Dietary Iron Intake and New-Onset Hypertension: A Nationwide Cohort Study from China

Impact of multi-metal exposure on blood pressure: a mediation analysis through oxidative stress markers in China's Southern Jiangxi Province

Hypertension is a prevalent condition that contributes significantly to the global disease burden. Recent research endeavors have been investigating the potential causal link between metal exposure and the development of hypertension, yet consensus remains elusive. Nevertheless, studies examining the interplay among metal exposure, hypertension, and oxidative stress are relatively limited. This study utilized data from a cross-sectional survey conducted in southern Jiangxi Province, China. We evaluated urinary concentrations of 19 metals, including aluminum and manganese, in conjunction with measurements of systolic and diastolic blood pressures, as well as three oxidative stress biomarkers: glutathione peroxidase (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA). In the monometallic model, chromium, iron, manganese, and molybdenum exhibited positive correlations with blood pressure. These findings were consistent in the mixed exposure model. Conversely, all the aforementioned metals exhibited a negative correlation with GSH and SOD, while demonstrating a positive correlation with MDA. Mediation effect analysis revealed that GSH and SOD mediated the relationships between urinary concentrations of aluminum, iron, manganese, and antimony and blood pressure. In contrast, MDA mediated the associations between urinary silver and antimony and blood pressure. Furthermore, GSH and SOD were identified as mediators in part of the relationship between mixed metal exposure and blood pressure, with mediation rates of 19.09% for GSH and 27.36% for SOD. The results of this study suggest that exposure to both individual and combined metals effects blood pressure levels, which are further associated with changes in oxidative stress levels. Moreover, oxidative stress levels may modulate the changes in blood pressure related to metal exposure, providing a basis for further investigation into the health risks associated with these metal exposures.

Assessment of blood metals and dietary health risks in older adults from an Eastern Chinese community based on Monte Carlo simulation

Assessing blood metal levels in older adults is crucial for monitoring nutritional, occupational, and environmental exposures, as environmental metals may potentially affect the health of older people through dietary intake. In this study, we collected blood samples from 2493 older participants in Yiwu, China. 11 metal elements in whole blood were measured using ICP-MS. Monte Carlo simulation was applied to estimate population-level blood metal distributions and use for risk quantification. Dietary metal intake was assessed through food frequency questionnaires. Then it was employed to evaluate health risks from dietary metal exposure. Results of Monte Carlo simulation showed that the medians of Cu, As, Cd, Mn and Cr were 752.69 (682.84, 824.36), 1.94 (1.36, 2.80), 1.40 (0.85, 2.32), 12.78 (10.56, 15.48), 0.44 (0.28, 0.70) µg/L and Fe, and Zn were 332.59 (276.73, 385.13), 4.95 (4.45, 5.48) mg/L. Concentrations of Se, Fe, Zn, As, Cd, Hg, and Pb were significantly higher in men than in women, while Cu and Mn levels were lower in men. Hazard quotients (HQ > 1) for Zn (HQ = 1.108, IQR = 0.857-1.215) indicated unacceptable non-carcinogenic risks, while incremental lifetime cancer risks (ILCR > 1 × 10⁻4) for Cr (ILCR = 1.295 × 10⁻3, IQR = 8.725 × 10⁻4-1.798 × 10⁻3), As (ILCR = 3.299 × 10⁻4, IQR = 2.049 × 10⁻4-5.991 × 10⁻4), and Cd (ILCR = 3.263 × 10⁻4, IQR = 2.747 × 10⁻4-3.878 × 10⁻4) suggested potential carcinogenic risks. Findings indicated potential health risks from dietary metal exposure in this population. Implementing comprehensive interventions to reduce exposure levels and optimize dietary patterns was essential. Future monitoring should prioritize heavy metal surveillance in food and drinking water.

Metabolic diseases in the East Asian populations

East Asian populations, which account for approximately 20% of the global population, have become central to the worldwide rise of metabolic diseases over the past few decades. The prevalence of metabolic disorders, including type 2 diabetes mellitus, hypertension and metabolic dysfunction-associated steatotic liver disease, has escalated sharply, contributing to a substantial burden of complications such as cardiovascular disease, chronic kidney disease, cancer and increased mortality. This concerning trend is primarily driven by a combination of genetic predisposition, unique fat distribution patterns and rapidly changing lifestyle factors, including urbanization and the adoption of Westernized dietary habits. Current advances in genomics, proteomics, metabolomics and microbiome research have provided new insights into the biological mechanisms that might contribute to the heightened susceptibility of East Asian populations to metabolic diseases. This Review synthesizes epidemiological data, risk factors and biomarkers to provide an overview of how metabolic diseases are reshaping public health in East Asia and offers insights into biological and societal drivers to guide effective, region-specific strategies.

