Memantine hydrochloride

研究借助先进的流行病学统计方法，针对入住专业护理机构的老年人群开展大规模分析，清晰验证了 RZV 与痴呆风险之间的关联。 在全球人口深度老龄化的大背景下，痴呆已经成为全球性重大公共卫生难题。按照国际阿尔茨海默病协会的统计数据，全球平均每 3 秒就会新增一例痴呆患者，高龄、体弱的老年群体更是疾病负担的主要承载者。 多年来，医学界一直在探索痴呆的各类预防手段，而一项有趣的关联现象逐渐进入大众视野：多项观察性研究发现，带状疱疹疫苗的接种或与痴呆发病风险降低存在联系。不过早期相关研究大多围绕美国现已停用的带状疱疹减毒活疫苗展开，不仅研究方法存在局限，对于目前临床主流的重组带状疱疹疫苗（RZV），其在高龄、体弱高危老年群体中的实际保护效果，此前一直缺乏严谨的真实世界证据。 就在近期，布朗大学等多家机构的研究团队在权威期刊《Annals of Internal Medicine》发表了题为 Dementia Risk After Recombinant Herpes Zoster Vaccination in Older Adults With a Recent Skilled-Nursing Facility Stay : A Target Trial Emulation 的重磅研究，借助先进的流行病学统计方法，针对入住专业护理机构的老年人群开展大规模分析，清晰验证了 RZV 与痴呆风险之间的关联。 这项研究选取的目标人群极具临床代表性，聚焦 2017 年至 2022 年间全美 5500 余家专业护理机构中，因急性期康复或长期照护需求入院、年龄≥66 岁的美国医疗保险参保长者。研究人员整合了海量电子健康记录与医保理赔数据，最终筛选出 509926 名符合入组标准的受试者，这些老人入院时均无痴呆确诊记录，且满足 RZV 接种条件，整体平均年龄 79 岁，女性占比 63.6%，多数人在护理机构的停留时长集中在 9 至 36 天，中位入住时长为 18 天。 在全部受试者中，仅有 8843 人（占比 1.73%）在入院后的 12 个月内完成至少一剂 RZV 接种，而这部分接种人群里，87% 的疫苗接种行为都发生在离开护理机构出院之后。为了规避传统观察性研究的短板、最大程度模拟随机对照试验的严谨性，研究团队创新性采用目标试验仿真结合 “克隆-删失-加权” 的统计策略，同时纳入 57 项基线指标和动态变化的协变量校正混杂因素，对所有受试者开展最长 4 年的长期随访。随访的观察终点不仅包含新发痴呆，还涵盖医保退出、全因死亡等事件。 研究对痴呆的判定也设置了标准化规则，结合痴呆相关住院记录、间隔超过 30 天的痴呆专项医保账单以及乙酰胆碱酯酶抑制剂、美金刚等痴呆药物使用记录，这套判定标准经过验证，灵敏度达 79.3%、特异度高达 99.1%，保障了结果的准确性。 长达 4 年的随访数据给出了明确结论：未接种 R 的受试者痴呆累积发生率为 24.6%，而入院 12 个月内完成 RZV 接种的人群，痴呆累积发生率降至 18.8%。经过加权逻辑回归模型分析，接种 RZV 可使痴呆发病的绝对风险降低 5.8 个百分点，95% 置信区间为 3.9 至 7.5 个百分点；相对风险比（RR）为 0.76，意味着接种人群的痴呆发病风险整体下降 24%，按照数据推算，每 17 名完成 RZV 接种的高龄长者，就有望减少 1 例痴呆病例。 研究还开展了分层亚组分析，发现这种保护效果会受性别、既往疫苗接种史影响：女性群体的获益更突出，风险比为 0.75，男性群体的保护作用则有所减弱，风险比为 0.82；对于曾经接种过旧版带状疱疹减毒活疫苗的人群，RZV 带来的额外保护效应也出现衰减，风险比升至 0.86，而从未接种过减毒活疫苗的人群依旧能获得显著防护，风险比为 0.75。