Lap Band Diary

Guest Post By Matt Papa, PhD

As the obesity rates in the United States continue to rise, bariatric surgery has become an effective intervention for weight loss. Bariatric surgeries range from restrictive procedures such as adjustable lap banding and vertical banding to surgeries involving bypass methods. Gastric bypass (Roux-en-Y) and biliopancreatic diversion (BPD) with or without a duodenal switch (DS) implement bypassing part of the alimentary tract. Bariatric surgeries succeed in resolving comorbidities attributed to obesity and have a mortality rate of less than 1%. However, life-long health problems often emanate from bariatric surgeries—especially from the procedures utilizing bypass techniques.

In addition to anticipated short-term medical problems, patients are also at risk for metabolic abnormalities. Several vitamin and mineral deficiencies have been documented following bariatric procedures including iron. Iron deficient patients suffering from anemia require life-long medical attention. Menstruating females account for the majority of bariatric patients and pose a greater risk for iron deficiency. As such deficiencies can adversely affect the quality of life weight-loss surgery intends to promote, the prevalence of iron deficiency following bariatric surgery requires close examination.

A Scientific Review

A review on the correlation of iron deficiency and bariatric surgery was published in 2008 in The American Journal of Hematology. The review, conducted by Dr Love, included several studies related to the topic. Methods used to collect articles involved keyword searches on PubMed. Bibliographies associated with the studies reviewed were also considered. The objective of the review focused on exploring the association of iron deficiency and bariatric surgery. Love’s review concluded that patient preoperative assessments should include a complete hematological work-up followed by a postoperative prescribed supplement for patients undergoing bypass procedures.

Deficient Iron Levels and Gastric Bypass

Bariatric surgeries of the restrictive nature (lap band, vertical banding gastroplasty, sleeve gastrectomy) are less likely to cause iron deficiency and iron deficiency anemia than those of the malabsorptive nature (Roux-en-Y, BPD-DS). A significant majority of related studies indicate deficient levels of iron ranging from 6% up to 50% in bypass patients at different time periods following surgery [1].

Contributing Factors of Iron Deficiency

Dietary Intake

Some studies suggest that gastric bypass patients consume less red meat than needed to maintain appropriate iron levels. As red meat provides heme – an organic pigment which contains iron - lower consumption could cause deficiencies. One study documented several cases of the body’s intolerance in digesting red meat following gastric bypass. A patient questionnaire revealed that episodes of vomiting following intake of red meat. A related follow-up over 6 years after surgery supported lack of meat as a factor in iron deficiency [2]. Patients who considered themselves meat eaters recorded higher iron serum levels.

However, iron deficiency cannot be explained solely on the basis of meat intolerance. Here is why: Patients who undergo lap banding generally have even less meat tolerance than gastric bypass patients. Yet, when measurements were compared between the two patient groups in one study, only gastric bypass patients were iron deficient. Therefore, iron deficiency is multifactorial.

Reduced Gastric Acid

Studies investigating gastric acid secretion before and after bypass procedures have shown a much lower level of acid after surgery. This is because bypass surgeries decrease the number of parietal cells in the stomach, which are responsible for gastric acid production. As a result, gastric acid supply lowers [3]. In the case of gastric band however, the digestive tract continuity stays intact. For this reason, patients undergoing banding procedures have much less risk of iron deficiency or other nutrient deficiencies than patients who opt for a bypass operation.

Bypassing The Duodenum

When bariatric procedures bypass the duodenum digestive continuity is interrupted. The duodenum absorbs heme. Because bypass surgery excludes the duodenum, obviously heme can no longer be absorbed meaning less iron enters the digestive process. Bypass patients record a much lower level of hemoglobin and serum iron than patients undergoing banding surgeries [4].

The importance of the duodenum in iron deficiency is shown in biliopanceratic diversion procedures. In biliopancreatic diversion with duodenal switch (BPD-DS) part of the duodenum is preserved. In contrast, in biliopancreatic diversion without duodenal switch (BPD) the duodenum is completely excluded from the digestive system. It is not surprising that in one study comparing the two versions, there were higher serum ferritin levels in the BPD-DS patients .

Additional Factors

Bleeding may cause iron deficiency [5]. Bypass patients may have gastrointestinal blood loss as a result of loops of bowel no longer assisting in digestion. Ulcers may be another source of blood loss.

Intestinal bacteria can become extensive in the bypassed bowel loops. That damage can cause epithelial cells and the iron they carry to be excreted.

