[Bone mineral density in children and adolescents with idiopathic chronic musculoskeletal pain syndromes].

PURPOSE: There is a limited information regarding associations between bone mineral density (BMD) and idiopathic musculoskeletal pain in pediatric subjects. The aim of this cross-sectional study was to assess whether children and adolescents with pain syndrome have lower BMD than healthy subjects.

MATERIAL AND

METHODS

Eighty-nine subjects (49 girls, 40 boys) aged 5-18 years with chronic non-rheumatic musculoskeletal pain and daily calcium consumption below 500 mg were involved in the study. The subjects were divided in three groups: I--prepubertal (5-9 years), II--pubertal (9-15 years) and III--adolescents (15-18 years). Bone mineral density in the total skeleton (total BMD) and lumbar spine (spine BMD) was examined using dual energy x-ray absorptiometry (DXA) and compared to reference data. Serum calcium, ionized calcium, phosphate, alkaline phosphatase and its bone-fraction were estimated.

RESULTS

Low BMD (below the 5th percentile) was found in about 50% of the participants with pain syndromes in each measurement site. A significantly decreased Spine BMD was observed in those children who reported pain symptoms in the spine region and lower limbs (Z-score for Spine BMD was = -1.55; -1.41) compared to subjects with non-localized pain. The lowest mean Z-score (-1.85) for Spine BMD was found in the postpubertal group (III) compared with groups I and II.

CONCLUSIONS

As one-half of children and adolescents reporting musculoskeletal pain had low BMD it is possible that the symptoms are associated with an inadequate bone mass accrual during growth. Pain localized in the spine region and in lower extremities may be a selective and site-specific symptom of juvenile osteoporosis without fractures. The chronic musculoskeletal pain suggests a rationale for bone density testing during growth.