Figueroa Arturo, Dillon Katherine N, Levitt Danielle E, Kang Yejin
Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79409, USA.
Department of Kinesiology, Albion College, Albion, MI 49224, USA.
Nutrients. 2025 Aug 28;17(17):2790. doi: 10.3390/nu17172790.
Patients with type 2 diabetes (T2D) develop vascular complications due to arginine deficiency-induced microvascular endothelial dysfunction, which is related to the loss of muscle strength (MS) associated with aging. Thus, increased nitric oxide (NO)-mediated vasodilation may improve MS. We investigated the impact of the NO precursor citrulline on microvascular function (endothelial and muscle reactivity) and MS in T2D patients.
Sixteen participants with T2D (53-72 years, nine females) were randomized to citrulline supplementation (CITS, 6 g/day) or placebo for 4 weeks prior to an 8-week washout period, followed by the opposite supplement for 4 weeks in a crossover trial. Endothelial function (log-transformed reactive hyperemia index, LnRHI), forearm muscle reactivity (near-infrared spectroscopy-derived tissue oxygen index (TOI) reperfusion indices), plasma arginine levels (ARG), and handgrip strength (HGS) and calf MS (CMS) adjusted for body weight were measured at baseline and 4 weeks for each condition.
CITS increased the LnRHI (∆0.11 ± 0.16 vs. ∆-0.08 ± 0.24, < 0.05), TOI range (∆2.6 ± 3.3 vs. ∆-1.5 ± 4.8%, < 0.01), TOI hyperemic response (∆1.2 ± 1.4 vs. ∆-0.6 ± 2.8%, < 0.05), TOI 2 min area under the curve (∆154 ± 187 vs. ∆-41 ± 194%/s, < 0.01), ARG (∆43 ± 28 vs. ∆1 ± 16μM/L, < 0.001), CMS (∆1.5 ± 2.8 vs. ∆-0.3 ± 1.2 kg, < 0.05), and CMS (∆0.02 ± 0.03 vs. ∆-0.01 ± 0.02 kg/kg, < 0.01) compared to placebo. The improvements in LnRHI and CMS were correlated ( = 0.37, < 0.05).
This study showed that CITS improves microvascular endothelial function, muscle microvascular reactivity, and calf muscle strength in middle-aged and older patients with T2D.
2型糖尿病（T2D）患者因精氨酸缺乏导致微血管内皮功能障碍而发生血管并发症，这与衰老相关的肌肉力量（MS）丧失有关。因此，增加一氧化氮（NO）介导的血管舒张可能改善肌肉力量。我们研究了NO前体瓜氨酸对T2D患者微血管功能（内皮和肌肉反应性）及肌肉力量的影响。
16名T2D参与者（53 - 72岁，9名女性）在为期8周的洗脱期前被随机分为瓜氨酸补充组（CITS，6克/天）或安慰剂组，为期4周，随后在交叉试验中接受相反的补充剂，为期4周。在每种情况下，于基线和4周时测量内皮功能（对数转换后的反应性充血指数，LnRHI）、前臂肌肉反应性（近红外光谱衍生的组织氧指数（TOI）再灌注指数）、血浆精氨酸水平（ARG）、握力（HGS）以及根据体重调整的小腿肌肉力量（CMS）。
与安慰剂相比，CITS增加了LnRHI（∆0.11±0.16对∆ - 0.08±0.24，P<0.05）、TOI范围（∆2.6±3.3对∆ - 1.5±4.8%，P<0.01）、TOI充血反应（∆1.2±1.4对∆ - 0.6±2.8%，P<0.05）、TOI 2分钟曲线下面积（∆154±187对∆ - 41±194%/秒，P<0.01）、ARG（∆43±28对∆1±16μM/L，P<0.001）、CMS（∆1.5±2.8对∆ - 0.3±1.2千克，P<0.05）以及CMS（∆0.02±0.03对∆ - 0.01±0.02千克/千克，P<0.01）。LnRHI和CMS的改善具有相关性（r = 0.37，P<0.05）。
本研究表明，CITS可改善中老年T2D患者的微血管内皮功能、肌肉微血管反应性及小腿肌肉力量。
