- Obesity is associated with increased incidence of dementia in the longer-term (10-14.9 years from baseline) in older people aged between 65 and 74 years (free of smoking, cancer, heart failure, multi-morbidity or dementia at baseline).
Why this matters
- Avoiding obesity may contribute to dementia prevention, even in older groups.
- Study enrolled 257,523 non-smokers (age, 65-74 years) without baseline cancer, dementia, heart failure or multi-morbidity factors (group A) and 161,927 with these confounders (group B) who were followed for ≤14.9 years.
- Outcomes included incident clinically diagnosed dementia and mortality.
- Funding: National Institute for Health Research School for Public Health Research and others.
- During ≤14.9 years follow-up, 9774 incident dementia cases and 29,466 deaths were reported in group A vs 6070 cases and 36,425 deaths in group B.
- During short-term follow-up (2) and overweight (25.0 to 2) showed inverse association with the risk for dementia in group A (obesity sub-Hazard Ratio [SHR], 0.69; 95% CI, 0.65-0.74) and group B (SHR, 0.79; 95% CI, 0.72-0.86).
- During long-term follow-up (10-14.9 years), obesity was linked to increased risk for dementia (HR, 1.17; 95% CI, 1.03-1.32) in group A.
- Overweight protective associations disappeared in longer-term analyses (HR, 1.01; 95% CI, 0.90-1.13).
- Risks for dementia subtypes were not examined.
- No data were available on other risk factors including head injuries or hearing loss.