The Relationship between Serum Ferritin and Insulin Resistance in Different Glucose Metabolism in Nonobese Han Adults

Adipose knockout of H-ferritin improves energy metabolism in mice

OBJECTIVE

Ferritin, the principal iron storage protein, is essential to iron homeostasis. How iron homeostasis affects the adipose tissue is not well understood. We investigated the role of ferritin heavy chain in adipocytes in energy metabolism.

METHODS

We generated adipocyte-specific ferritin heavy chain (Fth, also known as Fth1) knockout mice, herein referred to as FthAKO. These mice were analyzed for iron homeostasis, oxidative stress, mitochondrial biogenesis and activity, adaptive thermogenesis, insulin sensitivity, and metabolic measurements. Mouse embryonic fibroblasts and primary mouse adipocytes were used for in vitro experiments.

RESULTS

In FthAKO mice, the adipose iron homeostasis was disrupted, accompanied by elevated expression of adipokines, dramatically induced heme oxygenase 1(Hmox1) expression, and a notable decrease in the mitochondrial ROS level. Cytosolic ROS elevation in the adipose tissue of FthAKO mice was very mild, and we only observed this in the brown adipose tissue (BAT) but not in the white adipose tissue (WAT). FthAKO mice presented an altered metabolic profile and showed increased insulin sensitivity, glucose tolerance, and improved adaptive thermogenesis. Interestingly, loss of ferritin resulted in enhanced mitochondrial respiration capacity and a preference for lipid metabolism.

CONCLUSIONS

These findings indicate that ferritin in adipocytes is indispensable to intracellular iron homeostasis and regulates systemic lipid and glucose metabolism.

The association between triglyceride-glucose index and hyperferritinemia in patients with type 2 diabetes mellitus

PURPOSE

To investigate the relationship between the triglyceride-glucose (TyG) index and serum ferritin (SF) levels in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 881 T2DM patients were divided into T1(TyG index < 1.66), T2 (1.66 ≤ TyG index < 2.21), and T3 (TyG index ≥ 2.21) groups according to the tertiles of the TyG index. The differences in SF levels and the prevalence of hyperferritinemia (SF ≥ 300 ng/mL for male or SF ≥ 150 ng/mL for female) were compared. The independent correlations between the TyG index and SF, and between hyperferritinemia and TyG in T2DM patients were analyzed, respectively.

RESULTS

SF levels in male T2DM patients were higher in the T3 group (250.12 ng/mL) than in the T1 and T2 groups (180.45 and 196.56 ng/mL, both p < 0.01),while in female patients with T2DM,SF levels were higher in the T3 group (157.25 ng/mL) than in the T1 group (111.06 ng/mL, p < 0.05).The prevalence of hyperferritinemia in male T2DM patients was higher in the T3 group (31.3%) than those in the T1 and T2 groups (10.4% and 17.3%, both p < 0.05).The TyG index was positively correlated with SF levels in T2DM patients (R = 0.178, p < 0.001).TyG index was independently and positively correlated with SF levels after adjusting for confounders (β = 0.097, 95%CI [2.870,38.148], p = 0.023).The TyG index was positively independently correlated with hyperferritinemia in male T2DM patients (OR = 1.651, 95%CI [1.120,2.432], p = 0.011).

CONCLUSIONS

In parallel with increasing TyG index SF levels gradually increased. The TyG index was positively correlated with SF levels in patients with T2DM and was positively correlated with hyperferritinemia in male T2DM patients.

Evaluation of the relationship between serum ferritin and insulin resistance and visceral adiposity index (VAI) in women with polycystic ovary syndrome

PURPOSE

There is a relationship between polycystic ovary syndrome (PCOS) and adipose tissue dysfunction (ADD), but this relationship is not clear. It has been recently shown that iron accumulation in adipose tissue is among the causes of adipose tissue dysfunction. Data on adipose tissue dysfunction in women with PCOS are insufficient. In this study, we aimed to evaluate the relationship between serum ferritin levels (iron accumulation biomarker) and visceral adiposity index (an indicator of adipose tissue dysfunction).

METHODS

The study is a case-control study. Women with diagnosed PCOS with 2003 Rotterdam Diagnostic Criteria (n = 40) were compared with non-PCOS group (n = 40). In this study, the cholesterol ratios, the homeostatic model evaluation index for insulin resistance (HOMA-IR) and the quantitative insulin sensitivity control index were calculated using biochemical parameters, and the visceral adiposity index (VAI) and the lipid accumulation product (LAP) were calculated using both anthropometric and biochemical parameters. In this study, insulin resistance was evaluated by HOMA-IR and adipose tissue dysfunction was evaluated by VAI index.

RESULTS

According to the results of this study, women with PCOS have a worse metabolic status than women without PCOS. However, this has been shown only in overweight and obese women, not in women with normal weight.

