Weight-loss surgery is associated with a significantly lower risk of heart attack, stroke, heart failure and death, a new study reveals.
The study included more than 7,400 severely obese people, average age 36, in Denmark who had not suffered a heart attack or stroke. Half of the participants had weight-loss ("bariatric") surgery and half did not (the "control" group).
Over an average follow-up of 11 years, there were 37 fatal or non-fatal heart attacks or strokes in the weight-loss surgery group, and 93 in the control group, a 60% difference.
New diagnoses of heart failure during follow-up were 60% lower in the weight-loss surgery group than in the control group (22 versus 46) and death from any cause was 80% lower in the surgery group than in the control group (45 versus 182).
The researchers also found that those who had weight-loss surgery lost much more weight (an average of more than 10 kilograms — 22 pounds — or more), and their type 2 diabetes was more likely to improve to the point where they no longer needed medications to maintain normal blood sugar levels.
The study was published March 19 in the European Heart Journal.
The findings show that "bariatric surgery was associated with a 1.5% reduction in the absolute risk of heart attacks or strokes; 62 patients would need to have bariatric surgery to prevent one heart attack or stroke. As this was a young group of patients, in whom we would expect to see fewer such events than in older patients, the reduction in the absolute risk has important clinical implications," said study co-first author Maddalena Ardissino, an academic foundation trainee at Imperial College London.
According to study co-author Peter Collins, "It's important to emphasize that this is a retrospective study and can only show there is an association between bariatric surgery and a reduced risk of heart attacks and strokes, not that the surgery causes the reduction in risk. Large, prospective trials are required to show causation." Collins is a professor of clinical cardiology at the college's National Heart and Lung Institute.
"Nonetheless," he said in a journal news release, "the difference observed in cardiovascular events is striking, and it indicates that if a causative effect does indeed exist, its size has the potential to be very large and important."