137 Predictors and Prevalence of Iron Deficiency in Patients Living with Obesity: Insights from Bariatric Surgery Candidates

Abstract Introduction Iron deficiency anaemia (IDA) is a recognised complication of obesity, and its associated co-morbidities. Iron deficiency has been implicated in immunologic dysfunction in obesity. However, the patterns of iron deficiency in people with obesity, independent of IDA, and its implications for patients with obesity remain unclear. Methods A retrospective review of a prospectively maintained database of consecutive patients undergoing bariatric surgery was performed. Pre-operative haematologic assessments were reviewed. Linear regression models were used to identify the associations of iron deficiency in patients with obesity. Results 384 consecutive patients over a 2-year time period were included in the analysis. 72.1% of patients were female. The mean age was 49.44±10.2. The mean weight of patients was 144.1±31.02 kg, and the mean BMI was 50.66±9.61 kg/m2. 2.45% of patients met the criteria for iron deficiency anaemia. However, over 40% had iron deficiency. Including 15.49 % with low serum iron(<9 mmol/L), 12.1% had low ferritin(<30mg/L), 1.38% had low transferrin(<2g/L), 15.17% had high TIBC (>71.6mmol/L), 37.93% had low transferrin saturation(<20%). High BMI was a significant predictor of low serum iron(b=-0.206, p=0.031). Dysregulated glycaemic metabolism(HbA1c and glucose) was not a significant predictor of iron deficiency. Baseline inflammation (elevated CRP) was associated with low serum iron(b=-0.320, p=<0.001) and low transferrin(b=-0.205, p=0.028). Conclusion Iron deficiency in patients with obesity is common, but not IDA dependent. It does not appear to be linked to patients’ glycaemic regulation. It may instead be attributable to systemic inflammation caused by obesity.