Nonlinear association between blood lead and hyperhomocysteinemia among adults in the United States

The effect of cumulative exposure with unhealthy lifestyles on the H-type hypertension among Chinese adults: a community-based, propensity-score-matched, and case-control study

Objective

To assess whether cumulative exposure of unhealthy lifestyles is associated with HTH in Chinese adults and to explore the combination of unhealthy lifestyles.

Methods

This study combined a community-based cross-sectional study with a 1:1 matched case-control study using propensity scores among adults in six randomly selected districts from Hunan Province, China. We recruited 5,258 people, of whom 4,012 met the criteria. Lifestyles and personal characteristics were collected by a questionnaire. Lifestyle score was calculated using cigarette smoking, heavy alcohol consumption, inactive exercise, unhealthy diet and abnormal BMI. HTH was defined as having a diagnosis of essential hypertension with Hcy ≥ 15 umol/L. Logistic regression models and multivariate analyses were used to explore the associations. We calculated odds ratios (ORs) and attributable risk proportion (ARP) for the association of HTH with lifestyle score. The dose-response relationship was evaluated using restricted cubic splines method.

Results

Of the 4,012 adults, 793 had HTH, with a population prevalence of 19.8%. In the propensity-score-matched case-control study, 1,228 (614 cases and 614 controls) were included, and those with at least four unhealthy lifestyle factors had a higher risk of HTH than those with 0 unhealthy lifestyle factor (adjusted OR = 2.60, 95%CI:1.42-4.78), with an ARP of the cumulative exposure of unhealthy lifestyle was 28.23% (95% CI: 6.34-37.86%). For three unhealthy lifestyles group, the combination of heavy alcohol consumption, unhealthy diet and BMI ≥24 Kg/m2 was most associated with HTH (OR = 7.49, 95%CI: 1.12-50.08). For four unhealthy lifestyles group, the combination of smoking, heavy alcohol consumption, unhealthy diet and BMI ≥24 Kg/m2 had the greatest correlation with HTH (OR = 3.75, 95%CI: 1.24-7.38). Notably, there was a monotonically increasing curve (J-shaped) relationship between unhealthy lifestyles and the risk of HTH (p = 0.014).

Conclusion

Our findings suggest that there was a significant cumulative exposure effect of unhealthy lifestyles on the risk of HTH, with the largest effect combination being heavy alcohol consumption, unhealthy diet and BMI ≥24 Kg/m2. Targeted interventions that reducing heavy alcohol consumption, quitting smoking, promoting physical activity and a healthy diet, and keep a normal BMI could substantially reduce the burden of HTH.

Blood Homocysteine Levels Mediate the Association Between Blood Lead Levels and Cardiovascular Mortality

Lead is a heavy, toxic metal and its exposure to humans can lead to increased risk of cardiovascular disease development and mortality. Lead exposure has been shown to induce hyperhomocysteinemia (HHCy) which may be a major pathogenic risk for the risk of CVDs. The aim of this study was to investigate whether homocysteine (Hcy) mediates the effect of lead on cardiovascular mortality. A total of 17,915 adults aged ≥ 20 who participated in the National Health and Nutrition Examination Survey (1999 to 2006). Information on mortality was ascertained via probabilistic matching to the death certificates from the National Death Index recorded up to December 31, 2015. Cox proportional hazards regression was performed to assess the association between blood lead levels and mortality. Mediation via Hcy was examined using a logit model. During a mean follow-up of 11.6 years, the incidences of CVD mortality were 0.73, 2.18, 3.03 and 4.94 per 1000 person-years across quarterlies of blood lead levels from low to high. Following multivariable adjustment, blood lead levels were strongly associated with CVD mortality in all mortality models (p-trend < 0.001). This association remained statistically significant after further adjusting for quartiles of homocysteine (model 3; HR 1.38 (95% CI 1.01-1.89) p-trend < 0.001). Furthermore, blood lead levels increased the odds of CVD mortality via homocysteine (indirect effect) (OR 1.42 (95% CI 1.30-1.55)), demonstrating the mediatory effect of homocysteine. This the first study that demonstrates that increased homocysteine mediates nearly half of CVD mortality related to blood lead levels.

Genome-wide analysis of DNA methylation and its relationship with serum homocysteine levels in patients with hypertension

BACKGROUND

Homocysteine (Hcy) is an independent risk factor for cardiovascular diseases, and elevated plasma Hcy levels could aggravate vascular injury in hypertension. Hyperhomocysteinemia can change the methylation status of global DNA and specific genes. In the present study, we aim to examine the comprehensive influence of Hcy levels on DNA methylation status in patients with hypertension.

