Magnesium intake and mortality due to liver diseases: Results from the Third National Health and Nutrition Examination Survey Cohort

A Comprehensive Investigation of Dietary Micronutrient Intakes and Risk of Alcoholic Liver Disease

BACKGROUND

The investigation of dietary micronutrient intakes and risk of alcoholic liver disease (ALD) based on observational studies was limited.

OBJECTIVES

Our study aimed to explore the associations of 30 dietary micronutrients intakes with risk of ALD, interactions between dietary micronutrients and genetic variation, and mediation effects of blood and urinary biomarkers on the associations between dietary micronutrients and risk of ALD.

METHODS

A case-control study was conducted within the UK Biobank cohort, with 231 incident ALD cases and 1386 controls. Dietary data were collected using a dietary questionnaire that relied on a 24-h dietary recall of the previous day. Logistic regression models were employed to assess the associations of dietary micronutrient intakes with risk of ALD. We conducted stratified analyses on the associations between dietary micronutrient intakes and risk of ALD by PNPLA3 rs738409 and tested the interactions between dietary micronutrients and genetic variation. In addition, we conducted mediation analyses to investigate the mediating effects of biomarkers on the associations between dietary micronutrients and risk of ALD.

RESULTS

Our findings indicated significant inverse associations of thiamin, riboflavin, niacin equivalent, pantothenic acid, vitamin B-6, folate, vitamin E, calcium, magnesium, phosphorus, potassium, copper, iodine, and manganese with risk of ALD (all false discovery rate-Ptrend < 0.050). We also found a significant interaction between PNPLA3 rs738409 and magnesium (Pinteraction = 0.028). Creatinine (enzymatic) in urine, aspartate aminotransferase, and insulin-like growth factor 1 were the top 3 biomarkers with the highest number of significant mediation effects on the associations between the dietary micronutrients and risk of ALD.

CONCLUSIONS

Dietary intakes of thiamin, riboflavin, niacin equivalent, pantothenic acid, vitamin B-6, folate, vitamin E, calcium, magnesium, phosphorus, potassium, copper, iodine, and manganese were inversely associated with risk of ALD.

Exploring the link: magnesium intake and hepatic steatosis in Americans

Purpose

The connection between magnesium and hepatic steatosis has not been well-studied. This study aimed to explore the link between magnesium intake and hepatic steatosis, utilizing data from the National Health and Nutrition Examination Survey (NHANES) 2017-2020.

Materials and methods

The analysis included 5,935 participants, excluding individuals with hepatitis infection or substantial alcohol consumption. Magnesium intake assessment was based on 24-h dietary recalls. Hepatic steatosis evaluation employed the controlled attenuation parameter (CAP), measured via transient elastography. Multivariate regression and subgroup analyses were conducted to scrutinize the relationship between magnesium intake and CAP values.

Results

A higher magnesium intake was associated with lower CAP values, after adjusting for potential confounders. Subgroup analyses indicated an inverted U-shaped correlation between magnesium intake and CAP in women, White people, and non-hypertensive individuals, with respective inflection points at 126, 124.5, and 125 mg/day, respectively. Below these thresholds, a higher magnesium intake correlated with increased CAP values, while above these points, it was associated with decreased CAP.

Conclusion

This extensive population-based study indicates an inverse relationship between magnesium intake and hepatic steatosis in Americans. This relationship displays an inverted U-curve, varying before and after specified inflection points in women, White people, and non-hypertensive individuals. These findings offer insights into tailored magnesium supplementation strategies for preventing and treating liver steatosis, based on gender and ethnicity.

Differential Protective Effect of Zinc and Magnesium for the Hepatic and Renal Toxicity Induced by Acetaminophen and Potentiated with Ciprofloxacin in Rats

