Association of Vitamin D, Zinc and Selenium Related Genetic Variants With COVID-19 Disease Severity

Vitamin D receptor gene polymorphisms role in COVID-19 severity: Results of a Mexican patients' cohort

Vitamin D status has been involved with coronavirus disease 19 (COVID-19) severity. This may be mediated by vitamin D metabolism regulatory genes. Of interest is the vitamin D receptor (VDR) gene, which has been previously associated with other inflammatory and respiratory diseases. In order to investigate the role of VDR gene polymorphisms in COVID-19 severity and outcome, a total of 292 COVID-19 patients were classified according to severity in moderate (n = 56), severe (n = 89) and critical (n = 147) and, according to outcome in survivor (n = 163) and deceased (n = 129), and analysed for FokI and TaqI VDR gene polymorphisms by polymerase chain reaction-based restriction enzyme digestion. The FokI and TaqI single nucleotide polymorphisms (SNPs) were not associated with COVID-19 severity or mortality individually but when analysed by haplotype, TC was associated with an increased risk of presenting critical COVID-19. Additionally, FokI CT genotype was more frequent in COVID-19 patients with hypertension, and T allele carriers presented higher aspartate aminotransferase levels. Our results suggest a relationship between VDR FokI and TaqI SNPs and COVID-19 severity in Mexican population. Although there are some previous reports of VDR polymorphisms in COVID-19, this represents the first report in Latin American population. Further studies on other populations are encouraged.

The Association Between CYP2R1 rs10741657 Polymorphisms and Bone Variables, Vitamin D, and Calcium in Iranian Children and Adolescents: A Cross-Sectional Study

Osteoporosis is a common disorder with a strong genetic component. Bone mineral density (BMD), vitamin D, and calcium levels declining are a main contributor of osteoporosis and fragility fractures. This cross-sectional study designed to explore the possible link between CYP2R1 rs10741657 polymorphism and BMD of the total hip, lumbar spine and femoral neck, vitamin D, and calcium in Iranian children and adolescents. 247 children and adolescents (127 girls and 120 boys) between 9 and 18 years old from Kawar (an urban area located 50 km east of Shiraz, the capital city of the Fars province in the south of Iran) were randomly selected based on age-stratified systematic sampling and recruited for genetic analysis. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for genotyping CYP2R1 rs10741657. Anthropometric, biochemical, and bone mineral density (BMD) parameters were also measured. The results specified that in the dominant [P < 0.0001, - 2.943 (- 4.357-1.529)] and over-dominant [P < 0.0001, 2.789 (1.369-4.209)] models, vitamin D concentration significantly differed between genotypes. The highest vitamin D levels were displayed for participants carrying the rs10741657 AG genotype (16.47 ng/ml). In regard to calcium, in a dominant model [P = 0.012, 0.194 (0.043-0.345)] and over-dominant model [P = 0.008, 0.206 (- 0.357-0.055), there was a significant association. AG genotype displayed the highest (9.96 mg/dl) and GG genotype the lowest (9.75 mg/dl) calcium values. This study reported the association of CYP2R1 rs10741657 polymorphisms with calcium and vitamin D levels in Iranian children and adolescents.

