Serum ferritin is associated with non-alcoholic fatty liver disease and decreased Β-cell function in non-diabetic men and women

Metabolic-associated fatty liver disease is characterized by a post-oral glucose load hyperinsulinemia in individuals with mild metabolic alterations

Metabolic-associated fatty liver disease (MAFLD) has been identified as risk factor of incident type 2 diabetes (T2D), but the underlying postprandial mechanisms remain unclear. We compared the glucose metabolism, insulin resistance, insulin secretion, and insulin clearance post-oral glucose tolerance test (OGTT) between individuals with and without MAFLD. We included 50 individuals with a body mass index (BMI) between 25 and 40 kg/m2 and ≥1 metabolic alteration: increased fasting triglycerides or insulin, plasma glucose 5.5-6.9 mmol/L, or glycated hemoglobin 5.7-5.9%. Participants were grouped according to MAFLD status, defined as hepatic fat fraction (HFF) ≥5% on MRI. We used oral minimal model on a frequently sampled 3 h 75 g-OGTT to estimate insulin sensitivity, insulin secretion, and pancreatic β-cell function. Fifty percent of participants had MAFLD. Median age (IQR) [57 (45-65) vs. 57 (44-63) yr] and sex (60% vs. 56% female) were comparable between groups. Post-OGTT glucose concentrations did not differ between groups, whereas post-OGTT insulin concentrations were higher in the MAFLD group (P < 0.03). Individuals with MAFLD exhibited lower insulin clearance, insulin sensitivity, and first-phase pancreatic β-cell function. In all individuals, increased insulin incremental area under the curve and decreased insulin clearance were associated with HFF after adjusting for age, sex, and BMI (P < 0.02). Among individuals with metabolic alterations, the presence of MAFLD was characterized mainly by post-OGTT hyperinsulinemia and reduced insulin clearance while exhibiting lower first phase β-cell function and insulin sensitivity. This suggests that MAFLD is linked with impaired insulin metabolism that may precede T2D.NEW & NOTEWORTHY Using an oral glucose tolerance test, we found hyperinsulinemia, lower insulin sensitivity, lower insulin clearance, and lower first-phase pancreatic β-cell function in individuals with MAFLD. This may explain part of the increased risk of incident type 2 diabetes in this population. These data also highlight implications of hyperinsulinemia and impaired insulin clearance in the progression of MAFLD to type 2 diabetes.

Iron status and non-alcoholic fatty liver disease: A Mendelian randomization study

OBJECTIVES

The aim of this study was to assess the association of genetically determined iron status with the risk for non-alcoholic fatty liver disease (NAFLD) using two-sample Mendelian randomization (MR) analysis.

METHODS

We applied single nucleotide polymorphisms (SNPs) associated at genome-wide significance with iron status proxied by serum iron, ferritin, transferrin, and transferrin saturation from the Genetics of Iron status Consortium (N = 48 793), in a genome-wide association study of 1664 NAFLD cases and 400 055 controls from the United Kingdom Biobank. A SNP associated with multiple markers of iron status was only applied to one marker with the strongest association in the main analysis. Their effects on NAFLD were calculated using inverse variance weighting after excluding SNPs associated with alkaline phosphatase and lipid metabolism.

RESULTS

The risk for NAFLD is negatively associated with genetically predicted serum transferrin level with a 20% reduction in NAFLD risk per SD (0.65g/L) increase in transferrin (95% confidence interval [CI], 0.66-0.97), and trending positive association with transferrin saturation (odds ratio [OR], 1.50; 95% CI, 0.96-2.35) but it was not associated with serum iron (OR, 0.90; 95% CI, 0.63-1.29) and ferritin (OR, 1.33; 95% CI, 0.54-3.30).

CONCLUSIONS

MR analysis provided evidence that genetically predicted higher serum transferrin, indicating lower iron status, may be protective against NAFLD, whereas higher transferrin saturation, indicating higher iron status, might increase the risk for NAFLD and its pathogenesis.

