Trabecular Bone Score (TBS)

I will be asking that a Trabecular Bone Score (TBS) be included with my next DXA scan. The doctor who read my latest scan wrote, "Follow up with DEXA and TBS: As needed." 

I found a review of TBS. The review includes a section on "Changes in TBS with Treatment of Osteoporosis." Below is the paragraph comparing the effects of strontium ranelate and alendronate (Fosamax) on TBS. 

"The effects of strontium ranelate (SrRan) and alendronate on TBS were evaluated in a post hoc analysis performed in 79 women with postmenopausal osteoporosis of 189 included in a double‐blind, double‐dummy, randomized study. Women were randomized to either SrRan 2 g/day or alendronate 70 mg/week for 2 years. TBS and BMD parameters were assessed in the LS after 12 and 24 months of treatment. Over 1 and 2 years, LS BMD increased significantly by 5.6% and 9.0% in the SrRan group and by 5.2% and 7.6%, respectively, in the alendronate group. LS TBS increased by 2.3% (p < 0.001) and 3.1% (p < 0.001) in the SrRan group, but the change in the alendronate group was not significant (0.5% and 1.0%, respectively). There was a significant between‐group difference with SrRan showing larger TBS increases than alendronate."

Let me reiterate: Over one and two years, Lumbar Spine (LS) BMD increased in both the SrRan (5.6%, 9.0%) and alendronate groups (5.2%, 7.6%). You will note that the SrRan BMD numbers are higher, especially after the second year, than the alendronate numbers. The results are as expected because strontium results in an overestimation of BMD.  

HERE IS THE KICKER: LS TBS increased by 2.3% and 3.1% in the SrRan group, but the change in the alendronate group was not significant (0.5% and 1.0%, respectively). There was a significant between‐group difference with SrRan showing larger TBS increases than alendronate.

Keep in mind that TBS is related to bone microarchitecture and provides skeletal information that is not captured from the standard BMD measurement. TBS may be a better predictor of fracture risk than BMD alone. 
https://www.panoramaortho.com/wp-content/uploads/2019/03/TBS-Rev...

 

B Vitamins and Homocysteine and Fracture Risk

“Some studies suggest high blood levels of the amino acid homocysteine may be linked to lower bone density and higher risk of hip fracture in the elderly. Vitamins B6 and B12, as well as folic acid, play a role in changing homocysteine into other amino acids for use by the body, so it is possible that they might play a protective role in osteoporosis. Research is ongoing as to whether supplementation with these B vitamins might reduce fracture risk^4,5.”

4. McLean RR, Jacques PF, Selhub J, et al. (2004) Homocysteine as a predictive factor for hip fracture in older persons. N Engl J Med 350:2042-49
 

5. Morris MS, Jacques PF, Selhub J (2005) Relation between homocysteine and B-vitamin status indicators and bone mineral density in older Americans. Bone 37:234-42

http://www.iofbonehealth.org/nutrition

WebMD ranks the effectiveness of vitamin B12 for various uses. The rankings are “effective for,” “likely effective for,” “possibly effective for,” “possibly ineffective for,” and “insufficient evidence for.”

According to webMD, vitamin B12 is likely effective for “high level of homocysteine in the blood (Hyperhomocysteinemia).” “Taking vitamin B12 by mouth, along with folic acid and sometimes pyridoxine (vitamin B6), can lower blood levels of homocysteine.”

 
http://www.webmd.com/vitamins-supplements/ingredientmono-926-vitamin%20b12.aspx?activeingredientid=926&activeingredientname=vitamin%20b12

Fracture Risk

“Osteoporosis and resultant fractures of the spine, hip and other sites are important public health problems with significant individual and societal costs. The risk for osteoporotic fracture is based upon low bone density and the presence of one or more clinical risk factors (see Table 1). A history of fracture during adulthood or falls are important clinical factors in determining the risk of future fracture; however, age is the most influential risk factor, such that middle-aged adults with other risk factors are likely to be at low absolute fracture risk in the medium term. Using these clinical risk factors and BMD when available, fracture risk assessment tools (based upon data collected from large prospective observational studies) have been developed to estimate the 5–10 year probability of hip fracture and other fractures in untreated patients. Clinicians should be aware that fracture risk can also be estimated using the FRAX or Garvan tools without BMD data. Chronic glucocorticoid use is an established risk factor for osteoporosis, with studies showing that use of glucocorticoids leads to accelerated bone loss and an increased risk of fracture. Other drugs are increasingly recognized as potential causes of bone loss and fracture, particularly amongst predisposed individuals….”

