Background Osteoporosis (OP) is being increasingly recognized in pediatric practice as a consequence of several factors. The diagnosis of OP in children and adolescents should not be made on the basis of densitometry criteria alone. It requires the presence of a clinically significant fracture history alongside a low bone mineral density. In the management of children who have sustained OP, bisphosphonates, calcium and vitamin D supplementation are the drugs most widely used.
Objectives To estimate the OP frequency in children with rheumatic diseases followed in a Pediatric Rheumatology outpatient clinic, characterize the population, identify children at higher risk and to evaluate the treatment efficacy.
Methods Children with rheumatic diseases less than 18 years followed in a Pediatric Rheumatology outpatient clinic were enrolled in a prospective observational study, from September 1st 2010 to December 31st 2011. From the considered population we selected those with OP risk factors: chronic active inflammatory disease, clinical features, including cumulative glucocorticoids dose (for at least 1 year), reduced mobility, disordered puberty, fracture history or poor nutrition/low body weight. We analyzed calcium, vitamin D and bisphosphonates intake and spine BMD Z scores.
Results Two hundred and fifty one patients were analyzed of whom 31 (12,4%) had OP risk factors. Five were excluded because they did not have a densitometry exam. From the total (n=26), 53,9% were female and 46,1% male, with a mean age of 15,13±3,22 years. The most frequent primary risk factors were Osteogenesis Imperfecta (23,1%), Cystic fibrosis (23,1%), Reduced mobility (7,7%) and Chronic active inflammatory disease (46,1%) corresponding to Systemic Lupus Erythematosus, Autoinflammatory disease, Polyarteritis nodosa, Systemic Juvenile idiopathic arthritis, Crohn disease, Myositis, Idiopathic uveitis and Chronic recurrent multifocal osteomyelitis. The total sample was further divided in 4 groups: 11,5% (n=3) had OP, 42,3% (n=11) had a low BMD without fractures, 15,4% (n=4) had fracture history without low BMD and the remainder 30,8% (n=8) had neither. All the children with fracture history were treated with bisphosphonates (86% on pamidronate and 14% on alendronate) and calcium and vitamin D supplementation. All the children with low BMD were on calcium and vitamin D supplements and 4 on pamidronate. From the remaining without low BMD or fracture history, 37,5% were on calcium and vitamin D supplementation. After initiation of therapy there was no fracture in none of the groups. In the total of the population BMD improved on average 8,07±2,5%/year.
Conclusions There is a risk of OP in the children followed in our Pediatric Rheumatology outpatient clinic. Not only by the impact of the inflammatory condition on bone, but also because many of these conditions are treated with glucocorticoids. Vitamin D, calcium supplements and bisphosphonates showed efficacy, however, establishment of protocols with therapeutic indications and their dosage are required.
Fewtrell MS; British Paediatric and Adolescent Bone Group. Bone densitometry in children assessed by dual X-ray absorptiometry: uses and pitfalls. Arch Dis Child 2003;88:795-798.
Disclosure of Interest None Declared