。因此，补充磷脂酰胆碱对血脂的影响仍不确定，但可能不大。叶酸补充似乎不影响血脂，因此仍然是降低血同型半胱氨酸浓度的首选治疗方法。降低同型半胱氨酸可能会降低患心脏病的风险。甜菜碱似乎对血脂有不良影响。这将使它不适合叶酸，叶酸不影响血脂。
Betaine (trimethylglycine) lowers plasma homocysteine, a possible risk factor for cardiovascular disease. However, studies in renal patients and in obese individuals who are on a weight-loss diet suggest that betaine supplementation raises blood cholesterol; data in healthy individuals are lacking. Such an effect on cholesterol would counteract any favourable effect on homocysteine. We therefore investigated the effect of betaine, of its precursor choline in the form of phosphatidylcholine, and of the classical homocysteine-lowering vitamin folic acid on blood lipid concentrations in healthy humans. We measured blood lipids in four placebo-controlled, randomised intervention studies that examined the effect of betaine (three studies, n = 151), folic acid (two studies, n = 75), and phosphatidylcholine (one study, n = 26) on plasma homocysteine concentrations. We combined blood lipid data from the individual studies and calculated a weighted mean change in blood lipid concentrations relative to placebo. Betaine supplementation (6 g/d) for 6 wk increased blood LDL cholesterol concentrations by 0.36 mmol/l (95% confidence interval: 0.25–0.46), and triacylglycerol concentrations by 0.14 mmol/l (0.04–0.23) relative to placebo. The ratio of total to HDL cholesterol increased by 0.23 (0.14–0.32). Concentrations of HDL cholesterol were not affected. Doses of betaine lower than 6 g/d also raised LDL cholesterol, but these changes were not statistically significant. Further, the effect of betaine on LDL cholesterol was already evident after 2 wk of intervention. Phosphatidylcholine supplementation (providing approximately 2.6 g/d of choline) for 2 wk increased triacylglycerol concentrations by 0.14 mmol/l (0.06–0.21), but did not affect cholesterol concentrations. Folic acid supplementation (0.8 mg/d) had no effect on lipid concentrations. Betaine supplementation increased blood LDL cholesterol and triacylglycerol concentrations in healthy humans, which agrees with the limited previous data. The adverse effects on blood lipids may undo the potential benefits for cardiovascular health of betaine supplementation through homocysteine lowering. In our study phosphatidylcholine supplementation slightly increased triacylglycerol concentrations in healthy humans. Previous studies of phosphatidylcholine and blood lipids showed no clear effect. Thus the effect of phosphatidylcholine supplementation on blood lipids remains inconclusive, but is probably not large. Folic acid supplementation does not seem to affect blood lipids and therefore remains the preferred treatment for lowering of blood homocysteine concentrations. Lowering homocysteine might reduce the risk for heart disease. Betaine seems to have an adverse effect on blood lipids. This would make it less suitable than folic acid, which does not affect blood lipids.
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影响因子：
2
作者：
Curtin, F;Altman, DG;Elbourne, D
通讯作者：
Elbourne, D
影响因子：
5.5
作者：
Natarajan, S;Glick, H;Kinosian, B
通讯作者：
Kinosian, B
影响因子：
4.2
作者：
Niculescu, MD;Zeisel, SH
通讯作者：
Zeisel, SH
DOI：
10.1097/00043798-199604000-00014
发表时间：
1996-04-01
期刊：
Journal of cardiovascular risk
影响因子：
--
作者：
Hokanson, J E;Austin, M A
通讯作者：
Austin, M A
影响因子：
5.3
作者：
GRETEN, H;RAETZER, H;SCHETTLER, G
通讯作者：
SCHETTLER, G