Serum cobalt in children with essential hypertension

Associations between maternal exposure to multiple metals and metalloids and blood pressure in preschool children: A mixture-based approach

BACKGROUND

Exposure to metals during pregnancy can potentially influence blood pressure (BP) in children, but few studies have examined the mixed effects of prenatal metal exposure on childhood BP. We aimed to assess the individual and combined effects of prenatal metal and metalloid exposure on BP in preschool children.

METHODS

A total of 217 mother-child pairs were selected from the Zhuang Birth Cohort in Guangxi, China. The maternal plasma concentrations of 20 metals [e.g. lead (Pb), rubidium (Rb), cesium (Cs), and zinc (Zn)] in early pregnancy were measured by inductively coupled plasmamass spectrometry. Childhood BP was measured in August 2021. The effects of prenatal metal exposure on childhood BP were explored by generalized linear models, restricted cubic spline and Bayesian kernel machine regression (BKMR) models.

RESULTS

In total children, each unit increase in the log10-transformed maternal Rb concentration was associated with a 10.82-mmHg decrease (95% CI: -19.40, -2.24) in childhood diastolic BP (DBP), and each unit increase in the log10-transformed maternal Cs and Zn concentrations was associated with a 9.67-mmHg (95% CI: -16.72, -2.61) and 4.37-mmHg (95% CI: -8.68, -0.062) decrease in childhood pulse pressure (PP), respectively. The log10-transformed Rb and Cs concentrations were linearly related to DBP (P nonlinear=0.603) and PP (P nonlinear=0.962), respectively. Furthermore, an inverse association was observed between the log10-transformed Cs concentration and PP (β =-12.18; 95% CI: -22.82, -1.54) in girls, and between the log10-transformed Rb concentration and DBP (β =-12.54; 95% CI: -23.87, -1.21) in boys, while there was an increasing association between the log10-transformed Pb concentration and DBP there was an increasing in boys (β =6.06; 95% CI: 0.36, 11.77). Additionally, a U-shaped relationship was observed between the log10-transformed Pb concentration and SBP (P nonlinear=0.015) and DBP (P nonlinear=0.041) in boys. Although there was no statistically signiffcant difference, there was an inverse trend in the combined effect of maternal metal mixture exposure on childhood BP among both the total children and girls in BKMR.

CONCLUSIONS

Prenatal exposure to both individual and mixtures of metals and metalloids influences BP in preschool children, potentially leading to nonlinear and sex-specific effects.

Evaluation of Arsenic and Cobalt Levels in Pediatric Patients Receiving Long-Term Parenteral Nutrition

This study continues the research in which we determined the concentration of aluminum in children receiving long-term parenteral nutrition (LPN). Since our results were interesting, we decided to assay arsenic (As) and cobalt (Co) in the collected material, which, like aluminum, constitute contamination in the mixtures used in parenteral nutrition. Excesses of these trace elements in the human body are highly toxic, and deficiencies, particularly in the case of Co, can lead to various complications. The aim of this study was to determine the impact of LPN in children on their serum levels of As and Co, as well as the excretion of these elements in urine, and to compare them with a control group of healthy children. The study group consisted of 83 children receiving home parenteral nutrition from two Polish centers, while the control group included 121 healthy children. In both groups, the levels of As and Co in serum and urine were measured. The elemental compositions of the samples were determined using inductively coupled plasma mass spectrometry (ICP-MS). It was demonstrated that the children receiving LPN did not have increased As exposure compared to the controls. Greater exposure compared to the control group was shown for Co. In conclusion, children receiving LPN are not exposed to As, and even though the concentrations of Co in serum and urine were higher in the LPN group than in the healthy controls, neither trace element poses a health threat to children requiring LPN.

