Nonlinear relationship between dietary calcium and magnesium intake and peripheral neuropathy in the general population of the United States

Relationship Between Sural Nerve Function, Physical Function, and the Ability to Perform Activities of Daily Living in Hospitalized Elderly Patients With Proximal Femoral Fractures: A Prospective Observational Study

Background Falls in older adults, specifically causing proximal femoral fractures, greatly affect daily functioning and life expectancy. Peripheral neuropathy is an established risk factor for falls. However, the relationship between nerve conduction velocity (CV), action potential (AP), and fall risk or functional recovery after rehabilitation is not well understood. This study aimed to clarify whether sural nerve function can predict fall risk and functional improvement in activities of daily living. Methods We assessed elderly patients hospitalized with proximal femoral fractures in a convalescent rehabilitation ward. Sural nerve function was evaluated using the DPNCheck (NeuroMetrix, Inc., Woburn, MA, USA), with additional data collected on demographics, blood tests, medication use at admission and discharge, incidence of falls during hospitalization, physical function (Short Physical Performance Battery, or SPPB), and activities of daily living (Functional Independence Measure, or FIM). Statistical analyses explored the associations between the sural nerve CV/AP and the collected measures. Results In 27 patients (7 men and 20 women), sural nerve CV and AP were significantly correlated with both SPPB and FIM scores. Logistic regression identified FIM toileting as a significant predictor of reduced sural nerve AP (<5 μV; odds ratio: 3.22, p = 0.025). Multiple regression analysis showed that age and AP were significant predictors of the total FIM cognitive scores at discharge, with an adjusted R² of 0.464. Conclusion This study suggests that sural nerve function may help predict functional abilities in patients with proximal femoral fractures, particularly in the FIM motor tasks. Assessing peripheral nerve function can enhance rehabilitation plans by targeting fall risk management and promoting improvements in daily activities.

Relationship between prenatal metals exposure and neurodevelopment in one-year-old infants in the CLIMB study

BACKGROUND

Prenatal metals exposure and its effects on infant neurodevelopment have garnered significant attention. However, most studies focus on individual metals, neglecting combined effects.

OBJECTIVES

We aimed to assess the effects of both single and combined prenatal metals exposure on one-year-old infants' neurodevelopment.

METHODS

This study included 189 mother-infant pairs from the Complex Lipids in Mothers and Babies (CLIMB) cohort. The concentrations of 21 metallic elements and 2 metalloids in umbilical cord blood (UCB) serum were measured using inductively coupled plasma mass spectrometry (ICP-MS). Neurodevelopment was measured using Chinese version of Bayley Scales of Infant Development (BSID) for the Psychomotor Development Index (PDI) and the Mental Development Index (MDI). Multiple statistical methods, including linear models, restricted cubic splines (RCS), weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR).

RESULTS

After adjusting for potential confounders, prenatal arsenic (As) and strontium (Sr) levels were associated with lower PDI scores (As: β = -2.324; 95 % CI: -4.61, -0.04; Sr: β = -2.426; 95 % CI: -4.67, -0.18) by linear regression, while Sr was associated with lower MDI scores (β = -2.841; 95 % CI: -5.44, -0.25). RCS models revealed nonlinear dose-response relationships between manganese (Mn) and calcium (Ca) with PDI, and for Mn, As, and zirconium (Zr) with MDI. Interactions between certain metals were also identified. Metals mixture had an overall negative effect on both PDI and MDI scores, with Mn being the primary contributor.

CONCLUSION

Prenatal exposure to selected metals or metal mixtures is associated with poorer neurodevelopment in one-year-old infants.

Minerals and Human Health: From Deficiency to Toxicity

Minerals are essential nutrients that play critical roles in human health by regulating various physiological functions. Examples include bone development, enzyme function, nerve signaling, and the immune response. Both the deficiencies and toxicities of minerals can have significant health implications. Deficiencies in macrominerals such as calcium, magnesium, and phosphate can lead to osteoporosis (associated with falls and fractures), cardiovascular events, and neuromuscular dysfunction. Trace mineral deficiencies, such as iron and zinc. Selenium deficiency impairs oxygen transport, immune function, and antioxidant defenses, contributing to anemia, delaying wound healing, and increasing susceptibility to infectious diseases. Conversely, excessive intake of minerals can have severe health consequences. Hypercalcemia can cause kidney stones and cardiac arrhythmias as well as soft-tissue calcification, whereas excessive iron deposition can lead to oxidative stress and organ/tissue damage. Maintaining adequate mineral levels through a balanced diet, guided supplementation, and monitoring at-risk populations is essential for good health and preventing disorders related to deficiencies and toxicities. Public health interventions and education about dietary sources of minerals are critical for minimizing health risks and ensuring optimal well-being across populations. While a comprehensive analysis of all macro and micronutrients is beyond the scope of this article, we have chosen to focus on calcium, magnesium, and phosphate. We summarize the consequences of deficiency and the adverse events associated with the overconsumption of other minerals.

The relationship between dietary phosphorus and peripheral neuropathy in the general population of the United States: A preliminary research

BACKGROUND

Dietary phosphorus intake may serve as a potential predictor for peripheral neuropathy (PN). While past research has predominantly focused on the relationship between dietary phosphorus and bone health, relatively little is known about its role in the nervous system, particularly its association with PN.

METHODS

A cross-sectional study was conducted using data from NHANES 1999-2004. Participants were categorized into different dietary phosphorus intake groups, and the relationship between dietary phosphorus and PN was explored using multifactorial logistic regression, restricted cubic splines (RCS) analysis, and threshold effect analysis based on dietary intake.

RESULTS

The final study included 7726 participants, with 1378 diagnosed with PN and 6348 without. The study revealed a U-shaped non-linear relationship between dietary calcium and magnesium intake levels and PN, indicating that both excessive and insufficient dietary phosphorus intake may increase the risk of PN. Specifically, the incidence rates in the first quintile (1.433, 95% CI: 1.080-1.901), the fourth quintile (1.284, 95% CI: 1.000-1.648), and the fifth quintile (1.533, 95% CI: 1.155-2.035) significantly higher than the second quintile, with an overall trend showing a decrease followed by an increase in incidence rates. The results of RCS and threshold effect analysis indicate that when dietary phosphorus intake is below 939.44mg, the risk of PN decreases with increasing dietary phosphorus intake. On the contrary, when dietary phosphorus intake exceeds 939.44mg, the risk of PN increases with increasing dietary phosphorus intake.

CONCLUSION

This study reveals a U-shaped correlation between dietary phosphorus intake and PN. Future research should further elucidate the molecular mechanisms underlying this association, providing guidance for more scientifically informed dietary adjustments to prevent the occurrence of PN.