THE MICROSTRUCTURE OF EATING IN PEOPLE WITH DEMENTIA WHO ARE HYPERPHAGIC

Abstract

Objectives. To describe (a) the nature of eating abnormalities and (b) mechanisms of hunger and satiation in hyperphagic subjects with dementia. Design. Case-control study. Three groups of subjects were compared: people with dementia, reported by their carers to be hyperphagic and who overate under experimental conditions; people with dementia who ate normally; normal elderly. Subjects were individually matched across groups. Setting. Subjects with dementia: living either in the community or in long-stay, psychogeriatric wards; the normal elderly controls lived at home. All lived in the UK. Participants. Participants with dementia fulfilled criteria for Alzheimer's disease. Hyperphagic group (n=18): aged 54–91, MMSE scores 0–20. Normal elderly controls (n=14) were individually matched for age and sex. Non-hyperphagic demented controls (n=14) were also matched for cognitive impairment. Measures. Two standardised test meals were given: a single food meal and a mixed food meal. Eating microstructure (latency period before eating; loading rate; chewing rate; rate of energy consumption and behaviour patterns during meal), were measured from videorecordings. Present Behavioural Examination was used to assess eating behaviour and MMSE to test cognitive impairment. Results. The hyperphagic group started to eat much more rapidly than non-hyperphagic demented controls, (W=59.0;p=0.006) and had a significantly higher initial eating rate (t=2.28,p<0.0005). Unlike the normal elderly, neither group with dementia showed a significant deceleration during the meal. Conclusions. People with dementia have impaired satiation mechanisms. Hyperphagic subjects with dementia have more marked impairment of satiation and increased hunger compared with non-hyperphagic demented subjects.