Gu Yian, Scarmeas Nikolaos, Cosentino Stephanie, Brandt Jason, Albert Marilyn, Blacker Deborah, Dubois Bruno, Stern Yaakov
Taub Institute for Research in Alzheimer's Disease and the Aging Brain, Columbia University, 630 W. 168th Street, P&S Box 16, New York, NY 10032, USA.
Curr Alzheimer Res. 2014 May;11(4):349-56. doi: 10.2174/1567205010666131120110930.
A high body mass index (BMI) in middle-age or a decrease in BMI at late-age has been considered a predictor for the development of Alzheimer's disease (AD). However, little is known about the BMI change close to or after AD onset.
BMI of participants from three cohorts, the Washington Heights and Inwood Columbia Aging Project (WHICAP; population-based) and the Predictors Study (clinic-based), and National Alzheimer's Coordinating Center (NACC; clinic-based) were analyzed longitudinally. We used generalized estimating equations to test whether there were significant changes of BMI over time, adjusting for age, sex, education, race, and research center. Stratification analyses were run to determine whether BMI changes depended on baseline BMI status.
BMI declined over time up to AD clinical onset, with an annual decrease of 0.21 (p=0.02) in WHICAP and 0.18 (p=0.04) kg/m2 in NACC. After clinical onset of AD, there was no significant decrease of BMI. BMI even increased (b=0.11, p=0.004) among prevalent AD participants in NACC. During the prodromal period, BMI decreased over time in overweight (BMI≥25 and <30) WHICAP participants or obese (BMI≥30) NACC participants. After AD onset, BMI tended to increase in underweight/normal weight (BMI<25) patients and decrease in obese patients in all three cohorts, although the results were significant in NACC study only.
Our study suggests that while BMI declines before the clinical AD onset, it levels off after clinical AD onset, and might even increase in prevalent AD. The pattern of BMI change may also depend on the initial BMI.
中年时高体重指数（BMI）或老年时BMI下降被认为是阿尔茨海默病（AD）发生的预测因素。然而，对于AD发病前后或接近发病时BMI的变化知之甚少。
对来自三个队列的参与者的BMI进行纵向分析，这三个队列分别是华盛顿高地和因伍德哥伦比亚老龄化项目（WHICAP；基于人群）、预测因素研究（基于诊所）以及国家阿尔茨海默病协调中心（NACC；基于诊所）。我们使用广义估计方程来检验BMI随时间是否有显著变化，并对年龄、性别、教育程度、种族和研究中心进行了校正。进行分层分析以确定BMI变化是否取决于基线BMI状态。
在AD临床发病前，BMI随时间下降，在WHICAP队列中每年下降0.21（p = 0.02），在NACC队列中每年下降0.18（p = 0.04）kg/m²。AD临床发病后，BMI没有显著下降。在NACC队列中，现患AD参与者的BMI甚至有所增加（b = 0.11，p = 0.004）。在前驱期，超重（BMI≥25且<30）的WHICAP参与者或肥胖（BMI≥30）的NACC参与者的BMI随时间下降。AD发病后，所有三个队列中体重过轻/正常体重（BMI<25）的患者BMI往往会增加，肥胖患者的BMI往往会下降，不过只有NACC研究的结果具有统计学意义。
我们的研究表明，虽然BMI在临床AD发病前下降，但在临床AD发病后趋于平稳，在现患AD患者中甚至可能增加。BMI变化模式也可能取决于初始BMI。
