Combined Associations of Serum Ferritin and Body Size Phenotypes With Cardiovascular Risk Profiles: A Chinese Population-Based Study

Serum ferritin associated with atherogenic lipid profiles in a high-altitude living general population

Background

Serum ferritin (SF) levels are associated with metabolic syndrome and dyslipidemia. However, the association between SF and atherogenic lipid profiles in high-altitude living populations remains unclear.

Methods

In 2021, a cross-sectional study was conducted on adult Tajik individuals residing in Tashkurgan Tajik Autonomous County (average altitude 3,100 meters). Demographic information and anthropometric measurements were collected in local clinics. Fasting blood samples were analyzed using a Beckman AU-680 Automatic Biochemical analyzer at the biochemical laboratory of Fuwai Hospital. Univariate linear regression analyses were used to explore the association between SF and atherogenic lipid levels. Subgroup analysis was used based on gender and different high-sensitivity C-reactive protein (hs-CRP) and serum amyloid A (SAA) levels. The association between higher SF quartiles and different kinds of dyslipidemia were analyzed by logistic regression.

Results

There were 1,703 participants in total, among which 866 (50.9%) being men. The mean ages of male and female participants were similar (41.50 vs. 42.38 years; P = 0.224). SF levels were significantly correlated with total cholesterol (TC) (Beta = 0.225, P < 0.001), low-density lipoprotein cholesterol (LDL-C) (Beta = 0.197, P < 0.001), high-density lipoprotein cholesterol (HDL-C) (Beta = -0.218, P < 0.001), triglycerides (TG) (Beta = 0.332, P < 0.001), and small dense LDL-C (sdLDL-C) (Beta = 0.316, P < 0.001), with the exception of lipoprotein (a) (Lp(a)) (Beta = 0.018, P = 0.475). SF was significantly correlated with LDL-C and HDL-C in women, and correlated with TC, TG, and sdLDL-C levels in both men and women in different inflammatory conditions. Elevated SF levels was significantly correlated with high TC (OR: 1.413, 95% CI [1.010-1.978]), high TG (OR: 1.602, 95% CI [1.299-1.976]), and high sdLDL-C (OR: 1.631, 95% CI [1.370-1.942]) in men and high TC (OR: 1.461, 95% CI [1.061-2.014]), high LDL-C (OR: 2.104, 95% CI [1.481-2.990]), low HDL-C (OR: 1.447, 95% CI [1.195-1.752]), high TG (OR: 2.106, 95% CI [1.454-3.050]), and high sdLDL-C (OR: 2.000, 95% CI [1.589-2.516]) in women. After adjusting for potential confounders, elevated SF levels continue to be correlated with high TG in male (OR: 1.382, 95% CI [1.100-1.737]) and female (OR: 1.677, 95% CI [1.070-2.628]) participants. In both young and middle-aged subgroups, the associations between SF and TG, TC, HDL-C, LDL-C, and sdLDL-C were still significant.

Conclusions

SF was closely related to atherogenic lipid profiles, especially with regard to TG in high-altitude populations. This association cannot be attributed to its role as an inflammation marker.

Serum Ferritin Levels and Liver-Related Events in Individuals With Steatotic Liver Disease: A Longitudinal Cohort Study

BACKGROUND

Serum ferritin has been suggested as a potential biomarker associated with disease progression in metabolic dysfunction-associated steatotic liver disease (MASLD).

AIMS

We investigated the association between serum ferritin levels and liver-related events (LREs) in individuals with steatotic liver disease (SLD).

METHODS

This cohort study included 17,560 adults with SLD (MASLD [n = 15,744], MASLD with increased alcohol intake (MetALD) [n = 1103] and cryptogenic SLD [n = 713]) without LRE at baseline. A steatotic liver was diagnosed using ultrasound, and LRE was defined as the development of decompensation (ascites, variceal bleeding and hepatic encephalopathy) or hepatocellular carcinoma. Participants were categorised into high (≥ 300 μg/L for males, ≥ 200 μg/L for females) or normal to low (< 300 μg/L for males, < 200 μg/L for females) ferritin levels.

RESULTS

During 211,425 person-years of follow-up (median: 12.3 years), 74 incident LRE cases were identified, with 63 cases in MASLD, 10 in MetALD and 1 in cryptogenic SLD. The multivariable-adjusted hazard ratio (aHR) for LRE comparing individuals with high and normal-to-low ferritin level was 3.13 (95% confidence interval [CI] 1.89-5.18). Increased risk of LRE in individuals with high serum ferritin level compared to those with normal to low serum ferritin level was consistent across SLD subtypes (aHR 2.69, 95% CI 1.55-4.67 for MASLD; aHR 5.73, 95% CI 1.31-25.0 for MetALD), and SLD severity assessed by Fibrosis-4 (FIB-4) index (aHR 2.38, 95% CI 1.34-4.21 for FIB-4 ≥ 1.3; aHR 3.13, 95% CI 1.18-8.29 for FIB-4 < 1.3).

CONCLUSIONS

Serum ferritin levels correlated with the risk of LRE in patients with SLD.

New Perspectives on Circulating Ferritin: Its Role in Health and Disease

The diagnosis of iron disturbances usually includes the evaluation of serum parameters. Serum iron is assumed to be entirely bound to transferrin, and transferrin saturation-the ratio between the serum iron concentration and serum transferrin-usually reflects iron availability. Additionally, serum ferritin is commonly used as a surrogate of tissue iron levels. Low serum ferritin values are interpreted as a sign of iron deficiency, and high values are the main indicator of pathological iron overload. However, in situations of inflammation, serum ferritin levels may be very high, independently of tissue iron levels. This presents a particularly puzzling challenge for the clinician evaluating the overall iron status of the patient in the presence of an inflammatory condition. The increase in serum ferritin during inflammation is one of the enigmas regarding iron metabolism. Neither the origin, the mechanism of release, nor the effects of serum ferritin are known. The use of serum ferritin as a biomarker of disease has been rising, and it has become increasingly diverse, but whether or not it contributes to controlling the disease or host pathology, and how it would do it, are important, open questions. These will be discussed here, where we spotlight circulating ferritin and revise the recent clinical and preclinical data regarding its role in health and disease.

