Gumpeny R Sridhar, Gumpeny Lakshmi, Gumpeny Nagamani, Endocrine and Diabetes Centre, Department of Obstetrics and Gynecology, Andhra Medical College, Visakhapatnam 530002, India.
World J Diabetes. 2015 Jun 10;6(5):744-51. doi: 10.4239/wjd.v6.i5.744.
Type 2 diabetes mellitus and Alzheimer's disease are both associated with increasing age, and each increases the risk of development of the other. Epidemiological, clinical, biochemical and imaging studies have shown that elevated glucose levels and diabetes are associated with cognitive dysfunction, the most prevalent cause of which is Alzheimer's disease. Cross sectional studies have clearly shown such an association, whereas longitudinal studies are equivocal, reflecting the many complex ways in which the two interact. Despite the dichotomy, common risk and etiological factors (obesity, dyslipidemia, insulin resistance, and sedentary habits) are recognized; correction of these by lifestyle changes and pharmacological agents can be expected to prevent or retard the progression of both diseases. Common pathogenic factors in both conditions span a broad sweep including chronic hyperglycemia per se, hyperinsulinemia, insulin resistance, acute hypoglycemic episodes, especially in the elderly, microvascular disease, fibrillar deposits (in brain in Alzheimer's disease and in pancreas in type 2 diabetes), altered insulin processing, inflammation, obesity, dyslipidemia, altered levels of insulin like growth factor and occurrence of variant forms of the protein butyrylcholinesterase. Of interest not only do lifestyle measures have a protective effect against the development of cognitive impairment due to Alzheimer's disease, but so do some of the pharmacological agents used in the treatment of diabetes such as insulin (especially when delivered intranasally), metformin, peroxisome proliferator-activated receptors γ agonists, glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors. Diabetes must be recognized as a risk for development of Alzheimer's disease; clinicians must ensure preventive care be given to control and postpone both conditions, and to identify cognitive impairment early to manage it appropriately.
2 型糖尿病和阿尔茨海默病均与年龄增长相关，且两者互为风险因素。流行病学、临床、生化和影像学研究表明，血糖升高和糖尿病与认知功能障碍相关，而认知功能障碍最常见的病因是阿尔茨海默病。横断面研究明确表明了这种相关性，而纵向研究则存在争议，这反映了两者相互作用的许多复杂方式。尽管存在这种二分法，但人们已经认识到共同的风险和病因因素（肥胖、血脂异常、胰岛素抵抗和久坐不动的习惯）；通过生活方式改变和药物治疗纠正这些因素，可以预期预防或延缓这两种疾病的进展。这两种疾病的共同发病因素广泛存在，包括慢性高血糖本身、高胰岛素血症、胰岛素抵抗、急性低血糖发作（尤其是在老年人中）、微血管疾病、纤维状沉积物（在大脑中为阿尔茨海默病，在胰腺中为 2 型糖尿病）、胰岛素处理改变、炎症、肥胖、血脂异常、胰岛素样生长因子水平改变以及变异型丁酰胆碱酯酶的出现。值得注意的是，生活方式措施不仅对因阿尔茨海默病导致的认知障碍的发展具有保护作用，而且一些用于治疗糖尿病的药物也具有保护作用，如胰岛素（尤其是经鼻内给药时）、二甲双胍、过氧化物酶体增殖物激活受体 γ 激动剂、胰高血糖素样肽-1 受体激动剂和二肽基肽酶-4 抑制剂。必须认识到糖尿病是阿尔茨海默病发展的风险因素；临床医生必须确保提供预防保健以控制和延缓这两种疾病，并及早识别认知障碍，以进行适当管理。