Associations of Serum Iron Status with MAFLD and Liver Fibrosis in the USA: a Nationwide Cross-Section Study

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a new terminology characterized by liver steatosis. Iron status is related to many metabolic diseases. However, the researches on the associations of serum iron status with MAFLD are limited. The objective of this study was to investigate the associations of serum iron status biomarkers with MAFLD and liver fibrosis. A total of 5892 adults were enrolled in the current cross-sectional study using the 2017-March 2020 National Health and Nutrition Examination Survey. Liver steatosis and liver fibrosis were defined by the median values of controlled attenuation parameter ≥ 274 dB/m and liver stiffness measurement ≥ 8 kPa, respectively. The multivariable logistic/linear regression and restricted cubic spline analysis were conducted. After adjusting for potential confounders, higher ferritin levels were associated with higher odds of MAFLD (OR 4.655; 95% CI 2.301, 9.418) and liver fibrosis (OR 7.013; 95% CI 3.910, 12.577). Lower iron levels were associated with a higher prevalence of MAFLD (OR 0.622; 95% CI 0.458, 0.844) and liver fibrosis (OR 0.722; 95% CI 0.536, 0.974). Lower transferrin saturation (TSAT) was associated with a higher prevalence of MAFLD (OR 0.981; 95% CI 0.970, 0.991) and liver fibrosis (OR 0.988; 95% CI 0.979, 0.998). Higher ferritin levels, lower iron levels, and TSAT were associated with a higher prevalence of MAFLD and liver fibrosis. This study extended the knowledge of modifying iron status to prevent MAFLD and liver fibrosis. More prospective and mechanism studies were warranted to confirm the conclusions.

Associations between serum ferritin, iron, and liver transaminases in adolescents: a large cross-sectional study

Introduction

Introduction: few previous studies suggest that serum iron status may be associated with liver function, but the relevant evidence remains limited, especially in adolescents. Objective: we aimed to investigate the association between serum ferritin, iron, and liver transaminases in adolescents. Methods: a cross-sectional study including 3,404 adolescents aged 10-19 was performed based on the National Health and Nutrition Examination Survey. Weighted multivariate regression, subgroup analysis, and sensitivity analysis were used. Results: a total of 3,404 adolescents were eventually included. Serum ferritin and iron were positively correlated to alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The association between serum ferritin and ALT remained positive in all genders and races, but only remained positive in girls and several races between serum ferritin and AST. The positive correlations kept present among girls between serum iron and ALT, and also kept present among girls and non-Hispanic whites between serum iron and AST. Additionally, serum ferritin and iron were also positively correlated to elevated ALT and elevated AST using binary logistic regression analysis. After excluding the subjects with serum ferritin levels above the upper limit of normal, the main results remained the same basically. Conclusion: the present results add novel evidences about the associations between serum ferritin, iron, and liver transaminases, which requires more confirmatory studies.

Serum Ferritin and Non-alcoholic Fatty Liver Disease: A Meta-analysis and Systematic Review

BACKGROUND/AIMS

Previous studies have shown that hyperferritinemia is a common phenomenon in non-alcoholic fatty liver dis- ease patients. We aim to further explore the relationship between serum ferritin levels and non-alcoholic fatty liver disease using a meta-analysis.

MATERIALS AND METHODS

Four Library databases were electronically searched from inception until December 2021 to find prospective cohort or case-control studies examining the relationship between serum ferritin levels and non-alcoholic fatty liver disease, and all kinds of literature were screened according to the inclusion and exclusion criteria. The odds ratio and other related data were extracted, and a meta-analysis was performed.

RESULTS

Eleven studies examining the relationship between serum ferritin levels and non-alcoholic fatty liver disease were included. The serum ferritin levels in the non-alcoholic fatty liver disease group were significantly higher than those without non-alcoholic fatty liver disease group (1.54 ng/mL, 95% CI: 0.85-2.23, P < .001). Serum ferritin levels were significantly associated with the risk of non-alcoholic fatty liver disease in both men and women (odds ratio = 2.36, 95% CI: 1.41-3.93, P = .001 and odds ratio = 2.93, 95% CI: 1.83-4.69, P < .001, respectively), and after adjusting for the parameters, the relationships were still shown to be significant in men and women (odds ratio = 2.24, 95% CI: 1.64-3.05, P < .001 and odds ratio = 3.30, 95% CI: 2.13-5.11, P < .001, respectively).

CONCLUSION

Serum ferritin levels were higher in patients with non-alcoholic fatty liver disease than in those without non-alcoholic fatty liver disease and were associated with the risk of non-alcoholic fatty liver disease in both men and women.

Oxidative Stress and Lipid Peroxidation: Prospective Associations Between Ferroptosis and Delayed Wound Healing in Diabetic Ulcers

Diabetic ulcers are one of the major complications of diabetes, and patients usually suffer from amputation and death due to delayed ulcer wound healing. Persistent inflammation and oxidative stress at the wound site are the main manifestations of delayed wound healing in diabetic ulcers. In addition, chronic hyperglycemia in patients can lead to circulatory accumulation of lipid peroxidation products and impaired iron metabolism pathways leading to the presence of multiple free irons in plasma. Ferroptosis, a newly discovered form of cell death, is characterized by intracellular iron overload and accumulation of iron-dependent lipid peroxides. These indicate that ferroptosis is one of the potential mechanisms of delayed wound healing in diabetic ulcers and will hopefully be a novel therapeutic target for delayed wound healing in diabetic patients. This review explored the pathogenesis of diabetic ulcer wound healing, reveals that oxidative stress and lipid peroxidation are common pathological mechanisms of ferroptosis and delayed wound healing in diabetic ulcers. Based on strong evidence, it is speculated that ferroptosis and diabetic ulcers are closely related, and have value of in-depth research. We attempted to clarify prospective associations between ferroptosis and diabetic ulcers in terms of GPX4, iron overload, ferroptosis inhibitors, AGEs, and HO-1, to provide new ideas for exploring the clinical treatment of diabetic ulcers.

