Gastrointestinal conditions and iron deficiency with or without anemia
"Gastrointestinal conditions and iron deficiency anaemia, Learn when to watch out for it”
Iron deficiency anaemia (IDA) in gastrointestinal conditions
There are multiple gastrointestinal (GI) conditions and factors that lead to an increased risk of iron deficiency. Dietary iron absorption primarily occurs in the duodenum and upper jejunum, and so a dysfunction of these structures can result in malabsorption of iron and iron deficiency. In addition, the GI tract is also a common site of chronic blood loss, which can deplete the body’s iron stores.
GI conditions that lead to an increased risk of iron deficiency anaemia include stomach ulcers, GI cancers, and chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) as well as inflammatory bowel disease (IBD), coeliac disease22 and bariatric surgery.2
Inflammatory bowel disease (IBD) refers to ulcerative colitis and Crohn’s disease, two autoimmune conditions that cause inflammation of the GI tract. Ulcerative colitis only affects the colon (large intestine), whereas Crohn’s disease can affect any portion of the GI tract from mouth to anus.3
A major symptom of IBD is intestinal bleeding, which may occur as occult blood loss for patients with Crohn’s disease, and may become apparent as visible bleeding in ulcerative colitis.4
Iron deficiency in IBD can also result from inflammation, which can reduce the absorption of iron from food, and from oral iron supplements (by increased hepcidin release).5
On average, 45% of people with IBD suffer from ID.6
Coeliac disease, also known as gluten-sensitive enteropathy, is an inflammatory disease of the small intestine.7
Coeliac disease causes chronic inflammation within the small intestine when gluten is ingested, which results in villous atrophy and the flattening of mucosa.7,8 This can reduce the absorption of iron and other nutrients such as folic acid and vitamin B12 from the diet.7,9 It also leads to occult blood loss from the gastrointestinal tract in 25–54% of patients with coeliac disease.10
The prevalence of IDA for those with coeliac disease is approximately 10-15%.11
This prevalence can raise between 32-69% if we consider both conditions iron deficiency or anaemia.22
Bariatric surgery is weight-loss surgery for obese individuals. It includes gastric banding, gastric bypass, biliopancreatic diversion and duodenal switch. Each type of gastric surgery has a different risk of iron deficiency. Generally, gastric bypass procedures are more likely to lead to iron deficiency than gastric bands.2
Both gastric bands and gastric bypass reduce the production of gastric acid, which is required to convert non-haem iron (that is iron from non-meat sources such as vegetables, fortified cereals etc.) into an absorbable form.12 Gastric bypass procedures can also cause malabsorption by excluding the intestinal sections where iron absorption naturally occurs.13 Additionally, some patients may reduce their intake of some iron-rich foods, especially red meat, due to no longer being able to tolerate them.12
Fifty percent of people who have had surgery gastric bypass are iron deficient within one year of surgery. This rises to up to 62% (according to the type of surgery) over a 4–12-year period after surgery.14
Other gastrointestinal bleeding disorders
Any other causes of internal bleeding within the GI tract can also lead to iron deficiency. For example, peptic ulceration including duodenal ulcers, gastric ulcers and anastomotic ulcers may be found in patients with IDA.15 Angiodysplasia and colorectal cancers are further causes of gastrointestinal bleeding.16,17,23
The importance of treating IDA in patients with GI conditions
Iron deficiency without anaemia can be associated with fatigue23 , restless legs syndrome24, impaired physical performance25, impaired cognitive function26,27, hairloss28 and body temperature deregulation29. When iron deficiency progresses to IDA, additional symptoms can include headache, dizziness, tachycardia and dyspnoea.18
The most common systemic complication in IBD patients is anemia.19 , 18 , 20 , 21 The negative effects of anemia in IBD are considerable20:
- Impairment of the quality of life (physical, emotional, cognitive) and workability
- More frequent hospitalization
- Increased treatment costs
For this reason, the European Crohn`s and Colitis Organization (=ECCO) recommends, in its current guidelines, to check the iron status of IBD patients and to treat a present iron deficiency consistently.20
Gastroenterology: Compared to intravenous iron treatment, oral treatment distinctly alters the intestinal microbiota and metabolome in IBD patients.30
- NHS. Iron deficiency anaemia – Causes. http://www.nhs.uk/Conditions/Anaemia-iron-deficiency-/Pages/Causes.aspx (accessed March 2016).
- Love AL & Billett HH. Obesity, bariatric surgery, and iron deficiency: true, true, true and related. Am J Hematol 2008; 83(5): 403-9.
- Baumgart DC, Sandborn WJ. Inflammatory bowel disease: clinical aspects and established and evolving therapies. Lancet. 2007 May 12;369(9573):1641-57.