METHODS

Epigenome-wide methylation profiles of the peripheral leukocyte DNA of 218 patients with hypertension were analyzed using the Illumina Infinium Methylation EPIC BeadChip. Differentially methylated positions (DMPs) associated with serum Hcy levels were identified by mixed linear regression with the adjustment of potential confounders. Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis were conducted to determine the potential functions of the identified DMPs. The association between the methylation level of DMPs and carotid-femoral pulse wave velocity (Cf-PWV) was also analyzed.

RESULTS

Five DMPs at cg13169662, cg03179312, cg21976560, cg25262698, and cg09433843 showed significant association with serum Hcy levels (false discovery rate-corrected P  < 0.05). An additional six CpG sites met the threshold for suggestive significance ( P  < 1 × 10 -6 ), among which three DMPs (cg25781123, cg26463106, and cg06679221) were annotated to THUMPD3 . Furthermore, the methylation levels of cg13169662 and cg25262698 (RPRD1A) were significantly associated with Cf-PWV.

CONCLUSION

Our results suggest that Hcy could induce DNA methylation alteration in patients with hypertension. Further functional research is warranted to elucidate the concrete role of DMPs in hypertension.

Landscape of cardiometabolic risk factors in Chinese population: a narrative review

With rapid economic growth and changes at all levels (including environmental, social, individual), China is facing a cardiovascular disease (CVD) crisis. In China, more than 40% of deaths are attributable to CVDs, and the number of CVD deaths has almost doubled in the past decades, in contrast to a decline in high-income countries. The increasing prevalence of cardiometabolic risk factors underlies the rise of CVDs, and thus curbing the rising cardiometabolic pandemic is imperative. Few articles have addressed this topic and provided an updated review of the epidemiology of cardiometabolic risk factors in China.In this narrative review, we describe the temporal changes in the prevalence of cardiometabolic risk factors in the past decades and their management in China, including both the well-recognized risk factors (general obesity, central obesity, diabetes, prediabetes, dyslipidemia, hypertension) and the less recognized ones (hyperhomocysteinemia, hyperuricemia, and high C-reactive protein). We also summarize findings from landmark clinical trials regarding effective interventions and treatments for cardiometabolic risk factors. Finally, we propose strategies and approaches to tackle the rising pandemic of cardiometabolic risk factors in China. We hope that this review will raise awareness of cardiometabolic risk factors not only in Chinese population but also global visibility, which may help to prevent cardiovascular risk.

Prevalence and correlative factors of hyperhomocysteinemia in elderly patients with femoral neck fracture: A cross-sectional study

Aims

The occurrence of hyperhomocysteinemia (HHcy) in elderly patients with femoral neck fracture (FNF) draws little attention from surgeons preoperatively. The aim of our study was to determine the prevalence and correlative factors of HHcy in elderly patients (≥65 years) with FNF prior to surgery.

Methods

We retrospectively investigated 286 elderly FNF patients aged 65–98 years admitted to our institution from September 2020 to September 2021. Categorical variables were compared using the Chi‐squared test, and continuous variables were compared using the Mann–Whitney U test. Univariable and multivariable logistic regression were used to determine the associations of variables with the odds of HHcy.

Results

Among the 286 elderly FNF patients, the prevalence of HHcy was 30.77% and the mean Hcy level was 14.52 ± 10.49 μmol/L. The mean Hcy level and the prevalence of HHcy in male patients were significantly higher than that in female patients (16.41 ± 9.58 μmol/L vs. 14.00 ± 10.69 μmol/L, p = 0.002; 43.55% vs. 27.23%, p = 0.014). Multivariate analysis indicated that being male patient (OR 2.187, 95% CI 1.187–4.028, p = 0.012), hypertension (OR 1.993, 95% CI 1.141–3.479, p = 0.015), and low HDL‐C (OR 2.979, 95% CI 1.353–6.558, p = 0.007) were significant correlative factors of HHcy among elderly FNF patients.

Conclusions

This study found a high prevalence of HHcy in elderly FNF patients, with being male patient, hypertension, and low levels of HDL‐C as the significant correlative factors after adjusting for age and other covariables. However, further large‐scale studies in wider regions are warranted to confirm these findings.

Hyperhomocysteinemia (HHcy), which have been associated with increased cardiovascular, cerebrovascular, and thromboembolic diseases in elderly patients, are frequently neglected by orthopedic surgeons in their clinical practices. Using the descriptive statistical analysis and logistic regression model, we found a high prevalence (30.77%) of HHcy among elderly patients with femoral neck fracture (FNF), with being male patient, hypertension, and low levels of HDL‐C as the significant correlates after adjusting for age and other covariables. The current findings may help to the preoperative assessment and optimization of patient with FNF.

