[Bone mass evolution in patients with precocious and advanced puberty treated with LHRH analogs]

Our aim was to know the long-term effects of treatment with LHRH analogs on the bone mass of patients with precocious or advanced puberty.

Forty-six patients (11 boys and 35 girls) received a-LHRH throughout a 2-year period. The diagnoses were precocious or advance puberty alone or associated to other pathologies. The bone mass was indirectly estimated by measuring the cortical thickness (CT) and the metacarpal diameter (BD) of the 2nd, 3rd, and 4th metacarpals, taking as a reference values the results of the longitudinal Aragonese study of the "Andrea Prader" Center.

The CT was 1.3 SD at the beginning and decreased to 0.3 SD (p < 0.002) by the end of therapy and continuing losing to reach 0.1 SD after withdrawal. The BA decreased from 0.8 SD to 0.7 SD (p < 0.0002) and continued decreasing to reach 0.5 SD after withdrawal (p < 0.05). The BD went from -0.64 to -0.62 and to -0.9 SD (p < 0.04) after withdrawal. The longitudinal study of the same 18 cases gave similar results. No significant difference was found between sexes.

In precocious or advance puberty, the bone age and the cortical thickness are increased. After two years of treatment with a-LHRH both decreased significantly and stabilized one year after its suppression. The BD does not change during the treatment, but continues losing value thereafter. This loss of bone mass, not well known in this pediatric situation, is probably related to estrogen deprivation and needs the attention of the physician in order to take possible preventative measures.