Bone disease and hypercalciuria in children.

There have been relatively few studies of bone mass in children with idiopathic hypercalciuria (IH). When performed, bone mineral density (BMD) measurements have consistently disclosed decreased Z-scores for children with IH at the lumbar spine and, to a lesser extent, at the femoral neck. Few investigations have delineated the nature of the mechanism(s) that may contribute to the bone loss in these children. Some studies have been consistent, showing increased bone resorption as the probable mechanism of bone loss. To date, there have been no reports regarding the assessment of biochemical markers specific for bone formation in children with IH. However, since most of the children with IH in these reports had demonstrated normal longitudinal growth, it seems less likely that there is an alteration in bone formation. The causes for increased bone resorption also are not firmly established, but genetics, dietary indiscretions, and altered cytokine production have been proposed as being contributory to the decreased BMD observed in these children with IH. Optimal bone mineral accretion during childhood and adolescence is important in attaining peak bone mass and may serve to prevent the development of osteoporosis in adulthood. Thus, a better understanding of bone loss in children with IH is warranted.