Non-invasive methods for iron overload evaluation in dysmetabolic patients

INTRODUCTION

Although hyperferritinemia may reflect the inflammatory status of patients with non-alcoholic fatty liver disease (NAFLD), approximately 33% of hyperferritinemia cases reflect real hepatic iron overload.

AIM

To evaluate a non-invasive method for assessing mild iron overload in patients with NAFLD using 3T magnetic resonance imaging (MRI) relaxometry, serum hepcidin, and the expression of ferritin subunits.

METHODS

This cross-sectional study assessed patients with biopsy-proven NAFLD. MRI relaxometry was performed using a 3T scanner in all patients, and the results were compared with iron content determined by liver biopsy. Ferritin, hepcidin, and ferritin subunits were assessed and classified according to ferritin levels and to siderosis identified by liver biopsy.

RESULTS

A total of 67 patients with NAFLD were included in the study. MRI revealed mild iron overload in all patients (sensitivity, 73.5%; specificity, 70%). For mild (grade 1) siderosis, the transverse relaxation rate (R₂*) threshold was 58.9 s^-1 and the mean value was 72.5 s^-1 (SD, 33.9), while for grades 2/3 it was 88.2 s^-1 (SD, 31.9) (p < 0.001). The hepcidin threshold for siderosis was > 30.2 ng/mL (sensitivity, 87%; specificity, 82%). Ferritin H and ferritin L subunits were expressed similarly in patients with NAFLD, regardless of siderosis. There were no significant differences in laboratory test results between the groups, including glucose parameters and liver function tests.

CONCLUSIONS

MRI relaxometry and serum hepcidin accurately assessed mild iron overload in patients with dysmetabolic iron overload syndrome.

The association between non-alcoholic fatty liver disease and serum ferritin levels in American adults

BACKGROUND

Elevated serum ferritin levels (SFLs) was previously reported to be related with hepatic histologic severity and advanced liver fibrosis among non-alcoholic fatty liver disease (NAFLD) patients. However, whether NAFLD influences SFLs remains uncertain and needs more clinical evidences. This study explored the differences of SFLs in US adults with or without NAFLD.

METHODS

We conducted a cross-sectional study of 3689 participants aged 18-80 years using the National Health and Nutrition Examination Survey (NHANES) 2017-2018 cycle. NAFLD status was confirmed based on controlled attenuation parameter (CAP) values ≥274 dB/m through vibration controlled and transient elastography (VCTE). We performed weighted multivariable logistic regression models to evaluate the associations between NAFLD and SFLs in different age and gender.

RESULTS

There was a positive association between NAFLD and SFLs in all three models (model 1:β = 23.07, 95% CI: 10.32, 35.81; model 2:β = 23.68, 95% CI: 10.86, 36.50; model 3:β = 13.86, 95% CI: 0.29, 27.43). After adjusting for the covariates, this positive association persisted in females (β = 16.22, 95% CI: 2.81, 29.62). Further, relationships between NAFLD and SFLs were significantly different in various age groups. In the subgroup stratified by gender, their associations further differed. In males, the positive association was more prominent in 50-64 age group (β = 70.89, 95% CI: 25.14, 116.64). In females, this positive association was more prominent in 18-34 age group (β = 20.72, 95% CI: 7.45, 33.99). However, no correlations between severe steatosis, significant fibrosis, advanced fibrosis, cirrhosis, and SFLs in adults with NAFLD were found.

CONCLUSION

This study indicated that US adults suffered with NAFLD had significantly higher SFLs compared with their counterparts in non-NAFLD group. Moreover, the associations between NAFLD and SFLs further differed by age and gender.

Determinants of hyperglucagonemia in pediatric non-alcoholic fatty liver disease

OBJECTIVE

Over the years, non-alcoholic fatty liver (NAFLD) disease has progressed to become the most frequent chronic liver disease in children and adolescents. The full pathology is not yet known, but disease progression leads to cirrhosis and hepatocellular carcinoma. Risk factors included hypercaloric diet, obesity, insulin resistance and genetics. Hyperglucagonemia appears to be a pathophysiological consequence of hepatic steatosis, thus, the hypothesis of the study is that hepatic fat accumulation leads to increased insulin resistance and impaired glucagon metabolism leading to hyperglucagonemia in pediatric NAFLD.