Background and Objectives: The purpose of this study was to investigate the influence induced by magnesium chloride (MgCl2) and zinc gluconate (ZnG) supplementation on liver and kidney injuries experimentally induced with acetaminophen (AAPh) and potentiated by a ciprofloxacin addition in rats. Material and Methods: The experiment was performed on five animal groups: group 1-control, treated for 6 weeks with normal saline, 1 mL/kg; group 2-AAPh, treated for 6 weeks with AAPh, 100 mg/kg/day; group 3-AAPh + C, treated for 6 weeks with AAPh 100 mg/kg/day and ciprofloxacin 50 mg/kg/day, only in the last 14 days of the experiment; group 4-AAPh + C + Mg, with the same treatment as group 3, but in the last 14 days, MgCl2 10 mg/ kg/day was added; and group 5-AAPh + C + Zn, with the same treatment as group 3, but in the last 14 days, zinc gluconate (ZnG), 10 mg/kg/day was added. All administrations were performed by oral gavage. At the end of the experiment, the animals were sacrificed and blood samples were collected for biochemistry examinations. Results: Treatment with AAPh for 6 weeks determined an alteration of the liver function (increases in alanine aminotransferase, aspartate aminotransferase, lactic dehydrogenase, and gamma-glutamyl transferase) and of renal function (increases in serum urea and creatinine) (p < 0.001 group 2 vs. group 1 for all mentioned parameters). Furthermore, the antioxidant defense capacity was impaired in group 2 vs. group 1 (superoxide dismutase and glutathione peroxidase activity decreased in group 2 vs. group 1, at 0.001 < p < 0.01 and 0.01 < p < 0.05, respectively). The addition of ciprofloxacin, 50 mg/kg/day during the last 14 days, resulted in further increases in alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, urea, and creatinine (0.01 < p < 0.05, group 3 vs. group 2). MgCl2 provided a slight protection against the increase in liver enzymes, and a more pronounced protection against the increase in serum urea and creatinine (0.001 < p < 0.01 group 4 vs. group 3). MgCl2 provided a slight protection against the decrease in superoxide dismutase (0.01 < p < 0.05 group 4 vs. group 3), but not against decrease of glutathione peroxidase. The improvement of mentioned parameters could also be seen in the case of ZnG, to a higher extent, especially in the case of alanine aminotransferase and lactic dehydrogenase (0.01 < p < 0.05 group 5 vs. group 4). Conclusions: This study presents further proof for the beneficial effect of magnesium and zinc salts against toxicity induced by different agents, including antibacterials added to the analgesic and antipyretic acetaminophen; the protection is proven on the liver and kidney's function, and the antioxidant profile improvement has a key role, especially in the case of zinc gluconate.

Ratiometric Fluorescent Sensors Illuminate Cellular Magnesium Imbalance in a Model of Acetaminophen-Induced Liver Injury

Magnesium(II) plays catalytic, structural, regulatory, and signaling roles in living organisms. Abnormal levels of this metal have been associated with numerous pathologies, including cardiovascular disease, diabetes, metabolic syndrome, immunodeficiency, cancer, and, most recently, liver pathologies affecting humans. The role of Mg2+ in the pathophysiology of liver disease, however, has been occluded by concomitant changes in concentration of interfering divalent cations, such as Ca2+, which complicates the interpretation of experiments conducted with existing molecular Mg2+ indicators. Herein, we introduce a new quinoline-based fluorescent sensor, MagZet1, that displays a shift in its excitation and emission wavelengths, affording ratiometric detection of cellular Mg2+ by both fluorescence microscopy and flow cytometry. The new sensor binds the target metal with a submillimolar dissociation constant─well suited for detection of changes in free Mg2+ in cells─and displays a 10-fold selectivity against Ca2+. Furthermore, the fluorescence ratio is insensitive to changes in pH in the physiological range, providing an overall superior performance over existing indicators. We provide insights into the metal selectivity profile of the new sensor based on computational modeling, and we apply it to shed light on a decrease in cytosolic free Mg2+ and altered expression of metal transporters in cellular models of drug-induced liver injury caused by acetaminophen overdose.

Severity of Hepatocyte Damage and Prognosis in Cirrhotic Patients Correlate with Hepatocyte Magnesium Depletion

We aimed to evaluate the magnesium content in human cirrhotic liver and its correlation with serum AST levels, expression of hepatocellular injury, and MELDNa prognostic score. In liver biopsies obtained at liver transplantation, we measured the magnesium content in liver tissue in 27 cirrhotic patients (CIRs) and 16 deceased donors with healthy liver (CTRLs) by atomic absorption spectrometry and within hepatocytes of 15 CIRs using synchrotron-based X-ray fluorescence microscopy. In 31 CIRs and 10 CTRLs, we evaluated the immunohistochemical expression in hepatocytes of the transient receptor potential melastatin 7 (TRPM7), a magnesium influx chanzyme also involved in inflammation. CIRs showed a lower hepatic magnesium content (117.2 (IQR 110.5-132.9) vs. 162.8 (IQR 155.9-169.8) μg/g; p < 0.001) and a higher percentage of TRPM7 positive hepatocytes (53.0 (IQR 36.8-62.0) vs. 20.7 (10.7-32.8)%; p < 0.001) than CTRLs. In CIRs, MELDNa and serum AST at transplant correlated: (a) inversely with the magnesium content both in liver tissue and hepatocytes; and (b) directly with the percentage of hepatocytes stained intensely for TRPM7. The latter also directly correlated with the worsening of MELDNa at transplant compared to waitlisting. Magnesium depletion and overexpression of its influx chanzyme TRPM7 in hepatocytes are associated with severity of hepatocyte injury and prognosis in cirrhosis. These data represent the pathophysiological basis for a possible beneficial effect of magnesium supplementation in cirrhotic patients.

