Nutritional predictors of cognitive impairment severity in demented elderly patients: the key role of BMI.
BACKGROUND
The body mass index (BMI) is commonly used to assess nutritional status and the Mini Mental State Examination (MMSE) is a validated tool for assessing cognitive status in elderly people. Nutritional and cognitive aspects are closely related in dementia.


OBJECTIVE
To establish whether BMI predicts cognitive decline in demented patients and whether an "alarm" BMI cut-off exists for declining MMSE scores.


METHODS
82 elderly demented patients underwent clinical, bio-chemical and functional assessment.


METHODS
Transversal study.


RESULTS
The mean BMI was 26.08±4.48 kg/m² and the mean MMSE 18.68±5.38. Patients with BMI<25 kg/m² had significantly lower MMSE scores (16.5±5.53 vs 20.38±4.64; p 0.001), fat-free mass (FFM; 27.76±8.99 vs 37.38±10.58 kg; p<0.001), fat-free mass index (FFMI; 11.52±3.03 vs 14.67±2.89 kg/m²; p<0.001), and fat mass (FM; 24.90±6.89 vs 36.86±6.77 kg; p<0.001), as well as lower Mini Nutritional Assessment (MNA) scores (23.80±2.50 vs 25.00±2.29; p=0.03) and higher vitamin B12 levels (460.95±289.80 vs 332.43±82.07 pg/ml; p=0.01). In the sample as a whole, MMSE scores significantly correlated with scores for MNA (r=0.27, p=0.01), FFM (r=0.27, p=0.01), BMI (r=0.19, p=0.05), ADL (r=0.28, p=0.01) and instrumental activities of daily living (IADL; r=0.34, p=0.002). On multiple logistic regression, BMI<25 kg/m² was independently associated with the risk of moderate-severe cognitive impairment (OR=2.96; 95% CI; 1.16-7.55) and female gender was independently associated with severity of dementia (OR=3.14; 95% CI; 1.09-9.03).


CONCLUSIONS
BMI seems to indicate global health status in elderly demented people and a BMI of 25 kg/m² can be considered an "alarm" cut-off, lower values coinciding with a worse cognitive status based on MMSE scores.
Department of Medical and Surgical Sciences, Division of Geriatrics, University of Padova, Padova, Italy. alessandra.coin@unipd.it
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A
Coin
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N
Veronese
M
M
De Rui
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M
Mosele
F
F
Bolzetta
A
A
Girardi
E
E
Manzato
G
G
Sergi
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003072:Cognition Disorders / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D003704:Dementia / Q000503:physiopathology*; D004032:Diet / Q000009:adverse effects*; D018450:Disease Progression; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D007558:Italy; D016015:Logistic Models; D008297:Male; D015596:Nutrition Assessment; D009752:Nutritional Status; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D012727:Sex Characteristics; D014805:Vitamin B 12 / Q000097:blood
D014805:Vitamin B 12