Genome-Wide Approach of Gene-Nutrient Intake Interaction Study for Essential Hypertension in a Large Korean Cohort (KoGES)

Background/Objectives: There is limited evidence on gene-nutrient interaction associated with hypertension (HTN). We examined interactions between genotypes and various nutrients that influenced high blood pressure (BP). Methods: Data were obtained from a total of 50,808 participants from the Korean Genome and Epidemiology Study (KoGES). Dietary intake was assessed by a food frequency questionnaire, and dietary reference intakes (DRIs) were set. We performed genome-wide association analyses (GWAS) and subsequent interaction analyses with genome-wide significant SNPs to identify genomic loci that interact with specific nutrients associated with HTN. Results: We identified one locus near the CUB and Sushi Multiple Domains 1 (CSMD1) gene that showed interaction with dietary iron and vitamin B6 (Vit.B6) intake and significantly influenced HTN risk. Among the individuals consuming iron above DRI (9.5 mg/day for men, 9.25 mg/day for women), carriers of the rs13282715 minor allele (A) at 8p23.2 showed a lower risk of HTN than those who did not (odds ratio [OR] 0.723, 95% confidence interval [CI] (0.644-0.813), p-value 4.858 × 10-8; interaction p-value 1.336 × 10-3). Among the individuals consuming Vit.B6 above DRI (1.5 mg/day for men, 1.4 mg/day for women), carriers of the same variant rs13282715 minor allele (A) also showed a lower risk of HTN (OR 0.733, 95% CI 0.733 (0.656-0.819), p-value 4.121 × 10-8; interaction p-value 7.183 × 10-4). Conclusions: We identified a novel gene-nutrient interaction regarding dietary iron and Vit.B6 intake affecting the risk of HTN in Korean adults. This suggests individuals with the variant may benefit from lower HTN risk from dietary intervention of iron and Vit.B6 intake. Further studies with larger diverse populations are warranted to validate our findings.

Association Between Dietary Antioxidant Quality Score (DAQS) and All-Cause Mortality in Hypertensive Adults: A Retrospective Cohort Study from the NHANES Database

This study aimed to explore the association between the dietary antioxidant quality scores (DAQS) and all-cause mortality in hypertensive adults. In this retrospective cohort study, participants aged ≥ 18 years with hypertension were extracted from the National Health and Nutrition Examination Survey (NAHNES) 2007-2018. Outcome was all-cause mortality of hypertensive participants. DAQS was the exposure variable calculated based on the intake of vitamin A, C, E, zinc, selenium, and magnesium. The weighted univariable and multivariable COX proportional hazards regression models were utilized to explore the association between the DAQS and the all-cause mortality in hypertensive patients and were described as hazard ratios (HRs) and 95% confidence intervals (CIs). Subgroup analyses based on different age, gender, diabetes, and cardiovascular disease (CVD) history were further assessed this association. A total of 16,240 participants were finally included in this study. Until 12 December 2019, 2710 (16.69%) all-cause deaths were documented. After adjustment for confounding variables, high DAQS was associated with the lower all-cause mortality (HR = 0.83, 95%CI: 0.72-0.96) in hypertensive patients. Subgroup analyses suggested that the association between DAQS and the all-cause mortality in hypertensive patients remain robust, especially in patients with female (HR = 0.77, 95%CI: 0.63-0.95), aged ≥ 60 years (HR = 0.81, 95%CI: 0.69-0.96). High DAQS was associated with the lower odds of all-cause mortality in adults with hypertension and are a promising intervention to be further explored in hypertensive patients.

Association Between Adherence to EAT-Lancet Diet and Risk of Hypertension: An 18-Year National Cohort Study in China

OBJECTIVE

The EAT-Lancet Commission has proposed an EAT-Lancet diet (ELD), also known as a planetary health diet (PHD), which is environmentally sustainable and promotes human health. However, the association between this diet and the risk of hypertension remains unclear. This study aimed to determine whether adherence to ELD was associated with a lower risk of hypertension.

METHODS

11,402 adults without hypertension at baseline from the China Health and Nutrition Survey were included. The PHD score was used to evaluate ELD adherence, with higher scores reflecting better compliance. Cox proportional hazards regression analysis was utilized to estimate the hazard ratio (HR) with a 95% confidence interval (CI). Additionally, a subgroup analysis was performed to identify the possible effect modifiers, and a mediation analysis was conducted to explore the mediation effects of anthropometric measurements on the association between ELD and hypertension.

