The correlation between vitamin D3 and arginine metabolism levels in newborns with amino acid metabolism disorders

Abstract

This study aimed to explore the correlation between vitamin D3 and arginine (Arg) metabolism indicators in newborns with amino acid metabolism disorders. Based on clinical data, 30 newborns with amino acid metabolism diseases admitted to Shijiazhuang Fourth Hospital from June 2021 to June 2022 were selected as the disease group, and 30 healthy newborns from the same period were selected as the healthy group. After enrollment, blood samples were collected to measure the levels of Arg, Glycine (Gly), and vitamin D3 levels. The levels of Arg metabolism indicators and vitamin D3 levels in the 2 groups and the correlation between vitamin D3 levels and Arg metabolism indicators in the affected group were analyzed. The Arg level in the diseased group was higher than that in the healthy group, whereas the Gly and vitamin D3 levels were lower than those in the healthy group (P < .05). There was a significant negative correlation between vitamin D3 and Arg levels in the affected group, and a significant positive correlation with Gly levels (P < .05). Newborns with amino acid metabolism disorders have abnormally high Arg levels, significantly reduced Gly levels, and significantly decreased vitamin D3 levels. The degree of decline was closely related to the levels of indicators of Arg metabolism. Vitamin D3 supplementation can improve the Arg metabolism status of newborns with amino acid metabolism disorders.

1. Introduction

Genetic metabolic diseases are mainly caused by mutations in genes encoding certain membrane receptors, transporters, enzymes, and other substances involved in the body metabolism and diseases that result in abnormal function of their coding products, leading to metabolic disorders.^[1,2] Amino acid metabolism diseases are also known as aminoaciduria or amino acid diseases.^[3] As an important type of genetic metabolic disease, birth defects are mainly caused by abnormal amino acid metabolism.^[4] It can cause delayed intellectual development, hyperammonemia, and impaired liver function in children. Death may occur in severe cases.^[3–5] Therefore, early diagnosis and evaluation of it is of great significance. This can guide the clinical implementation of targeted interventions as early as possible to ensure disease prognosis.^[6]

Research has found that arginine (Arg) has immune regulation and defense functions and can interact with immune cells, intestinal epithelial cells, etc to improve immune function, and supplementation with Arg can promote the production of various hormones in the body and improve metabolic status.^[7] Glycine (Gly) is an important precursor for glutathione synthesis, which can accelerate protein synthesis and inhibit oxidative stress damage.^[8] In addition, vitamin D plays an important role in maintaining cellular levels and can affect cell proliferation, lipid metabolism, glucose metabolism, and amino acid metabolism. Abnormal vitamin D levels may cause tissue calcification, hyperphosphatemia, hypercalcemia, and amino acid metabolism disorders.^[9]

Based on this, this study aimed to retrospectively select clinical data of newborns with amino acid metabolism disorders in Shijiazhuang Fourth Hospital as the research object and explore the correlation between vitamin D3 and Arg metabolism levels in newborns with amino acid metabolism disorders by setting up a healthy group.

2. Materials and methods

2.1 General information

Clinical data of 30 newborns with amino acid metabolism diseases admitted to Shijiazhuang Fourth Hospital between June 2021 and June 2022 were selected as the disease group, and 30 healthy newborns from the same period were selected as the healthy group based on clinical data.

2.2 Inclusion criteria

The diseased group met the diagnostic criteria for amino acid metabolism diseases;^[3] age range from 1 month to 1 year old; the family members of the research subjects provided informed consent for this study.

2.3 Exclusion criteria

Individuals who had previously received treatment with amino acid metabolism drugs, individuals with organic lesions in other important organs, multiple malformations, individuals with chromosomal disorders, and individuals with severe congenital abnormalities.