METHODS

132 children and adolescents between 10 and 18 years, with varying degrees of obesity, were included in the study. Using Magnetic Resonance Imaging (MRI) average liver fat was determined, and patients were stratified as NAFLD (>5% liver fat content) and non-NAFLD (<5%). All patients underwent a standardized oral glucose tolerance test (OGTT). Additionally, anthropometric parameters (height, weight, BMI, waist circumference, hip circumference) such as lab data including lipid profile (triglycerides, HDL, LDL), liver function parameters (ALT, AST), uric acid, glucose metabolism (fasting insulin and glucagon, HbA1c, glucose 120 min) and indices evaluating insulin resistance (HIRI, SPISE, HOMA-IR, WBISI) were measured.

RESULTS

Children and adolescents with NAFLD had significantly higher fasting glucagon values compared to the non-NAFLD cohort (p=0.0079). In the NAFLD cohort univariate analysis of fasting glucagon was associated with BMI-SDS (p<0.01), visceral adipose tissue volume (VAT) (p<0.001), average liver fat content (p<0.001), fasting insulin concentration (p<0.001), triglycerides (p<0.001) and HDL (p=0.034). This correlation equally applied to all insulin indices HOMA-IR, WBISI, HIRI (all p<0.001) and SPISE (p<0.002). Multivariate analysis (R² adjusted 0.509) for the same subgroup identified HIRI (p=0.003) and VAT volume (p=0.017) as the best predictors for hyperglucagonemia. Average liver fat content is predictive in pediatric overweight and obesity but not NAFLD.

CONCLUSIONS

Children and adolescents with NAFLD have significantly higher fasting plasma glucagon values, which were best predicted by hepatic insulin resistance and visceral adipose tissue, but not average liver fat content.

Genetic Support of A Causal Relationship Between Iron Status and Type 2 Diabetes: A Mendelian Randomization Study

CONTEXT

Iron overload is a known risk factor for type 2 diabetes (T2D); however, iron overload and iron deficiency have both been associated with metabolic disorders in observational studies.

OBJECTIVE

Using mendelian randomization (MR), we assessed how genetically predicted systemic iron status affected T2D risk.

METHODS

A 2-sample MR analysis was used to obtain a causal estimate. We selected genetic variants strongly associated (P < 5 × 10-8) with 4 biomarkers of systemic iron status from a study involving 48 972 individuals performed by the Genetics of Iron Status consortium and applied these biomarkers to the T2D case-control study (74 124 cases and 824 006 controls) performed by the Diabetes Genetics Replication and Meta-analysis consortium. The simple median, weighted median, MR-Egger, MR analysis using mixture-model, weighted allele scores, and MR based on a Bayesian model averaging approaches were used for the sensitivity analysis.

RESULTS

Genetically instrumented serum iron (odds ratio [OR]: 1.07; 95% CI, 1.02-1.12), ferritin (OR: 1.19; 95% CI, 1.08-1.32), and transferrin saturation (OR: 1.06; 95% CI, 1.02-1.09) were positively associated with T2D. In contrast, genetically instrumented transferrin, a marker of reduced iron status, was inversely associated with T2D (OR: 0.91; 95% CI, 0.87-0.96).

CONCLUSION

Genetic evidence supports a causal link between increased systemic iron status and increased T2D risk. Further studies involving various ethnic backgrounds based on individual-level data and studies regarding the underlying mechanism are warranted for reducing the risk of T2D.

Vitamin D decreases pancreatic iron overload in type 2 diabetes through the NF-κB-DMT1 pathway

Emerging evidence has deemed vitamin D as a potential candidate for the intervention of type 2 diabetes (T2D). Herein, we explored the underlying mechanisms of T2D prevention by vitamin D, concentrating on pancreatic iron deposition reported recently. Zucker diabetic fatty (ZDF) rats were treated by vitamin D, with age-matched Zucker lean rats as control. As expected, vitamin D treatment for ZDF rats normalized islet morphology and β-cell function. Moreover, vitamin D alleviated iron accumulation and apoptosis in pancreatic cells of ZDF rats, accompanied by lowered divalent metal transporter 1 (DMT1) expression. Consistently, similar results were observed in high glucose-stimulated INS-1 cells treated with or without vitamin D. Nuclear factor-κB (NF-κB), a transcription factor involving DMT1 regulation, was activated in pancreases of ZDF rats and INS-1 cells exposed to high glucose, but inactivated by vitamin D or BAY 11-7082, a NF-κB inhibitor. Futhermore, IL-1β functioning as NF-κB activator abolished the suppression of NF-κB activation, DMT1 induction and the attenuation of apoptosis as a consequence of vitamin D incubation. Our study showed that iron overload in pancreas may contribute to T2D pathogenesis and uncovered a potentially protective role for vitamin D on iron deposition of diabetic pancreas through NF-κB- DMT1 signaling.

