Dietary nitrate-induced increases in human muscle power: high versus low responders
Dietary nitrate-induced increases in human muscle power: high versus low responders
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DOI：
10.14814/phy2.13575
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发表时间：
2018-01-01
影响因子：
2.5
通讯作者：
Peterson, Linda R.
中科院分区：
文献类型：
--
作者：
Coggan, Andrew R.;Broadstreet, Seth R.;Peterson, Linda R.
在患者群体中，最大的神经肌肉力量是运动成绩的重要决定因素，也是生活质量、独立性甚至死亡率的重要决定因素。我们已经证明，饮食中的硝酸盐(NO3-)是一氧化氮(NO)的来源，可以提高部分但不是所有受试者的肌肉力量。本调查旨在确定导致这种个体间差异的因素。健康男性(n=13)和女性(n=7)2279岁，体重52.1-114.9 kg，采用随机、双盲、安慰剂对照、交叉设计进行研究。受试者在摄入甜菜根汁(BRJ)后2小时进行测试，无论这些甜菜根汁是否含有12.3+/-0.8 mmo3-NO3-。测定血浆NO3-和亚硝酸盐(NO2-)作为NO生物利用度的指标，并通过等速测力法测定最大伸膝速度(Vmax)、功率(P-max)和疲劳性。平均而言，饲粮NO3-使(P<；0.05)Pmax提高了4.4+/-8.1%。然而，个体变化的范围从-9.6%到+26.8%。这种个体间的变异性与年龄、体重(与每公斤N3剂量成反比)、体重指数(替代身体成分)或安慰剂试验Vmax或疲劳指数(体内肌肉纤维类型分布的指标)没有显著相关性。相反，Pmax的相对增加与血浆NO2-浓度的相对增加显著相关(r=0.60；P<；0.01)。在多变量分析中，女性(P=0.08)也倾向于与Pmax的增加更大相关。我们的结论是，饮食中NO3-诱导的肌肉力量增加的幅度取决于由此导致的血浆NO2-的增加的幅度，可能还取决于女性的性别。
Maximal neuromuscular power is an important determinant of athletic performance and also quality of life, independence, and perhaps even mortality in patient populations. We have shown that dietary nitrate (NO3-), a source of nitric oxide (NO), improves muscle power in some, but not all, subjects. The present investigation was designed to identify factors contributing to this interindividual variability. Healthy men (n = 13) and women (n = 7) 2279 year of age and weighing 52.1-114.9 kg were studied using a randomized, double-blind, placebo-controlled, crossover design. Subjects were tested 2 h after ingesting beetroot juice (BRJ) either containing or devoid of 12.3 +/- 0.8 mmol of NO3-. Plasma NO3- and nitrite (NO2-) were measured as indicators of NO bioavailability and maximal knee extensor speed (Vmax), power (P-max), and fatigability were determined via isokinetic dynamometry. On average, dietary NO3- increased (P < 0.05) Pmax by 4.4 +/- 8.1%. Individual changes, however, ranged from -9.6 to + 26.8%. This interindividual variability was not significantly correlated with age, body mass (inverse of NO3- dose per kg), body mass index (surrogate for body composition) or placebo trial Vmax or fatigue index (in vivo indicators of muscle fiber type distribution). In contrast, the relative increase in Pmax was significantly correlated (r = 0.60; P < 0.01) with the relative increase in plasma NO2- concentration. In multivariable analysis female sex also tended (P = 0.08) to be associated with a greater increase in Pmax. We conclude that the magnitude of the dietary NO3--induced increase in muscle power is dependent upon the magnitude of the resulting increase in plasma NO2- and possibly female sex.