Kaiser Finds Bariatric Hits And Misses

Bariatric surgery has been one of the leading methods to fight the nation's obesity epidemic in recent years, but there has been scant evidence regarding the long-term results and effects of the invasive procedure, which extensively restructures the digestive tract. 

A new study by Kaiser Permanente researchers suggests there is a significant difference in outcomes between white, black and Latino patients.

“The benefits of bariatric surgery are different for men and women and differentracial/ethnic groups,” said Karen J. Coleman of Kaiser's research and evaluation arm and lead author of the study.

The number of Americans undergoing bariatric procedures peaked at about 200,000 per year in 2010, although there has been a decline in recent years. The typical candidate has to be morbidly obese, with a BMI of about 40, or about 300 pounds for someone who is 6 feet tall, and about 220 pounds for someone who is about five feet, two inches tall.

The study focused on what is known as metabolic syndrome, a group of health conditions that include elevated blood pressure, blood sugar, cholesterol and levels of body fat. The syndrome puts individuals at much higher risk for heart attacks, strokes or diabetes. Although it affects more than a third of Americans overall, it is usually confined to patients who are obese or morbidly obese.

According to Kaiser's survey of nearly 4,100 patients in Southern California who underwent bariatric surgery between 2009 and 2011 – among the largest group who have had the procedure ever studied – about 44% of patients lost enough weight after the procedure to no longer be considered obese, and 85% saw their blood pressure drop to normal levels. The patients studied underwent two popular forms of the surgery: the Roux-en-Y gastric bypass or a laparoscopic vertical sleeve gastrectomy. They were considered eligible for surgery if they had a BMI of 40 or higher, or a 35 to 39 BMI with at least one medical condition connected to their being overweight.

Among those who underwent the procedure, 82% were women, and they had an average BMI of 47.1 at the time of surgery. Just under half were Latinos or African-Americans. About 57% were suffering from metabolic syndrome when they underwent the procedure.

There was a sharp difference in overall outcomes between non-Hispanic white women, Latinas and African-Americans who underwent bariatric surgery.

While 54% of whites experienced remission of metabolic syndrome after surgery, that applied to only 28% of Latinos and 10% of African-Americans.

“Although we do not know the reasons for the racial and ethnic differences we saw, one explanation could be that the black and Hispanic patients had surgery when they are much heavier and sicker than the non-Hispanic white patients,” Coleman observed.

Although BMI data was not broken out specifically for the gender and ethnic groups, the group that experienced remission of metabolic syndrome had a lower BMI: 44.5 versus nearly 49 among those who did not experience remission. And those who did experience remission lost 63% of their excess BMI after surgery, compared to the 51% of excess BMI lost by those who did not enter metabolic syndrome remission.

“Our study highlights that surgery may be an important intervention tool for people earlier in their weight gain trajectory. The heavier they become, the less likely that surgery will be successful at reducingthese cardiovascular disease risk factors,” Coleman said.

There also appeared to be a distinct socioeconomic factor aside from race. Those patients with annual household incomes above $75,000 were more likely to experience metabolic syndrome remission than those with lower incomes. And 58% of college graduates experienced remission, versus just 28% of those who had only a high school diploma.

The results of the Kaiser study were published in the most recent edition of the journal Annals of Surgery.