Drinking and laboratory biomarkers, and nutritional status characterize the clinical presentation of early-stage alcohol-associated liver disease

Chronic and heavy alcohol consumption is commonly observed in alcohol use disorder (AUD). AUD often leads to alcohol-associated organ injury, including alcohol-associated liver disease (ALD). Approximately 10-20% of patients with AUD progress to ALD. Progression of ALD from the development phase to more advanced states involve the interplay of several pathways, including nutritional alterations. Multiple pathologic processes have been identified in the progression and severity of ALD. However, there are major gaps in the characterization and understanding of the clinical presentation of early-stage ALD as assessed by clinical markers and laboratory measures. Several Institutions and Universities, including the University of Louisville, in collaboration with the National Institutes of Health, have published a series of manuscripts describing early-stage ALD over the past decade. Here, we comprehensively describe early-stage ALD using the liver injury and drinking history markers, and the laboratory biomarkers (with a focus on nutrition status) that are uniquely involved in the development and progression of early-stage ALD.

Characterization of Hypomagnesemia in Alcoholic Hepatitis Patients and Its Association with Liver Injury and Severity Markers

INTRODUCTION

Hypomagnesemia has been documented in alcohol-associated liver disease (ALD). This study aims to characterize hypomagnesemia in alcoholic hepatitis (AH) patients and identify its response with liver injury and severity markers.

MATERIALS AND METHODS

A total of 49 male and female AH patients with an age range of 27-66 years were enrolled in this study. Patients were grouped by MELD: MiAH (mild AH < 12 [n = 5]), MoAH (12 ≤ moderate AH ≤ 19 [n = 13]), and SAH (severe AH ≥ 20 [n = 31]). Patients were also evaluated by MELD grouping as non-severe (MELD ≤ 19 [n = 18]) and severe (MELD ≥ 20 [n = 31]). Data were collected on demographics (Age; BMI), drinking history (AUDIT; LTDH), liver injury (ALT; AST), and liver severity (Maddrey's DF; MELD; AST:ALT). Serum magnesium (SMg) levels were tested as SOC lab (normal ≥ 0.85 ≤ 1.10 mmol/L).

RESULTS

SMg was deficient in each group; the lowest in the MoAH patients. The true positivity of SMg values were at a good performance level when compared between severe and non-severe AH patients (AUROC: 0.695, p = 0.034). We found that the SMg level < 0.78 mmol/L could predict severe AH (sensitivity = 0.100 and 1-specificity = 0.000) at this true positivity, and subsequently analyzed patients with SMg < 0.78 mmol/L (Gr.4) and ≥0.78 mmol/L (Gr.5). Between Gr.4 and Gr.5, there were clinically as well as statistically significant differences in disease severity as defined by MELD, Maddrey's DF, and ABIC scores.

CONCLUSIONS

This study demonstrates the utility of SMg levels to identify AH patients who may have progressed to severe status. The extent of magnesium response in AH patients also corresponded significantly with the prognosis of liver disease. Physicians suspecting AH in patients with recent heavy drinking may use SMg as an indicator to guide further testing, referrals, or treatment.

Restoring cellular magnesium balance through Cyclin M4 protects against acetaminophen-induced liver damage

Acetaminophen overdose is one of the leading causes of acute liver failure and liver transplantation in the Western world. Magnesium is essential in several cellular processess. The Cyclin M family is involved in magnesium transport across cell membranes. Herein, we identify that among all magnesium transporters, only Cyclin M4 expression is upregulated in the liver of patients with acetaminophen overdose, with disturbances in magnesium serum levels. In the liver, acetaminophen interferes with the mitochondrial magnesium reservoir via Cyclin M4, affecting ATP production and reactive oxygen species generation, further boosting endoplasmic reticulum stress. Importantly, Cyclin M4 mutant T495I, which impairs magnesium flux, shows no effect. Finally, an accumulation of Cyclin M4 in endoplasmic reticulum is shown under hepatoxicity. Based on our studies in mice, silencing hepatic Cyclin M4 within the window of 6 to 24 h following acetaminophen overdose ingestion may represent a therapeutic target for acetaminophen overdose induced liver injury.

