Effects of bariatric surgery on mortality in Swedish obese subjects.
BACKGROUND
Obesity is associated with increased mortality. Weight loss improves cardiovascular risk factors, but no prospective interventional studies have reported whether weight loss decreases overall mortality. In fact, many observational studies suggest that weight reduction is associated with increased mortality.


METHODS
The prospective, controlled Swedish Obese Subjects study involved 4047 obese subjects. Of these subjects, 2010 underwent bariatric surgery (surgery group) and 2037 received conventional treatment (matched control group). We report on overall mortality during an average of 10.9 years of follow-up. At the time of the analysis (November 1, 2005), vital status was known for all but three subjects (follow-up rate, 99.9%).


RESULTS
The average weight change in control subjects was less than +/-2% during the period of up to 15 years during which weights were recorded. Maximum weight losses in the surgical subgroups were observed after 1 to 2 years: gastric bypass, 32%; vertical-banded gastroplasty, 25%; and banding, 20%. After 10 years, the weight losses from baseline were stabilized at 25%, 16%, and 14%, respectively. There were 129 deaths in the control group and 101 deaths in the surgery group. The unadjusted overall hazard ratio was 0.76 in the surgery group (P=0.04), as compared with the control group, and the hazard ratio adjusted for sex, age, and risk factors was 0.71 (P=0.01). The most common causes of death were myocardial infarction (control group, 25 subjects; surgery group, 13 subjects) and cancer (control group, 47; surgery group, 29).


CONCLUSIONS
Bariatric surgery for severe obesity is associated with long-term weight loss and decreased overall mortality.
Sjöström
Lars
L
Institute of Medicine, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden. lars.sjostrom@medfak.gu.se
Narbro
Kristina
K
Sjöström
C David
CD
Karason
Kristjan
K
Larsson
Bo
B
Wedel
Hans
H
Lystig
Ted
T
Sullivan
Marianne
M
Bouchard
Claude
C
Carlsson
Björn
B
Bengtsson
Calle
C
Dahlgren
Sven
S
Gummesson
Anders
A
Jacobson
Peter
P
Karlsson
Jan
J
Lindroos
Anna-Karin
AK
Lönroth
Hans
H
Näslund
Ingmar
I
Olbers
Torsten
T
Stenlöf
Kaj
K
Torgerson
Jarl
J
Agren
Göran
G
Carlsson
Lena M S
LM
D050110:Bariatric Surgery; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000401:mortality*; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000401:mortality* / Q000601:surgery*; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D015431:Weight Loss