CONCLUSION

As a result, the presence of obesity in women with PCOS exacerbates metabolic status.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Influence of ferritin levels and inflammatory markers on HbA1c in the Type 2 Diabetes mellitus patients

Objective:

Diabetes Mellitus (DM) is a significant public health issue worldwide due to the associated comorbidities. Recent studies have demonstrated a strong relationship between blood glucose levels and serum ferritin levels in patients with type 2 DM. The aim of the study was to investigate the association between Ferritin Levels and Inflammatory Markers on HbA1c in the Type 2 Diabetes Mellitus Patients.

Methods:

This single-center, cross-sectional, controlled study included patients who were admitted to the Endocrine and Metabolic Disorders outpatient clinics of the Private Kütahya Hospital in the province of Kutahya in the Western Turkey. The study included a total of 172 patients, 84 of whom had type 2 DM and 88 without diabetes and constituted the control group. A total of 190 patients with DM were admitted to the Adult Endocrine and Metabolic Diseases Outpatient Clinics of the hospital between July 1, 2018 and September 1, 2018, and among these, the study was conducted on 172 volunteer patients who met the study inclusion criteria and who did not have any missing data. The HbA1c levels, serum ferritin, hemoglobin (Hb), insulin, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), C-Reactive Protein (CRP), lipid profiles, and uric acid levels were compared between the groups.

Results:

The serum ferritin levels of the patients with type 2 DM significantly increased with increasing HbA1c levels (p<0.01). A strong positive correlation was found between serum ferritin levels and HbA1c and fasting blood glucose (FBG) levels (p<0.01).

Conclusions:

Our study results show a significant relationship between HbA1c levels and serum ferritin and CRP levels, suggesting that serum ferritin and CRP levels can be used as a routine screening tool for the early diagnosis of DM. However, further large-scale, prospective studies are needed to confirm these findings.

Gender difference in the relationship between the ferritin and homeostasis model assessment of insulin resistance in non-diabetic Korean adults

Background

The present study was conducted to assess gender difference in the relationship between the ferritin and homeostasis model assessment of insulin resistance (HOMA-IR) and beta cell function (HOMA-B) in non-diabetic Korean adults.

Materials and methods

A sample including 5,414 adults (2,279 men, 1,529 postmenopausal women, and 1,606 premenopausal women) aged ≥ 20 years from the fifth Korean National Health and Nutrition Examination Survey (KNHANES V-1, 2010) was analyzed.

Results

There were several key findings in the present study. First, in men, HOMA-IR (β = 0.119, 95% confidence interval [CI], 3.304 to 8.003) constituted the independent factor determining ferritin, but this was not the case for HOMA-B (β = -0.042, 95% CI, -0.100 to 0.011). Second, in postmenopausal women, HOMA-IR (β = 0.087, 95% CI, 0.899 to 5.238) was the independent factor determining ferritin, but this was not the case for HOMA-B (β = -0.043, 95% CI, -0.065 to 0.010). Third, in premenopausal women, neither HOMA-IR (β = -0.050, 95% CI, -3.056 to 0.364) nor HOMA-B (β = -0.009, 95% CI, -0.028 to 0.020) constituted the independent factors determining ferritin.

Conclusions

Ferritin was positively associated with insulin resistance in non-diabetic Korean men and postmenopausal women, but not in non-diabetic Korean premenopausal women.

Association of serum ferritin levels with metabolic syndrome and insulin resistance in a Chinese population

AIMS

Increased iron is associated with type 2 diabetes, dyslipidemia, and high blood pressure. Therefore, serum ferritin may be a suitable biomarker to detect metabolic syndrome (MetS). We investigated the relationship between serum ferritin, and the prevalence of MetS and insulin resistance (IR).

METHODS

This cross-sectional study assessed 2,786 Chinese participants, aged 25-75 years. MetS was defined using the 2006 International Diabetes Federation guidelines. IR was assessed with homeostasis model assessment estimated IR (HOMA-IR). Regression analysis was used to estimate the association between serum ferritin and the prevalence of MetS and IR.

RESULTS

MetS prevalence within each serum ferritin quartile (Q1-4) was 31.7%, 37.1%, 43.6%, and 55.4%, respectively in men (P<0.001), and 30.1%, 34.8%, 48.2%, and 66.9%, respectively in women (P<0.001). Increased serum ferritin correlated with the number of MetS components (P<0.001). The odds ratio for MetS in the ferritin Q4 group was 1.95 (1.39-2.73) for men and 1.66(1.12-2.47) for women, compared with Q1. Serum ferritin correlated positively with HOMA-IR in men (regression coefficient: 0.058, P=0.009) and women (regression coefficient: 0.082, P=0.001).

CONCLUSION

MetS prevalence increased with elevated serum ferritin levels, and serum ferritin levels were independently associated with MetS and IR.