Ca:Mg ratio, medium-chain fatty acids, and the gut microbiome

BACKGROUND & AIMS

Ketogenic medium-chain fatty acids (MCFAs) with profound health benefits are commonly found in dairy products, palm kernel oil and coconut oil. We hypothesize that magnesium (Mg) supplementation leads to enhanced gut microbial production of MCFAs and, in turn, increased circulating MCFAs levels.

METHODS

We tested this hypothesis in the Personalized Prevention of Colorectal Cancer Trial (PPCCT) (NCT01105169), a double-blind 2 × 2 factorial randomized controlled trial enrolling 240 participants. Six 24-h dietary recalls were performed for all participants at the baseline and during the intervention period. Based on the baseline 24-h dietary recalls, the Mg treatment used a personalized dose of Mg supplementation that would reduce the calcium (Ca): Mg intake ratio to around 2.3. We measured plasma MCFAs, sugars, ketone bodies and tricarboxylic acid cycle (TCA cycle) metabolites using the Metabolon's global Precision Metabolomics™ LC-MS platform. Whole-genome shotgun metagenomics (WGS) sequencing was performed to assess microbiota in stool samples, rectal swabs, and rectal biopsies.

RESULTS

Personalized Mg treatment (mean dose 205.58 mg/day with a range from 77.25 to 389.55 mg/day) significantly increased the plasma levels of C7:0, C8:0, and combined C7:0 and C8:0 by 18.45%, 25.28%, and 24.20%, respectively, compared to 14.15%, 10.12%, and 12.62% decreases in the placebo arm. The effects remain significant after adjusting for age, sex, race and baseline level (P = 0.0126, P = 0.0162, and P = 0.0031, respectively) and FDR correction at 0.05 (q = 0.0324 for both C7:0 and C8:0). Mg treatment significantly reduced the plasma level of sucrose compared to the placebo arm (P = 0.0036 for multivariable-adjusted and P = 0.0216 for additional FDR correction model) whereas alterations in daily intakes of sucrose, fructose, glucose, maltose and C8:0 from baseline to the end of trial did not differ between two arms. Mediation analysis showed that combined C7:0 and C8:0 partially mediated the effects of Mg treatment on total and individual ketone bodies (P for indirect effect = 0.0045, 0.0043, and 0.03, respectively). The changes in plasma levels of C7:0 and C8:0 were significantly and positively correlated with the alterations in stool microbiome α diversity (r = 0.51, p = 0.0023 and r = 0.34, p = 0.0497, respectively) as well as in stool abundance for the signatures of MCFAs-related microbiota with acyl-ACP thioesterase gene producing C7:0 (r = 0.46, p = 0.0067) and C8:0 (r = 0.49, p = 0.003), respectively, following Mg treatment.

CONCLUSIONS

Optimizing Ca:Mg intake ratios to around 2.3 through 12-week personalized Mg supplementation leads to increased circulating levels of MCFAs (i.e. C7:0 and C8:0), which is attributed to enhanced production from gut microbial fermentation and, maybe, sucrose consumption.

Association of Hypomagnesemia and Liver Injury, Role of Gut-Barrier Dysfunction and Inflammation: Efficacy of Abstinence, and 2-Week Medical Management in Alcohol Use Disorder Patients