H. Shehada A, Abdelnasser AbouHassanein E, Moawad J, Bawadi H, Shi Z. Association between central obesity indices and iron status indicators among Qatari adults

Co-existence of iron deficiency and obesity in adults has been reported in many countries. However, little is known on the association between obesity and iron deficiency in Qatar. This study aimed to investigate the link between abdominal obesity indices and iron status among adults in Qatar. A random sample of 1000 healthy Qatari adults, aged 20-50 years, was obtained from Qatar Biobank study. Body weight, waist circumference, dual x-ray absorptiometry (DXA) parameters and iron status indicators were measured using standard techniques. Multiple regression analysis was used to examine the associations. The prevalence of iron deficiency and anaemia were 35.4 and 25%, respectively. Of the participants with a large waist circumference, 31.7% had anaemia. Ferritin significantly increased with the increase in the android fat to gynoid fat ratio and visceral fat in both genders. Serum iron and transferring saturation decreased significantly with the increase in waist circumference in women. In both genders, C-reactive protein increased with the increase in all obesity indices. Standardized values of waist circumference, android fat, gynoid fat ratio and visceral fat were significantly associated with log transformed ferritin in men and women. Waist circumference was inversely related to serum iron (β:-0.95, 95% CI:-1.50,-0.39) and transferrin saturation (β:-1.45, 95%CI:-2.46, -0.43) in women. In men, waist circumference was positively associated with haemoglobin level (β: 0.16, 95% CI:0.04, 0.29). Central obesity coexists with anaemia among the study population. Elevated central obesity indices were associated with an increase in ferritin concentration. The increased ferritin concentration may be attributed to the increase in inflammatory status as a result of an increase in c-reactive protein concentration associated with central obesity.

The relationship between pancreas steatosis and the risk of metabolic syndrome and insulin resistance in Chinese adolescents with concurrent obesity and non-alcoholic fatty liver disease

BACKGROUND

The incidence of childhood obesity and associated comorbidities are on an increasing trend worldwide. More than 340 million children and adolescents aged between 5 and 19 years old were overweight or had obesity in 2016, from which over 124 million children and adolescents (6% of girls and 8% of boys) had obesity.

OBJECTIVE

To describe the relationship between pancreas steatosis, body fat and the risk of metabolic syndrome, insulin resistance in Hong Kong Chinese adolescents with both obesity and non-alcoholic fatty liver disease (NAFLD).

METHODS

Fifty two adolescents with obesity and NAFLD were analysed (14-18 years), stratified into fatty and non-fatty pancreas groups using chemical shift encoded MRI-pancreas proton density fat fraction ≥5%. Pancreatic, abdominal subcutaneous adipose tissue (SAT)/visceral adipose tissue (VAT) volumes, biochemical and anthropometric parameters were measured. Mann-Whitney U test, multiple linear/binary logistic regression analyses and odds ratios were used.

RESULTS

Fifty percent had fatty pancreas, 38% had metabolic syndrome and 81% had insulin resistance. Liver proton density fat fraction (PDFF) and VAT were independent predictors of insulin resistance (P = .006, .016). Pancreas and liver PDFF were both independent predictors of beta cells dysfunction (P = .015, .050) and metabolic syndrome (P = .021, .041). Presence of fatty pancreas in obesity was associated with insulin resistance (OR = 1.58, 95% CI = 0.39-6.4) and metabolic syndrome (OR = 1.70, 95% CI = 0.53-5.5).

CONCLUSION

A significant causal relationship exists between fatty pancreas, fatty liver, body fat and the risk of developing metabolic syndrome and insulin resistance.

KEY POINTS

Fatty pancreas is a common finding in adolescents with obesity, with a prevalence rate of 50% in this study cohort. Liver PDFF and VAT are independent predictors of insulin resistance while pancreas PDFF and liver PDFF are independent predictors of both beta cells dysfunction and metabolic syndrome. Presence of fatty pancreas at imaging should not be considered as a benign finding but rather as an imaging biomarker of emerging pancreatic metabolic and endocrine dysfunction.

