Significant interaction between frailty and Alzheimer’s disease
After the investigators adjusted for age, sex, and education, frailty (odds ratio, 1.76) and Alzheimer’s disease pathology (OR, 4.81) were independently associated with Alzheimer’s dementia. When the investigators added frailty to the model for the relationship between Alzheimer’s disease pathology and Alzheimer’s dementia, the model fit improved. They found a significant interaction between frailty and Alzheimer’s disease pathology (OR, 0.73). People with a low amount of frailty were better able to tolerate Alzheimer’s disease pathology, and people with higher amounts of frailty were more likely to have more Alzheimer’s disease pathology and clinical dementia.
One of the study’s limitations is that it is a secondary analysis, according to Dr. Rockwood and his colleagues. In addition, frailty was measured close to participants’ time of death, and the measurements may thus reflect terminal decline. Participant deaths resulting from causes other than those related to dementia might have confounded the results. Finally, the sample came entirely from people living in retirement homes in Illinois, which might have introduced bias. Future research should use a population-based sample, said the authors.
Frailty could be a basis for risk stratification and could inform the management and treatment of older adults, said Dr. Rockwood and his colleagues. The study results have “the potential to improve our understanding of disease expression, explain failures in pharmacologic treatment, and aid in the development of more appropriate therapeutic targets, approaches, and measurements of success,” they concluded.
The study had no source of funding. The authors reported receiving fees and grants from DGI Clinical, GlaxoSmithKline, Pfizer, and Sanofi. Authors also received support from governmental bodies such as the National Institutes of Health and the Canadian Institutes of Health Research.
SOURCE: Wallace LMK et al. Lancet Neurol. 2019;18:177-84.