Consensus Statement on the definition and classification of metabolic hyperferritinaemia

Hyperferritinaemia is a common laboratory finding that is often associated with metabolic dysfunction and fatty liver. Metabolic hyperferritinaemia reflects alterations in iron metabolism that facilitate iron accumulation in the body and is associated with an increased risk of cardiometabolic and liver diseases. Genetic variants that modulate iron homeostasis and tissue levels of iron are the main determinants of serum levels of ferritin in individuals with metabolic dysfunction, raising the hypothesis that iron accumulation might be implicated in the pathogenesis of insulin resistance and the related organ damage. However, validated criteria for the non-invasive diagnosis of metabolic hyperferritinaemia and the staging of iron overload are still lacking, and there is no clear evidence of a benefit for iron depletion therapy. Here, we provide an overview of the literature on the relationship between hyperferritinaemia and iron accumulation in individuals with metabolic dysfunction, and on the associated clinical outcomes. We propose an updated definition and a provisional staging system for metabolic hyperferritinaemia, which has been agreed on by a multidisciplinary global panel of expert researchers. The goal is to foster studies into the epidemiology, genetics, pathophysiology, clinical relevance and treatment of metabolic hyperferritinaemia, for which we provide suggestions on the main unmet needs, optimal design and clinically relevant outcomes.

Relationship between Serum Ferritin Level and Dyslipidemia in US Adults Based on Data from the National Health and Nutrition Examination Surveys 2017 to 2020

Previous research has suggested that high serum ferritin (SF) levels may be associated with dyslipidemia. This study investigated the association between SF levels and dyslipidemia in American adults, which held relevance for both clinical and public health areas concerned with screening and prevention. Data from the pre-pandemic National Health and Nutrition Examination Surveys (NHANES), conducted between 2017 and 2020, were utilized for this analysis. Multivariate linear regression models were used to explore the correlation between lipid and SF concentrations, and the connection between SF and the four types of dyslipidemia was further assessed by using multivariate logistic regression analysis. Odds ratios (ORs; 95% CI) for dyslipidemia were calculated for quartiles of SF concentrations, with the lowest ferritin quartile as the reference. The final subjects consisted of 2676 participants (1290 males and 1386 females). ORs for dyslipidemia were the highest in the fourth quartile (Q4) of SF both in males (OR: 1.60, 95% CI: 1.12-2.28) and females (OR: 1.52, 95% CI: 1.07-2.17). The crude ORs (95% CI) for the risk of High TC and High LDL-C increased progressively in both genders. However, after adjusting for covariates, the trend of significance was only present in females. Finally, the association between total daily iron intake and the four types of dyslipidemia was examined, revealing that the risk of High TG in the third quartile of the total daily iron intake was 2.16 times greater in females (adjusted OR: 3.16, 95% CI: 1.38-7.23). SF concentrations were remarkably associated with dyslipidemia. In females, daily dietary iron intake was associated with High-TG dyslipidemia.

The effect of sodium-glucose cotransporter 2 inhibitors on biomarkers of inflammation: A systematic review and meta-analysis of randomized controlled trials

Aims: Inflammatory biomarkers may play vital roles in the pathophysiology of diabetes and diabetic cardiorenal complications. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have a potential cardiovascular and renal protective effect in type 2 diabetes. The aim of this meta-analysis was to quantify the effects of SGLT2 inhibitors on biomarkers of inflammation in randomized controlled trials (RCTs). Methods: PubMed, Cochrane Library, EMBASE, and Web of Science were searched for eligible RCTs of adults with type 2 diabetes (T2D) with no time limit (updated to 12 October 2022). The biomarkers selected included C-reactive protein (CRP), interleukin-6, tumor necrosis factor-alpha, leptin, adiponectin, ferritin, plasminogen activator inhibitor (PAI)-1, and vascular cell adhesion molecule-1. Data were analyzed using a random-effect model in Review Manager 5.4. Results: Thirty-four studies with 6,261 patients (68.6% male) were eligible for this meta-analysis. The mean age of the participants was 62.57(±11.13) years old, and the median treatment duration length with follow-up was 24 weeks. Generally, the included trials were of good methodological quality. The meta-analysis revealed that ferritin levels were significantly reduced in SGLT2 inhibitor treatment groups versus placebo or standard diabetes therapies (SMD: -1.21; 95% CI: -1.91, -0.52, p < 0.001). The effects of CRP (SMD: 0.25; 95% CI: -0.47, -0.03, p = 0.02) and leptin (SMD: -0.22; 95% CI: -0.43, -0.01, p = 0.04) were reduced, and the effects of adiponectin were improved (SMD: 0.28; 95% CI: 0.15, 0.41, p < 0.001) in placebo-controlled studies. PAI-1 levels were significantly reduced in studies controlled for diabetes therapies (SMD: -0.38; 95% CI: -0.61, -0.15, p = 0.001). Conclusion: This analysis provides strong evidence supporting anti-inflammatory effects of SGLT2 inhibitors in T2D subjects. The mechanisms and possible targets for the inflammation reducing and cardiorenal protective properties of SGLT2 inhibitors remain to be explored.