P4-062: added diagnostic value of cerebrospinal fluid in predicting decline in memory clinic subjects in clinical practice

We found that delayed onset in AD subjects was related to decreased tau, lower BMI, and better cognitive performance (Table 3, Figure 1). We then grouped subjects into extraordinary delayers 25 AD and 38 non-AD subjects who had at least a five-year delay between predicted and actual onset compared to all other 380 subjects. Delayers had significantly lower BMI, lower cognitive performance, lower Ab 42, and more AD-like atrophy (Table 1). Since the high proportion of AD subjects was a potential confound, we repeated this analysis with just the non-AD subjects. Only lower BMI remained significantly different in the delayer group. Conclusions: It was possible to forecast the age of clinical symptoms with a correlation of over 0.3 using variation in the APOE gene. Contrary to previous evidence implicating hypertension in increased risk, we found no clear relationship with blood pressure and accelerated onset. We found no protective effect from more years of education. We also found a consistent relationship that lower BMI is associated with delayed onset (Figure 1). In other cohorts, a higher risk of developing dementia was associated with mid-life obesity (Profenno 2010), but this relationship may reverse in old age, due to weight loss associated with dementia (Buchman 2005; Tolppanen 2014). However, our results suggest that lower BMI is protective, even in subjects without AD.