Kumar Pankaj, Lele Vikram R, Akhtar Md Jawed
Department of Nuclear Medicine, All India Institute of Medical Sciences, Patna, IND.
Department of Nuclear Medicine and PET/CT, Jaslok Hospital and Research Centre, Mumbai, IND.
Cureus. 2025 Aug 9;17(8):e89682. doi: 10.7759/cureus.89682. eCollection 2025 Aug.
Diabetes mellitus (DM) is a known risk factor for cognitive decline and Alzheimer's disease (AD), possibly due to insulin resistance and impaired cerebral glucose metabolism. Fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) imaging has shown AD-like hypometabolism patterns in diabetic individuals in various global studies. However, such data is lacking in the Indian population. This study investigated the presence of AD-like hypometabolism in Indian diabetic patients compared to non-diabetic controls.
This study aimed to evaluate whether the Indian diabetic patients show AD-like reduction in brain glucose metabolism, as several studies reported AD-like hypometabolism in the brain at very early stages before making a clinical diagnosis of probable AD.
A prospective, observational study was conducted on 78 patients (39 diabetics and 39 non-diabetics; age range 43-87 years) at a tertiary care center. After excluding patients with a recent history of stroke, transient ischemic attack, or structural brain abnormalities, all participants underwent dedicated brain FDG PET-CT imaging just after a whole-body scan. Scans were analyzed using CORTEX-ID software (GE Healthcare, Chicago, IL, USA), comparing cerebral glucose metabolism to age-matched normative data. Regional hypometabolism was normalized to thalamic activity. Appropriate tests of significance were used, and P< 0.05 was considered statistically significant. Results: The study included 78 patients, 39 diabetics and 39 non-diabetic controls, matched for sex (19 males and 20 females in each group). Diabetic patients had a higher mean age (66.4 ± 10.6 years). The Mini-Mental State Examination (MMSE) score was lower in diabetics (25.3 ± 2.3) than in controls (26.8 ± 1.9). About 5.1% of diabetic patients showed an AD-like pattern, and the remaining 94.9% did not show an AD-like pattern on the FDG PET-CT scan. An AD-like pattern was not seen in any patient among the non-diabetic control group. No statistically significant association was found between the AD-like pattern in the brain on FDG PET-CT and diabetes (P 0.494).
No significant incidence of "AD-like pattern" in the brain on PET-CT images using FDG was seen in this research study on the Indian diabetic populations. However, abnormal brain scans with no AD-like hypometabolism patterns possibly suggested other etiologies, likely depression. More prospective multicentric research studies on a large Indian diabetic population with age-matched non-diabetic control groups need to be explored for definite conclusions.
糖尿病（DM）是认知功能下降和阿尔茨海默病（AD）的已知危险因素，可能是由于胰岛素抵抗和脑葡萄糖代谢受损。在各种全球研究中，氟脱氧葡萄糖正电子发射断层扫描 - 计算机断层扫描（FDG PET - CT）成像显示糖尿病个体存在类似AD的代谢减低模式。然而，印度人群缺乏此类数据。本研究调查了与非糖尿病对照组相比，印度糖尿病患者中是否存在类似AD的代谢减低情况。
本研究旨在评估印度糖尿病患者是否表现出类似AD的脑葡萄糖代谢降低，因为多项研究报告在临床诊断可能的AD之前的非常早期阶段，大脑中就存在类似AD的代谢减低。
在一家三级医疗中心对78例患者（39例糖尿病患者和39例非糖尿病患者；年龄范围43 - 87岁）进行了一项前瞻性观察研究。在排除近期有中风、短暂性脑缺血发作或脑结构异常病史的患者后，所有参与者在全身扫描后立即接受专门的脑FDG PET - CT成像。使用CORTEX - ID软件（美国伊利诺伊州芝加哥市通用电气医疗集团）对扫描结果进行分析，将脑葡萄糖代谢与年龄匹配的正常数据进行比较。区域代谢减低以丘脑活动进行标准化。使用了适当的显著性检验，P < 0.05被认为具有统计学意义。
该研究包括78例患者，39例糖尿病患者和39例非糖尿病对照组，性别匹配（每组19例男性和20例女性）。糖尿病患者的平均年龄较高（66.4 ± 10.6岁）。糖尿病患者的简易精神状态检查表（MMSE）评分（25.3 ± 2.3）低于对照组（26.8 ± 1.9）。约5.1%的糖尿病患者在FDG PET - CT扫描中表现出类似AD的模式，其余94.9%未表现出类似AD的模式。非糖尿病对照组中没有患者表现出类似AD的模式。在FDG PET - CT上大脑中类似AD的模式与糖尿病之间未发现统计学上的显著关联（P = 0.494）。
在这项针对印度糖尿病人群的研究中，使用FDG的PET - CT图像上未发现大脑中“类似AD模式”的显著发生率。然而，没有类似AD代谢减低模式的异常脑扫描可能提示其他病因，可能是抑郁症。需要对大量印度糖尿病人群以及年龄匹配的非糖尿病对照组进行更多前瞻性多中心研究以得出明确结论。
