Background Schizophrenic patients may have decreased bone mass and elevated risk of hip fractures. The cause is probably multifactorial including bone loss due to hyperprolactinaemia induced hypogonadism. Some recent studies indentified prolactin receptors in osteoblast and therefore hyperprolactinaemia could act directly and affect bone metabolism in postmenopausal women and elder men.

Objectives To investigate the prevalence of fragility fractures, risk of new fractures and factors associated with bone loss in severe mental disease patients taking antipsychotic drugs.

Methods We select 170 people over 60 years (154 women, 16 men) living in a mental institution that were not taking bone active drugs. Demographic data, fracture risk factors, clinical low impact fractures and morphometric dorsal spine fractures were collected. Prolactin, 25 hydroxyvitamin D and betacrosslap levels were measured. Basal spine and hip densitometry were done and in a subgroup of 100 women a second bone measurement was repeated one year after. The Spanish version of FRAX® tool was employed in order to evaluate risk of fractures.

Results In this group of aged patients: 74 ± 8,5 years, prevalence of “classical” risk factors was very low. Hip osteoporosis was found in 42.1%. Previous fragility fractures in 55.7%, and the prevalence of vertebral fractures in women was higher than age matched Spanish women.

Very high risk of fractures was considered in 43,2%:prior hip fracture, multiple fragility fractures or FRAX score of 20% for principal fractures of 6% for hip fracture.

The prevalence of hyperprolactinaemia was 44.7% and severe vitamin D deficiency was found in 74.1%. Hyperprolactinaemia was not associated with differences in betacrosslap levels o lumbar spine bone loss. The only factor associated with bone loss was vitamin D levels: in a multivariate analysis people with severe deficiency have higher probability of spine bone loss above 2,5%: OR 5 (1.2-20.7).

Conclusions The results supported the opinion that patients with severe mental disease, especially those who lived in mental institutions, have high prevalence of fractures and very high estimate of fracture risk. Hyperprolactinaemia seems to have not influence in bone metabolism after menopause. Severe vitamin D deficiency is very prevalent and is associated with bone loss but it is difficult to ascertain if it is related to its effect in bone mediated by hyperparathyroidism, or merely a marker of poor health and frailty.

References Howart L, Kirkwood G, Leese M. Risk of hip fracture in patients with a history of schizophrenia. Br J Psychiatry 2007; 190:129-34.

Meaney AM, Smith S, Howes OD, O´Brien M, Murray RM, O´Keane V. Effects of long-term prolactín raising antipsychotic medication on bone mineral density in patients with schizophrenia. Br J Psychiatry 2004; 184:503-8.

Díaz Curiel M, et al. Prevalence of vertebral fractures. Med Clin 2001;116: 86-88.

Disclosure of Interest None Declared