See the following link for more on other drugs that can cause bone loss and fractures:

http://strontiumforbones.blogspot.com/2015/01/adverse-skeletal-effects-of-drugs.html

Table 1.  Clinical risk factors for fracture

Advancing age

Previous fracture during adulthood

History of a fall or falls in the past 12 months

Glucocorticoid therapy

Parental history of hip fracture

Low body weight

Current cigarette smoking

Excessive alcohol consumption

Medical diseases (e.g. rheumatoid arthritis, hyperparathyroidism, coeliac disease, hypogonadism)

This introduction and table appeared in “Adverse Skeletal Effects of Drugs – Beyond Glucocorticoids,” Susannah O'Sullivan, Andrew Grey, Clin Endocrinol. 2015; 82(1):12-22. 

http://www.medscape.com/viewarticle/837369?src=wnl_edit_tpal&uac=127701PY

Adverse Skeletal Effects of Drugs

There is an expanding list of drugs for which there are concerns regarding adverse skeletal effects. The effect of long-term use of glucocorticoid drugs to cause accelerated bone loss and increase the risk of fracture is well recognized. For some drugs (TKIs, calcineurin inhibitors and loop diuretics), the available data are inconsistent and/or do not support a definite adverse skeletal effect. Patients receiving these drugs can be managed in line with guidelines for the general population (See table). Other drugs (SSRIs, antipsychotic drugs, AEDs and PPIs) do not seem to affect bone metabolism or BMD, but there is evidence for increased fracture risk. However, the evidence is limited to observational data, and any relationship may be attributable either to nonbone effects of the drug or effects of the underlying condition to increase fracture rate. In these patients, evaluation for other risk factors for fracture and management of these risk factors should be considered. In a third group (depot MPA, chemotherapy and ART), there is evidence for increased bone loss and/or fracture, but the patient population is generally at low risk for fracture. In these cases, patients may require an assessment of risk, but will rarely require specific treatment for fracture risk reduction. In the last group (aromatase inhibitors, GnRH agonists and thiazolidinediones), there is evidence of increased risk of bone loss and/or fracture, and the drugs are more frequently prescribed to individuals at higher baseline fracture risk. Patients receiving these drugs require risk assessment and those at high risk of fracture should receive alternative treatments (or "add-back" HRT in the case of GnRH agonists) or, if necessary, specific treatment for osteoporosis.

Table:  Summary of management recommendations
Example drugs	Evidence for risk	Management recommendations
Tyrosine kinase inhibitors    Calcineurin inhibitors    Loop diuretics	No adverse  skeletal effect  or data  inconsistent	Manage as per general population
Selective serotonin re-uptake inhibitors (SSRIs)    Antipsychotics    Anti-epileptic drugs    Proton pump inhibitors	Evidence for increased fracture risk but fracture risk seems to relate to nonbone effects of the drug or effects of the underlying condition	Evaluate for other risk factors for fracture and manage these risk factors
Depot medroxyprogesterone acetate    Chemotherapy    Antiretroviral therapy	Evidence for increased bone loss and/or  fracture, but low risk population	Assessment of fracture risk, but will rarely require specific treatment
Aromatase inhibitors    Gonadotrophin hormone-releasing hormone agonists    Thiazolidinediones	Evidence for increased risk of bone loss and/or fracture, and the drugs are more frequently prescribed to individuals at higher baseline fracture risk	Assessment of fracture risk and those at high risk should receive alternative treatments and/or specific treatment for osteoporosis.

 The conclusions and table are from a longer article, “Adverse Skeletal Effects of Drugs – Beyond Glucocorticoids,” by Susannah O'Sullivan and Andrew Grey, Clin Endocrinol. 2015;82(1):12-22. 

http://www.medscape.com/viewarticle/837369_1

Use of Computed Tomography for Assessing Bone Mineral Density

Dual x-ray absorptiometry (DXA) is currently the standard for assessing bone mineral density (BMD) and has been correlated with fracture risk and treatment efficacy. DXA includes the posterior elements of the spine, and therefore may be inaccurate or not possible in cases of severe spinal degeneration, scoliosis, or following lumbar surgery. T-score evaluations are somewhat limited in clinical utility, as the majority of patients who sustain fragility fractures are not in the osteoporotic range.

Assessing local bone quality on CT scans with Hounsfield unit (HU) quantification is being used with increasing frequency. Correlations between HU and bone mineral density have been established, and normative data have been defined throughout the spine. Recent investigations have explored the utility of HU values in assessing fracture risk, implant stability, and spinal fusion success. The information provided by a simple HU measurement can alert the treating physician to decreased bone quality, which can be useful in both medically and surgically managing these patients.

The purpose of this paper is to review the reliability and validity of the techniques used to estimate bone health using CT scans with Hounsfield unit (HU) quantification. Such scans can be used to identify patients at risk for osteoporosis, and these values could be used for surgical planning in cases of trauma, degeneration, and deformity. There was good correlation of HU value to DXA for both BMD and T-score.

www.medscape.com