(1) We investigated the involvement of serum magnesium level in early alcoholic liver disease (ALD), gut barrier dysfunction, and inflammation in alcohol use disorder (AUD) patients; and lastly, the efficacy of 2-week abstinence and medical management to alleviate hypomagnesemia. (2) Forty-eight heavy drinking AUD patients (34 males (M)/14 females (F)) participated in this study. Patients were grouped by serum alanine aminotransferase (ALT) level (a marker of liver injury) as group 1 (Group 1 (Gr.1); ALT ≤ 40 U/L, 7M/8F, without any indication of early-stage ALD) and group 2 (Group 2 (Gr.2); ALT > 40 U/L, 27M/6F or early-stage ALD). These patients were sub-divided within each group into patients with normal magnesium (0.85 and more mmol/L) and deficient magnesium (less than 0.85 mmol/L) levels. All participants were assessed at baseline (BL) and received standard medical management for 2 weeks with reassessment at the treatment end (2w). (3) Female participants of this study showed a significantly lower baseline level of magnesium than their male counterparts. Gr.2 patients showed a greater propensity in the necrotic type of liver cell death, who reported higher chronic and recent heavy drinking. Magnesium level improved to the normal range in Gr.2 post-treatment, especially in the hypomagnesemia sub-group (0.77 ± 0.06 mmol/L (BL) vs. 0.85 ± 0.05 mmol/L (2w), p = 0.02). In Gr.2, both apoptotic (K18M30) and necrotic (K18M65) responses were significantly and independently associated with inflammasome activity comprising of LBP (Lipopolysaccharide binding-protein) and TNFα (Tumor necrosis factor -α), along with serum magnesium. (4) In AUD patients with liver injury, 2-week medical management seems to improve magnesium to a normal level. This group exhibited inflammatory activity (LBP and TNFα) contributing to clinically significant hypomagnesemia. In this group, the level of magnesium, along with the unique inflammatory activity, seems to significantly predict apoptotic and necrotic types of hepatocyte death.

Heavy metals exposure is associated with early liver dysfunction among rural residents aged 40-75 years in southwest China

Heavy metals exposure has been associated with liver dysfunction in recent reports, while the hepatoxicity of lead (Pb) and cadmium (Cd) has been well established. However, the combined effects of multi-metal in real-world scenario on liver dysfunction are still unclear. This cross-sectional study examined associations between 10 biomarkers of early liver injury and multiple heavy metals levels. The levels of heavy metals/metalloid (magnesium [Mg], calcium [Ca], iron [Fe], zinc [Zn], arsenic [As], Cd, copper [Cu], and Pb) were measured in blood and urinary sample collected from 725 participants in a Cd-polluted area and an unpolluted area in southwest China. The early liver dysfunction biomarkers included the liver enzymes (ALT, ALP, AST, and GGT), proteins (TP, ALB, and GLO), and bilirubin (TBIL, DBIL, and IBIL). Confounder-adjusted beta coefficients were determined using multiple linear regression model analysis for the group-classified and gender-classified samples. Our results showed that blood Fe, Cd, and Cu levels were found to be positively related to elevated ALT levels and blood Cu was positively associated with AST levels in the Cd-polluted area, while the highest blood Zn quartile in the polluted area and blood Mg quartile in the unpolluted area were associated with lower ALT levels. Our finding implies that industrial pollution results in heavy metals of Cd and Pb exposure and effects of Fe, Cd, Cu, and Pb in the Cd-polluted area may be the main contributors to increase the risk of liver dysfunction while Zn in the Cd-polluted area and Mg in the unpolluted area may be the protective factors.

The Role of Micronutrients in the Pathogenesis of Alcohol-Related Liver Disease

AIMS

Chronic alcohol consumption may result in liver injury and chronic liver disease, but other factors are likely to influence disease progression. Malnutrition, specifically micronutrient deficiency, is frequently associated with both alcohol use disorder and chronic liver disease. We hypothesize that micronutrient deficiencies may affect the progression of liver disease in this population.

METHODS

Systematic integrative review of the medical literature; electronic search of MEDLINE 1950-2021; studies investigating role of any micronutrient in the acceleration of alcohol-related liver injury in humans or animals. Studies which specifically related to alcoholic hepatitis were excluded. Outcomes were extracted and recorded in tabulated form and discussed narratively.

RESULTS

We identified 46 studies investigating the role of micronutrient deficiencies in the pathogenesis of alcohol-related liver disease. Specific micronutrients which were identified included folic acid or related B vitamins (n = 9 studies), Vitamin D (n = 9 studies), magnesium (n = 8 studies), zinc (n = 8 studies) and selenium (n = 12 including one systematic review). Observational evidence suggests a potential role of magnesium deficiency in accelerating alcohol-related liver injury with weak or negative evidence for other micronutrients.

CONCLUSIONS

Magnesium deficiency may increase the risk of alcohol-related liver injury and adverse liver outcomes. However, currently, there is insufficient evidence to support magnesium supplementation except for clinically relevant magnesium deficiency. Long-term prospective cohort studies assessing the impact of micronutrients on liver disease progression in patients with alcohol use disorder are lacking and may help determine whether there is a causal role for micronutrient deficiencies in alcohol-related liver injury.

