Cohort studycited by the Tayebat archiveabstract only checked A-BAR-18 standard review
Bone after gastric bypass: depends on the scanner
Bone loss after bariatric surgery: discordant results between DXA and QCT bone density.
Overview
Yu EW et al.. J Bone Miner Res 2014 · PMID 23929784 · DOI 10.1002/jbmr.2063
Spine bone density fell about 3% in one year; hip loss seen on DXA was not confirmed by CT.
Does the study support the specific claim? Partly · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Bone loss
- How was the study done?
Prospective controlled
- How many people, animals or samples were studied?
50
- What was actually found?
Spine loss; hip uncertain
- How large was the observed effect?
-3.3% spine
- What do the results mean in everyday life?
Some bone loss is real
- What are the study's limitations?
Small
- What does it say about Elawady's specific claim?
Partly supports
- Do the results apply to Germany and Europe?
Applicable
- What can explicitly not be concluded from this study?
Fracture risk
Scientific in-depth review
1. Full reference
- Authors
- Yu EW, Bouxsein ML, Roy AE, Baldwin C, Cange A, Neer RM, Kaplan LM, Finkelstein JS
- Journal
- J Bone Miner Res
- Year
- 2014
- Identifier
- PMID 23929784 DOI 10.1002/jbmr.2063 · PMC3918250
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
COI: not stated in record | Grants: NCRR NIH HHS, NICHD NIH HHS, NIDDK NIH HHS
2. Research question
Bone density change 1 year after RYGB measured by DXA vs QCT
3. Study design and population
- Study design
- Cohort study – Prospective controlled study with DXA and QCT
- Population
Morbidly obese adults
- Country
USA
- Period
1 year
- Sample size
30 RYGB, 20 controls
4. Methods and endpoints
- Exposure / intervention
RYGB
- Comparator
Obese non-surgical controls
- Endpoints
Spine and hip BMD
5. Actual results
- Results
Spine BMD: DXA -3.3% vs -1.1%; QCT -3.4% vs +0.2%. Hip DXA -8.9% vs -1.1%, but no hip change by QCT. Bone turnover markers rose (P1NP +82%, CTX +220%).
- Absolute risks
not reported
- Authors' conclusion
Moderate vertebral bone loss occurs in first year; striking DXA hip declines not confirmed by QCT, suggesting measurement artifacts.
6. Strengths
- Two imaging methods
7. Weaknesses
- Small
- 1 year
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
9. Assessment of the statistical interpretation
10. Relevance to the specific claim
Partly supports C-BAR-06.
11. Independent contrary findings
12. Transferability to Germany and Europe
Applicable.
13. Overall methodological judgement
Spine supported; hip uncertain at 1 year.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
15. Linked fact checks
- Bariatric surgery causes measurable hip and spine bone loss (and fracture risk). – Studies supporting the claim
Use by the Tayebat archive
Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.
- What the archive says about the study
Listed in the archive bibliography only; the archive gives no specific interpretation.
- A. What was actually studied?
Bone loss measurement
- B. What did the authors find?
Spine loss real; hip loss partly artifact
- C. What conclusions do the authors themselves draw?
As found
- D. What does the archive derive from it?
Used for 'measurable hip and spine bone loss'.
- E. Is this derivation scientifically justified?
Partly: spine loss confirmed; hip loss in this study was not confirmed by QCT.
- Adequacy of the interpretation (by the archive)
- not applicable