Association of Urinary Strontium Levels with Pregnancy-induced Hypertension

Environmental exposure to metal(loid)s and hypertensive disorders of pregnancy: A systematic review

BACKGROUND

Environmental exposure to metal(loid)s has been associated with adverse effects on human health, but the systemic repercussion of these elements on the development of hypertensive disorders of pregnancy (HDP) is still poorly understood.

OBJECTIVE

To summarize evidence published about the influence of environmental exposure to aluminum, arsenic, barium, cadmium, lead, strontium and mercury on the development of HDP.

METHODS

We conducted a systematic literature review according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The search strategy was validated by the Peer Review of Electronic Search Strategies. We searched for articles published up to February 2023 in seven databases without language restriction. Two researchers conducted the steps for selection, data extraction and evaluation of the methodological quality of the instruments for epidemiological studies of the Joanna Briggs Institute. Any disagreements were resolved by a third researcher.

RESULTS

We obtained 5076 records, of which 37 articles met the inclusion criteria moderate to high methodological quality. Single exposure to metal(loid)s was predominant, and the leading biological matrix analyzed to detect the concentrations from exposure was maternal blood. Lead was the metal investigated the most, and had the largest number of studies showing positive association with HDP. In relation to the other metal(loid)s, higher levels were found in women with HDP in comparison with healthy women, but the finding of a cause-effect relationship was inconsistent.

CONCLUSIONS

Although we found evidence of harmful effects of the metal(loid)s studied on human health, the results were inconclusive with regard to HDP. Longitudinal studies that consider prospective investigation, adjustment of confounding factors and the interference of other contaminants in the exacerbation of oxidative stress in women from the preconception phase to the puerperal period should be encouraged.

Microelement strontium and human health: comprehensive analysis of the role in inflammation and non-communicable diseases (NCDs)

Strontium (Sr), a trace element with a long history and a significant presence in the Earth's crust, plays a critical yet often overlooked role in various biological processes affecting human health. This comprehensive review explores the multifaceted implications of Sr, especially in the context of non-communicable diseases (NCDs) such as cardiovascular diseases, osteoporosis, hypertension, and diabetes mellitus. Sr is predominantly acquired through diet and water and has shown promise as a clinical marker for calcium absorption studies. It contributes to the mitigation of several NCDs by inhibiting oxidative stress, showcasing antioxidant properties, and suppressing inflammatory cytokines. The review delves deep into the mechanisms through which Sr interacts with human physiology, emphasizing its uptake, metabolism, and potential to prevent chronic conditions. Despite its apparent benefits in managing bone fractures, hypertension, and diabetes, current research on Sr's role in human health is not exhaustive. The review underscores the need for more comprehensive studies to solidify Sr's beneficial associations and address the gaps in understanding Sr intake and its optimal levels for human health.

Associations between multiple urinary metals and the risk of hypertension in community-dwelling older adults

Although metal exposure has been associated with hypertension, the conclusions remain controversial, and studies investigating the predictive effect of multiple metals on hypertension are limited. In this study, we aimed to evaluate the nonlinear dose-response relationship between a single urinary metal and the risk of hypertension, and to assess the predictive effect of multiple urinary metals on hypertension. Of the Yinchuan community-dwelling elderly cohort launched in 2020, 3,733 participants (803 with hypertension and 2,930 without hypertension) were analysed in this study, and the concentrations of 13 metal elements in urine were measured. We found that urinary vanadium (odds ratio (OR): 1.16, 95% confidence interval [CI]: 1.08-1.25), molybdenum (OR: 1.08, 95% CI: 1.01-1.16), and tellurium (OR: 1.14, 95% CI: 1.06-1.22) were associated with higher risk of hypertension, whereas iron (OR: 0.92, 95% CI: 0.85-0.98) and strontium (0.92, 95% CI: 0.85-0.99) were significantly associated with lower risk of hypertension. Restricted cubic splines analysis was conducted in patients with iron concentrations of ≥ 15.48 μg/g and ≤ 399.41 μg/g and a strontium concentration of ≤ 69.41 μg/g, results showed that the risk of hypertension decreased gradually as the urinary concentrations of these metals increased. With an increase in the vanadium concentration in urine, the risk of hypertension gradually increased. In patients with a molybdenum concentration of ≥ 56.82 μg/g and a tellurium concentration of ≥ 21.98 μg/g, the risk of hypertension gradually decreased as the urinary concentrations of these metals increased. Predictive scores based on the 13 metallic elements were significantly associated with a higher risk of hypertension (OR: 1.34 (95% CI: 1.25-1.45). After additionally including urinary metal concentrations as a parameter variable in the traditional hypertension risk assessment model, integrated discrimination and net reclassification increased by 8.00% (P < 0.001) and 2.41% (P < 0.001), respectively. Urinary vanadium, Mo, and Te concentrations were associated with a higher risk of hypertension, while iron and strontium concentrations were associated with a lower risk of hypertension. Multiple urinary metal concentrations can significantly improve the predictive ability of traditional hypertension risk-assessment models.

In vivo quantification of strontium in bone among adults using portable x-ray fluorescence

BACKGROUND AND OBJECTIVE

Bone strontium (Sr) is a reliable biomarker for studying related bone health outcomes and the effectiveness of Sr supplements in osteoporosis disease treatment. In this study, we evaluated the sensitivity of portable x-ray fluorescence (XRF) technology for in vivo bone Sr quantification among adults.

MATERIALS AND METHODS

Sr-doped bone-equivalent phantoms were used for system calibration. Using the portable XRF, we measured bone Sr levels in vivo in mid-tibia bone in 76 adults, 38-95 years of age, living in Indiana, US; we also analyzed bone data of 29 adults, 53-82 years of age, living in Shanghai, China. The same portable XRF device and system settings were used in measuring their mid-tibia bone. We compared bone Sr concentrations by sex, age, and recruitment site. We also used multiple linear regression model to estimate the association of age with bone Sr concentration, adjusting for sex and recruitment site.

RESULTS

The uncertainty of in vivo individual measurement increased with higher soft tissue thickness overlying bone, and it ranged from 1.0 ug/g dry bone (ppm) to 2.4 ppm with thickness ranging from 2 to 7 mm, with a measurement time of 5 min. Geometric mean (95% confidence interval (CI)) of the bone Sr concentration was 79.1 (70.1, 89.3) ppm. After adjustment for recruitment site and sex, an increase in five years of age was associated with a 8.9% (95% CI: 2.5%, 15.6%) increase in geometric mean bone Sr concentration.

DISCUSSION AND CONCLUSION

Sr concentrations were consistently well above detection limits of the portable XRF, and exhibited an expected increase with age. These data suggest that the portable XRF can be a valuable technology to quantify Sr concentration in bone, and in the study of Sr-related health outcomes among adults, such as bone mineral density (BMD) and bone fracture risk.