Single-nucleotide polymorphisms related to vitamin D metabolism and severity or mortality of COVID-19: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to verify the association between single-nucleotide polymorphisms (SNPs) in vitamin D-related genes and the severity or mortality of coronavirus disease 19 (COVID-19). We systematically searched PubMed, BVS/Bireme, Scopus, Embase, and Web of Science for relevant studies published until November 24, 2023. Twelve studies were included. Thirty-one SNPs related to four genes were studied (VDR, 13 SNPs; GC, 6 SNPs; DHCR7/NADSYN1, 6 SNPs; CYP2R1, 6 SNPs). Eight SNPs were examined in two or more studies (VDR rs731236, rs2228570, rs1544410, rs7975232, rs739837, rs757343, rs11568820, and rs4516035). Meta-analysis showed a significant association between the VDR rs1544410 Bb + bb genotype and b allele and an increased odds of developing severe/critical COVID-19 (Bb + bb vs. BB = 2 studies, OR = 1.73, 95% confidence interval (CI): 1.16-2.57, P = 0.007, I2 = 0%; b allele vs. B allele = 2 studies, OR = 1.31, 95% CI: 1.03-1.67; P = 0.03; I2 = 0%). Regarding the mortality rate, VDR rs731236 TT-genotype, TT + Tt genotype, and T allele; VDR rs1544410 bb-genotype, Bb + bb genotype, and b allele; VDR rs7975232 AA-genotype, AA + Aa genotype, and A allele; and VDR rs2228570 ff-genotype, Ff + ff genotype, and f allele were associated with increased odds of death due to COVID-19. In conclusion, the present study suggests that SNPs rs1544410 may serve as a predictive biomarker for COVID-19 severity and rs731236, rs1544410, rs7975232, and rs2228570 as predictive biomarkers for COVID-19 mortality. More well-designed studies involving a larger number of COVID-19 patients are required to validate and replicate these findings.

Comparing vitamin D receptor gene polymorphisms in rs11568820, rs7970314, rs4334089 between COVID-19 patients with mild and severe symptoms: a case control study

The associations of vitamin D receptor (VDR)- single nucleotide polymorphisms (SNPs) with the symptoms of COVID-19 may vary between patients with different severities of COVID-19. Therefore, in the present study, we aim to compare VDR polymorphisms in severe and mild COVID-19 patients. In this study, a total number of 85 hospitalized patients and 91 mild/moderate patients with COVID-19 were recruited. SNPs in VDR genes were determined using ARMS and then confirmed by sanger sequencing. The mean (SD) age of participants in hospitalized and non-hospitalized group was 59.0 (12.4) and 47.8 (14.8) years, respectively. Almost 46% of participants in hospitalized and 48% of participant in non-hospitalized group were male. The frequency of TT genotype of SNP rs11568820 was significantly lower in hospitalized than non-hospitalized group (3.5% vs. 17.6%; P = 0.018). However, there was no significant differences between genotypes of SNPs rs7970314 and rs4334089 and also alleles frequencies in all SNPs of two groups. The genotype of rs11568820 SNP had an inverse association with hospitalization of patients with COVID-19 after adjustment for comorbidities [OR 0.18, 95% CI 0.04, 0.88; P = 0.034]. While, there was no relationship between genotypes of SNPs rs7970314 and rs4334089 and hospitalization. The TT genotype of rs11568820 plays protective role in sever COVID-19 and hospitalization. Further studies with a large sample size which consider various confounding factors are warranted to confirm our results.

Role of Vitamin D and Vitamin D Polymorphisms in COVID-19 Risk and Severity in Children: A Systematic Review

The role of vitamin D in the susceptibility to coronavirus disease 2019 (COVID-19) disease has been investigated since the beginning of the pandemic, but there is still scarce data on children. We investigated the impact of vitamin D status and the related genetic variants on COVID-19 vulnerability and severity of the disease in children. A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to identify reports on vitamin D status and genetic polymorphisms, their association with the susceptibility of children to COVID-19 and multisystem inflammatory syndrome in children (MIS-C), and the effect of supplementation on the clinical course. Of an initial total of 279 articles, 26 studies, published between September 2020 and May 2023, were finally included in this review according to inclusion criteria. Quantitative data provided by 11 studies revealed that 43.05% of pediatric COVID-19 patients had low vitamin D levels. Mean serum 25(OH)D levels were observed to be significantly low in COVID-19 cases, with an estimated pooled mean value of 17 ng/mL, as provided by 16 studies. Vitamin D deficiency and the vitamin D receptor (VDR) FokI polymorphism may suggest independent risk factors for susceptibility to COVID-19 in the pediatric population. The 25(OH)D level may constitute a significant biomarker associated with the COVID-19 severity and MIS-C. While supplementation of COVID-19 cases with vitamin D showed favorable results, the effect on the outcome of the disease remains uncertain.