Dysregulated Iron Metabolism-Associated Dietary Pattern Predicts an Altered Body Composition and Metabolic Syndrome

Diet plays an important role in the development of obesity and may contribute to dysregulated iron metabolism (DIM). A cross-sectional survey of 208 adults was conducted in Taipei Medical University Hospital (Taipei, Taiwan). A reduced-rank regression from 31 food groups was used for a dietary pattern analysis. DIM was defined as at least four of the following criteria: serum hepcidin (men >200 ng/mL and women >140 ng/mL), hyperferritinemia (serum ferritin of >300 ng/mL in men and >200 ng/mL in women), central obesity, non-alcoholic fatty liver disease, and two or more abnormal metabolic profiles. Compared to non-DIM patients, DIM patients were associated with an altered body composition and had a 4.52-fold (95% confidence interval (CI): (1.95–10.49); p < 0.001) greater risk of metabolic syndrome (MetS) after adjusting for covariates. A DIM-associated dietary pattern (high intake of deep-fried food, processed meats, chicken, pork, eating out, coffee, and animal fat/skin but low intake of steamed/boiled/raw foods and dairy products) independently predicted central obesity (odds ratio (OR): 1.57; 95% CI: 1.05–2.34; p < 0.05) and MetS (OR: 1.89; 95% CI: 1.07–3.35; p < 0.05). Individuals with the highest DIM pattern scores (tertile 3) had a higher visceral fat mass (%) (β = 0.232; 95% CI: 0.011–0.453; p < 0.05) but lower skeletal muscle mass (%) (β = −1.208; 95% CI: −2.177–−0.239; p < 0.05) compared to those with the lowest DIM pattern scores (tertile 1). In conclusion, a high score for the identified DIM-associated dietary pattern was associated with an unhealthier body composition and a higher risk of MetS.

Hepatic Insulin Extraction in NAFLD Is Related to Insulin Resistance Rather Than Liver Fat Content

CONTEXT

Total insulin clearance is decreased in nonalcoholic fatty liver disease (NAFLD), but the relationship between liver fat and hepatic insulin extraction (HIE) is unknown.

OBJECTIVE

This cross-sectional study addresses the hypothesis that HIE is reduced in NAFLD and investigates metabolic and/or anthropometric characteristics most closely associated with insulin clearance.

PARTICIPANTS

Nondiabetic subjects with NAFLD (n = 13) and age- and body mass index (BMI)-matched controls with normal liver enzymes (n = 15) underwent abdominal CT, dual-energy X-ray absorptiometry, oral glucose tolerance test (OGTT), and labeled two-step hyperinsulinemic-euglycemic clamps.

OUTCOME MEASUREMENTS

Liver fat was estimated by the CT liver/spleen ratio. Hepatic and extrahepatic insulin clearances were modeled using clamp and OGTT data.

RESULTS

Extrahepatic insulin clearance and HIE were not different between NAFLD and controls and did not correlate with liver fat. HIE was positively correlated with insulin sensitivity [rate of glucose disposal (Rd; low r = +0.7, P < 0.001; high r = +0.6, P = 0.001), adiponectin (r = +0.55, P = 0.004), and insulin-mediated suppression of clamp nonesterified free fatty acid (NEFA; r = +0.67, P < 0.001)] but was not associated with fasting NEFA, insulin-mediated suppression of glucose production, or measures of adiposity. Extrahepatic insulin clearance was positively associated with percent body fat (r = +0.44, P = 0.02) and subcutaneous fat (r = +0.42, P = 0.03) but not BMI, intra-abdominal fat, liver fat, Rd, adiponectin, or NEFA.

CONCLUSIONS

HIE is not directly associated with hepatic steatosis but is associated with muscle and adipose tissue insulin resistance. The data suggest differential regulation of insulin clearance with extrahepatic insulin clearance being associated with body fat and not insulin sensitivity.

Association of serum ferritin levels with non-alcoholic fatty liver disease in postmenopausal women

OBJECTIVE

This study aimed to investigate the association between serum ferritin levels and the presence of non-alcoholic fatty liver disease (NAFLD) in postmenopausal women.

METHODS

Two hundred and forty-one postmenopausal women who participated in a heath examination program were enrolled in the present study. Serum ferritin tertiles were categorized as follows: T1, ≤46.4 ng/ml; T2, 46.5-76.1 ng/ml; and T3, ≥76.2 ng/ml. The odds ratios (ORs) and 95% confidence intervals (CIs) for NAFLD were calculated after adjusting for confounding variables across serum ferritin tertiles using multiple logistic regression analysis.

