Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.
Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
Neuroimage Clin. 2022;35:103115. doi: 10.1016/j.nicl.2022.103115. Epub 2022 Jul 14.
Improving brain insulin sensitivity may be a promising approach in the prevention and treatment of metabolic and cognitive diseases. Our aim was to investigate acute effects of inorganic nitrate on regional cerebral blood flow (CBF) responses to intranasal insulin in abdominally obese men.
Eighteen apparently healthy men, aged 18-60 years and with a waist circumference ≥ 102 cm, participated in a randomized, double-blind, placebo-controlled cross-over trial. The study consisted of two test days separated by at least one week. Men received in random order a drink providing 10 mmol (i.e., 625 mg nitrate) potassium nitrate or an isomolar placebo drink with potassium chloride. Brain insulin action was assessed 120-150 min after the drinks by quantifying acute effects of nasal insulin on regional CBF using arterial spin labeling Magnetic Resonance Imaging. Glucose and insulin concentrations were measured at regular intervals, while blood pressure was determined fasted and at 240 min.
Inorganic nitrate intake increased regional insulin action in five brain clusters. The two largest clusters were located in the right temporal lobe (ΔCBF: 7.0 ± 3.8 mL/100 g/min, volume: 5296 mm, P < 0.001; and ΔCBF: 6.5 ± 4.3 mL/100 g/min, volume: 3592 mm, P < 0.001), while two other cortical clusters were part of the right frontal (ΔCBF: 9.0 ± 6.0 mL/100 g/min, volume: 1096 mm, P = 0.007) and the left parietal lobe (ΔCBF: 6.1 ± 4.3 mL/100 g/min, volume: 1024 mm, P = 0.012). One subcortical cluster was located in the striatum (ΔCBF: 5.9 ± 3.2 mL/100 g/min, volume: 1792 mm, P < 0.001). No effects of nitrate were observed on CBF before administration. Following nitrate intake, circulating nitrate plus nitrite concentrations increased over time (P = 0.003), but insulin and glucose concentrations and blood pressure did not change.
Acute inorganic nitrate intake may improve regional brain insulin action in abdominally obese men. These regions are involved in the regulation of different metabolic and cognitive processes. The trial was registered on January 6th, 2021 at ClinicalTrials.gov as NCT04700241.
提高大脑胰岛素敏感性可能是预防和治疗代谢和认知疾病的一种有前途的方法。我们的目的是研究无机硝酸盐对腹部肥胖男性经鼻胰岛素引起的局部脑血流 (CBF) 反应的急性影响。
18 名年龄在 18-60 岁之间、腰围≥102cm 的健康男性参加了一项随机、双盲、安慰剂对照的交叉试验。该研究由至少相隔一周的两个测试日组成。男性随机接受含有 10mmol（即 625mg 硝酸盐）硝酸钾或等渗的含氯化钾的安慰剂饮料。在饮料摄入后 120-150 分钟，通过动脉自旋标记磁共振成像量化经鼻胰岛素对局部 CBF 的急性影响，评估脑胰岛素作用。定期测量血糖和胰岛素浓度，同时在空腹和 240 分钟时测量血压。
无机硝酸盐摄入增加了五个脑区的局部胰岛素作用。最大的两个脑区位于右侧颞叶（ΔCBF：7.0±3.8mL/100g/min，体积：5296mm，P<0.001；和ΔCBF：6.5±4.3mL/100g/min，体积：3592mm，P<0.001），而另外两个皮质区位于右侧额叶（ΔCBF：9.0±6.0mL/100g/min，体积：1096mm，P=0.007）和左侧顶叶（ΔCBF：6.1±4.3mL/100g/min，体积：1024mm，P=0.012）。一个皮质下脑区位于纹状体（ΔCBF：5.9±3.2mL/100g/min，体积：1792mm，P<0.001）。硝酸盐给药前对 CBF 没有影响。硝酸盐摄入后，循环硝酸盐和亚硝酸盐浓度随时间增加（P=0.003），但胰岛素和葡萄糖浓度以及血压没有变化。
急性摄入无机硝酸盐可改善腹部肥胖男性的局部脑胰岛素作用。这些区域参与了不同代谢和认知过程的调节。该试验于 2021 年 1 月 6 日在 ClinicalTrials.gov 上注册，编号为 NCT04700241。