Magnesium accumulation upon cyclin M4 silencing activates microsomal triglyceride transfer protein improving NASH

BACKGROUND & AIMS

Perturbations of intracellular magnesium (Mg2+) homeostasis have implications for cell physiology. The cyclin M family, CNNM, perform key functions in the transport of Mg2+ across cell membranes. Herein, we aimed to elucidate the role of CNNM4 in the development of non-alcoholic steatohepatitis (NASH).

METHODS

Serum Mg2+ levels and hepatic CNNM4 expression were characterised in clinical samples. Primary hepatocytes were cultured under methionine and choline deprivation. A 0.1% methionine and choline-deficient diet, or a choline-deficient high-fat diet were used to induce NASH in our in vivo rodent models. Cnnm4 was silenced using siRNA, in vitro with DharmaFECT and in vivo with Invivofectamine® or conjugated to N-acetylgalactosamine.

RESULTS

Patients with NASH showed hepatic CNNM4 overexpression and dysregulated Mg2+ levels in the serum. Cnnm4 silencing ameliorated hepatic lipid accumulation, inflammation and fibrosis in the rodent NASH models. Mechanistically, CNNM4 knockdown in hepatocytes induced cellular Mg2+ accumulation, reduced endoplasmic reticulum stress, and increased microsomal triglyceride transfer activity, which promoted hepatic lipid clearance by increasing the secretion of VLDLs.

CONCLUSIONS

CNNM4 is overexpressed in patients with NASH and is responsible for dysregulated Mg2+ transport. Hepatic CNNM4 is a promising therapeutic target for the treatment of NASH.

LAY SUMMARY

Cyclin M4 (CNNM4) is overexpressed in non-alcoholic steatohepatitis (NASH) and promotes the export of magnesium from the liver. The liver-specific silencing of Cnnm4 ameliorates NASH by reducing endoplasmic reticulum stress and promoting the activity of microsomal triglyceride transfer protein.

The relation between acute changes in the systemic inflammatory response and circulating thiamine and magnesium concentrations after elective knee arthroplasty

Thiamine diphosphate (TDP) and magnesium are co-factors for key enzymes in human intermediary metabolism. However, their role in the systemic inflammatory response (SIR) is not clear. Therefore, the aim of the present study was to examine the relation between acute changes in the SIR and thiamine and magnesium dependent enzyme activity in patients undergoing elective knee arthroplasty (a standard reproducible surgical injury in apparently healthy individuals). Patients (n = 35) who underwent elective total knee arthroplasty had venous blood samples collected pre- and post-operatively for 3 days, for measurement of whole blood TDP, serum and erythrocyte magnesium, erythrocyte transketolase activity (ETKA), lactate dehydrogenase (LDH), glucose and lactate concentrations. Pre-operatively, TDP concentrations, erythrocyte magnesium concentrations, ETKA and plasma glucose were within normal limits for all patients. In contrast, 5 patients (14%) had low serum magnesium concentrations (< 0.75 mmol/L). On post-operative day1, both TDP concentrations (p < 0.001) and basal ETKA (p < 0.05) increased and serum magnesium concentrations decreased (p < 0.001). Erythrocyte magnesium concentrations correlated with serum magnesium concentrations (r_s = 0.338, p < 0.05) and remained constant during SIR. Post-operatively 14 patients (40%) had low serum magnesium concentrations. On day1 serum magnesium concentrations were directly associated with LDH (p < 0.05), WCC (p < 0.05) and neutrophils (p < 0.01). Whole blood TDP and basal ETKA increased while serum magnesium concentrations decreased, indicating increased requirement for thiamine and magnesium dependent enzyme activity during SIR. Therefore, thiamine and magnesium represent potentially modifiable therapeutic targets that may modulate the host inflammatory response. Erythrocyte magnesium concentrations are likely to be reliable measures of status, whereas serum magnesium concentrations and whole blood TDP may not.

ClinicalTrials.gov: NCT03554668.

Magnesium deficiency in liver cirrhosis: a retrospective study

BACKGROUND

Magnesium, known as "the forgotten electrolyte", is an essential element of life. Magnesium deficiency is implicated in many diseases, including liver cirrhosis. This study aimed to explore the prevalence of magnesium deficiency in liver cirrhosis and investigate the relationship between magnesium levels and complication of liver cirrhosis and clinical outcomes.

