Overweight and obesity in old age are not associated with greater dementia risk.
OBJECTIVE
To describe the association between body mass index (BMI) and dementia risk in older persons.


METHODS
Prospective population-based study, with 8 years of follow-up.


METHODS
The municipality of Lieto, Finland, 1990/91 and 1998/99.


METHODS
Six hundred five men and women without dementia aged 65 to 92 at baseline (mean age 70.8).


METHODS
Weight and height were measured at baseline and at the 8-year follow-up. Dementia was clinically assessed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria.


RESULTS
Eighty-six persons were diagnosed with dementia. Cox regression analyses, adjusted for age, sex, education, cardiovascular diseases, smoking, and alcohol use, indicated that, for each unit increase in BMI score, the risk of dementia decreased 8% (hazard ratio (HR)=0.92, 95% confidence interval (CI)=0.87-0.97). This association remained significant when individuals who developed dementia early during the first 4 years of follow-up were excluded from the analyses (HR=0.93, 95% CI=0.86-0.99). Women with high BMI scores had a lower dementia risk (HR=0.90, 95% CI=0.84-0.96). Men with high BMI scores also tended to have a lower dementia risk, although the association did not reach significance (HR=0.95, 95% CI=0.84-1.07).


CONCLUSIONS
Older persons with higher BMI scores have less dementia risk than their counterparts with lower BMI scores. High BMI scores in late life should not necessarily be considered to be a risk factor for dementia.
Dahl
Anna K
AK
Institute of Gerontology, School of Health Sciences, Jönköping University, Jönköping, Sweden. anna.dahl@hhj.hj.se
Löppönen
Minna
M
Isoaho
Raimo
R
Berg
Stig
S
Kivelä
Sirkka-Liisa
SL
D000368:Aged; D015992:Body Mass Index; D003704:Dementia / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000150:complications; D050177:Overweight / Q000150:complications*; D011446:Prospective Studies; D012307:Risk Factors