Type 2 diabetes after bariatric surgery in Sweden: a nationwide, matched, observational cohort study

Björn Eliasson, Vasileios Liakopoulos, Stefan Franzén, Ingmar Näslund, Ann-Marie Svensson, Johan Ottosson, Soffi a Gudbjörnsdottir


Background In patients with diabetes and obesity specifically, no studies have examined mortality after bariatric surgery. We did a nationwide study in Sweden to examine risks of cardiovascular disease and mortality in patients with obesity and diabetes who had undergone bariatric surgery (Roux-en-Y gastric bypass [RYGB]).

Methods In this nationwide, matched, observational cohort study, we merged data for patients who had undergone RYGB registered in the Scandinavian Obesity Surgery Registry with other national databases, and identifi ed matched controls (on the basis of sex, age, BMI, and calendar time [year]) who had not undergone bariatric surgery from the National Diabetes Registry. We assessed risks of cardiovascular disease and death using a Cox proportional-hazards regression model and other methods to examine the treatment eff ect while accounting for residual confounding. Primary outcomes were total mortality, cardiovascular death, and fatal or non-fatal myocardial infarction.

Findings Between Jan 1, 2007, and Dec 31, 2014, we obtained data for 6132 patients who had undergone RYGB and 6132 control patients who had not. Median follow-up was 3·5 years (IQR 2·1–4·7). We noted a 58% relative risk reduction (hazard ratio [HR] 0·42, 95% CI 0·30–0·57; p<0·0001) in overall mortality in the RYGB group compared with the controls. The risk of fatal or non-fatal myocardial infarction was 49% lower (HR 0·51, 0·29–0·91; p=0·021) and that of cardiovascular death was 59% lower (0·41, 0·19–0·90; p=0·026) in the RYGB group than in the control group. 5 year absolute risks of death were 1·8% (95% CI 1·5–2·2) in the RYGB group and 5·8% (5·0–6·8) in the control group.


Our findings provide support for the benefits of RYGB surgery for patients with obesity and type 2 diabetes. The causes of these beneficial effects may be the weight reduction per se, changes in physiology and metabolism, improved care and treatment, improvements in lifestyle and risk factors, or combinations of these factors.

Funding Swedish Association of Local Authorities and Regions and Region Västra Götaland.


Above is the summary of a fine study, recently published, of work done in Sweden, involving 12,000 patients.

It may be of specific interest to one or two of our members - especially those contemplating surgery (Auda ?)

If anyone would like the full PDF of the paper (it is very technical!) please advise your email by private message and I will send it.

2 Replies

  • That is very interesting. I'm below the weight where I would be considered for this kind of surgery, although my starting weight was not. I do however take home the point that normalising my weight would benefit not only my GORD symptoms as others have pointed out but also reduce my risk of other serious conditions.

    I am definetly considering surgery to control the reflux, assuming (and hoping) that reflux is the cause of my current problems with eating.

    Thankyou for sharing this.

  • My guess is that patients with serious obesity and diabetes have significant health risks anyway, and that the decision to go for surgery is therefore based on reducing health risks, vindicated by this study. The issue about whether the surgery is also justified to prevent reflux is probably different in degree rather than in principle, if people have not responded to medication.

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