Association of genetic polymorphisms with COVID-19 infection and outcomes: An updated meta-analysis based on 62 studies

Background

The relationship between genetic polymorphisms and coronavirus disease 2019 (COVID-19) remains to be inconsistent. This meta-analysis aimed to provide an updated evaluation of the role of genetic polymorphisms in the infection, severity and mortality of COVID-19 based on all available published studies.

Methods

A systematic search was performed using six databases: PubMed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang. Summary odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were used to calculate the genotypic comparison. All statistical analyses were conducted in Stata 12.0.

Results

A total of 62 studies with 19600 cases and 28899 controls was included in this meta-analysis. For COVID-19 infection, ACE Ins/Del polymorphism might be related with significantly decreased risk of COVID-19 infection under dominant, homozygote and allelic models. Meanwhile, the IFITM3 rs12252 and TMPRSS2 rs12329760 polymorphisms were significantly associated with the increased risk of COVID-19 infection under one or more models. Regarding COVID-19 severity, ACE2 rs2074192, ACE2 rs2106809, IFITM3 rs12252 and VDR rs1544410 polymorphisms might be related with significantly increased risk of COVID-19 severity in one or more models. Moreover, the analysis of TMPRSS2 rs2070788 indicated that a variant A allele decreased the risk of COVID-19 severity in recessive model. For COVID-19 mortality, the variant C allele of IFITM3 rs12252 polymorphism might be related with significantly increased risk of COVID-19 mortality under all genetic models.

Conclusions

This meta-analysis indicated that he infection, severity or mortality of COVID-19 were related to the above genetic polymorphisms, which might provide an important theoretical basis for understanding the clinical feature of COVID-19 disease.

Exploring the Influence of VDR Genetic Variants TaqI, ApaI, and FokI on COVID-19 Severity and Long-COVID-19 Symptoms

There is increasing evidence regarding the importance of vitamin D in the prognosis of coronavirus disease 2019 (COVID-19). Genetic variants in the vitamin D receptor (VDR) gene affect the response to vitamin D and have been linked to various diseases. This study investigated the associations of the major VDR genetic variants ApaI, FokI, and TaqI with the severity and long post-infection symptoms of COVID-19. In total, 100 Jordanian patients with confirmed COVID-19 were genotyped for the VDR ApaI, FokI, and TaqI variants using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. COVID-19 severity, the most commonly reported long-COVID-19 symptoms that lasted for >4 weeks from the onset of infection, and other variables were analyzed according to VDR genetic variants. In this study, ApaI and FokI polymorphisms showed no significant associations with COVID-19 severity (p > 0.05). However, a significant association was detected between the TaqI polymorphism and the severity of symptoms after infection with the SARS-CoV-2 virus (p = 0.04). The wild-type TaqI genotype was typically present in patients with mild illness, whereas the heterozygous TaqI genotype was present in asymptomatic patients. With regard to long-COVID-19 symptoms, the VDR heterozygous ApaI and wild-type TaqI genotypes were significantly associated with persistent fatigue and muscle pain after COVID-19 (p ˂ 0.05). Most carriers of the heterozygous ApaI genotype and carriers of the wild-type TaqI genotype reported experiencing fatigue and muscle pain that lasted for more than 1 month after the onset of COVID-19. Furthermore, the TaqI genotype was associated with persistent shortness of breath after COVID-19 (p = 0.003). Shortness of breath was more common among individuals with homozygous TaqI genotype than among individuals with the wild-type or heterozygous TaqI genotype. VDR TaqI is a possible genetic variant related to both COVID-19 severity and long-COVID-19 symptoms among Jordanian individuals. The associations between VDR TaqI polymorphisms and long-COVID-19 symptoms should be investigated in larger and more diverse ethnic populations.

