CNP and hyperthyroidism: Exactly similar directional responses in NTproCNP (fall), ALP (rise), and PINP (rise) occur during the course of correcting metabolism in subjects with hyperthyroidism.(16) Collectively these directional changes in NTproCNP during bone repair in two quite different clinical settings confirm CNP's participation in bone remodeling and raise the possibility that CNP could be a unique marker of vertebral bone status.