2.4 Observation indicators

Arg and Gly: One-time blood collection and acupuncture on the outer or inner side of the heel, with a depth of <3 mm; blood samples were dropped onto a specially designed Scheicher and Schuell 903 filter paper sample card (diameter ≥ 8 mm); all samples were naturally air dried, collected, sealed by a dedicated person, and stored in an environment of 2°C to 8°C for testing; preparation of extraction solutions containing internal standards in proportion, taking circular blood spots (3.2 mm) from filter paper and placing them in a 96 well polypropylene plate; using an excess transfer method, add 100 µL of extraction solution to each well using a multi-channel pipette; seal with a sticky microporous plate and shaken for 45 minutes in a 45°C environment at 750 r/minute in the incubator. After incubation, the mixture was allowed to stand at room temperature for 15 minutes. Transferred 75 µL of filter paper dry blood plate eluent to a heat-resistant 96-well V-shaped plate, the sample was covered with aluminum film and allowed to stand for 120 minutes at room temperature, then detection was performed using a tandem mass spectrometer, and the contents of Arg and Gly in the sample were automatically obtained based on the ion peak intensity of isotopic internal standards and amino acids. Vitamin D3: Extract 4 mL of fasting venous blood from the subject, centrifuge (3500 r/min, 10 minutes), and the supernatant was collected and stored in a dark environment at −80°C for testing, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology. The mass spectrometer was an API4000 LC-MS/MS system (Applied Biosystems Inc.), and the serum from the sample was tested and placed in a centrifuge tube (15 mL). Then, 10 µL of internal standard working solution was added, vortexed, and mixed well; 200 μL of zinc sulfate solution (0.2 mmol/L) was added to the centrifuge tube mentioned above, shaken and mixed evenly, allowed to stand at room temperature for 10 minutes, 500 μL of methanol was added, shaken, and mixed evenly; after protein precipitation, 1 mL of n-hexane/ethyl acetate (2:1) was added, vortexed for 1 minute, and centrifuged (4000 rpm, 10 minutes), and 900 μL of the supernatant was added to a new centrifuge tube. Acetonitrile water (50%) was added to the centrifuge tube and 200 μL again. After centrifugation (4000 r/min, 5 minutes), the supernatant was collected for machine detection, and the serum vitamin D3 content was measured by LC-MS/MS.

2.5 Statistical method

Data were analyzed using SPSS 26.0, mean and standard deviation, t-test, frequency and composition ratio (%), and chi-square test, and the correlation between vitamin D3 levels and Arg metabolism indicators (Arg, Gly) was analyzed using Pearson analysis; P < .05, indicating a statistically significant difference.

3. Results

There was no significant difference in the basic information between the diseased and healthy groups (P > .05) (Table 1). Arg levels in the affected group were significantly higher than those in the healthy group, whereas Gly and vitamin D3 levels were significantly lower than those in the healthy group (P < .05) (Fig. 1). The Pearson test confirmed that there was a significant negative correlation between vitamin D3 level and Arg level in the patient group and a significant positive correlation with Gly level (P < .05) (Fig. 2).

Table 1.

Comparison of general information between 2 groups.

Item	Patient group (n = 30)	Health group (n = 30)	t/χ2	P
Gender [n (%)]
Male	14 (46.67)	20 (66.67)	2.443	.118
Female	16 (53.33)	10 (33.33)
Age (mo)	6.87 ± 2.53	6.50 ± 2.24	0.594	.555
Delivery method
Vaginal delivery	19 (63.33)	21 (70.00)	0.300	.584
Cesarean section	11 (36.67)	9 (30.00)
Birth weight (g)	2878.7 ± 449.2	2978.7 ± 602.5	-0.729	.469
Gestational age (wk)	36.87 ± 1.94	36.20 ± 2.06	1.290	.202

Figure 1.

Comparison of Arg, Gly, and vitamin D3 levels between the 2 groups. Arg = arginine, Gly = glycine.

Figure 2.

Correlation between vitamin D3, Arg, and Gly in patients with patient group. Arg = arginine, Gly = glycine.

