Obesity Surgery

, Volume 26, Issue 11, pp 2590–2601 | Cite as

Effects of Bariatric Surgery on Mortality, Cardiovascular Events, and Cancer Outcomes in Obese Patients: Systematic Review and Meta-analysis

  • Xu Zhou
  • Jiajie Yu
  • Ling Li
  • Viktoria Luise Gloy
  • Alain Nordmann
  • Maria Tiboni
  • Youping Li
  • Xin SunEmail author
Original Contributions



The long-term effects of bariatric surgery have yet to be established, and a number of important studies have recently emerged. This systematic review aimed to assess the effects of bariatric surgery on all-cause mortality, cardiovascular events, and cancer compared to non-surgical treatment.


We searched PubMed, EMBASE, and CENTRAL up to July 13, 2015, and included randomized controlled trials (RCTs) and non-randomized controlled studies comparing bariatric surgery versus non-surgical treatment and reporting data on the three defined outcomes at 1 year or longer. We analyzed RCTs and non-randomized controlled studies, respectively.


Eleven RCTs, 4 non-randomized controlled trials, and 17 cohort studies were included. The randomized evidence suggested substantial uncertainty regarding the effects on all-cause mortality (0/382 vs. 1/287; 7 studies), cancer (OR 0.77, 95 % CI 0.22 to 2.71; 4 studies), and cardiovascular events (no data). The pooled adjusted estimates from non-randomized studies suggested that, compared to the control, the surgical group had lower risk of all-cause mortality (OR 0.55, 95 % CI 0.46 to 0.65; 10 studies), cancer (OR 0.74, 95 % CI 0.65 to 0.85; 2 studies), and cardiovascular events (MI: OR 0.71, 95 % CI 0.54 to 0.94; stroke: OR 0.66, 95 % CI 0.49 to 0.89; and their composite: OR 0.67, 95 % CI 0.54 to 0.83; 1 study).


In conclusion, bariatric surgery could reduce all-cause mortality and probably reduce the risk of any type of cancer. The inference was, however, based on studies with limited methodological rigor. Uncertainty remains regarding the effects on cardiovascular events.


Bariatric surgery Mortality Cardiovascular events Cancer 


Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no competing interests.

Statement of Ethical Approval

For this type of study, formal consent is not required.

Statement of Informed Consent

For this type of study, informed consent does not apply.

Supplementary material

11695_2016_2144_MOESM1_ESM.docx (218 kb)
ESM 1 (DOCX 217 kb)


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Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Xu Zhou
    • 1
  • Jiajie Yu
    • 1
  • Ling Li
    • 1
    • 2
  • Viktoria Luise Gloy
    • 3
  • Alain Nordmann
    • 3
  • Maria Tiboni
    • 4
  • Youping Li
    • 1
    • 2
  • Xin Sun
    • 1
    • 2
    • 5
    Email author
  1. 1.Chinese Evidence-based Medicine Center, West China HospitalSichuan UniversityChengduChina
  2. 2.Clinical Research and Evaluation Unit, West China HospitalSichuan UniversityChengduChina
  3. 3.Basel Institute of Clinical Epidemiology & BiostatisticsUniversity Hospital BaselBaselSwitzerland
  4. 4.Saint Joseph’s Hospital and McMaster UniversityHamiltonCanada
  5. 5.Center for Evidence-Based Medicine and Clinical Research, Taihe HospitalHubei University of MedicineShiyanChina

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