Genome-wide association and Mendelian randomization study of blood copper levels and 213 deep phenotypes in humans

The biotoxic effects of heavy metals exposure in miners and non-miners

Since little is known about the comparison of the biotoxic effects of heavy metals exposure on biochemical and hematological parameters in miners and non-miners, the current study aimed to compare the effects of arsenic (As), lead (Pb), and copper (Cu) in both groups. Demographic information and blood samples were collected from all participants and measures of As, Pb and Cu were obtained using Atomic Absorption Spectrophotometry. As and Pb mean concentrations in miners and Cu concentration were greater in non-miners. Miners also showed significantly higher level of RBC, HBG and HCT. In the adjusted model, cholesterol showed a positively association with Pb and Cu levels. Triglycerides, GGT, ALP, WBC and PLT positively and HDL-cholesterol negatively were associated with Cu. Creatinine was negatively associated with group variable. In conclusion, miners' high blood heavy metals concentrations can impact biochemical and hematological indices. These observations make monitoring of heavy metals necessary in miners.

Association between machine learning-assisted heavy metal exposures and diabetic kidney disease: a cross-sectional survey and Mendelian randomization analysis

Background and objective

Heavy metals, ubiquitous in the environment, pose a global public health concern. The correlation between these and diabetic kidney disease (DKD) remains unclear. Our objective was to explore the correlation between heavy metal exposures and the incidence of DKD.

Methods

We analyzed data from the NHANES (2005-2020), using machine learning, and cross-sectional survey. Our study also involved a bidirectional two-sample Mendelian randomization (MR) analysis.

Results

Machine learning reveals correlation coefficients of -0.5059 and - 0.6510 for urinary Ba and urinary Tl with DKD, respectively. Multifactorial logistic regression implicates urinary Ba, urinary Pb, blood Cd, and blood Pb as potential associates of DKD. When adjusted for all covariates, the odds ratios and 95% confidence intervals are 0.87 (0.78, 0.98) (p = 0.023), 0.70 (0.53, 0.92) (p = 0.012), 0.53 (0.34, 0.82) (p = 0.005), and 0.76 (0.64, 0.90) (p = 0.002) in order. Furthermore, multiplicative interactions between urinary Ba and urinary Sb, urinary Cd and urinary Co, urinary Cd and urinary Pb, and blood Cd and blood Hg might be present. Among the diabetic population, the OR of urinary Tl with DKD is a mere 0.10, with a 95%CI of (0.01, 0.74), urinary Co 0.73 (0.54, 0.98) in Model 3, and urinary Pb 0.72 (0.55, 0.95) in Model 2. Restricted Cubic Splines (RCS) indicate a linear linkage between blood Cd in the general population and urinary Co, urinary Pb, and urinary Tl with DKD among diabetics. An observable trend effect is present between urinary Pb and urinary Tl with DKD. MR analysis reveals odds ratios and 95% confidence intervals of 1.16 (1.03, 1.32) (p = 0.018) and 1.17 (1.00, 1.36) (p = 0.044) for blood Cd and blood Mn, respectively.

Conclusion

In the general population, urinary Ba demonstrates a nonlinear inverse association with DKD, whereas in the diabetic population, urinary Tl displays a linear inverse relationship with DKD.

A genome-wide association study provides insights into the genetic etiology of 57 essential and non-essential trace elements in humans

Trace elements are important for human health but may exert toxic or adverse effects. Mechanisms of uptake, distribution, metabolism, and excretion are partly under genetic control but have not yet been extensively mapped. Here we report a comprehensive multi-element genome-wide association study of 57 essential and non-essential trace elements. We perform genome-wide association meta-analyses of 14 trace elements in up to 6564 Scandinavian whole blood samples, and genome-wide association studies of 43 trace elements in up to 2819 samples measured only in the Trøndelag Health Study (HUNT). We identify 11 novel genetic loci associated with blood concentrations of arsenic, cadmium, manganese, selenium, and zinc in genome-wide association meta-analyses. In HUNT, several genome-wide significant loci are also indicated for other trace elements. Using two-sample Mendelian randomization, we find several indications of weak to moderate effects on health outcomes, the most precise being a weak harmful effect of increased zinc on prostate cancer. However, independent validation is needed. Our current understanding of trace element-associated genetic variants may help establish consequences of trace elements on human health.

Exploring the causal associations of micronutrients on urate levels and the risk of gout: A Mendelian randomization study

BACKGROUND & AIMS

Growing evidence has indicated a potential association between micronutrient levels, urate levels, and the risk of gout. However, the causal association underlying these associations still remains uncertain. Previous observational studies and randomized controlled trials investigating the association between micronutrients, urate levels, and the risk of gout have been limited in their scope and depth. The aim of this study was to utilize Mendelian randomization (MR) to investigate the causal associations between genetically predicted micronutrient levels, urate levels, and the risk of gout.

