Bariatric surgery and long-term cardiovascular events.
BACKGROUND
Obesity is a risk factor for cardiovascular events. Weight loss might protect against cardiovascular events, but solid evidence is lacking.


OBJECTIVE
To study the association between bariatric surgery, weight loss, and cardiovascular events.


METHODS
The Swedish Obese Subjects (SOS) study is an ongoing, nonrandomized, prospective, controlled study conducted at 25 public surgical departments and 480 primary health care centers in Sweden of 2010 obese participants who underwent bariatric surgery and 2037 contemporaneously matched obese controls who received usual care. Patients were recruited between September 1, 1987, and January 31, 2001. Date of analysis was December 31, 2009, with median follow-up of 14.7 years (range, 0-20 years). Inclusion criteria were age 37 to 60 years and a body mass index of at least 34 in men and at least 38 in women. Exclusion criteria were identical in surgery and control patients. Surgery patients underwent gastric bypass (13.2%), banding (18.7%), or vertical banded gastroplasty (68.1%), and controls received usual care in the Swedish primary health care system. Physical and biochemical examinations and database cross-checks were undertaken at preplanned intervals.


METHODS
The primary end point of the SOS study (total mortality) was published in 2007. Myocardial infarction and stroke were predefined secondary end points, considered separately and combined.


RESULTS
Bariatric surgery was associated with a reduced number of cardiovascular deaths (28 events among 2010 patients in the surgery group vs 49 events among 2037 patients in the control group; adjusted hazard ratio [HR], 0.47; 95% CI, 0.29-0.76; P = .002). The number of total first time (fatal or nonfatal) cardiovascular events (myocardial infarction or stroke, whichever came first) was lower in the surgery group (199 events among 2010 patients) than in the control group (234 events among 2037 patients; adjusted HR, 0.67; 95% CI, 0.54-0.83; P < .001).


CONCLUSIONS
Compared with usual care, bariatric surgery was associated with reduced number of cardiovascular deaths and lower incidence of cardiovascular events in obese adults.
Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. lars.v.sjostrom@medfak.gu.se
Lars
L
Sjöström
Markku
M
Peltonen
Peter
P
Jacobson
C David
CD
Sjöström
Kristjan
K
Karason
Hans
H
Wedel
Sofie
S
Ahlin
Åsa
Å
Anveden
Calle
C
Bengtsson
Gerd
G
Bergmark
Claude
C
Bouchard
Björn
B
Carlsson
Sven
S
Dahlgren
Jan
J
Karlsson
Anna-Karin
AK
Lindroos
Hans
H
Lönroth
Kristina
K
Narbro
Ingmar
I
Näslund
Torsten
T
Olbers
Per-Arne
PA
Svensson
Lena M S
LM
Carlsson
D000328:Adult; D050110:Bariatric Surgery; D002318:Cardiovascular Diseases / Q000401:mortality* / Q000517:prevention & control; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000517:prevention & control; D009765:Obesity / Q000601:surgery*; D011446:Prospective Studies; D020521:Stroke / Q000401:mortality / Q000517:prevention & control; D013548:Sweden / Q000453:epidemiology; D015431:Weight Loss