- Gasche C. Anemia in IBD: the overlooked villain. Inflamm Bowel Dis 2000; 6(2): 142-150.
- Rayan Bou-Fakhredin, Racha Halawi, Joseph Roumi & Ali Taher (2017): Insights into the Diagnosis and Management of Iron Deficiency in Inflammatory Bowel Disease, Expert Review of Hematology, DOI: 10.1080/17474086.2017.1355233.
- Gisbert JP et F Gomollón. Common misconceptions in the diagnosis and management of anemia in inflammatory bowel disease. Am J Gastroenterol. 2008 May;103(5):1299-307. doi: 10.1111/j.1572-0241.2008.01846.x
- Nelsen D. Gluten-sensitive enteropathy (celiac disease): more common than you think. Am Fam Physician 2002; 66(12): 2259-66.
- Sollid LM. Coeliac disease: dissecting a complex inflammatory disorder. Nat Rev Immunol 2002; 2(9): 647-55.
- Halfdanarson TR et al. Hematologic manifestations of celiac disease. Blood 2007; 109(2): 412-21.
- Fine KD. The prevalence of occult gastrointestinal bleeding in celiac sprue. N Engl J Med 1996; 334(18): 1163-7.
- Presutti RJ et al. Celiac disease. Am Fam Physician 2007; 76(12): 1795-802.
- Shah M et al. Review: long-term impact of bariatric surgery on body weight, comorbidities, and nutritional status. J Clin Endocrinol Metab 2006; 91(11): 4223-31.
- Warsch S & Byrnes J. Emerging causes of iron deficiency anemia refractory to oral iron supplementation. World J Gastrointest Pharmacol Ther 2013; 4(3): 49-53.
- Jáuregui-Lobera I. Iron deficiency and bariatric surgery. Nutrients 2013; 5(5): 1595-608.
- Rockey D & Cello D. Evaluation of the gastrointestinal tract in patients with iron-deficiency anemia. N Engl J Med 1993; 329(23): 1691-1695.
- Tung KT & Millar AB. Gastric angiodysplasia--a missed cause of gastrointestinal bleeding. Postgrad Med J 1987; 63: 865-866.
- Aapro M et al. Prevalence and management of cancer-related anaemia, iron deficiency and the specific role of i.v. iron. Ann Oncol 2012; 23(8): 1954-62.
- Stein J, Dignass AU. Management of iron deficiency anemia in inflammatory bowel disease – a practical approach. Ann.s of Gastroenterol. 2013; 26(2):104-13.
- Hastka H, Heimpel H, Metzgeroth G, et al. DGHO Leitlinie Eisenmangel und Eisenmangelanämie. Onkopedia 2011; 1-24.
- Dignass AU et al. European consensus on the diagnosis and management of iron deficiency and anaemia in inflammatory bowel diseases. J Crohns Colitis. 2015 Mar;9(3):211-22. doi: 10.1093/ecco-jcc/jju009. Epub 2014 Dec 3.
- Evstatiev R, Marteau P, Iqbal T, et al. FERGIcor, a randomized controlled trial on ferric carboxymaltose for iron deficiency anemia in inflammatory bowel disease. Gastroenterology. 2011; 141(3):846-853.
- Stein J, Connor S, Virgin G, et al. Anemia and iron deficiency in gastrointestinal and liver conditions. World J Gastroenterol. 2016 Sep 21;22(35):7908-25.
- Verdon F et al. Iron supplementation for unexplained fatigue in non-anaemic women: double blind randomized placebo controlled trial. BMJ 2003, 326: 1124-1126.
- Allen RP et al. Evidence-based and consensus clinical practice guidelines for the iron treatment of restless legs syndrome/Willis-Ekbom disease in adults and children: an IRLSSG task force report. Sleep Med. 2018, 41, 27-44.
- Brownlie T, Utermohlen V, Hinton PS, et al. Tissue iron deficiency without anemia impairs adaptation in endurance capacity after aerobic training in previously untrained women. Am J Clin Nutr 2004;79:437–443.
- Gasche C, Lomer MC, Cavill I, et al. Iron, anaemia, and inflammatory bowel diseases. Gut 2004;53:1190–1197.
- Bruner AB, Joffe A, Duggan AK, et al. Randomised study of cognitive effects of iron supplementation in non-anaemic iron-deficient adolescent girls. Lancet 1996;348:992–996.
- Deloche C et al. Low iron stores: a risk factor for excessive hair loss in non-menopausal women. Eur J Dermatol 2007;17:507-512.
- Martines-Torres C et al. Effect of exposure to low temperature on normal and iron-deficient subjects. On J Physiol 1984, 246: R380-R383.
- Lee T et al. Oral versus intravenous iron replacement therapy distinctly alters the gut microbiota and metabolome in patients with IBD. Gut. 2017 May;66(5):863-871