Association between bone turnover markers and bone mineral density in puberty and constitutional delay of growth and puberty.

The aim of this study was to evaluate associations between the markers of bone formation and resorption and bone mineral density in healthy children throughout puberty and in children with constitutional delay of growth and puberty (CDGP). For this reason, 15 boys with CDGP and 75 other boys in different pubertal stages were included in this study. Although mean serum phosphorus level was higher in stages II, III, IV, V compared to stage I and CDGP, mean bone specific akaline phosphatase (b-AP), parathyroid hormone (PTH), bone mineral density (BMD), bone mineral content (BMC) levels were higher in stages III, IV, V compared to stage I and CDGP Mean serum calcium (Ca) levels were lower in stages III, IV, V compared to stage I and CDGP. During puberty, urine DPry/Cr levels were not significant. The peak level of b-AP occurred at stage IV. Serum PTH, Ca, b-AP levels, urine Ca/Cr ratio, BMC and BMD measurements significantly changed during puberty in healthy children. While serum Ca levels progressively decreased, serum b-AP, PTH levels, urine Ca/Cr ratio and bone mineralization increased in healthy children with the level of sexual development. The only significant correlation is found between serum PTH levels and bone mineral density (p < 0.05). In our opinion, PTH may be a potent stimulator of skeletal dynamics in boys and may be associated with substantial increases in lumbar spine. We conclude that PTH behaved as a valuable marker in bone mineralization during puberty. Accelerated bone mineralization is reflected by high levels of serum PTH during puberty. All values of the markers of bone formation and bone resorption in children with CDGP were similar to those of prepubertal children. Children with CDGP had prepubertal properties. We suggest that there is a critical age period for accumulation of bone mass according to the results in this study.