NO EVIDENCE FOR A HIGHER RESTING METABOLIC-RATE IN NONINSTITUTIONALIZED ALZHEIMERS-DISEASE PATIENTS

OBJECTIVE: It has previously been suggested that Alzheimer's disease p atients have higher resting energy requirements than healthy individua ls, 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 health y older controls. DESIGN: Cross-sectional SETTING: General Clinical Re search Center and Baltimore VA Medical Center PATIENTS: Twenty-five no ninstitutionalized demented patients (74 +/- 8 years; mean +/- SD) wit h a wide range of Mini-Mental Examination scores (1 to 20) and 73 heal thy older individuals (69 +/- 7 years). MEASUREMENTS: Resting metaboli c rate was measured by indirect calorimetry, fat-free mass and fat mas s by dual energy X-ray absorptiometry, and daily energy intake by food diaries. RESULTS: No differences in fat-free mass and fat mass were n oted between Alzheimer's disease patients and healthy older controls. Resting metabolic rate was similar in Alzheimer's disease patients (54 46 +/- 962 kJ/day) and healthy older individuals (5647 +/- 887 kJ/day) . These results persisted when resting metabolic rate was statisticall y adjusted for differences in body composition and age. CONCLUSION: Th ese results provide no evidence for an elevation in resting energy req uirements in noninstitutionalized demented patients.