The cross-sectional relationship between body mass index, waist-hip ratio, and cognitive performance in postmenopausal women enrolled in the Women's Health Initiative.
OBJECTIVE
To determine whether body mass index (BMI) is independently associated with cognitive function in postmenopausal women and the relationship between body fat distribution as estimated by waist-hip ratio (WHR).


METHODS
Cross-sectional data analysis.


METHODS
Baseline data from the Women's Health Initiative (WHI) hormone trials.


METHODS
Eight thousand seven hundred forty-five postmenopausal women aged 65 to 79 free of clinical evidence of dementia who completed the baseline evaluation in the WHI hormone trials.


METHODS
Participants completed a Modified Mini-Mental State Examination (3MSE), health and lifestyle questionnaires, and standardized measurements of height, weight, body circumference, and blood pressure. Statistical analysis was performed of associations between 3MSE score, BMI, and WHR after controlling for known confounders.


RESULTS
With the exception of smoking and exercise, vascular disease risk factors, including hypertension, waist measurement, heart disease, and diabetes mellitus, were significantly associated with 3MSE score and were included as covariables in subsequent analyses. BMI was inversely related to 3MSE score; for every 1-unit increase in BMI, 3MSE score decreased 0.988 points (P<.001) after adjusting for age, education, and vascular disease risk factors. BMI had the most pronounced association with poorer cognitive functioning scores in women with smaller waist measurements. In women with the highest WHR, cognitive scores increased with BMI.


CONCLUSIONS
Higher BMI was associated with poorer cognitive function in women with smaller WHR. Higher WHR, estimating central fat mass, was associated with higher cognitive function in this cross-sectional study. Further research is needed to clarify the mechanism for this association.
Kerwin
Diana R
DR
Division of Geriatrics, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA. d-kerwin@northwestern.edu
Zhang
Yinghua
Y
Kotchen
Jane Morley
JM
Espeland
Mark A
MA
Van Horn
Linda
L
McTigue
Kathleen M
KM
Robinson
Jennifer G
JG
Powell
Lynda
L
Kooperberg
Charles
C
Coker
Laura H
LH
Hoffmann
Raymond
R
D000368:Aged; D015992:Body Mass Index; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D009765:Obesity / Q000453:epidemiology; D017698:Postmenopause; D016032:Randomized Controlled Trials as Topic; D049629:Waist-Hip Ratio