RESULTS

A total of 3993 participants (35%) developed hypertension during 93,058 person-years of follow-up. In the covariate-adjusted model, hypertension risk was reduced in the highest quartile participants compared to the lowest quartile of the PHD score (adjusted HR: 0.79, 95%CI: 0.71-0.87; P-trend < 0.001), which remained significant after sensitivity analysis. Notably, the association was also observed in isolated systolic hypertension, isolated diastolic hypertension, and systolic-diastolic hypertension. Subgroup analysis revealed that the inverse association between the PHD score and hypertension risk was more pronounced in nonsmokers and high-sodium intake consumers than in smokers and low-sodium consumers (P-interaction < 0.05). Additionally, mediation analysis revealed that 23.3% of the association between the PHD score and hypertension risk was mediated by the waist-to-height ratio.

CONCLUSION

Our findings suggest that a higher adherence to ELD is associated with a lower risk of hypertension. These results emphasize that ELD may serve as a potential strategy to prevent hypertension.

Association of composite dietary antioxidant index with mortality in adults with hypertension: evidence from NHANES

Objective

The objective of this study is to assess the correlation between composite dietary antioxidant index (CDAI) with all-cause mortality and cause-specific mortality in adults with hypertension.

Methods

The cohort study comprised adult participants with hypertension from the NHANES database, spanning 9 cycles from 2001 to 2018. Follow-up was conducted until December 31, 2019. Multi-variable Cox regression analysis was utilized to ascertain hazard ratios (HR) and their corresponding 95% confidence intervals, evaluating the relationship between CDAI and the risks of all-cause and cause-specific mortality. To further investigate the association between CDAI and mortality rates in adults with hypertension, Kaplan-Meier survival curves, restricted cubic splines (RCS), subgroup analyses and sensitivity analyses were employed.

Results

The analysis included 16,713 adults with hypertension (mean age 56.93 ± 0.23 years, 8,327 [49.61%] male). During the mean follow-up time 102.11 ± 1.22 months, with 3,908 (18.08%) all-cause mortality occurred, 1,082 (4.84%) cardiovascular mortality and 833 (3.80%) cancer mortality. Compared to the lowest quartile of CDAI, the weighted multivariate hazard ratios of participants in the highest quartile was 0.77 (95% CI, 0.68-0.87) for all-cause mortality, 0.83 (95% CI, 0.67-1.04) for cardiovascular mortality, and 0.64 (95% CI, 0.50-0.82) for cancer mortality. RCS analysis demonstrated a nonlinear association of CDAI with all-cause and cancer mortality, and a linear association between CDAI and cardiovascular mortality. The results were robust in subgroup analyses and sensitivity analyses.

Conclusion

Higher CDAI is associated with reduced all-cause mortality, cardiovascular mortality, and cancer mortality in hypertensive adults. Our findings highlight the importance of an antioxidant diet in improving outcomes in adults with hypertension.

Crosstalk between intestinal flora and human iron metabolism: the role in metabolic syndrome-related comorbidities and its potential clinical application

The interaction of iron and intestinal flora, both of which play crucial roles in many physiologic processes, is involved in the development of Metabolic syndrome (MetS). MetS is a pathologic condition represented by insulin resistance, obesity, dyslipidemia, and hypertension. MetS-related comorbidities including type 2 diabetes mellitus (T2DM), obesity, metabolism-related fatty liver (MAFLD), hypertension polycystic ovary syndrome (PCOS), and so forth. In this review, we examine the interplay between intestinal flora and human iron metabolism and its underlying mechanism in the pathogenesis of MetS-related comorbidities. The composition and metabolites of intestinal flora regulate the level of human iron by modulating intestinal iron absorption, the factors associated with iron metabolism. On the other hand, the iron level also affects the abundance, composition, and metabolism of intestinal flora. The crosstalk between these factors is of significant importance in human metabolism and exerts varying degrees of influence on the manifestation and progression of MetS-related comorbidities. The findings derived from these studies can enhance our comprehension of the interplay between intestinal flora and iron metabolism, and open up novel potential therapeutic approaches toward MetS-related comorbidities.

The Association of Iron Intake and Hypertension, Does Iron Intake Decrease Blood Pressure?

Previous studies reported that iron may have an indispensable role in the risk of hypertension (HTN). However, the result of the studies on the relationship between iron and risk of HTN is inconsistent. This study aimed to assess the association between the association of dietary iron intake and HTN in the Iranian population. This case-control study was conducted on 4184 people aged 35 to 70, including 1239 people with HTN and 2945 people with normal blood pressure (BP) in Sabzevar, Iran. Dietary intake was assessed using a food frequency questionnaire (FFQ). The Nutritionist IV software was used in terms of the assessment of dietary intake of iron. An inverse association was found between iron intake and HTN (OR = 0.97, CI 95%: 0.94-0.99, P = 0.04). The association remained significant after adjustment for age, gender, smoking, drinking alcohol, calorie intake, and BMI (OR = 0.94, CI 95%: 0.89-0.98, P = 0.01). As a conclusion, iron intake was inversely associated with HTN. Further longitudinal studies on the effect of iron intake on BP are required to confirm this finding.