PATIENTS AND METHODS

Cirrhotic patients with serum magnesium levels measured were retrospectively identified from 2016 to 2017. Demographics, laboratory parameters, complications were collected. The Child-Pugh class, MELD score, and ALBI score were calculated.

RESULTS

The mean serum magnesium level of all 152 patients was lower than the normal, including 92 patients diagnosed with magnesium deficiency. Compared to Child-Pugh class A, magnesium levels were significantly lower in the patients with Child-Pugh class B or C (F = 10.26, p < .05). Magnesium levels were also considerably lower in the group with MELD score ≥21, compared to the other two groups with MELD score < 15 or 15-20 (F = 6.59, p < .05). Similarly, magnesium levels were significantly lower in the group with ALBI score > -1.39 (grade 3), compared to the other two groups with ALBI with score ≤ -2.6 (grade 1) or > -2.6, ≤ -1.39 (grade 2) (F = 8.44, p<.001). Furthermore, magnesium levels were lower in cirrhotic patients with infection. Magnesium-deficient patients had lower transplant-free survival rates than non-deficient patients.

CONCLUSION

Magnesium deficiency is highly prevalent in cirrhotic patients. Magnesium deficiency is related to worse transplant-free survival, infection and the severity of liver cirrhosis.

Magnesium intake is associated with a reduced risk of incident liver cancer, based on an analysis of the NIH-American Association of Retired Persons (NIH-AARP) Diet and Health Study prospective cohort

BACKGROUND

Liver cancer incidence and mortality are escalating globally. Magnesium intake has been studied extensively in nonmalignant liver pathology, but the association between dietary intake of magnesium and primary liver malignancy has not been previously evaluated.

OBJECTIVES

We aimed to determine the association between total magnesium intake and primary liver cancer risk.

METHODS

Using the NIH-American Association of Retired Persons (NIH-AARP) Diet and Health Study prospective cohort, we estimated the association between magnesium intake and the risk of incident primary liver cancer using Cox proportional hazard modeling adjusted for relevant confounders. Comprehensive stratified and sensitivity analyses were performed.

RESULTS

During 6.4 million person-years of follow-up time, 1067 primary liver cancers occurred in 536,359 participants. Higher magnesium intake was independently associated with a lower risk of liver cancer (P-trend = 0.005), with intakes in the highest compared with lowest quartile associated with 35% lower risk (HR: 0.65; 95% CI: 0.48, 0.87). The dose-related inverse association was more pronounced in moderate and heavy alcohol users (HR: 0.54; 95% CI: 0.35, 0.82; P-trend = 0.006), and this interaction was statistically significant (P-interaction = 0.04).

CONCLUSIONS

Based on a prospective cohort analysis, we demonstrated that magnesium intake is associated with a lower risk of primary liver cancer, which was more pronounced among moderate and heavy alcohol users. Robust experimental and mechanistic data provide a biological basis to support these findings.

Total, Dietary, and Supplemental Magnesium Intakes and Risk of All-Cause, Cardiovascular, and Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

A meta-analysis of prospective studies was conducted to examine the association of total, supplemental, and dietary magnesium intakes with risk of all-cause, cancer, and cardiovascular disease (CVD) mortality and identify the dose-response relations involved in these association. We performed a systematic search of PubMed, Scopus, Google Scholar, and ISI Web of Knowledge up to April 2020. Prospective cohort studies that reported risk estimates for the association between total, supplemental, and dietary magnesium intakes and risk of mortality were included. Random effects models were used. Nineteen publication with a total of 1,168,756 participants were included in the current meta-analysis. In total, 52,378 deaths from all causes, 23,478 from CVD, and 11,408 from cancer were identified during the follow-up period of 3.5 to 32 years. Dietary magnesium intake was associated with a lower risk of all-cause [pooled effect size (ES): 0.87; 95% CI: 0.79, 0.97; P = 0.009; I2 = 70.7%; P < 0.001] and cancer mortality (pooled ES: 0.80; 95% CI: 0.67, 0.97; P = 0.023; I2 = 55.7%; P = 0.027), but not with CVD mortality (pooled ES: 0.93; 95% CI: 0.82, 1.07; P = 0.313; I2 = 72.3%; P < 0.001). For supplemental and total magnesium intakes, we did not find any significant associations with risks of all-cause, CVD, and cancer mortality. However, linear dose-response meta-analysis indicated that each additional intake of 100 mg/d of dietary magnesium was associated with a 6% and 5% reduced risk of all-cause and cancer mortality, respectively. In conclusion, higher intake of dietary magnesium was associated with a reduced risk of all-cause and cancer mortality, but not CVD mortality. Supplemental and total magnesium intakes were not associated with the risk of all-cause, CVD, and cancer mortality. These findings indicate that consumption of magnesium from dietary sources may be beneficial in reducing all-cause and cancer mortality and thus have practical importance for public health.

