Digital computerized absorptiometry in the diagnosis of osteoporosis in a group of the severely mentally retarded

BACKGROUND: The loss of bone mass after a certain age is a physiological fact that, in certain circumstances, is capable of inducing osteoporosis. In the diagnostic strategies for this condition, densitometry is a well-accepted technique now widely used. On patients with severe mental retardation, a number of circumstances come into play and may foster a greater frequency of osteoporosis. GOAL AND SCOPE OF STUDY: The goal of the study is to identify the bone mineral density values in a group of severe mentally retarded individuals using a digital densitometry technique in order to compare these with the general population and investigate the possible influence on these values of certain clinical variables and therapeutic regimens. VOLUNTEERS: One hundred and ninety-two patients of both sexes and treated at an institution devoted to the study and care of severely mentally retarded individuals. ACTIONS TAKEN: In all cases, the bone mineral density value has been obtained by means of digital densitometry using a compact desktop system using dual X-ray absorption measurement technology The data obtained have been contrasted with sex, age, degree of mobility and anti-epilepsy or sedative medication. RESULTS: In the population under study, the bone mineral density is significantly lower than that of the general population: 25% present osteopenia and 22% osteoporosis. These results are associated with the fact that they move little and are regularly taking phenobarbital medication. The population with Down's syndrome is also seen to be a group at risk. CONCLUSIONS: Osteoporosis is frequent among severe mentally retarded patients. The greatest risk is associated with insufficient mobility, Down's syndrome and regular medication with phenobarbital. Digital densitometry is a simple procedure that may be useful to identify the true dimension of this problem and the efficacy of the various preventive or curative procedures put forward.