The amount of weight loss and/or the time it took to lose the weight appear to have no bearing on absorption of iron.

Gender and Age Implications

Many obese people have pre-existing conditions of low iron. Females have a higher risk of iron deficiency and other nutrient deficiencies than males in the same age group. One study revealed no iron deficiencies in males while about 75% of female patients were deficient.

Women pose a greater risk than men for iron deficiency and anemia due to menstruation which often results in lower iron storage prior to surgery. Women who continue menstruating after surgery have higher levels of iron deficiencies than those who are past menstruation age. All bariatric surgeries demonstrate lower serum iron levels for menstruating women compared to nonmenstruating women—including banding procedures.

Fertility in women generally improves after bariatric surgery, but the surgery also results in iron deficiency for those women of child-bearing age. In addition, more iron is needed during pregnancy. Risks to the baby and the mother may stem from iron deficiency and anemia. Iron deficiency tends to result in more preterm or low-birth weight babies [6].

Banding procedures may be a better option for women who plan to have children after weight-loss surgery. This is because iron is still absorbed in the duodenum in restrictive procedures.

Gender plays a role in iron deficient rates in obese children as it does in adolescents. As pediatrics deals with higher levels of obesity, more surgical intervention takes place as a weight management tool. These procedures prove to be effective for younger patients by improving quality of life. Mortality rates are low. However, life-long iron deficiency and other vitamin and mineral deficiencies pose a risk—especially for girls [7].

Prevention of Iron Deficiency

Multi-vitamins are usually prescribed for all bariatric patients to address nutrient deficiencies. For high-risk patients such as menstruating women, many surgeons also recommend iron supplements [8].

An increase in gastric acids leading to more iron absorption occurs when vitamin C is added to an iron supplement. Adding vitamin C promotes more absorption by reducing iron to ferrous. A study of patients treated with iron supplements for a month followed by iron supplements and vitamin C the next month, indicated the benefit of the oral iron supplement. During the second month, even higher rates of ferritin and hemoglobin were noted indicating the significance of adding vitamin C.

Summary

Iron deficiency and anemia are risks resulting from bariatric surgeries. Due to the obesity rates increasing, surgical interventions also increase causing long-term deficiencies in vitamins and minerals, including iron. These deficiencies are higher for all females. Within that group, menstruating women, those who become pregnant and some adolescents have the highest risk of becoming iron deficient. Patients who pose risks may need to take oral iron supplements with the possibility of more aggressive treatments required. Bariatric patients opting for banding procedures may have a lower risk of becoming iron deficient due to the non-malabsorptive nature of the surgeries. However, patients undergoing any bariatric surgery should expect the need for medical supervision to monitor hemoglobin and iron for the rest of their lives.

Matt Papa

As a biologist and research fellow at Washington University School of Medicine in St. Louis, MO, Matt Papa, PhD, studies cardio-vascular diseases. A related interest, he follows current scientific research on obesity interventions and effective weight loss methods. Matt’s summaries of professional peer-reviewed journals, as well as other resources, (such as a BistroMD coupon discount and a Diet-To-Go savings coupon) are published on his website to offer support and tips for readers faced with the challenge of losing weight.

References

1. JG Halverson, Micronutrient deficiencies after gastric bypass for morbid obesity, Am Surg, 1986;52:594-598.

2. E Avinoah, Nutritional status seven years after Roux-en-Y gastric bypass surgery, Surgery, 1992; 111:137-142.

3. KE Behrns, Prospective evaluation of gastric acid secretion and cobalamin absorption following gastric bypass for clinically severe obesity, Dig Dis Sci, 1994; 39:315-320.

4. HJ Sugarman, Weight loss with vertical banded gastroplasty and Roux-Y gastric bypass for morbid obesity with selective versus random assignment, Am J Surg, 1989; 157:93-102.

5. PP Toskes, Hematologic abnormalities following gastric resection, Major Probl Clin Surg, 1976;20:1190128.

6. RE Brolin, Multivitamin prophylaxis in prevention of post-gastric bypass vitamin and mineral deficiencies, Int J Obes 1991; 15:661-667.

7. RS Strauss, Gastric bypass surgery in adolescents with morbid obesity, J Pediatric, 2001; 138: 499-504.

8. BM Rhode, Iron absorption and therapy after gastric bypass, Obes Surg 1999; 9:17-21.