Host genetic polymorphisms involved in long-term symptoms of COVID-19

Host genetic polymorphisms are recognized as a critical determinant of diversity in clinical symptoms of Coronavirus disease 2019 (COVID-19). Accordingly, this study aimed to determine possible associations between single nucleotide polymorphisms (SNPs) in 37 candidate genes and clinical consequences of COVID-19 - especially long-term symptoms, Long COVID. A total of 260 COVID-19 patients, divided into mild (n=239) and severe (n=21) and further categorized based on the presence of Long COVID (no, n=211; yes, n=49), were recruited. Genotyping of selected polymorphisms in 37 genes responsible for viral entry, immune response, and inflammation was performed using MassARRAY system. Out of 37 SNPs, 9 including leucine zipper transcription factor like-1 (LZTFL1) rs10490770 C allele, LZTFL1 rs11385942 dupA allele, nicotinamide adenine dinucleotide synthetase-1 (NADSYN1) rs12785878 TT genotype, plexin A-4 (PLXNA4) rs1424597 AA genotype, LZTFL1 rs17713054 A allele, interleukin-10 (IL10) rs1800896 TC genotype and C allele, angiotensin converting enzyme-2 (ACE2) rs2285666 T allele, and plasmanylethanolamine desaturase-1 (PEDS1) rs6020298 GG genotype and G allele were significantly associated with an increased risk of developing Long COVID, whereas interleukin-10 receptor subunit beta (IL10RB) rs8178562 GG genotype was significantly associated with a reduced risk of Long COVID. Kaplan-Meier curve displayed that polymorphisms in the above genes were significantly associated with cumulative rate of Long COVID occurrence. Polymorphisms in LZTFL1 rs10490770, LZTFL1 rs11385942, LZTFL1 rs17713054, NADSYN1 rs12785878, PLXNA4 rs1424597, IL10 rs1800896, ACE2 rs2285666, PEDS1 rs6020298, and IL10RB rs8178562 appear to be genetic factors involved in development of Long COVID.

Micronutrients, genetics and COVID-19

PURPOSE OF REVIEW

Marked inter-individual differences in the clinical manifestation of coronavirus disease 2019 (COVID-19) has initiated studies in the field of genetics. This review evaluates recent genetic evidence (predominantly in the last 18 months) related to micronutrients (vitamins and trace elements) and COVID-19.

RECENT FINDINGS

In patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), altered circulating levels of micronutrients may serve as prognostic markers of disease severity. Mendelian randomization (MR) studies did not find significant effect of variable genetically predicted levels of micronutrients on COVID-19 phenotypes, however, recent clinical studies on COVID-19 point out to vitamin D and zinc supplementation as a nutritional strategy to reduce disease severity and mortality. Recent evidence also points to variants in vitamin D receptor ( VDR ) gene, most notably rs2228570 (FokI) "f" allele and rs7975232 (ApaI) "aa" genotype as poor prognostic markers.

SUMMARY

Since several micronutrients were included in the COVID-19 therapy protocols, research in the field of nutrigenetics of micronutrients is in progress. Recent findings from MR studies prioritize genes involved in biological effect, such as the VDR gene, rather than micronutrient status in future research. Emerging evidence on nutrigenetic markers may improve patient stratification and inform nutritional strategies against severe COVID-19.

Could Selenium Supplementation Prevent COVID-19? A Comprehensive Review of Available Studies

The purpose of this review is to systematically examine the scientific evidence investigating selenium's relationship with COVID-19, aiming to support, or refute, the growing hypothesis that supplementation could prevent COVID-19 etiopathogenesis. In fact, immediately after the beginning of the COVID-19 pandemic, several speculative reviews suggested that selenium supplementation in the general population could act as a silver bullet to limit or even prevent the disease. Instead, a deep reading of the scientific reports on selenium and COVID-19 that are available to date supports neither the specific role of selenium in COVID-19 severity, nor the role of its supplementation in the prevention disease onset, nor its etiology.

