Diabetes Research Group (Denmark Hill), Faculty of Life Sciences and Medicine, King's College London, London, UK.
School of Life Sciences, MRC-ARUK Centre of Excellence in Musculoskeletal Ageing, Nottingham University Medical School, Queen's Medical Centre, Nottingham, UK.
J Cereb Blood Flow Metab. 2022 Aug;42(8):1451-1462. doi: 10.1177/0271678X221082911. Epub 2022 Feb 25.
Behavioural responses to hypoglycaemia require coordinated recruitment of broadly distributed networks of interacting brain regions. We investigated hypoglycaemia-related changes in brain connectivity in people without diabetes (ND) and with type 1 diabetes with normal (NAH) or impaired (IAH) hypoglycaemia awareness. Two-step hyperinsulinaemic hypoglycaemic clamps were performed in 14 ND, 15 NAH and 22 IAH participants. BOLD timeseries were acquired at euglycaemia (5.0 mmol/L) and hypoglycaemia (2.6 mmol/L), with symptom and counter-regulatory hormone measurements. We investigated hypoglycaemia-related connectivity changes using established seed regions for the default mode (DMN), salience (SN) and central executive (CEN) networks and regions whose activity is modulated by hypoglycaemia: the thalamus and right inferior frontal gyrus (RIFG). Hypoglycaemia-induced changes in the DMN, SN and CEN were evident in NAH (all p < 0.05), with no changes in ND or IAH. However, in IAH there was a reduction in connectivity between regions within the RIFG (p = 0.001), not evident in the ND or NAH groups. We conclude that hypoglycaemia induces coordinated recruitment of the DMN and SN in diabetes with preserved hypoglycaemia awareness which is absent in IAH and ND. Changes in connectivity in the RIFG, a region associated with attentional modulation, may be key in impaired hypoglycaemia awareness.
行为对低血糖的反应需要协调募集广泛分布的相互作用的大脑区域网络。我们研究了无糖尿病 (ND) 人群和具有正常 (NAH) 或受损 (IAH) 低血糖意识的 1 型糖尿病患者的低血糖相关脑连接变化。在 14 名 ND、15 名 NAH 和 22 名 IAH 参与者中进行了两步高胰岛素低血糖钳夹。在正常血糖（5.0mmol/L）和低血糖（2.6mmol/L）时采集 BOLD 时间序列，同时测量症状和代偿性激素。我们使用默认模式 (DMN)、显着性 (SN) 和中央执行 (CEN) 网络的已有种子区域以及受低血糖调节的区域（丘脑和右侧额下回（RIFG））来研究低血糖相关的连接变化。NAH 中明显出现低血糖诱导的 DMN、SN 和 CEN 变化（均 p<0.05），ND 或 IAH 中则没有变化。然而，IAH 中 RIFG 内区域之间的连接减少（p=0.001），而 ND 或 NAH 组则没有。我们得出结论，低血糖在具有保留低血糖意识的糖尿病中诱导 DMN 和 SN 的协调募集，而在 IAH 和 ND 中则不存在。与注意力调节相关的 RIFG 中连接变化可能是低血糖意识受损的关键。
