“(三)糖尿病是最常见的糖代谢紊乱疾病
临床上将糖尿病分为四型:胰岛素依赖型(1型)、非胰岛素依赖型(2型)、妊娠糖尿病(3型)和特殊类型糖尿病(4型)。1型糖尿病多发生于青少年,因自身免疫而使胰腺B细胞功能缺陷,导致胰岛素分泌不 足。2型糖尿病和肥胖关系密切,可能是由细胞膜上胰岛素受体功能缺陷所致。”
问题：3型糖尿病和妊娠糖尿病(3型)是同一种疾病吗
其中表示：术语“3型糖尿病”准确地反映了这样一个事实，即阿尔兹海默病代表一种选择性涉及大脑的糖尿病，具有与1型糖尿病和2型糖尿病重叠的分子和生化特征。
谢谢提供更多资料，我也学习到新知识了。 看来我前面的回复欠妥，武断了。知识上的盲点能通过这样的讨论有所弥补是很开心的事 ：-）
不过，就所查的资料，我以为教材上的说法也没问题。目前临床上公认的主要三种类型糖尿病就是Type1 diabetes（T1DM），Type 2 diabetes（T2DM）和Gestational diabetes (GDM)。从临床诊断的角度，中文语境下说妊娠糖尿病是第三种类型没有问题，只是和英文“type 3 diabetes” 不是一回事。
你提到的那篇2008年的文章（“Alzheimer’s Disease Is Type 3 Diabetes—Evidence Reviewed” ，Journal of Diabetes Science and Technology，Volume 2, Issue 6, November 2008）比较有影响力，被引用次数已超千次。 类似的review也有若干，包括近几年的，发表在一般的杂志，被引频率不高。
这篇2008年的文章里，作者说“We have proposed that T3DM represents a major pathogenic mechanism of AD neurodegeneration” “Altogether, the results from these studies provide strong evidence in support of the hypothesis that AD represents a form of diabetes mellitus that selectively afflicts the brain.”
该文章研究团队更早是在2005年提出该假说，发表在 Journal of Alzheimer's Disease 的文章 “Impaired insulin and insulin-like growth factor expression and signaling mechanisms in Alzheimer's disease – is this type 3 diabetes?” 摘要里说： “Therefore, we propose the term, “Type 3 Diabetes” to reflect this newly identified pathogenic mechanism of neurodegeneration.” 该文目前被引近2000次。研究团队From the Departments of Pathology and Medicine, Rhode Island Hospital and Brown Medical School, Providence, RI, USA
就我目前看到的其他一些资料来看，“3型糖尿病”这个词是一些学者鉴于AD与T2DM有许多相似之处而提出的解释AD的一种假说，认为AD是由大脑对胰岛素的抵抗引起的。该假说在学术界还有很大的争议。“3型糖尿病”这个词还不是公认的医学术语或公认的病症，但现在用于研究阿尔茨海默病的病因。
英文维基下有Type 3 Diabetes 词条，里面有下述内容：
“Type 3 diabetes is a proposed term to describe the interlinked association between type 1 and type 2 diabetes, and Alzheimer's disease.[1] This term is used to look into potential triggers of Alzheimer's disease in people with diabetes.[1]
While Type 3 diabetes is not a diagnosis in itself, a [2] diagnosis of suspected Alzheimer's disease can be established through observational signs and sometimes with neuroimaging techniques such as Magnetic Resonance Imaging (MRI) to observe abnormalities in diabetic patient's brain tissue.[2]
Labelling Alzheimer's disease as Type 3 Diabetes is generally controversial, and this definition is not a known medical diagnosis. While insulin resistance is a risk factor for the development of Alzheimer's disease and some other dementias, causes of Alzheimer's disease are likely to be much more complex than being explained by insulin factors on their own, and indeed several patients with Alzheimer's disease have normal insulin metabolism.[5]“
英文维基在Alzheimer’s Disease 词条下，Causes里提到了多种假说，但没有提及 type 3 diabetes。还有， Diabetes 词条下也没有出现“type 3 diabetes” 的说法，有 “Gestational diabetes is the third main form” 。
非专家，所查资料有限，以上仅供参考哈。 欢迎继续交流！