Plasma 25-Hydroxyvitamin D Level and VDR Gene Single Nucleotide Polymorphism rs2228570 Influence on COVID-19 Susceptibility among the Kazakh Ethnic Group-A Pilot Study

Low plasma levels of the vitamin D metabolite 25-hydroxyvitamin D [25(OH)D] and the vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) have been associated with the body's susceptibility to infectious diseases, including COVID-19. In this pilot retrospective study, representatives of the Kazakh population (central Kazakhstan) were divided into groups based on the test for IgM and IgG for coronavirus infection. We compared the 25(OH)D plasma levels and concluded that the COVID-19-positive group values (25.17 ng/mL ± 16.65) were statistically lower (p = 0.0114) compared to the COVID-19-negative ones (35.58 ng/mL ± 20.67). There was no association between age, gender and 25(OH)D concentration within the groups (p > 0.05). The genotyping of rs2228570 was performed using a TaqMan Real-Time PCR assay. Allele C predominated among the COVID-19-negative participants and significantly reduced the likelihood of coronavirus infection (p < 0.0001; OR = 0.0804; 95% CI 0.02357-0.2798). There were no statistically significant differences in the frequencies of the A, G and T alleles in the studied groups (p > 0.05). The GG genotype of rs2228570 was associated with a 4.131-fold increased likelihood of COVID-19 infection (p = 0.0288; χ2 = 5.364; OR = 4.131; 95% CI 1.223-13.71). Comprehensive studies are required to determine whether low 25(OH)D plasma concentrations and genetic background represent a risk factor for COVID-19 infection.

Genetic Variations of the Vitamin D Metabolic Pathway and COVID-19 Susceptibility and Severity: Current Understanding and Existing Evidence

The immunomodulatory and metabolic effects of vitamin D receptor (VDR) activation have been considered beneficial in mitigating the susceptibility and severity of COVID-19 infection. Furthermore, vitamin D-binding protein (DBP) has pleiotropic effects on the immune system that may influence inflammation associated with COVID-19. Multiple observational studies have demonstrated an association between low levels of serum 25-hydroxyvitamin D and risk and the severity of COVID-19 infection. However, the impact of vitamin D supplementation as an adjunctive treatment for COVID-19 based on evidence from randomized clinical trials is unclear. Equally important is that certain variations of the genes involved in the vitamin D metabolic pathway have been shown to affect immune function and linked with various clinical outcomes, including cardio-metabolic disorders, autoimmune diseases, infections, and cancers. This indicates inter-individual difference in body response to vitamin D. There is also emerging evidence that common polymorphisms of these genes may influence the susceptibility and severity of COVID-19, although the confidence of these findings is limited by a small number of studies and participants. Further studies are needed to address the potential role of VDR activation and DBP in the pathophysiology of COVID-19 which take into account the genetic variations of vitamin D metabolic pathway.

Preliminary In Vivo Evidence of Oral Selenium Supplementation as a Potentiating Agent on a Vector-Based COVID-19 Vaccine in BALB/c Mice

Evidence of efficacy and toxicity of oral selenium supplementation in vaccine administration against severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) in mice models is scarce. In this study, 4 × 109 virus particles (40 µL) dose of Janssen COVID-19 intramuscular injection vaccine was supplemented with a commercial selenium supplement and sodium selenite orally in BALB/c mice (N = 18). Qualitative determination of anti-spike IgG antibody response using indirect Enzyme-Linked Immunosorbent Assay (ELISA) showed significant (p ≤ 0.001) increase in anti-spike IgG antibody response for mice groups immunized with vaccine and supplemented selenium. Furthermore, cytokine profiling using real-time quantitative polymerase chain reaction also showed an increase in IL-6 and IL-10 mRNA levels normalized using hypoxanthine phosphoribosyl transferase 1 (Hprt1) and glyceraldehyde 3-phosphate dehydrogenase (Gadph) housekeeping genes. There was no statistical significance (p < 0.465) among treated and untreated groups for alanine transaminase (ALT), aspartate transaminase (AST), urea, and creatinine parameters. The study presents preliminary findings and suggests that supplementing Janssen COVID-19 vaccines with selenium can generate more robust immune responses.

