Body weight and the three-year prognosis in very old people.

We studied prospectively the three-year prognosis of persons aged 84-88 years living in their own homes in the city of Tampere, Finland in 1981-84. Out of the target population 722 persons (64 per cent), 181 of them male (25 per cent), participated in the initial survey. A re-examination was carried out annually for the next three years. Increased mortality was observed for subjects with body mass index less than or equal to 22.0 kg/m2, statistically significantly in women but not in men. Mortality was not increased in those with body mass index greater than or equal to 30.0 kg/m2 in either sex. Low body mass index was associated with mortality due to stroke. Low body mass index was related to permanent hospitalization and also to failure to cope with living at home. On average, body weight was somewhat reduced during the follow-up period. Both a loss and a gain in weight by two kilograms or more during the first follow-up year were associated with increased mortality but not with institutionalization during the next two years.