即便单独筛选入院时无任何认知损伤的受试者，结果依然稳定，接种组 4 年痴呆发生率为 14.6%，未接种组为 18.8%，风险比 0.77。除此之外，研究还发现接种 RZV 的老年人群，全因死亡风险也同步出现明显下降。 为验证结论的稳健性，团队开展了多轮敏感性分析与阴性对照试验，通过调整权重计算方式、更换痴呆判定标准、以髋部骨折和常规健康随访作为阴性对照等多重手段反复校验。即便采用最保守的双阴性对照模型进行校正后，RZV 依旧能让受试者的痴呆风险降低 12%，一系列测试都证明该关联并非偶然。 这项研究的核心价值，在于填补了重组带状疱疹疫苗在护理机构高龄高危人群中的研究空白。这类长者同时面临带状疱疹和痴呆的双重威胁，本就是疾病预防的重点人群，但目前该群体的 RZV 整体接种率仅 1.73%，现状不容乐观。而老人入住专业护理机构的这段时间，本是医护人员评估疫苗 eligibility、开展接种干预的黄金窗口期，却未能充分利用，这也为全球老年照护体系敲响了警钟。 不过研究团队始终保持科学审慎的态度，客观指出了研究存在的多项局限性。尽管研究已经纳入数十项混杂变量进行校正，但阴性对照分析结果显示，研究仍存在少量未被排除的残留混杂因素，比如愿意主动接种疫苗的长者往往健康意识更强、生活习惯更健康，这类隐性因素可能对结果产生干扰，因此目前只能证实二者存在显著统计学关联，尚不能直接判定 RZV 与痴呆预防存在绝对的因果关系。 同时，由于重组带状疱疹疫苗2017 年才在美国获批上市，研究随访时长受到客观限制；依托医保和电子病历开展分析，也会导致疫苗接种记录、痴呆诊断存在细微偏差；另外，受试者的死亡事件会对痴呆终点判定产生中介效应，这一复杂影响也有待后续研究进一步拆解。 从作用机制层面分析，研究团队结合现有理论推测，带状疱疹疫苗对大脑的潜在保护作用是多维度的：一方面疫苗能阻断水痘-带状疱疹病毒活化引发的神经炎症，减少大脑内错误折叠蛋白、神经原纤维缠结等病理物质堆积；另一方面，疫苗触发的全身性免疫调节，也可能间接起到守护神经的效果，而性别差异、既往疫苗史对保护效果的影响，也与不同人群的免疫应答差异相契合。 放眼公共卫生领域，带状疱疹疫苗的核心临床价值本是预防带状疱疹及其后遗剧烈神经痛，而本次大规模真实世界研究带来的新发现，为疫苗接种增添了重要加分项。对于老年群体、养老机构以及老年照护从业者而言，这一成果具备很强的现实指导意义：抓住老人入院照护的关键节点推广 RZV 接种，不仅能帮助长者规避带状疱疹的折磨，还有望降低远期痴呆的发病概率，相当于为老年大脑健康增添一份额外保障。 目前，全球多项针对带状疱疹疫苗与痴呆的研究已形成相互印证的证据链，逐步拼凑出完整的研究图景，但想要彻底厘清二者的因果关系、明确具体作用通路，还需要设计前瞻性随机对照试验开展更深层次探索。 对于普通老年人和家属来说，无需将带状疱疹疫苗当作 “抗痴呆神药”，但可以将这份研究结论作为参考，更加重视常规老年疫苗接种，用科学手段全方位守护晚年健康。（生物谷Bioon.com） 参考文献： Kaleen N Hayes,Daniel A Harris,Kevin W McConeghy, et al. Dementia Risk After Recombinant Herpes Zoster Vaccination in Older Adults With a Recent Skilled-Nursing Facility Stay : A Target Trial Emulation, Ann Intern Med. 2026 Jun 16. doi:10.7326/ANNALS-25-04689.