Effects of Selenium on Chronic Kidney Disease: A Mendelian Randomization Study

BACKGROUND

Previous observational studies have shown that there is a controversial association between selenium levels and chronic kidney disease (CKD). Our aim was to assess the causal relationship between selenium levels and CKD using Mendelian randomization (MR) analysis.

METHODS

We used the two-sample Mendelian randomization (MR) method to analyze the causal role of selenium levels on CKD risk. The variants associated with selenium levels were extracted from a large genome-wide association study (GWAS) meta-analysis of circulating selenium levels (n = 5477) and toenail selenium levels (n = 4162) in the European population. Outcome data were from the largest GWAS meta-analysis of European-ancestry participants for kidney function to date. Inverse variance weighted (IVW) method was used as the main analysis and a series of sensitivity analyses were carried out to detect potential violations of MR assumptions.

RESULTS

The MR analysis results indicate that the genetically predicted selenium levels were associated with decreased estimated glomerular filtration (eGFR) (effect = -0.0042, 95% confidence interval [CI]: -0.0053-0.0031, p = 2.186 × 10^-13) and increased blood urea nitrogen (BUN) (effect = 0.0029, 95% confidence interval [CI]: 0.0006-0.0052, p = 0.0136) with no pleiotropy detected.

CONCLUSIONS

The MR study indicated that an increased level of selenium is a causative factor for kidney function impairment.

The association of COVID-19 severity and susceptibility and genetic risk factors: A systematic review of the literature

BACKGROUND

COVID-19 is associated with several risk factors such as distinct ethnicities (genetic ancestry), races, sexes, age, pre-existing comorbidities, smoking, and genetics. The authors aim to evaluate the correlation between variability in the host genetics and the severity and susceptibility towards COVID-19 in this study.

METHODS

Following the PRISMA guidelines, we retrieved all the relevant articles published until September 15, 2021, from two online databases: PubMed and Scopus.

FINDINGS

High-risk HLA haplotypes, higher expression of ACE polymorphisms, and several genes of cellular proteases such as TMPRSS2, FURIN, TLL-1 increase the risk of susceptibility and severity of COVID-19. In addition, upregulation of several genes encoding for both innate and acquired immune systems proteins, mainly CCR5, IFNs, TLR, DPPs, and TNF, positively correlate with COVID-19 severity. However, reduced expression or polymorphisms in genes affecting TLR and IFNλ increase COVID-19 severity.

CONCLUSION

Higher expression, polymorphisms, mutations, and deletions of several genes are linked with the susceptibility, severity, and clinical outcomes of COVID-19. Early treatment and vaccination of individuals with genetic predisposition could help minimize the severity and mortality associated with COVID-19.

Genome-Wide Association Study of COVID-19 Outcomes Reveals Novel Host Genetic Risk Loci in the Serbian Population

Host genetics, an important contributor to the COVID-19 clinical susceptibility and severity, currently is the focus of multiple genome-wide association studies (GWAS) in populations affected by the pandemic. This is the first study from Serbia that performed a GWAS of COVID-19 outcomes to identify genetic risk markers of disease severity. A group of 128 hospitalized COVID-19 patients from the Serbian population was enrolled in the study. We conducted a GWAS comparing (1) patients with pneumonia (n = 80) against patients without pneumonia (n = 48), and (2) severe (n = 34) against mild disease (n = 48) patients, using a genotyping array followed by imputation of missing genotypes. We have detected a significant signal associated with COVID-19 related pneumonia at locus 13q21.33, with a peak residing upstream of the gene KLHL1 (p = 1.91 × 10⁻⁸). Our study also replicated a previously reported COVID-19 risk locus at 3p21.31, identifying lead variants in SACM1L and LZTFL1 genes suggestively associated with pneumonia (p = 7.54 × 10⁻⁶) and severe COVID-19 (p = 6.88 × 10⁻⁷), respectively. Suggestive association with COVID-19 pneumonia has also been observed at chromosomes 5p15.33 (IRX, NDUFS6, MRPL36, p = 2.81 × 10⁻⁶), 5q11.2 (ESM1, p = 6.59 × 10⁻⁶), and 9p23 (TYRP1, LURAP1L, p = 8.69 × 10⁻⁶). The genes located in or near the risk loci are expressed in neural or lung tissues, and have been previously associated with respiratory diseases such as asthma and COVID-19 or reported as differentially expressed in COVID-19 gene expression profiling studies. Our results revealed novel risk loci for pneumonia and severe COVID-19 disease which could contribute to a better understanding of the COVID-19 host genetics in different populations.