METHODS

In this study, we conducted a comprehensive examination of 10 specific micronutrients (vitamin B6, vitamin B12, vitamin C, vitamin D, folate, calcium, iron, copper, zinc, and selenium) as potential exposures. Two-sample MR analyses were performed to explore their causal associations with urate levels and the risk of gout. In these analyses, gout data were collected from the Global Biobank Meta-Analysis Initiative (N = 1,069,839, N cases = 30,549) and urate levels data from CKDGen Consortium (N = 288,649) by utilizing publicly available summary statistics from independent cohorts of European ancestry. We performed inverse-variance weighted MR analyses as main analyses, along with a range of sensitivity analyses, such as MR-Egger, weighted median, simple mode, weighted mode, Steiger filtering, MR-PRESSO, and Radial MR analysis, to ensure the robustness of our findings.

RESULTS

The results of our study indicate that there were negative associations between serum vitamin B12 and urate levels, as well as serum folate and the risk of gout. Specifically, we found a negative association between vitamin B12 levels and urate levels, with a β coefficient of -0.324 (95% CI -0.0581 to -0.0066, P = 0.0137) per one standard deviation (SD) increase. Similarly, a negative association was observed between folate levels and gout risk, with an odds ratio of 0.8044 (95% CI 0.6637 to 0.9750, P = 0.0265) per one SD increase. On the other hand, we identified positive associations between serum calcium levels and both urate levels and the risk of gout. Specifically, there was a positive association between serum calcium levels and urate levels (β coefficient: 0.0994, 95% CI 0.0519 to 0.1468, P = 4.11E-05) per one SD increase. Furthermore, a positive association was found between serum calcium levels and the risk of gout, with an odds ratio of 1.1479 (95% CI 1.0460 to 1.2598, P = 0.0036) per one SD increase. These findings were robust in extensive sensitivity analyses. By employing MR-PRESSO and Radial MR to eliminate outliers, the observed associations have been reinforced. No clear associations were found between the other micronutrients and the urate levels, as well as the risk of gout.

CONCLUSION

Our findings provided evidence that there were negative associations between serum vitamin B12 and urate levels, as well as serum folate and the risk of gout, while positive associations existed between the serum calcium levels and urate levels, as well as the risk of gout.

Sex-Specific Associations of Five Serum Essential Metal Elements with Thyroid Nodules in Euthyroid Adults: a Cross‑sectional Study

The association between the serum essential metal elements (magnesium, iron, copper, zinc, and calcium) and thyroid nodules is still inconsistent. The current study aims to investigate the relationship of metal elements with thyroid nodules and their malignant tendency. A total of 6480 Chinese euthyroid adults were included in our study. We collect basic information through questionnaires and medical checkups. We diagnose thyroid nodules by ultrasound and detect serum trace metal concentrations by using an automatic biochemical analyzer. Binary and multinomial logistic regressions were used to investigate the associations. As a result, we found that serum copper concentrations were positively associated with thyroid nodules in the second, third, and fourth quartiles, compared to the first quartile (P = 0.024, P = 0.016, P = 0.032) in women and P for trend is 0.038. There is a significant sex-specific association between copper concentrations and thyroid nodules (P for interaction = 0.009). The results of the multinomial logistic regression analyses indicate high serum calcium and magnesium concentrations emerged as consistent risk factors for thyroid nodules in both genders, whereas low zinc was a sex-specific factor. We also observed significant sex interactions in the relationships of magnesium (P for interaction = 0.043) with thyroid nodules with malignant tendency among participants with thyroid nodules. In conclusion, our study suggests that gender is an important factor when studying the association between serum metals and thyroid nodules. The imbalance of selected metal elements (calcium, copper, zinc, and magnesium) may relate to thyroid nodules and their malignant tendency, and future prospective studies are needed to further confirm the associations.

The Physiological and Pathological Role of Acyl-CoA Oxidation

Fatty acid metabolism, including β-oxidation (βOX), plays an important role in human physiology and pathology. βOX is an essential process in the energy metabolism of most human cells. Moreover, βOX is also the source of acetyl-CoA, the substrate for (a) ketone bodies synthesis, (b) cholesterol synthesis, (c) phase II detoxication, (d) protein acetylation, and (d) the synthesis of many other compounds, including N-acetylglutamate-an important regulator of urea synthesis. This review describes the current knowledge on the importance of the mitochondrial and peroxisomal βOX in various organs, including the liver, heart, kidney, lung, gastrointestinal tract, peripheral white blood cells, and other cells. In addition, the diseases associated with a disturbance of fatty acid oxidation (FAO) in the liver, heart, kidney, lung, alimentary tract, and other organs or cells are presented. Special attention was paid to abnormalities of FAO in cancer cells and the diseases caused by mutations in gene-encoding enzymes involved in FAO. Finally, issues related to α- and ω- fatty acid oxidation are discussed.