4. Discussion

The results of this study confirmed that there was a certain degree of Arg Gly metabolism disorder in newborns with amino acid metabolic disease, which manifested as an abnormal increase in Arg levels and a significant decrease in Gly levels. At the same time, Annette et al^[10] discussed the application value of Arg in the screening of neonatal hyperargininemia; The results showed that Arg could be used as an important diagnostic marker of neonatal hyperargininemia, and could be used to identify children with arginase deficiency and unaffected newborns. David et al^[11] pointed out that Arg was abnormally increased in children with neonatal arginase deficiency, and the diagnosis of neonatal arginase deficiency by Arg could improve the sensitivity and accuracy of diagnosis, so as to ensure that children receive targeted intervention as soon as possible and avoid delaying the best intervention time. Research also shows that as an immunonutritional amino acid, Arg can not only provide the energy required by the body, but also reduce the harmful and excessive inflammatory reaction, strengthen the immune function of the body, promote the repair of intestinal mucosal barrier function, and maintain the integrity of the intestinal mucosal barrier function, so as to restore the stability of the body. Andrea et al^[12] explored the clinical value of Arg with pregnant women as the research object; The results showed that abnormal Arg could affect the maternal and fetal hemodynamic status and increase the risk of adverse maternal and fetal outcomes; As a double base amino acid, Arg is not a necessary amino acid for adults; However, in some cases, if the body is not yet mature and the body is under inflammatory stress, the abnormal expression of Arg is difficult to maintain the normal physiological function and positive nitrogen balance of the body; And for infants (especially premature infants), abnormal Arg expression can affect their growth and development. Olivier et al^[13] confirmed in mouse experiments that for those with weakened hepatic enzyme metabolic activity, insufficient synthetase content, immature liver development, and low body mass, in vivo stress regulation can cause changes in Gly content. Mohammed et al^[14] found that Gly levels in children with congenital metabolic defects decreased abnormally, which is consistent with the results of this study, confirming that Gly is an important precursor for the synthesis of glutathione, which can promote protein synthesis, reduce the degree of oxidative stress damage, and play an important role in the growth and proliferation of the intestinal epithelium.

This study also confirmed that vitamin deficiency is prevalent in newborns with amino acid metabolic disease. Bacchetta et al^[15] also confirmed that vitamin D plays an important role in cell proliferation, amino acid metabolism, lipid metabolism, glucose metabolism, etc; if the vitamin D level is insufficient, it may also cause tissue calcification, hyperphosphatemia, hypercalcemia, atherosclerosis, and amino acid metabolic diseases. It is consistent with this study. Kim et al^[16] found that vitamin D3 can inhibit cell growth in a time- and dose-dependent manner. The levels of glutamate, methionine, and glutamine in the cell lines of patients in the vitamin D group with an IC50 dose (145 nmol/L) were affected to varying degrees; acylcarnitine content was abnormally increased compared with the healthy group. Neelakanta et al^[17] also confirmed that exogenous 1,25-(OH) 2D supplementation can effectively upregulate the expression and protein levels of glutamate cysteine ligase and glutathione reductase in monocytes and promote the formation of glutathione.

Additionally, this study explored the correlation between vitamin D3 and Arg metabolism in neonates with amino acid metabolic diseases. Results: The Pearson test showed that vitamin D3 levels were negatively correlated with Arg levels and significantly positively correlated with Gly levels in neonates with amino acid metabolic disease (P < .05). Therefore, it is believed that clinical practice can regulate the metabolism of Arg Gly and improve the health status, growth, and development of newborns with amino acid metabolic diseases by supplementing vitamins.

Limitations: First, all participants were recruited from the same hospital. Second, neither group was randomly assigned, and the baseline information may have been unbalanced or biased. In the future, will continue to conduct higher-quality research to verify this conclusion.

5. Conclusion

The level of Arg in newborns with amino acid metabolic disease is abnormally increased, and the level of Gly is significantly decreased. The level of vitamin D3 decreased significantly, and the degree of decline was closely related to the Arg Gly metabolism index. Vitamin D3 supplementation can improve Arg Gly metabolism in neonates with amino acid metabolic diseases.

Author contributions

Conceptualization: Yao Zhang.

Data curation: Yao Zhang, Yanjie Han.

Formal analysis: Shikuan Hou.

Investigation: Suyan Gu, Wei Han.

Writing – original draft: Yao Zhang.

Writing – review & editing: Yao Zhang.