The association of ACE1, ACE2, TMPRSS2, IFITM3 and VDR polymorphisms with COVID-19 severity: A systematic review and meta-analysis

Genes involved in the regulation of viral recognition and its entry into a host cell have been identified as candidates for genetic association studies on COVID-19 severity. Published findings on the effects of polymorphisms within ACE1, ACE2, TMPRSS2, IFITM3 and VDR genes remained inconclusive, so we conducted a systematic review and meta-analysis in order to elucidate their potential involvement in the genetic basis underlying the severity of COVID-19 and/or an outcome of SARS-CoV-2 infection. Identification of potentially eligible studies was based on PubMed, Scopus and Web of Science database search. Relevant studies (n=29) with a total number of 8247 SARS-CoV-2-positive participants were included in qualitative synthesis, while results of 21 studies involving 5939 were pooled in meta-analysis. Minor allele I of rs1799752 located within ACE1 was identified as a protective variant against severe COVID-19, while its effect on mortality rate was opposite. Similarly, minor allele A of ACE2 polymorphism, rs2285666, was found to associate with a decreased risk of severe COVID-19 (P = 0.003, OR = 0.512, 95 % CI = 0.331-0.793). Statistical significance was also seen for the association between COVID-19 severity and rs12329760 located within TMPRSS2. Our results did not support the supposed association of rs12252 in IFITM3 and polymorphisms within VDR with disease severity. We conclude that genetic variants within ACE1, ACE2 and TMPRSS2 may be potential biomarkers of COVID-19 severity, which needs to be further confirmed in a larger set of studies.

Genetically Predicted Circulating Concentrations of Micronutrients and COVID-19 Susceptibility and Severity: A Mendelian Randomization Study

Background

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which since 2019 has caused over 5 million deaths to date. The pathogenicity of the virus is highly variable ranging from asymptomatic to fatal. Evidence from experimental and observational studies suggests that circulating micronutrients may affect COVID-19 outcomes.

Objectives

To complement and inform observational studies, we investigated the associations of genetically predicted concentrations of 12 micronutrients (β-carotene, calcium, copper, folate, iron, magnesium, phosphorus, selenium, vitamin B-6, vitamin B-12, vitamin D, and zinc) with SARS-CoV-2 infection risk and COVID-19 severity using Mendelian randomization (MR).

Methods

Two-sample MR was conducted using 87,870 individuals of European descent with a COVID-19 diagnosis and 2,210,804 controls from the COVID-19 host genetics initiative. Inverse variance-weighted MR analyses were performed with sensitivity analyses to assess the impact of potential violations of MR assumptions.

Results

Compared to the general population, nominally significant associations were noted for higher genetically predicted vitamin B-6 (Odds ratio per standard deviation [OR_SD]: 1.06; 95% confidence interval [CI]: 1.00, 1.13; p-value = 0.036) and lower magnesium concentrations (OR_SD: 0.33; 95%CI: 0.11, 0.96; P = 0.042) with COVID-19 infection risk. However, the association for magnesium was not consistent in some sensitivity analyses, and sensitivity analyses could not be performed for vitamin B-6 as only two genetic instruments were available. Genetically predicted levels of calcium, folate, β-carotene, copper, iron, vitamin B-12, vitamin D, selenium, phosphorus, or zinc were not associated with the outcomes from COVID-19 disease.

