No evidence for a higher resting metabolic rate in noninstitutionalized Alzheimer's disease patients.
OBJECTIVE
It has previously been suggested that Alzheimer's disease patients have higher resting energy requirements than healthy individuals, which may contribute to their unexplained weight loss. We examined whether resting metabolic rate, the largest component of daily energy expenditure, is elevated in Alzheimer's patients compared with healthy older controls.


METHODS
Cross-sectional.


METHODS
General Clinical Research Center and Baltimore VA Medical Center.


METHODS
Twenty-five noninstitutionalized demented patients (74 +/- 8 years; mean +/- SD) with a wide range of Mini-Mental Examination scores (1 to 20) and 73 healthy older individuals (69 +/- 7 years).


METHODS
Resting metabolic rate was measured by indirect calorimetry, fat-free mass and fat mass by dual energy X-ray absorptiometry, and daily energy intake by food diaries.


RESULTS
No differences in fat-free mass and fat mass were noted between Alzheimer's disease patients and healthy older controls. Resting metabolic rate was similar in Alzheimer's disease patients (5446 +/- 962 kJ/day) and healthy older individuals (5647 +/- 887 kJ/day). These results persisted when resting metabolic rate was statistically adjusted for differences in body composition and age.


CONCLUSIONS
These results provide no evidence for an elevation in resting energy requirements in noninstitutionalized demented patients.
Donaldson
K E
KE
Department of Medicine, University of Maryland at Baltimore, USA.
Carpenter
W H
WH
Toth
M J
MJ
Goran
M I
MI
Newhouse
P
P
Poehlman
E T
ET
D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism*; D001481:Basal Metabolism; D001823:Body Composition; D002153:Calorimetry, Indirect; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values