Prevalence and Factors Associated with Hepatic Iron Overload in Obese Individuals Undergoing Bariatric Surgery: a Cross-Sectional Study.

Abstract

Slight to moderate hepatic iron overload (HIO) can be found in cases of liver disease, including non-alcoholic fatty liver disease (NAFLD), but the mechanism is not completely understood, as well as its relationship with obesity. To determine the prevalence of HIO assessed through histopathological examination in obese individuals undergoing bariatric surgery and to identify correlations between this condition and demographic, anthropometric, clinical, laboratory, and NAFLD-related aspects. This is a cross-sectional study which enrolled individuals undergoing bariatric surgery from January 2018 to February 2019 at a tertiary university hospital. NAFLD and HIO were assessed through histological examination. Of 125 individuals, 87.2% were female and the average age was 38.8 ± 9.2years. The average BMI was 37.2 ± 3.1kg/m2. NAFLD was present in 66.4% and HIO in 17.6%, with 63.6% of patients with overload classified as mild (grade I) and 22.7% moderate (grade II). HIO was significantly more frequent in males (p = 0.003) and was significantly associated with higher levels of glucose (92.1 ± 28.4 vs. 80.7 ± 39.6; p = 0.02), ferritin (385.5 ± 290.9 vs. 131.6 ± 99.7; p < 0.0001), serum iron (82.4 ± 35.7 vs. 66.6 ± 25.1; p = 0.03), glutamic-oxaloacetic transaminase (27.3 ± 19.5 vs. 20.6 ± 8.8; p = 0.02), and glutamic-pyruvic transaminase (37.6 ± 36.4 vs. 24.6 ± 16.3; p = 0.01). Multivariate analysis showed that HIO intensity was significant and independently associated with ferritin levels (R = 0.19; p = 0.01), serum iron (R = 0.25; p < 0.0001), blood glucose (R = 0.16; p = 0.001), and total cholesterol (R = - 0.17; p < 0.0001). In obese individuals, HIO presented a high prevalence and was associated with higher levels of ferritin, serum iron, glucose, and transaminases; lower levels of total cholesterol; and male gender.