Posts Tagged ‘BMD’
National Bone Health treatment goals are changing for those patients with high fracture risk. Simply preserving bones already at a too high fracture risk never made much sense to this former orthopedic surgeon. Now the national leadership is stressing the need to lower fracture risk first, then preserve bones at a lower level of fracture risk.
We now have 3 anabolic medications which substantially lower fracture risk by increasing the thickness and strength of bone structure: Teriparatide (Forteo), Abaloparitide (Tymlos), and Romosozumab (Evenity). They all decrease fracture risk substantially more than the antiresorptive (preserving) medications alone. The difference in fracture risk grows for up to 5 years. After that the difference in fracture risk between anabolic meds followed by preserving meds vs. preserving meds alone remains the same.
Calcium can take up to 3 additional years to collect in newly formed bone matrix. DXA shows calcium in bone (Bone Mineral Density). Much of the increased BMD can only be seen on DXA after the anabolic med is completed and the antiresorptive med is started.
All of the anabolic medications must be followed by antiresorptive medication to preserve the gains made by the anabolic. No medication to grow or preserve bone can work without adequate nutrition in the form of absorbable calcium, vitamin D3, protein and other vitamins and minerals.
Jay Ginther, MD
Our goal is NO NEW FRACTURES. Therefore, Treat to Target means a FRAX score of <20% for “major osteoporotic” and <3% for hip fracture. Alternately, T-score of better than -1.5 if there are any fractures.
Antiresorptives do not substantially increase bone mass or BMD. While a 3-5% BMD improvement can be seen when a long term deficiency in calcium absorption is corrected, the function of an antiresorptive is to maintain current bone mass.
If you want to substantially increase bone mass, you must use an anabolic medication. We now have 2. Forteo (teriparatide) has been available for 15 years. Tymlos (abaloparatide) was approved late last spring, but has only achieved good coverage by a majority of insurance companies in the last month.
Both can be given for up to 24 months. Both must be followed by an antiresorptive to avoid loss of gains. Both will show continued improvement in BMD for up to 3 years after switching to an antiresorptive because calcium takes up to 3 years to fully accumulate in new bone matrix formed by an anabolic.
Both should NOT be given to anyone with open growth plates, Paget’s, radiation to bone, cancers which have or could spread to bone, elevated bone specific alkaline phosphatase other than from fracture healing, or pregnant or nursing women.
Tymlos is approved for postmenopausal women only. It does not stimulate bone turnover significantly and therefore shows faster BMD increase initially in the hip. It has not been tested for use after antiresorptives.
Forteo is approved for men and women with osteoporosis which is “age-related”, or from steroid use, or from idiopathic hypogonadism. Forteo significantly increases both osteoblast and osteoclast activity, thereby stimulating bone turnover, which is often suppressed after long-term antiresorptives. Forteo is the default treatment for ONJ and AFF.
If you are dealing with vertebral fractures on VFA, or really low BMD on DXA, or with multiple fragility fractures, you need an ANABOLIC FIRST, to decrease fracture risk. Then follow with antiresorptives to maintain a low enough fracture risk.
Remember, even these medications will fail without proper nutrition.
jay Ginther, MD
Treat to Target of NO NEW FRACTURES. How do we find that target? DXA >-2.5 is a start. Fragility fractures increase new fracture risk. FRAX adds many more risk factors to the calculation and TBS refines FRAX.
Vertebral Fracture Assessment (VFA) looks at the spine from the side and independently identifies additional fracture risk. This can be done on a DXA machine or by x-ray. A single vertebral compression fracture of 25% or more pre-empts DXA, BMD, and FRAX in diagnosing Clinical Osteoporosis and recommending treatment.
VFA should be done because the majority of vertebral compression fractures are first noticed by x-ray or DXA VFA imaging. If you do not personally view the images, be sure the radiologist specifically checked for vertebral deformities as described by Genant.
I recently published my retrospective review of 1259 sequential first time VFA patients in Endocrine Practice 2017:23:1375-8.
VFA identified many patients not identified as high fracture risk (Clinical Osteoporosis) by DXA or fragility fracture or height loss or kyphosis or FRAX.
We should consider including VFA in every first time Complete Bone Health Evaluation.
And how should we treat? Next time…
Jay Ginther, MD
Our goal is NO NEW FRACTURES. Cancellous (spongy, like the ends of the drumstick) bone should be a strong latticework of struts called trabeculi. Clinical Osteoporosis, an increased fracture risk, occurs when some of the struts disappear.
Trabecular Bone Score (TBS) evaluates the spongy bone in the DXA images of the vertebrae (spine) looking for irregularities. When TBS finds uneven bone mineral density within the spine DXA, that indicates a higher fracture risk, regardless of the total BMD.
Adding the TBS feature to a DXA machine allows the quality of bone in the spine to influence the FRAX score, just like the BMD in the femoral neck part of the hip influences the FRAX score. Adding TBS detects more patients at high fracture risk who should be treated to avoid fractures.
Diabetes increases a person’s fracture risk for any given DXA BMD or T-score. Controlled diabetes adds about the same risk as rheumatoid arthritis, so we usually check that box in FRAX. Uncontrolled diabetes is more serious requiring further adjustment to FRAX.
FRAX is pre-empted by a hip fracture. “Do not pass GO, do not collect $200, start a pharmaceutical” Vertebral (spine) Fracture is the same, but the majority of spine fractures are not noticed clinically. “Morphometric” (first noticed on x-ray) vertebral fractures count, but how to find them?
VFA next time
Jay Ginther, MD