Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
Department of Geriatric Psychiatry, The Zucker Hillside Hospital, Glen Oaks, NY 11004, USA.
Psychiatry Res. 2014 Apr 30;222(1-2):84-90. doi: 10.1016/j.pscychresns.2014.01.009. Epub 2014 Feb 1.
Evidence exists for late-life depression (LLD) as both a prodrome of and risk factor for Alzheimer׳s disease (AD). The underlying neurobiological mechanisms are poorly understood. Impaired peripheral glucose metabolism may explain the association between depression and AD given the connection between type 2 diabetes mellitus with both depression and AD. Positron emission tomography (PET) measures of cerebral glucose metabolism are sensitive to detecting changes in neural circuitry in LLD and AD. Fasting serum glucose (FSG) in non-diabetic young (YC; n=20) and elderly controls (EC; n=12) and LLD patients (n=16) was correlated with PET scans of cerebral glucose metabolism on a voxel-wise basis. The negative correlations were more extensive in EC versus YC and in LLD patients versus EC. Increased FSG correlated with decreased cerebral glucose metabolism in LLD patients to a greater extent than in EC in heteromodal association cortices involved in mood symptoms and cognitive deficits observed in LLD and dementia. Negative correlations in YC were observed in sensory and motor regions. Understanding the neurobiological consequences of diabetes and associated conditions will have substantial public health significance given that this is a modifiable risk factor for which prevention strategies could have an important impact on lowering dementia risk.
存在老年期抑郁症（LLD）既是阿尔茨海默病（AD）的前驱期又是其危险因素的证据。其潜在的神经生物学机制尚不清楚。鉴于 2 型糖尿病与抑郁症和 AD 均有关联，外周葡萄糖代谢受损可能可以解释抑郁与 AD 之间的关联。正电子发射断层扫描（PET）测量大脑葡萄糖代谢对检测 LLD 和 AD 中神经回路的变化敏感。在非糖尿病的年轻对照者（YC；n=20）和老年对照者（EC；n=12）以及 LLD 患者（n=16）中，空腹血清葡萄糖（FSG）与大脑葡萄糖代谢的 PET 扫描进行了基于体素的相关性分析。EC 与 YC 相比以及 LLD 患者与 EC 相比，负相关更为广泛。与 EC 相比，LLD 患者中 FSG 升高与大脑葡萄糖代谢降低的相关性更大，而 LLD 和痴呆症中观察到的情绪症状和认知缺陷的异模态联合皮质中则更大。YC 中也观察到了在感觉和运动区域的负相关。鉴于糖尿病及其相关病症是一种可改变的危险因素，预防策略可能会对降低痴呆症风险产生重要影响，因此了解其对神经生物学的影响具有重要的公共卫生意义。
