Iron deficiency after bariatric surgery: what is the real problem?

Abstract

The growing prevalence of obesity explains the rising interest in bariatric surgery. Compared with non-surgical treatment options, bariatric surgery results in greater and sustained improvements in weight loss, obesity associated complications, all-cause mortality and quality of life. These encouraging metabolic and weight effects come with a downside, namely the risk of nutritional deficiencies. Particularly striking is the risk to develop iron deficiency. Postoperatively, the prevalence of iron deficiency varies between 18 and 53 % after Roux-en-Y gastric bypass and between 1 and 54 % after sleeve gastrectomy. Therefore, preventive strategies and effective treatment options for iron deficiency are crucial to successfully manage the iron status of patients after bariatric surgery. With this review, we discuss the risks and the contributing factors of developing iron deficiency after bariatric surgery. Furthermore, we highlight the discrepancy in the diagnosis of iron deficiency, iron deficiency anaemia and anaemia and highlight the evidence supporting the current nutritional recommendations in the field of bariatric research. In conclusion, we advocate for more nutrition-related research in patient populations in order to provide strong evidence-based guidelines after bariatric surgery.

Iron deficiency

“…A recognized cause of dysregulation of iron metabolism is obesity, which may lead to iron deficiency, especially after bariatric surgery because of global absorption impairment (Table 1). 42 In Western countries, as a result of increased life expectancy, these types of iron deficiency are expected to increase in coming years.…”

The True Story on Deficiencies After Sleeve Gastrectomy: Results of a Double-Blind RCT

“…More importantly, the present study illustrates that nutritional deficiencies are highly prevalent after SG, despite the anatomy of the intestinal tract remaining unaltered. There are several factors that put patients at risk for developing nutritional deficiencies after SG, including reduced food intake, decreased hydrochloric acid and intrinsic factor secretion, vomiting, poor food choices, and food intolerance [7,21]. Yet, others believe that SG has minimal impact on nutrient status [3] and that maintenance of MVS more than 3 months postoperatively seems to be of no benefit [8].…”

“…We observed iron deficiency, expressed in low serum ferritin levels, in seven patients (5.1%). After surgery, reduced secretion of HCl, use of proton-pump inhibitors (PPI), and faster gastric emptying may limit absorption [13,14,21,24]. Besides low absorption, reduced oral intake and intolerance to iron-rich sources such as red meat might be a cause of iron deficiency post-sleeve [14,21].…”

Bariatric Surgery in Obesity: Effects on Gut Microbiota and Micronutrient Status

“…Iron deficiency following VSG is determined by the malabsorption secondary to the gastric resection that prevents reduction of Fe 3+ to Fe 2+ [151]. Iron deficiency is very common after BS and has been reported in 18-53% of patients after RYGB and respectively, in 1-53% patients after VSG [153].…”