Diabetes and dementia appear to be closely intertwined, with each condition potentially influencing the other. Problems with insulin and glucose can affect the brain’s energy supply, increase inflammation, and damage blood vessels linked to memory loss. Researchers are also finding that some popular diabetes medications may lower dementia risk. These discoveries are opening new possibilities for protecting brain health as people age.The link between diabetes and dementia is becoming increasingly clear. New research shows how blood sugar problems affect brain health and vice versa. Here are ten evidence-based insights into how the two conditions are related. People with diabetes are about 60% more likely to develop dementia than those without, and frequent episodes of low blood sugar are linked to a 50% higher chance of cognitive decline. Insulin resistance – the major cause of type 2 diabetes – happens when cells stop responding properly to insulin. This means that too much sugar, in the form of glucose, is left in the blood, leading to complications. It usually affects the liver and muscles, but it also affects the brain. In Alzheimer’s, this resistance may make it harder for brain cells to use glucose for energy, contributing to cognitive decline. The brain is only 2% of our body weight, but uses about 20% of the body’s energy. In dementia, brain cells appear to lose the ability to use glucose properly. This mix of poor use of glucose and insulin resistance is sometimes unofficially called type 3 diabetes. People with Alzheimer’s often have higher fasting blood glucose, even if they don’t have diabetes. This is a form of pre-diabetes. Animal studies also show that Alzheimer’s-like changes in the brain raise blood glucose levels. Also, the highest genetic risk factor for Alzheimer’s, the APOE4 genetic variant, reduces insulin sensitivity by trapping the insulin receptor inside the cell, where it cannot be switched on properly. Diabetes damages blood vessels, causing complications in the eyes, kidneys and heart. The brain is also at risk. High or varying blood glucose levels can injure vessels in the brain, reducing blood flow and oxygen delivery. Diabetes can also weaken the brain’s protective barrier, letting harmful substances in. This leads to inflammation. Reduced blood flow and brain inflammation are strongly linked to dementia. Memantine, used to treat moderate to severe Alzheimer’s symptoms, was originally developed as a diabetes medication. It didn’t succeed in controlling blood glucose, but researchers later discovered its benefits for brain function. This story shows how diabetes research may hold clues for treating brain disorders. Metformin, the most widely used diabetes drug, does more than just lower blood glucose. It gets in to the brain and may lower brain inflammation. Some studies suggest that people with diabetes who take metformin are less likely to develop dementia, and those who stop taking it may see their risk increase again. Trials are testing its effects in people without diabetes. GLP-1 receptors agonist drugs, such as semaglutide (Ozempic, Wegovy), lower blood glucose and support weight loss. Records show that people with diabetes on these drugs have a lower dementia risk. Comparing GLP1 drugs to metformin, studies have found that they were even more effective than metformin at reducing dementia risk. Two major trials, Evoke and Evoke Plus, are testing oral semaglutide in people with mild cognitive impairment or early mild Alzheimer’s. Since insulin resistance in the brain is a problem, researchers have tested insulin sprays given through the nose. This method delivers insulin straight to the brain while reducing effects on blood sugar. Small studies suggest these sprays may help memory or reduce brain shrinkage, but delivery methods remain a challenge. Sprays vary in how much insulin reaches the brain, and long-term safety has not yet been proven. New evidence suggests that compared to GLP-1 receptor agonists, SGLT2 inhibitors, (a type of diabetes drug) are superior at reducing dementia risk, including Alzheimer’s and vascular dementia, in people with type 2 diabetes. These tablets lower blood sugar by increasing sugar removal in urine. This study builds on early evidence suggesting they lower dementia risk by reducing inflammation in the brain. This growing body of evidence suggests that managing diabetes protects more than the heart and kidneys, it also helps preserve brain function. Questions remain whether diabetes drugs only reduce the diabetes-associated dementia risk or whether these drugs could also reduce risk in people without diabetes. However, diabetes research has been very successful in creating at least 13 different classes of drugs, multiple combination therapies, giving rise to at least 50 different medicines. These reduce blood sugar, improve insulin sensitivity and reduce inflammation. A “side-effect” may be better preservation of brain health during aging.