Meta-analysisindependent cross-checkabstract checked I-BAR-133 standard review
Meta-analysis: eye and kidney damage in diabetes after surgery
Benefits of bariatric surgery on microvascular outcomes in adult patients with type 2 diabetes: a systematic review and meta-analysis.
Overview
Obeso-Fernández et al.. Surg Obes Relat Dis 2023 · PMID 37169666 · DOI 10.1016/j.soard.2023.02.024
People with diabetes who had surgery had fewer eye and kidney complications than those treated with medicines alone.
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Microvascular outcomes
- How was the study done?
Meta-analysis
- How many people, animals or samples were studied?
160,072
- What was actually found?
Less retinopathy, nephropathy, ESRD
- How large was the observed effect?
OR 0.29-0.41
- What do the results mean in everyday life?
Benefit even if diabetes returns
- What are the study's limitations?
Observational
- What does it say about Elawady's specific claim?
Context for relapse
- Do the results apply to Germany and Europe?
Applicable
- What can explicitly not be concluded from this study?
Causation
Scientific in-depth review
1. Full reference
- Authors
- Obeso-Fernández et al.
- Journal
- Surg Obes Relat Dis
- Year
- 2023
- Identifier
- PMID 37169666 DOI 10.1016/j.soard.2023.02.024
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref API
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract
2. Research question
Does bariatric surgery added to medical therapy reduce microvascular complications in adults with type 2 diabetes?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and meta-analysis (cohorts and RCTs)
- Population
Adults with T2D
- Country
Multinational
- Period
Search to March 2021 (PROSPERO CRD42021243739)
- Sample size
25 studies, 160,072 participants
- Inclusion and exclusion criteria
Cohorts/RCTs, >=6 months follow-up
4. Methods and endpoints
- Exposure / intervention
Bariatric surgery + medical therapy
- Comparator
Medical therapy alone
- Endpoints
Retinopathy, nephropathy, ESRD, neuropathy
- Statistical methods
Pooled OR
5. Actual results
- Results
Retinopathy OR 0.29 (0.10-0.91); nephropathy OR 0.41 (0.17-0.96); haemodialysis/ESRD OR 0.31 (0.20-0.48); neuropathy OR 0.11 (0.01-1.37, NS); albuminuria regression OR 15.15.
- Absolute risks
not reported in abstract
- Authors' conclusion
Surgery reduced odds of retinopathy, ESRD and nephropathy; many individual outcomes remain uncertain.
6. Strengths
- Large pooled sample
7. Weaknesses
- Mostly observational
- Wide CIs
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Abstract only.
9. Assessment of the statistical interpretation
Wide CIs; retinopathy OR CI 0.10-0.91 imprecise.
10. Relevance to the specific claim
Shows clinical benefit persists despite remission relapse.
11. Independent contrary findings
12. Transferability to Germany and Europe
International.
13. Overall methodological judgement
Supports benefit beyond remission.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
RCT data on hard microvascular outcomes.
15. Linked fact checks
- The diabetes remission achieved by bariatric surgery erodes over time (SOS: 72% at 2 years to 30.4% at 15 years; Adams: 75% to 51%). – Studies contradicting or limiting the claim