Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China.
J Alzheimers Dis. 2020;77(1):449-456. doi: 10.3233/JAD-200524.
Higher late-life body mass index (BMI) was associated with reduced risk of Alzheimer's disease (AD), which might be explained by a reverse causal relationship.
To investigate whether weight loss was a preclinical manifestation of AD pathologies and could be a predictor of cognitive impairment.
A total of 1,194 participants (mean age = 73.2 [range: 54 to 91] years, female = 44.5%) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) were grouped according to AD biomarker profile as indicated by amyloid (A) and tau (TN) status and clinical stage by clinical dementia rating (CDR). BMI across the biomarker-defined clinical stages was compared with Bonferroni correction. Pearson correlation analysis was performed to test the relationship between the amyloid change by PET and the BMI change. Multiple regression models were used to explore the influences of amyloid pathologies on BMI change as well as the effects of weight loss on longitudinal changes of global cognitive function.
BMI was significantly decreased in AD preclinical stage (amyloid positive [A+] and CDR = 0) and dementia stage (A+/TN+ and CDR = 0.5 or 1), compared with the healthy controls (A-/TN-and CDR = 0, p < 0.005), while no significant differences were observed between preclinical AD and AD dementia. Amyloid PET change was inversely correlated with BMI change (p = 0.023, β= -14). Individuals in amyloid positive group exhibited faster weight loss (time×group interaction p = 0.019, β= -0.20) compared to the amyloid negative group. Greater weight loss predicted higher risk of developing cognitive disorders.
Elders who experienced greater weight loss might belong to preclinical stage of AD and could be targeted for primary prevention of the disease.
较高的晚年体质量指数（BMI）与阿尔茨海默病（AD）风险降低相关，这可能是由于反向因果关系所致。
探究体重减轻是否为 AD 病理的临床前期表现，以及是否可以作为认知障碍的预测指标。
共纳入 1194 名来自阿尔茨海默病神经影像学倡议（ADNI）的参与者（平均年龄 73.2 岁[范围：54 岁至 91 岁]，女性占 44.5%）。根据 AD 生物标志物谱（由淀粉样蛋白（A）和 tau（TN）状态以及临床痴呆评定量表（CDR）确定）将参与者分为不同组。比较了生物标志物定义的各临床阶段的 BMI，并进行了 Bonferroni 校正。进行 Pearson 相关分析以检验 PET 检测到的淀粉样蛋白变化与 BMI 变化之间的关系。使用多元回归模型来探究淀粉样蛋白病变对 BMI 变化的影响以及体重减轻对整体认知功能纵向变化的影响。
与健康对照组（A-/TN-和 CDR=0，p<0.005）相比，AD 临床前期（A+和 CDR=0）和痴呆阶段（A+/TN+和 CDR=0.5 或 1）的 BMI 显著降低，而 AD 临床前期与 AD 痴呆之间的 BMI 无显著差异。淀粉样蛋白 PET 变化与 BMI 变化呈负相关（p=0.023，β=-14）。与淀粉样蛋白阴性组相比，淀粉样蛋白阳性组的个体体重减轻更快（时间×组交互作用 p=0.019，β=-0.20）。体重减轻越多，发生认知障碍的风险越高。
体重减轻较多的老年人可能处于 AD 的临床前期，可作为疾病一级预防的目标人群。