Interactive Effects of Obesity and Hypertension on Patterns of Hair Essential Trace Element and Mineral Content in Adult Women

The objective of the present study was to evaluate potential similar patterns and interactive effects of obesity and hypertension on hair essential trace element and mineral content in adult women. In this cross-sectional study, a total of 607 adult women divided into controls (n = 101), groups with obesity without hypertension (n = 199), hypertension without obesity (n = 143), and both obesity and hypertension (n = 164) were included in the study. Assessment of hair mineral and trace element levels was performed by inductively-coupled plasma mass-spectrometry. Hair Ca, Mg, Co, and Mn levels in women with obesity, hypertension, and both diseases were significantly lower, compared to controls. Hair Mg levels in women with obesity and hypertension were significantly lower, whereas hair Na and K were found to be higher when compared to other groups. Hair Fe and V content in obese patients was lower than in other groups. Obesity was associated with lower hair Cu levels, whereas patients with hypertension had higher hair Cu content. Hypertension was also associated with higher hair Cr and Se content irrespective of body weight. Hair Zn levels in obese women with and without hypertension were significantly lower than those in healthy controls and normal-weight women with hypertension. In multiple regression models hair Mg was considered as a significant negative predictor of both systolic and diastolic blood pressure values. The observed alterations in hair trace element and mineral content provide an additional link between obesity and hypertension, although further detailed studies are required.

Prenatal metal mixtures and child blood pressure in the Rhea mother-child cohort in Greece

BACKGROUND

Child blood pressure (BP) is predictive of future cardiovascular risk. Prenatal exposure to metals has been associated with higher BP in childhood, but most studies have evaluated elements individually and measured BP at a single time point. We investigated impacts of prenatal metal mixture exposures on longitudinal changes in BP during childhood and elevated BP at 11 years of age.

METHODS

The current study included 176 mother-child pairs from the Rhea Study in Heraklion, Greece and focused on eight elements (antimony, arsenic, cadmium, cobalt, lead, magnesium, molybdenum, selenium) measured in maternal urine samples collected during pregnancy (median gestational age at collection: 12 weeks). BP was measured at approximately 4, 6, and 11 years of age. Covariate-adjusted Bayesian Varying Coefficient Kernel Machine Regression and Bayesian Kernel Machine Regression (BKMR) were used to evaluate metal mixture impacts on baseline and longitudinal changes in BP (from ages 4 to 11) and the development of elevated BP at age 11, respectively. BKMR results were compared using static versus percentile-based cutoffs to define elevated BP.

RESULTS

Molybdenum and lead were the mixture components most consistently associated with BP. J-shaped relationships were observed between molybdenum and both systolic and diastolic BP at age 4. Similar associations were identified for both molybdenum and lead in relation to elevated BP at age 11. For molybdenum concentrations above the inflection points (~ 40-80 μg/L), positive associations with BP at age 4 were stronger at high levels of lead. Lead was positively associated with BP measures at age 4, but only at high levels of molybdenum. Potential interactions between molybdenum and lead were also identified for BP at age 11, but were sensitive to the cutoffs used to define elevated BP.

CONCLUSIONS

Prenatal exposure to high levels of molybdenum and lead, particularly in combination, may contribute to higher BP at age 4. These early effects appear to persist throughout childhood, contributing to elevated BP in adolescence. Future studies are needed to identify the major sources of molybdenum and lead in this population.

Children with health impairments by heavy metals in an e-waste recycling area

E-waste recycling has become a global environmental health issue. Pernicious chemicals escape into the environment due to informal and nonstandard e-waste recycling activities involving manual dismantling, open burning to recover heavy metals and open dumping of residual fractions. Heavy metals derived from electronic waste (e-waste), such as, lead (Pb), cadmium (Cd), chromium (Cr), manganese (Mn), nickel (Ni), mercury (Hg), arsenic (As), copper (Cu), zinc (Zn), aluminum (Al) and cobalt (Co), differ in their chemical composition, reaction properties, distribution, metabolism, excretion and biological transmission. Our previous studies showed that heavy metal exposure have adverse effects on children's health including lower birth weight, lower anogenital distance, lower Apgar scores, lower current weight, lower lung function, lower hepatitis B surface antibody levels, higher prevalence of attention-deficit/hyperactivity disorder, and higher DNA and chromosome damage. Heavy metals influence a number of diverse systems and organs, resulting in both acute and chronic effects on children's health, ranging from minor upper respiratory irritation to chronic respiratory, cardiovascular, nervous, urinary and reproductive disease, as well as aggravation of pre-existing symptoms and disease. These effects of heavy metals on children's health are briefly discussed.