RESULTS

The overall prevalence of NAFLD was 41.4% and was significantly increased in accordance with the serum ferritin tertiles as follows: 30.0% for T1, 40.7% for T2, and 54.3% for T3, respectively. As compared with the lowest tertile, the OR (95% CI) for NAFLD in the highest tertile was 2.69 (1.16-5.28) after adjusting for age, body mass index, regular exercise, mean arterial pressure, fasting plasma glucose, triglyceride, high-density lipoprotein cholesterol, alanine aminotransferase, and leukocyte count.

CONCLUSION

The serum ferritin level was positively and independently associated with NAFLD in postmenopausal women and could be a useful additional measure in assessing the risk of NAFLD in postmenopausal women.

Altered microRNA-9 Expression Level is Directly Correlated with Pathogenesis of Nonalcoholic Fatty Liver Disease by Targeting Onecut2 and SIRT1

Background

MicroRNA-9 (miR-9) was detected in nonalcoholic fatty liver disease (NAFLD) patients to understand the role of miR-9 in NAFLD development.

Material/Methods

Between February 2014 and February 2015, 105 cases of NAFLD were recruited and confirmed by liver biopsy pathology, including patients with mild NAFLD (n=58) and moderate-severe NAFLD (n=47); nonalcoholic steatohepatitis (NASH) (n=53) and non-NASH (n=52); and 50 healthy participants were regarded as the healthy control group. MiR-9 expression was measured by qRT-PCR. For in vitro experiments, L-02 normal liver cells were divided into normal control group (cultured with original culture medium), dimethyl sulfoxide (DMSO) group (cultured with DMSO) and oleic acid group (cultured with oleic acid to induce fatty change), and MTT assay was used to measure the effect of different oleic acid concentrations on cell proliferation. Nile red staining was used to detect intracellular accumulation of lipid droplets. Further, synthetic miR-9 mimic and its control and miR-9 inhibitors and its control were independently transfected into L-02 cells.

Results

MiR-9 levels in the mild NAFLD group and moderate-severe NAFLD group were significantly higher than in the healthy control group (both P<0.05). Mean fluorescence intensity of lipid droplets increased with the duration of induction, and were dramatically higher in oleate-treated L-02 cells; intracellular triglyceride (TG) content was also higher. miR-9 levels significantly increased following oleate induction. Importantly, miR-9 levels were significantly elevated upon miR-9 mimic transfection. Conversely, miR-9 level was lowered with miR-9 inhibitors transfection. Additionally, Onecut2 and SIRT1 were identified as miR-9 targets.

Conclusions

A positive relationship between miR-9 and steatosis was established with our results that miR-9 mimic transfection decreased intracellular lipid content. Finally, we identified 2 miR-9 targets, Onecut2 and SIRT1, which may be crucial players in NAFLD development.

Serum ferritin levels predict histological severity in patients with nonalcoholic fatty liver disease in India

AIM

The aims of the study were to determine the levels of serum ferritin which predict fibrosis in Indian patients with nonalcoholic fatty liver disease (NAFLD) and to establish correlation between Fibroscan values and serum ferritin levels.

METHODS

The clinical, biochemical, radiologic, and histological findings of consecutive adult NAFLD patients accessed at a tertiary care center over a 3-year period were analyzed. Those with concurrent liver diseases were excluded. Fifty-five of 250 NAFLD patients with fatty liver on ultrasound and raised enzymes (>40 IU/L) underwent liver biopsy. Patients were stratified into two groups based on their histological stage steatosis (with or without inflammation) but no fibrosis and nonalcoholic steatohepatitis (NASH) with fibrosis/cirrhosis. Serum ferritin levels were measured at the same time as getting liver biopsy. Fibroscan was carried out in each of these patients. These were compared with 50 age- and sex-matched controls with normal ultrasound, liver enzymes, and no history of alcohol. Student's t test was used as the test for significance.

RESULTS

Fifty-five NAFLD patients diagnosed on ultrasound and with raised enzymes underwent biopsy. Steatosis (with or without inflammation, but no fibrosis/ballooning) was seen in 35 patients, fibrosis/ballooning in 14 patients, and cirrhosis in 6 patients. Mean ferritin levels in groups with nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH) were 39.4 and 72.7 ng/mL, respectively (p < 0.001). The mean ferritin levels in NAFLD and controls were 51.2 and 35.2 ng/mL, respectively (p < 0.05). The area under the curve (AUC) of serum ferritin at value 48.0 ng/mL was 0.779. The coefficient of correlation between Fibroscan and serum ferritin levels was 0.9864 while that with alanine transaminase and aspartate aminotransferase was 0.69. Serum ferritin at the cutoff of 48 ng/mL differentiated significantly patients with fibrosis and higher Fibroscan levels.

