Mice with osteoblast-specific deletion of parathyroid hormone-related protein (PTHrP) exhibit impaired recruitment and increased apoptosis of osteogenic cells resulting in decreased bone formation and premature osteoporosis. The PTHrP levels within the bone microenvironment are therefore critical in influencing bone mass acquisition. Whether this is applicable in humans has not been established. Here, we studied the association of a variable number of tandem repeats (VNTR) polymorphism in PTHrP with peak bone mass.
Enrolled in the study were 234 young Finnish males, with median age of 19.6 years (range 18.3-20.6 years). Lifestyle factors, serum bone markers, osteodensitometric measurements (lumbar spine and hip) and calcaneal quantitative ultrasound readings were obtained. The PTHrP VNTR length was determined by the PCR amplification of genomic DNA extracted from peripheral blood and correlated to bone parameters by the multiple regression models.
The presence of at least one 252 bp allele was associated with increased lumbar spine bone mineral density (BMD; P