Between 1987 and 2001, Dr. Lars Sjostrom in Sweden examined the hypothesis linking bariatric surgery to a reduction in the incidence of cardiovascular events. They examined the connection between weight fluctuation and cardiovascular events in the ongoing study and recruited over 2,000 obese participants who underwent bariatric surgery in Sweden. These participants were then compared to another 2,000 obese individuals (control group) who received standard care.
The study ended in 2009 with a median follow-up period of 14.7 years. All eligible participants fell between the ages of 37 and 60 years of age and had a body mass index of at least 34 in men and at least 38 in women. In the bariatric surgery group, 13% underwent gastric bypass, 19% underwent banding, and 68% underwent vertical banded gastroplasty. Amongst the control group, the Swedish primary health care system administered standard medical treatment.
During follow-up care, the investigators noted 49 cardiovascular deaths amongst patients in the control group compared with 28 cardiovascular deaths amongst those in the surgery group. Overall, patients in the control group suffered 234 fatal and non-fatal cardiovascular events compared with 199 fatal and non-fatal cardiovascular events amongst those in the surgery group. After the researchers adjusted for several known variables, they discovered that bariatric surgery was linked to a lower number of fatal cardiovascular deaths and a lower incidence of total cardiovascular events.
The researchers linked bariatric surgery to a reduced number (22) of fatal heart attack deaths compared with 37 deaths in the control group. The evaluation suggests that bariatric surgery was associated with both a reduced fatal heart attack incidence and total heart attack incidence. In addition, bariatric surgery was linked to a reduction in the number of fatal stroke events and total stroke events.
The study authors summarize that, "In conclusion, this is the first prospective, controlled intervention to our knowledge reporting that bariatric surgery is associated with reduced incidence of cardiovascular deaths and cardiovascular events. These results demonstrate that there are many benefits to bariatric surgery and that some of these benefits are independent of the degree of the surgically induced weight loss."