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To determine the association of weight loss and the onset of dementia of the Alzheimer type (DAT) and to characterize the rate of weight change over time in older adults (aged 65-95 years) who develop DAT vs those who remain without dementia.Design: Rates of weight change were investigated in older adult research participants (N = 449) who were enrolled as control subjects without dementia and followed up longitudinally (6 years on average) at the Alzheimer's Disease Research Center, Washington University School of Medicine. Some individuals (n = 125) eventually developed DAT; the others (n = 324) remained without dementia. Body weight was measured at each annual assessment. Piecewise linear regression and random effects models were used to test longitudinal rates of weight change between the groups.Results: Participants without dementia lost about 0.6 lb per year. For those individuals who developed DAT, about 1 year before the detection of DAT, the rate of weight loss doubled (1.2 lb per year). As a group, participants who eventually developed DAT weighed less (about 8 pounds) at study enrollment (ie, when they did not have dementia) than participants who remained without dementia.Conclusions: Aging with and without DAT is associated with weight loss; however, weight loss may accelerate before the diagnosis of DAT. Specific factors contributing to weight loss are unknown, but these data suggest they operate before the development of DAT. Hence, weight loss may be a preclinical indicator of Alzheimer disease.

This study examines the evolution of several model-based and satellite-derived drought metrics sensitive to soil moisture and vegetation conditions during the extreme flash drought event that impacted major agricultural areas across the central U.S. during 2012. Standardized anomalies from the remote sensing based Evaporative Stress Index (ESI) and Vegetation Drought Response Index (VegDRI) and soil moisture anomalies from the North American Land Data Assimilation System (NLDAS) are compared to the United States Drought Monitor (USDM), surface meteorological conditions, and crop and soil moisture data compiled by the National Agricultural Statistics Service (NASS). Overall, the results show that rapid decreases in the ESI and NLDAS anomalies often preceded drought intensification in the USDM by up to 6 weeks depending on the region. Decreases in the ESI tended to occur up to several weeks before deteriorations were observed in the crop condition datasets. The NLDAS soil moisture anomalies were similar to those depicted in the NASS soil moisture datasets; however, some differences were noted in how each model responded to the changing drought conditions. The VegDRI anomalies tracked the evolution of the USDM drought depiction in regions with slow drought development, but lagged the USDM and other drought indicators when conditions were changing rapidly. Comparison to the crop condition datasets revealed that soybean conditions were most similar to ESI anomalies computed over short time periods (2-4 weeks), whereas corn conditions were more closely related to longer-range (8-12 week) ESI anomalies. Crop yield departures were consistent with the drought severity depicted by the ESI and to a lesser extent by the NLDAS and VegDRI datasets.