SAN DIEGO – About one-quarter of patients referred to a private hematology practice had iron deficiency associated with gastric bypass surgery.

In addition, 57% demonstrated symptoms of pica syndrome – a craving for and compulsive eating of non-food substances such as ice and starch.

"As morbid obesity has become a large problem in this country and more and more people are undergoing gastric bypass surgery, iron deficiency anemia is an unintended consequence," Dr. Thomas A. Bensinger said at the annual meeting of the American Society of Hematology. "Some of these patients get very severely anemic."

Dr. Bensinger and his associates at Maryland Oncology Hematology in Greenbelt reviewed the medical records of 300 adults referred to the practice between March and November of 2010 with a diagnosis of anemia. Of the total, 130 demonstrated iron deficiency anemia after undergoing laboratory studies that included complete blood count, ferritin, iron/total iron-binding capacity, reticulocyte count and review of the peripheral blood film.

Of the 130 patients, 122 (94%) were women, 4 of whom were pregnant. Heavy menstrual bleeding was the most common cause of iron deficiency anemia (62%), followed by gastric bypass surgery (24%), gastrointestinal abnormalities (6%), and heavy menstrual bleeding associated with the presence of uterine fibroid (5%). In addition, 12% of patients had both heavy menstrual bleeding and had undergone gastric bypass surgery. The remaining 3% of patients were male.

More than half of patients (57%) demonstrated symptoms of pica syndrome, primarily the urge to eat ice. Two patients reported an urge to eat toilet paper while one patient reported eating leaves that were stripped from a plant in her garden. Such symptoms "were often not reported by the patient unless the patient was questioned in detail with the exception of a small subset of patients who had performed an internet search and found pica for ice to be associated with iron deficiency anemia," Dr. Bensinger said.

Pica syndrome symptoms typically resolved within 7-21 days of intravenous iron administration. "I speculate that the craving for ice is related to enzymes that are in the oral cavity in the mucosa," he said. "They get iron depleted and somehow the ice makes them feel better. When you give them the iron, those enzymes get repleted. It’s a very interesting phenomenon. Some of our patients know when they start to get iron deficient again because they realize they’re eating ice."

The study’s overall findings underscore the importance of paying close attention to key indicators of iron deficiency anemia, including low mean corpuscular volume and various forms of pica syndrome.

"You have to keep paying attention to the causes of anemia," he said.

Dr. Bensinger reported having no relevant financial disclosures.