CONCLUSION

Serum ferritin was low in Indian individuals, and levels even within apparently normal range indicated fibrosis and cirrhosis. A cutoff level of 48.0 IU/mL distinguished fibrosis in NAFLD. Fibroscan correlated well with serum ferritin levels.

Pleiotropic actions of iron balance in diabetes mellitus

As an essential element, iron plays a central role in many physiological processes, including redox balance, inflammation, energy metabolism, and environment sensing. Perturbations in iron homeostasis are associated with several conditions, including hyperglycemia and diabetes, both of which have been studied in patients and animal models. To clarify the pleiotropic role of iron homeostasis in diabetes development, the early studies on diseases with iron-overload, studies on clinical iron depletion therapies, associations between iron-related genetic polymorphisms and diabetes, and etiological mechanisms underlying iron perturbations-impaired insulin secretion and insulin sensitivity were carefully reviewed and discussed. Hereditary hemochromatosis, transfusion-dependent thalassemia, and excess heme iron intake can increase the risk of developing diabetes. Genetically modified mice and mice fed a high-iron diet present with discrepant phenotypes due to differences in tissue iron distribution. Moreover, several genetic polymorphisms related to iron homeostasis have been associated with the risk of developing diabetes. Tightly controlled iron metabolism is essential for insulin secretion and insulin sensitivity, and iron overload in pancreatic islets alters reactive oxygen species (ROS) generation, as well as hypoxia-inducible factor-1α (HIF-1α) stability and adenosine triphosphate (ATP) synthesis, thereby impairing the function and viability of β-cells. Decreased levels of adiponectin, macrophage-mediated inflammation, and ROS-mediated liver kinase B1 (LKB1)/adenosine monophosphate-activated protein kinase (AMPK) activation can contribute to iron overload-induced insulin resistance, whereas iron deficiency could also participate in obesity-related inflammation, hypoxia, and insulin resistance. Because iron homeostasis is closely correlated with many metabolic processes, future studies are needed in order to elucidate the finely tuned network among iron homeostasis, carbohydrate and lipid metabolism, inflammation, and hypoxia.

The clinical significance of serum ferritin in pediatric non-alcoholic Fatty liver disease

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) in children has become an important public health issue because of its high prevalence and severity. Several noninvasive methods for estimating NAFLD are under investigation. We aimed to evaluate the usefulness of serum ferritin as a biomarker of severity of pediatric NAFLD patients.

METHODS

A total of 64 NAFLD patient were enrolled from Severance Children's Hospital from March 2010 to February 2013. Serum ferritin levels, liver related laboratory tests, liver magnetic resonance imaging (MRI) (2-dimensional [2D] proton density-fat fraction) and NAFLD severity markers were compared between obese group and overweight group. Correlation analyses were performed between serum ferritin and laboratory values including NAFLD severity markers.

RESULTS

In obese group, serum ferritin, alanine aminotransferase (ALT), total bilirubin, international normalized ratio (INR), MRI 2D proton density-fat fraction, aspartate aminotransferase (AST) to platelet ratio index (APRI) and fibrosis-4 (FIB-4) (an index score calculated from platelet count, ALT, AST and age) were significantly higher than those of overweight group. NAFLD severity markers, APRI and FIB-4, and liver specific important laboratory values, AST, ALT, INR, cholesterol, triglyceride and low density lipoprotein show significant correlation with serum ferritin in NAFLD patients.

CONCLUSION

Serum ferritin concentrations could be a candidate of useful severity marker in the pediatric NAFLD patients.

Serum ferritin is an important inflammatory disease marker, as it is mainly a leakage product from damaged cells

"Serum ferritin" presents a paradox, as the iron storage protein ferritin is not synthesised in serum yet is to be found there. Serum ferritin is also a well known inflammatory marker, but it is unclear whether serum ferritin reflects or causes inflammation, or whether it is involved in an inflammatory cycle. We argue here that serum ferritin arises from damaged cells, and is thus a marker of cellular damage. The protein in serum ferritin is considered benign, but it has lost (i.e. dumped) most of its normal complement of iron which when unliganded is highly toxic. The facts that serum ferritin levels can correlate with both disease and with body iron stores are thus expected on simple chemical kinetic grounds. Serum ferritin levels also correlate with other phenotypic readouts such as erythrocyte morphology. Overall, this systems approach serves to explain a number of apparent paradoxes of serum ferritin, including (i) why it correlates with biomarkers of cell damage, (ii) why it correlates with biomarkers of hydroxyl radical formation (and oxidative stress) and (iii) therefore why it correlates with the presence and/or severity of numerous diseases. This leads to suggestions for how one might exploit the corollaries of the recognition that serum ferritin levels mainly represent a consequence of cell stress and damage.