Weight Loss and Alzheimer's Disease in Down Syndrome

Background: Virtually all adults with Down syndrome (DS) develop Alzheimer's disease (AD) pathology, but research gaps remain in understanding early signs of AD in DS. Objective: The goal of the present study was to determine if unintentional weight loss is part of AD in DS. The specific aims were to: 1) examine relation between chronological age, weight, AD pathology, and AD-related cognitive decline were assessed in a large cohort of adults with DS, and 2) determine if baseline PET amyloid-beta (A beta) and tau PET status (- versus+) and/or decline in memory and mental status were associated with weight loss prior to AD progression. Methods: Analyses included 261 adults with DS. PET data were acquired using [C-11] PiB for A beta and [F-18] AV-1451 for tau. Body mass index (BMI) was calculated from weight and height. Direct measures assessed dementia and memory. Clinical AD status was determined using a case consensus process. Percent weight decline across 16-20 months was assessed in a subset of participants (n = 77). Results: Polynomial regressions indicated an 0.23 kg/m(2) decrease in BMI per year beginning at age 36.5 years, which occurs alongside the period during which A beta and tau increase and memory and mental status decline. At a within-person level, elevated A beta, decline in memory and mental status were associated with higher percent weight loss across 16-20 months. Conclusion: Unintentional weight loss occurs alongside A beta deposition and prior to onset of AD dementia, and thus may be a useful sign of AD in DS.

Automated summary

This study aimed to determine if unintentional weight loss is part of Alzheimer's disease (AD) in adults with Down syndrome (DS). The results showed that unintentional weight loss is associated with A beta deposition and occurs prior to the onset of AD dementia in DS, indicating that it may be a useful sign of AD in this population.