Obesity Surgery Can Lead to Nerve Damage - Study
Thu Oct 14, 3:39 PM ET
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Operations to treat obesity such as stomach-stapling may work a little too well, causing some patients to develop nerve damage -- a symptom of malnutrition, doctors warned Thursday.
People who get these kinds of procedures may need to take vitamins and get regular checks from specialists, the researchers said.
They found a significant number of patients who got gastric bypass surgery or other operations to limit how much they could eat later developed signs of nerve damage called peripheral neuropathy.
Malnutrition appeared to be the culprit, Dr. James Dyck told a science briefing sponsored by the American Medical Association.
"We found that nutritional factors were the main risk factors," Dyck, a professor of neurology at the Mayo Clinic in Rochester, Minnesota, told the briefing.
"Patients who developed peripheral neuropathy lost more weight ... and they lost weight at a much faster rate."
The patients who developed the nervous system symptoms also tended to have more nausea, diarrhea as well as a symptom called dumping, in which food goes undigested from the stomach to the intestine.
All these can cause poor absorption of vitamins from food, Dyck said. Neuropathy can be caused by a lack of vitamin B-12 and can lead to permanent disability, with patients sometimes forced to use wheelchairs.
Symptoms include tingling, numbness and sometimes stabbing pain.
"It can be a sharp pain like somebody sticking you with a knife," Dyck said. "Or your husband or wife caresses you and instead of it being a pleasant sensation, it hurts like the dickens. Sometimes people walk around naked (because) their clothing hurts them."
For the study, published in this week's issue of the journal Neurology, Dyck and colleagues looked at the records of 435 patients who got obesity surgery, either at the Mayo Clinic or who later came to the clinic for follow-up treatment.
Dyck stressed that his study did not look at a representative sample of people getting such surgery. But in his case 71 patients, or 16 percent, developed peripheral neuropathy after surgery.
As a comparison, Dyck's team studied obese patients getting gallbladder surgery. Just 3 percent of them got symptoms of peripheral neuropathy.
An estimated 30 percent of Americans are clinically obese, meaning they are more than 20 percent above a healthy body weight. They develop diabetes, heart disease and some forms of cancer at a much higher rate than slimmer people.
Last year more than 100,000 people opted for surgery to treat obesity, usually involving an operation to bypass the stomach or make it smaller.
A report published in this week's Journal of the American Medical Association (news - web sites) found the surgery works well and often helps people lose 100 pounds or more.
The operations cured diabetes in 76 percent of the patients, high blood cholesterol problems were resolved or improved in 86 percent, high blood pressure was corrected in 61 percent and obstructive sleep apnea was resolved or improved in 83 percent.