Background: overweight or obesity at ages <65 years associates with increased dementia incidence, but at ≥65 years estimates are paradoxical. Weight loss before dementia diagnosis, plus smoking and diseases causing weight loss may confound
associations.
Objective: to estimate weight loss before dementia diagnosis, plus short and ...
Background: overweight or obesity at ages <65 years associates with increased dementia incidence, but at ≥65 years estimates are paradoxical. Weight loss before dementia diagnosis, plus smoking and diseases causing weight loss may confound
associations.
Objective: to estimate weight loss before dementia diagnosis, plus short and longer-term body mass index associations
with incident dementia in 65–74 year olds within primary care populations in England.
Methods: we studied dementia diagnosis free subjects: 257,523 non-smokers without baseline cancer, heart failure or multimorbidity (group A) plus 161,927 with these confounders (group B), followed ≤14.9 years. Competing hazard models
accounted for mortality.
Results: in group A, 9,774 were diagnosed with dementia and in those with repeat weight measures, 54% lost ≥2.5 kg during 10 years pre-diagnosis. During <10 years obesity (≥30.0 kg/m2
) or overweight (25.0 to <30.0) were inversely associated
with incident dementia (versus 22.5 to <25.0). However, from 10 to 14.9 years, obesity was associated with increased
dementia incidence (hazard ratio [HR] 1.17; 95% CI: 1.03–1.32). Overweight protective associations disappeared in longerterm analyses (HR, 1.01; 95% CI: 0.90–1.13). In group B, (n = 6,070 with incident dementia), obesity was associated with
lower dementia risks in the short and longer-term.
Conclusions: in 65–74 year olds (free of smoking, cancer, heart failure or multi-morbidity at baseline) obesity associates
with higher longer-term incidence of dementia. Paradoxical associations were present short-term and in those with likely
confounders. Reports of protective effects of obes