Ferroptosis mechanisms and regulations in cardiovascular diseases in the past, present, and future

Cardiovascular diseases (CVDs) are the main diseases that endanger human health, and their risk factors contribute to high morbidity and a high rate of hospitalization. Cell death is the most important pathophysiology in CVDs. As one of the cell death mechanisms, ferroptosis is a new form of regulated cell death (RCD) that broadly participates in CVDs (such as myocardial infarction, heart transplantation, atherosclerosis, heart failure, ischaemia/reperfusion (I/R) injury, atrial fibrillation, cardiomyopathy (radiation-induced cardiomyopathy, diabetes cardiomyopathy, sepsis-induced cardiac injury, doxorubicin-induced cardiac injury, iron overload cardiomyopathy, and hypertrophic cardiomyopathy), and pulmonary arterial hypertension), involving in iron regulation, metabolic mechanism and lipid peroxidation. This article reviews recent research on the mechanism and regulation of ferroptosis and its relationship with the occurrence and treatment of CVDs, aiming to provide new ideas and treatment targets for the clinical diagnosis and treatment of CVDs by clarifying the latest progress in CVDs research.

Positive association between dietary manganese intake and new-onset hypertension: A nationwide cohort study in China

BACKGROUND AND AIM

To date, few studies have investigated the association between dietary manganese intake and the risk of hypertension, so the prospective relationship of dietary manganese intake and new-onset hypertension remains uncertain. We aimed to investigate the association between dietary manganese intake and the risk of new-onset hypertension in the general Chinese population.

METHODS AND RESULTS

This prospective cohort study included 12,177 participants who were free of hypertension at baseline from China Health and Nutrition Survey (CHNS). Dietary intake was measured by 3 consecutive 24-h dietary recalls combined with a household food inventory. The study outcome was new-onset hypertension, defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg or diagnosed by a physician or under antihypertensive treatment during the follow-up. During a median follow-up duration of 6.1 years, 4269 (44.9 per 1000 person-years) participants developed new-onset hypertension. Overall, there was a positive association between dietary manganese intake and new-onset hypertension. The adjusted HRs (95%CIs) of new-onset hypertension were 1.00 (reference), 0.97 (0.87, 1.08), 1.24 (1.10, 1.39) and 1.75 (1.52, 2.01) across the quartiles of dietary manganese intake, respectively. Accordingly, a significantly higher risk of new-onset hypertension (HR, 1.38; 95%CI: 1.27, 1.50) was found in participants in quartiles 3-4 of dietary manganese intake (≥6.0 mg/day), compared with those in quartiles 1-2 (<6.0 mg/day).

CONCLUSIONS

In the general Chinese population, dietary manganese intake was positively associated with the risk of new hypertension, independent of sodium intake and other important covariates.

Dietary intakes of total, nonheme, and heme iron and hypertension risk: a longitudinal study from the China Health and Nutrition Survey

AIMS

Evidence is limited regarding the long-term impact of dietary iron intake on the development of hypertension. We investigated the association between dietary intakes of total, nonheme, and heme iron and hypertension risk in a large prospective cohort of Chinese populations over 26 years.

METHODS

A total of 16,122 adults (7810 men and 8312 women) who participated in the China Health and Nutrition Survey (1989-2015) were included. Dietary intake was repeatedly assessed by combining three consecutive 24‑h individual dietary recalls with household food inventory weighing at each survey round. Incident hypertension was defined as systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg, diagnosis by physicians, or current use of anti-hypertensive drugs.

RESULTS

During a median follow‑up of 11.1 years, 2863 men and 2532 women developed hypertension. After adjustment for non-dietary and dietary factors, a lower risk of hypertension was found in men and women with higher intakes of total, nonheme, or heme iron. The adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the highest vs. lowest quartiles were 0.76 (0.67, 0.87) in men and 0.85 (0.74, 0.97) in women for total iron intake, 0.77 (0.67, 0.87) in men and 0.85 (0.74, 0.98) in women for nonheme iron intake, and 0.73 (0.62, 0.87) in men and 0.69 (0.58, 0.82) in women for heme iron intake. Dose-response analyses further revealed a U-shaped association of total and nonheme iron intake and an L-shaped association of heme iron intake with hypertension risk in both men and women (all P for non-linearity < 0.001).

CONCLUSIONS

Our findings emphasize the importance of maintaining moderate iron intake in the prevention of hypertension. Both insufficient and excess intake of iron might increase the risk of hypertension.