Studies evaluating the effect of iron depletion with phlebotomy in NAFLD

Author, year [Ref]MethodFindingsConclusion
Facchini et al., 2002 [62]Iron depletion to a level of NID was induced by phlebotomy in 17 NAFLD patients.Although, at the baseline, they did not have any supranormal levels of body iron, at NID, NAFLD individuals exhibited a significant improvement of both fasting and glucose-stimulated plasma insulin concentrations and a significant decrease to almost-normal serum ALT.Iron depletion exerts an insulin-sparing activity.
Sumida et al., 2006 [63]Eleven individuals with biopsy-proven NASH were phlebotomized biweekly until NID (i.e., serum ferritin concentration < 30 ng/mL).Paralleling a significant drop in ferritin levels, ALT activity significantly decreased while body weight remained unaltered. Even though 2 patients withdrew, no significant side effects of repeated phlebotomy were observed.NID is associated with improved ALT activity irrespective of body weight changes.
Valenti et al., 2007 [64]Sixty-four individuals submitted to phlebotomy were compared to matched controls (based on age, sex, ferritin, obesity, and ALT levels) undergoing lifestyle changes alone.Compared to lifestyle changes alone and independent of confounding factors (changes in BMI, baseline HOMA-IR, and presence of the MetS), iron depletion was associated with a significantly higher reduction in IR (assessed with RIA and the HOMA-IR index, at baseline and after 8 months). The effect of iron depletion in reducing HOMA-IR was higher among those with higher ferritin concentrations and in carriers of the mutations in the HFE gene.Independent of confounding factors, phlebotomy reduces IR.
Valenti et al., 2011 [65]Italian multicenter (6-month to 8-month) observational study of 198 non-hemochromatosis NAFLD patients, (79 submitted to phlebotomy and 119 to counselling only). IR was measured with HOMA.Venesection was significantly associated with normal HOMA and normal ALT. These findings were confirmed in 57 pairs matched for propensity and in the cohort of those with normal baseline ferritin (< 350 ng/mL).Among NAFLD patients, venesection is associated with normal IR and normal ALT.
Beaton et al., 2014 [66]Fifty-six NAFLD patients were submitted to liver biopsy with assessment of liver iron concentration at the entry and 6 months after phlebotomy conducted until the patient had either low serum ferritin or manifested anemia.Iron removed with phlebotomy was correlated with the decrease in serum ferritin. However, no significant correlations were found between serum ferritin and ESR, CRP, or grade of liver inflammation.Serum ferritin mirrors liver iron storage in NAFLD. Phlebotomy, by decreasing body iron stores, induces a parallel decrease in serum ferritin. However, inflammation is not the cause of hyperferritinemia observed in NAFLD.
Adams et al., 2015 [67]Prospective 6-month RCT evaluating the impact of phlebotomy in 74 NAFLD subjects (33 assigned to phlebotomy compared to 41 controls). Primary endpoints of the study: HS (assessed with MRI) and liver injury (assessed with ALT and CK-18). Secondary endpoints: IR (assessed with ISI and HOMA), and systemic lipid peroxidation (assessed with plasma F2-isoprostane levels).Those assigned to phlebotomy exhibited a significantly greater reduction than controls in ferritin levels over 6 months. At 6 months, there was no difference between phlebotomy and control groups in HS or CK-18 levels. At the end of the study, there was no difference in ISI, HOMA, or F2-isoprostane levels between cases and controls. There was no difference in any of the endpoints in patients with baseline hyperferritinemia nor in relation to the number of phlebotomy sessions.

In NAFLD patients, reduction in ferritin obtained with phlebotomy is not associated with improved liver enzymes, intra-hepatic fat content, or IR.

Jaruvongvanich et al., 2016 [68]Meta-analytic review including 4 interventional studies totaling 438 participants.Phlebotomy was significantly associated with lower HOMA-IR, reduced ALT and TG levels, and increased HDL-C levels.

Phlebotomy in NAFLD individuals decreases IR and transaminase and improves lipid profile.

Lainé et al., 2017 [69]Prospective, RCT in 146 nondiabetic DIOS patients (randomly assigned to receive venesections with LFDA and 128 to LFDA only) with hepatic iron > 50 μmoL/g at MRI. Study outcomes: metabolic and hepatic outcomes of one-year maintenance of serum ferritin levels < 50 μg/L by phlebotomy.Iron depletion was associated with significantly reduced values of ferritin and HOMA; body weight increased; no significant changes were observed as regards glycemia ALT, AST, GGT, FLI, and FIB-4. As a side effect, fatigue occurred significantly more often among individuals submitted to phlebotomy than in controls. The cohort of those patients who lost weight,exhibited improved values of glycemia, HOMA, serum ferritin, lipid profile, and liver enzymes irrespective of phlebotomy.Phlebotomy fails to improve dysmetabolic traits and liver enzymes. Moreover, it is associated with weight gain and is not invariably well tolerated.
Britton et al., 2018 [70]This study compared paired serum samples (at baseline and after 6 months) in 28 controls and 23 patients submitted to phlebotomy. HIC was assessed with MR FerriScan.Unexpectedly, this study found that baseline serum adiponectin concentration was positively associated with HIC (this finding was strengthened after correction for modifiers). Moreover, significant inverse correlations between HIC and measures of IR [adipose tissue IR (Adipo-IR)], serum insulin, serum glucose, and homeostasis model assessment of IR, HbA1c, and HS were found. Finally, a positive correlation was noted with the insulin sensitivity index. Serum adipokines did not differ between the controls and phlebotomy groups.In NAFLD patients, there is a positive correlation between serum adiponectin and insulin sensitivity.
Murali et al., 2018 [71]Meta-analytic review of 9 published studies globally enrolling 820 patients with DIOS and/or NAFLD (427 submitted to phlebotomy and 393 to lifestyle changes only). Study quality was evaluated with the Cochrane collaboration tool.

Compared to lifestyle changes alone, iron depletion was not associated with changes of the HOMA index nor AST in DIOS and/or NAFLD patients (five studies, 626 patients).

There was a statistically significant, mild improvement in ALT, but the effect size was very small. Also, in the cohort of those exhibiting both NAFLD and hyperferritinemia, phlebotomy did not improve HOMA, insulin level, ALT, or AST.

Finally, no study showed that iron reduction was associated with significantly improved the grade of hepatitis or the stage of FIB.

Compared to lifestyle changes alone, among DIOS and/or NAFLD patients, phlebotomy fails to induce any significant improvement in IR, liver enzymes, or liver histology.

ALT: alanine transaminase; AST: aspartate transaminase; BMI: body mass index; CK-18: cytokeratin-18; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; FLI: fatty liver index; GGT: gamma glutamyl transferase; HbA1c: hemoglobin A1c; HDL-C: high-density cholesterol; HIC: hepatic iron concentration; HOMA: homeostasis model assessment; ISI: insulin sensitivity index; LFDA: lifestyle and diet advice; NID: near iron deficiency; RCT: randomized, controlled trial; RIA: radio-immuno assay