Behavior of Iron and Ferritin After Bariatric Surgery in Patients With and Without Hepatic Steatosis

Background: Iron deficiency and hepatic steatosis are common in bariatric surgery patients. Steatosis can falsely elevate ferritin values even in presence of iron deficiency. This study aims to assess the influence of hepatic steatosis on iron deficiency and replacement therapy after bariatric surgery.

Methods: Seventy-nine individuals undergoing gastric bypass have been studied at 4 time points (preoperative and 1, 3, and 6 months after surgery). Weight, body mass index (BMI), iron, ferritin, vitamin B12, folate, hemoglobin, gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and use of iron replacement were recorded.

Results: Forty-two individuals (53%) had moderate/severe steatosis assessed by ultrasound. No differences were seen in iron profile and replacement therapy features compared to individuals with no/mild steatosis both in the preoperative and postoperative periods. Mixed model analysis showed ferritin levels to be higher in the moderate/severe steatosis group than in no/mild steatosis at the 6th month (139 ± 131 vs. 60.9 ± 49.8, p < 0.05). Values in both groups were lower than baseline, with p < 0.0001. The same was observed with serum iron (92.1 ± 39.6 moderate/severe steatosis vs. 68.6 ± 33.4 no/mild steatosis, p < 0.001; p from baseline < 0.01 for both). GGT was higher in moderate/severe steatosis in the 3rd month (38.8 ± 40.5 vs. 28.8 ± 20.8, p < 0.05; p from baseline < 0.0001 for both).

Conclusions: Ferritin levels were consistently higher in individuals with steatosis in the follow-up of bariatric surgery, but no apparent implication on the diagnosis of iron deficiency and in the prescription of replacement therapy was demonstrated at 6 months of follow-up. Longer studies are probably necessary to investigate this matter.