- Skeletal changes in osteoprotegerin and receptor activator of nuclear factor-kappab ligand mRNA levels in primary hyperparathyroidism: effect of parathyroidectomy and association with bone metabolism. Stilgren, L.S., Rettmer, E., Eriksen, E.F., Hegedüs, L., Beck-Nielsen, H., Abrahamsen, B. Bone (2004)