Department of Public Health and Clinical Medicine, Family Medicine, Umeå University, Umeå, Sweden.
Department of Public Health and Clinical Medicine, Nutritional Research, Umeå University, Umeå, Sweden.
PLoS One. 2021 Mar 19;16(3):e0247753. doi: 10.1371/journal.pone.0247753. eCollection 2021.
How acute hyperglycaemia affects memory functions and functional brain responses in individuals with and without type 2 diabetes is unclear. Our aim was to study the association between acute hyperglycaemia and working, semantic, and episodic memory in participants with type 2 diabetes compared to a sex- and age-matched control group. We also assessed the effect of hyperglycaemia on working memory-related brain activity. A total of 36 participants with type 2 diabetes and 34 controls (mean age, 66 years) underwent hyperglycaemic clamp or placebo clamp in a blinded and randomised order. Working, episodic, and semantic memory were tested. Overall, the control group had higher working memory (mean z-score 33.15 ± 0.45) than the group with type 2 diabetes (mean z-score 31.8 ± 0.44, p = 0.042) considering both the placebo and hyperglycaemic clamps. Acute hyperglycaemia did not influence episodic, semantic, or working memory performance in either group. Twenty-two of the participants (10 cases, 12 controls, mean age 69 years) were randomly invited to undergo the same clamp procedures to challenge working memory, using 1-, 2-, and 3-back, while monitoring brain activity by blood oxygen level-dependent functional magnetic resonance imaging (fMRI). The participants with type 2 diabetes had reduced working memory during the 1- and 2-back tests. fMRI during placebo clamp revealed increased BOLD signal in the left lateral frontal cortex and the anterior cingulate cortex as a function of working memory load in both groups (3>2>1). During hyperglycaemia, controls showed a similar load-dependent fMRI response, whereas the type 2 diabetes group showed decreased BOLD response from 2- to 3-back. These results suggest that impaired glucose metabolism in the brain affects working memory, possibly by reducing activity in important frontal brain areas in persons with type 2 diabetes.
急性高血糖如何影响 2 型糖尿病患者和非 2 型糖尿病患者的记忆功能和大脑功能反应尚不清楚。我们的目的是研究与 2 型糖尿病患者相比，急性高血糖与工作记忆、语义记忆和情景记忆之间的关系，研究对象为 2 型糖尿病患者和性别、年龄匹配的对照组。我们还评估了高血糖对与工作记忆相关的大脑活动的影响。共有 36 名 2 型糖尿病患者和 34 名对照者（平均年龄 66 岁）接受了盲法和随机分组的高血糖钳夹或安慰剂钳夹。测试了工作记忆、情景记忆和语义记忆。总的来说，考虑到安慰剂和高血糖钳夹，对照组的工作记忆（平均 z 分数 33.15±0.45）高于 2 型糖尿病组（平均 z 分数 31.8±0.44，p=0.042）。急性高血糖对两组的情景记忆、语义记忆或工作记忆均无影响。22 名参与者（10 例病例，12 名对照者，平均年龄 69 岁）随机受邀接受相同的钳夹程序，通过 1-、2-和 3-回任务来挑战工作记忆，同时通过血氧水平依赖功能磁共振成像（fMRI）监测大脑活动。2 型糖尿病患者在 1-和 2-回测试中工作记忆降低。在安慰剂钳夹期间，两组的左外侧额皮质和前扣带皮质的 BOLD 信号随工作记忆负荷的增加而增加（3>2>1）。在高血糖期间，对照组显示出类似的负荷依赖性 fMRI 反应，而 2 型糖尿病组从 2-回至 3-回的 BOLD 反应减少。这些结果表明，大脑中葡萄糖代谢受损会影响工作记忆，可能是通过降低 2 型糖尿病患者重要的额前大脑区域的活动。