Elevated circulating levels of copper and nickel are found in elderly subjects with left ventricular hypertrophy

Identified risk factors for left ventricular hypertrophy (LVH) are hypertension, diabetes and obesity. However, since these risk factors only explain a part of the variation in left ventricular mass, we investigated if trace and heavy metals might also play a role in LVH. In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, left ventricular mass index (LVMI) and relative wall thickness (RWT) were determined by echocardiography together with eleven different trace and heavy metals in 993 subjects aged 70 years. Only copper levels were significantly related to LVMI following adjustment for sex, blood pressure, antihypertensive treatment, diabetes and body mass index (BMI) (p<0.0001). However, both copper (Cu) and nickel (Ni) were related to RWT following adjustment (p<0.0001). When divided into four geometric groups, both Cu and Ni were elevated in subjects with concentric remodelling and concentric LVH, but not in those with eccentric hypertrophy, when compared to subjects with a normal left ventricle. No relationships were found for zinc, aluminium, manganese, molybdenum, mercury, lead, cadmium, cobalt or chromium. Elevated levels of copper and nickel are found in elderly subjects with LVH, especially of the concentric type, following adjustment for known risk factors for LVH.

Gender differences for associations between circulating levels of metals and coronary risk in the elderly

Several studies have pointed out associations between various metals and cardiovascular disease. Since cardiovascular disease prevalence is different between males and females, we investigated whether circulating levels of metals related differently to coronary risk in men and women. In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, coronary risk was assessed by the Framingham Risk Score together with circulating blood levels of 11 different trace and heavy metals in 1016 subjects aged 70 years. Circulating levels of cadmium, copper and manganese were significantly higher in women than in men, while mercury, zinc and lead were significantly lower following adjustment for kidney function (measured by glomerular filtration rate, GFR). No significant differences between women and men were seen regarding levels of aluminium, molybdenum, cobalt, chromium and nickel. When all 11 metals were entered as independent variables together with GFR in multiple models in the Framingham Risk Score as the dependent variable, cadmium was the major determinant of the Framingham Risk Score in women (p<0.0001, followed by zinc p=0.03), while copper was the major determinant of the Framingham Risk Score in men (p<0.0001, followed by inverse relations vs. aluminium p=0.01 and nickel p=0.01). There are gender differences in levels of metals and also regarding the association between metals and coronary risk, with cadmium levels being most important for women and copper levels for men in this elderly population.

Evaluation of hypertension by the general pediatrician

PURPOSE OF REVIEW

To summarize the recommended work-up in a child who presents with elevated blood pressure as well as innovative evaluation techniques under development.

RECENT FINDINGS

'The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents' contains several updates on the diagnosis, evaluation and treatment of childhood hypertension. New risk factors for hypertension have been identified and include obesity, sleep apnea, and low birth weight. The roles of uric acid, leptin and C-reactive protein in the pathophysiology of hypertension have been examined. The presence of hypertensive end-organ damage has been demonstrated in hypertensive children.

SUMMARY

Current knowledge emphasizes the need to diagnose and treat hypertension when it develops in childhood to decrease the risk of cardiovascular morbidity in adulthood. End-organ injury is evident, illustrated by the presence of left ventricular hypertrophy, even in young children. Assessment for the presence of comorbidities and end-organ damage should be emphasized. Further study is needed to isolate the etiologic factors for childhood hypertension, improve evaluation techniques, and determine if end-organ damage is reversible with proper therapy.