Conclusion

These results, though based only on genetically predicated circulating micronutrient concentrations, provide scant evidence for possible associations of micronutrients with COVID-19 outcomes.

Hyperglycemia and Loss of Redox Homeostasis in COVID-19 Patients

The infection with SARS-CoV-2 impairs the glucose−insulin axis and this contributes to oxidative (OS) and nitrosative (NSS) stress. Here, we evaluated changes in glucose metabolism that could promote the loss of redox homeostasis in COVID-19 patients. This was comparative cohort and analytical study that compared COVID-19 patients and healthy subjects. The study population consisted of 61 COVID-19 patients with and without comorbidities and 25 healthy subjects (HS). In all subjects the plasma glucose, insulin, 8-isoprostane, Vitamin D, H2S and 3-nitrotyrosine were determined by ELISA. The nitrites (NO2−), lipid-peroxidation (LPO), total-antioxidant-capacity (TAC), thiols, glutathione (GSH) and selenium (Se) were determined by spectrophotometry. The glucose, insulin and HOMA-IR (p < 0.001), 8-isoprostanes, 3-nitrotyrosine (p < 0.001) and LPO were increased (p = 0.02) while Vitamin D (p = 0.01), H2S, thiols, TAC, GSH and Se (p < 0.001) decreased in COVID-19 patients in comparison to HS. The SARS-CoV-2 infection resulted in alterations in the glucose−insulin axis that led to hyperglycemia, hyperinsulinemia and IR in patients with and without comorbidities. These alterations increase OS and NSS reflected in increases or decreases in some oxidative markers in plasma with major impact or fatal consequences in patients that course with metabolic syndrome. Moreover, subjects without comorbidities could have long-term alterations in the redox homeostasis after infection.

Associations between Genetic Variants in the Vitamin D Metabolism Pathway and Severity of COVID-19 among UAE Residents

Vitamin D has many effects on cells in the immune system. Many studies have linked low vitamin D status with severity of COVID-19. Genetic variants involved in vitamin D metabolism have been implicated as potential risk factors for severe COVID-19 outcomes. This study investigated how genetic variations in humans affected the clinical presentation of COVID-19. In total, 646 patients with SARS-CoV-2 infection were divided into two groups: noncritical COVID-19 (n = 453; 70.12%) and a critical group (n = 193; 29.87%). Genotype data on the GC, NADSYN1, VDR, and CYP2R1 genes along with data on serum 25-hydroxyvitamin D levels were compiled in patients admitted to a major hospital in the United Arab Emirates between April 2020 and January 2021. We identified 12 single-nucleotide polymorphisms associated with the critical COVID-19 condition: rs59241277, rs113574864, rs182901986, rs60349934, and rs113876500; rs4944076, rs4944997, rs4944998, rs4944979, and rs10898210; and rs11574018 and rs11574024. We report significant associations between genetic determinants of vitamin D metabolism and COVID-19 severity in the UAE population. Further research needed to clarify the mechanism of action against viral infection in vitamin D deficiency. These variants could be used with vaccination to manage the spread of SARS-CoV-2 and could be particularly valuable in populations in which vitamin D deficiency is common.

Modifiable Risk Factors for SARS-CoV-2

As the COVID-19 pandemic has raged on, considerable research has been performed around the world evaluating the environmental, genetic, lifestyle, and nutritional factors that significantly impact the COVID-19 pandemic. Many studies have now shown that key risk factors for SARS-CoV-2 infection, severity, and even death are modifiable. Patients, whether partially vaccinated, fully vaccinated, or not vaccinated, are expecting their clinicians to provide them with evidence-based guidance and to help them prioritize the factors most important for them. In this editorial we review the current state of the research on modifiable risk factors for SARS-CoV-2 infection, disease severity, and death.