Posts Tagged ‘Bone Matrix’
Forteo (Teriparatide) increases the thickness of the struts making up spongy (cancellous) bone. ¬†Forteo is the only osteoporosis medication to do that. ¬†It also makes the hard outer shell (cortical bone) thicker. ¬†How? ¬†Forteo stimulates OsteoBlasts. ¬†They make bone matrix, the collagen protein that is more than 80% of bone.
Forteo also stimulates bone turnover. ¬†Healthy bone is constantly being resorbed and replaced. ¬†This allows bone to eliminate the micro-cracks that gradually accumulate with activity. ¬†Bone is strongest when it is a mixture of older more calcified (stiffer) material mixed thoroughly with younger less calcified (somewhat bendable) material. ¬†Cracks cannot enlarge. ¬†Strength is better. ¬†More force is required to fracture the bone.
Anabolic medication for osteoporosis actually increases bone thickness and strength! ¬†Antiresorptive medications for osteoporosis (Fosamax, Alendronate, Actonel, Atelvia, Boniva, Evista, Reclast, Prolia) only preserve bone.
We have talked about all of the Antiresorptive medications over the last 2 months.¬† They are excellent treatment if slowing down the OsteoClasts (cells that eat away your bone) is sufficient.¬† That is not always the case.
Now it is time to talk about something completely different.¬† Anabolic medication stimulates the OsteoBlasts (cells that make new bone matrix).¬†¬†OsteoBlasts can rebuild your bones.¬† If you have Fractures, your bones may need to be rebuilt.
Forteo (Teriparatide) is the only Anabolic medication for osteoporosis in the USA.¬† Close cousins of Forteo are available in other countries.
You may need the Anabolic, Forteo, if you have a hip fracture, multiple other fractures, or if VFA testing reveals a Vertebral Compression Fracture.¬† A DXA T-score well below -2.5 can be reason enough without fracture.
Glucocorticoid (Cortico-Steroid) medications (Prednisone, Steroid Inhalers) specifically supress OsteoBlasts (cells that make new bone).¬† Stimulating the OsteoBlasts with the Anabolic, Forteo, can offset the bone loss from Steroid medications.¬† Smoking also supresses OsteoBlasts, leading to bone loss.¬† Stopping Smoking would be best, but Forteo can help.
Not everyone needs an Anabolic, but some individuals do.¬† A Complete Bone Health Evaluation will tell you if an Anabolic is right for you.
More about Forteo (Teriparatide) next time.
Jay Ginther, MD
Bisphosphonates accumulate in your bone.¬† When OsteoClasts gobble up your bone, bisphosphonates are released into the Osteoclasts and disable or kill the Osteoclasts.¬† This is great news when the problem is Osteoclasts Gone Wild.¬† Bisphosphonates preserve bone by slowing down bone resorption.¬† However, after a few months, bone formation by OsteoBlasts also slows down, resulting in slow bone turnover.
Moderate and balanced¬†bone turnover is good.¬† You repair microcracks in your bone when OsteoClasts resorb the bone around them and OsteoBlasts fill in the void with new bone matrix.¬† A mix of new and old bone is far stronger than all old bone.¬† Some OsteoClast activity is necessary to heal fractures, especially incomplete (stress) fractures.¬† That is where long term bisphosphonates can be too much of a good thing.
Are your bones still good enough and just need to be maintained? ¬†Or have you fractured several times and need to rebuild your bones? ¬†Are Steroid Inhalers supressing your Osteoblasts – the cells that build new bone? ¬†(not good) ¬†Or have your Osteoclasts – the cells that eat away bone – gone wild (even worse) now that you are post-menopausal or an older guy?
Different problems require different classes of medication. ¬†Bisphosphonates, Hormone Replacement Therapy, Synthetic Estrogen Receptor Modifier – Evista, and RANK-Ligand Antibody – Prolia, are all Antiresorptives, which act in different ways. ¬†They slow down the Osteoclasts that have gone wild and are eating up the bone. ¬†The Anabolic, Forteo, stimulates the Osteoblasts that make new bone matrix. ¬†Antiresorptive and Anabolic are radically diferent actions.