Farah Mozaffar

Poor physical performance and dementia in the oldest old: the 90+ study.

OBJECTIVE To examine the cross-sectional relationship between physical performance and dementia in the oldest old (those ≥ 90 years of age). DESIGN Cross-sectional study. SETTING The 90+ Study is a population-based, longitudinal, epidemiologic study of aging and dementia performed at the University of California, Irvine, from January 1, 2003, through November 30, 2009. PARTICIPANTS A total of 629 participants from The 90+ Study were included in the study. The mean age was 94 years, and most (72.5%) were women. MAIN OUTCOME MEASURES All-cause dementia, based on Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria, was the main outcome measure. The independent variables were physical performance measures, including 4-m walk, 5 chair stands, standing balance, and grip strength, each scored from 0 to 4 (0, unable to perform; 4, best performance). Odds of dementia in relation to the physical performance measures were estimated by logistic regression after adjustment for age and sex. RESULTS Poor physical performance in all measures was significantly associated with increased odds of dementia (P< .001). Odds ratios for every unit decrease in physical performance score were 2.1 for 4-m walk, 2.1 for chair stands, 1.9 for standing balance, and 1.7 for grip strength. CONCLUSIONS We found a strong cross-sectional relationship between poor physical performance and dementia in people 90 years and older. Our findings suggest that dementia is a complex neurodegenerative process that may affect physical performance and cognition. Additional research is necessary to determine the temporal relationship between poor physical performance and cognitive dysfunction.

HISTORY OF VASCULAR DISEASE AND RISK OF DEMENTIA IN THE OLDEST-OLD: THE 90+ STUDY

Background: Coronary artery bypass graft surgery (CABG) is increasingly used in the elderly as a successful treatment for coronary artery disease. However, the long-term association between CABG and dementia risk remains unclear. Methods:We used data from the US Cardiovascular Health Study, a large, prospective population-based study and included 3155 older adults, who were dementia free and had their history of CABG assessed at baseline. Participants were followed up for a median of 6 years (interquartile range 4.7-6.5). We used Cox proportional hazards regression models to examine the association between history of CABG and time to incident all-cause dementia, Alzheimer’s disease (AD), vascular dementia (VaD) and mixed dementia. Our models were adjusted for age, sex, ethnicity, education, baseline hypertension, diabetes and clinical or subclinical cardiovascular disease. Results: History of CABG almost doubled the risk of all-cause dementia (hazard ratio [HR] 1⁄4 1.93, 95% confidence interval [CI] 1⁄4 1.362.74) and almost tripled the risk of mixed dementia (HR 1⁄4 2.73, 95% CI 1⁄4 1.55-4.80) compared to no history of CABG. The associations with AD (HR1⁄4 1.71, 95%CI1⁄4 0.98-2.98) and VaD (HR1⁄4 1.42, 95% CI 1⁄4 0.56-3.65) were in the same direction though statistically not significant.When we compared the risk of incident allcause dementia and its subtypes in those with history of CABG to those with history of percutaneous coronary intervention, HRs suggested that history of CABG may be associated with a higher though statistically not significant risk of all-cause dementia and mixed dementia. However, these analyses were underpowered due to a small number of participants in the comparison group. Conclusions: History of CABG is a long-term risk factor for allcause dementia and mixed dementia. Further research is needed to clarify the mechanisms of this association and to compare CABG to alternative treatments strategies in terms of long-term dementia risk.