Association and mediation analyses among multiple metals exposure, plasma folate, and community-based impaired estimated glomerular filtration rate in central Taiwan

BACKGROUND

Chronic kidney disease (CKD) is increasing, with heavy metal exposure an important risk factor. Additionally, the antioxidant folic acid has been studied for reducing blood arsenic levels and related tissue damage. Therefore, we explored the association and mediation effects among various heavy metal levels in blood, plasma folate, other CKD risk factors, and impaired estimated glomerular filtration rate (eGFR).

METHODS

We constructed a community-based cross-sectional study from the Human Biomonitoring and Environmental Health Program in central Taiwan. A total of 1643 participants had lived locally for > 5 years, > 40 years old, and completely received health examinations and biospecimen collections. Impaired eGFR was defined as one single eGFR < 60 mL/min/1.73 m². Plasma folate and metal levels in blood were determined, as well as urinary 8-hydroxy-2'-deoxyguanosine as an oxidative stress marker. Generalized weighted quantile sum (WQS) regression analysis was used to calculate a WQS score, reflecting overall body-burden of multiple metals (arsenic, cadmium, chromium, nickel, and lead) in blood.

RESULTS

Impaired eGFR was identified in 225 participants. Participants with high WQS scores had increased risk of impaired eGFR (odds ratio = 1.67; 95% confidence interval [CI]: 1.34, 2.07). Of five metals, arsenic, lead, and cadmium were weighted highly in impaired eGFR. Participants with high WQS and folate insufficiency (< 6 ng/mL) had 2.38-fold risk of impaired eGFR compared to those with low WQS and high folate (≥6 ng/mL) (95% CI: 1.55, 5.17). Similar increased 4.16-fold risk of impaired eGFR was shown in participants with high WQS and uric acid levels (95% CI: 2.63, 6.58). However, there were no significant WQS-folate (p = 0.87) or WQS-uric acid (p = 0.38) interactions on impaired eGFR risk. As a mediator, uric acid contributed 24% of the association between WQS score and impaired eGFR risk (p < 0.0001). However, no mediation effect of plasma folate was observed.

CONCLUSION

WQS analysis could be applied to evaluate the joint effects of multiple metals exposure. High WQS scores may influence impaired eGFR risk through increased uric acid levels. A large-scale and prospective cohort study is necessary to validate these results and demonstrate any causal relationship.

Prevalence of Hyperhomocysteinemia in China: An Updated Meta-Analysis

Simple Summary

Hyperhomocysteinemia has been defined as an elevated serum concentration of homocysteine exceeding 15 μmol/L and has been proven to play an important role in the pathogenesis of cerebrovascular disease. The prevalence of hyperhomocysteinemia in China has been outlined in a previous meta-analysis. Considering the key role of homocysteine in the process of vascular injury, more studies have been conducted to prevent hyperhomocysteinemia by nutritional supplements such as folic acid or other treatments. Additionally, studies have shown that the prevalence of hyperhomocysteinemia increases over time; therefore, it was necessary to provide an update from the previous meta-analysis on homocysteine status in China. This was needed to understand the prevalence, the trend in changes over time, and its determinants. The results highlight that the prevalence of hyperhomocysteinemia is increasing in China, especially among the elderly, men, and residents in the north, inland areas, and rural areas of China.

Abstract

We conducted a meta-analysis to systematically assess the prevalence of hyperhomocysteinemia (HHcy) in China, its change over time, and its determinants. Literature searches were conducted using English databases (PubMed, Embase, and Web of Science) and Chinese databases (CNKI, CBM, VIP, and Wanfang). The time ranges were from Jan 2014 to Mar 2021 in China. We adopted the random effects model to estimate the pooled positive rates of HHcy and corresponding 95% confidence intervals (95% CI). To find the sources of heterogeneity, we performed subgroup analysis and meta-regression. A total of 29 related articles were identified involving 338,660 participants with 128,147 HHcy cases. The estimated prevalence of HHcy in China was 37.2% (95% CI: 32.6–41.8%, I² = 99.8%, p for heterogeneity < 0.001). The trend of HHcy prevalence was gradually upward over time, with increases during 2015–2016 (comparison to 2013–2014, p < 0.001), but steady between 2015–2016 and 2017–2018. Subgroup analysis showed that the prevalence was higher in the elderly over 55 years old, males, and residents in the north, inland, and rural China (for each comparison, p < 0.001). Meta-regression analysis revealed that age and area of study contributed to 42.3% of the heterogeneity between studies. The current meta-analysis provides strong evidence that the prevalence of HHcy is increasing in China, and varies substantially across different ages, genders, and geographic distribution. Accordingly, high-risk population groups should be focused on, and public health policies and strategies should be carried out to prevent and control HHcy in China.