CNP and Osteopenia: However, antecedent vertebral stress including subclinical fracture—a strong possibility in this cohort(36)—cannot be excluded particularly in light of the abundance of CNP in vertebrae, which links with increase in plasma NTproCNP during interventions in experimental animals.(19) Future study employing serial NTproCNP sampling over 1 to 2 years in postmenopausal women, comparing values in those with and without osteopenia/porosis, can be expected to answer this question.