Magnesium, Little Known But Possibly Relevant: A Link between NASH and Related Comorbidities

Non-alcoholic steatohepatitis (NASH) is characterized by an abnormal hepatic lipid accumulation accompanied by a necro-inflammatory process and a fibrotic response. It comprises from 10% to 30% of cases of patients with non-alcoholic liver disease, which is a global health problem affecting around a quarter of the worldwide population. Nevertheless, the development of NASH is often surrounded by a pathological context with other comorbidities, such as cardiovascular diseases, obesity, insulin resistance or type 2 diabetes mellitus. Dietary imbalances are increasingly recognized as the root cause of these NASH-related comorbidities. In this context, a growing concern exists about whether magnesium consumption in the general population is sufficient. Hypomagnesemia is a hallmark of the aforementioned NASH comorbidities, and deficiencies in magnesium are also widely related to the triggering of complications that aggravate NASH or derived pathologies. Moreover, the supplementation of this cation has proved to reduce mortality from hepatic complications. In the present review, the role of magnesium in NASH and related comorbidities has been characterized, unraveling the relevance of maintaining the homeostasis of this cation for the correct functioning of the organism.

Magnesium bioavailability of dried and thinly shaved kombu in rats

BACKGROUND

Magnesium (Mg) is highly bioavailable in kombu compared with other edible seaweeds. However, a considerable amount of Mg is lost during industrial processing and cooking of kombu. We hypothesized that thinly shaved kombu (TSK), a traditional Japanese kombu product, is a suitable Mg source for daily diets because TSK hardly loses Mg during processing. Rats were fed diets containing TSK or magnesium oxide (MgO) to satisfy 25%, 50%, 75%, or 100% of their Mg requirements. We determined the relative Mg bioavailability of TSK compared to MgO and examined factors affecting Mg bioavailability in TSK.

RESULTS

The relative bioavailability of Mg in TSK compared with MgO was calculated as 92.3%, 111.4%, and 87.2% from apparent absorption, urinary excretion, and femoral concentration of Mg, respectively. The ultrafiltrable Mg concentration was lower in the cecal content of rats given TSK than those given MgO. However, the mRNA expression of TRPM6, an Mg channel responsible for Mg absorption, was higher in the cecum of rats given TSK than those given MgO.

CONCLUSION

Enhancement of TRPM6 expression in the large intestine negates the low bioaccessibility of Mg in TSK, and thus TSK shows Mg bioavailability comparable with MgO. © 2020 Society of Chemical Industry.

Association of Magnesium Intake with Liver Fibrosis among Adults in the United States

Liver fibrosis represents the consequences of chronic liver injury. Individuals with alcoholic or nonalcoholic liver diseases are at high risk of magnesium deficiency. This study aimed to evaluate the association between magnesium and calcium intakes and significant liver fibrosis, and whether the associations differ by alcohol drinking status. Based on the National Health and Nutrition Examination Survey (NHANES) 2017-2018, the study included 4166 participants aged >18 years who completed the transient elastography examination and had data available on magnesium intake. The median liver stiffness of 8.2 kPa was used to identify subjects with significant fibrosis (≥F2). The age-adjusted prevalence of significant fibrosis was 12.81%. Overall total magnesium intake was marginally associated with reduced odds of significant fibrosis (p trend = 0.14). The inverse association of total magnesium intake with significant fibrosis was primarily presented among those who had daily calcium intake <1200 mg. There were no clear associations for significant fibrosis with calcium intake. Findings suggest that high total magnesium alone may reduce risk of significant fibrosis. Further studies are needed to confirm these findings.

'Magnesium'-the master cation-as a drug-possibilities and evidences

Magnesium (Mg²⁺) is the 2nd most abundant intracellular cation, which participates in various enzymatic reactions; there by regulating vital biological functions. Magnesium (Mg²⁺) can regulate several cations, including sodium, potassium, and calcium; it consequently maintains physiological functions like impulse conduction, blood pressure, heart rhythm, and muscle contraction. But, it doesn't get much attention in account with its functions, making it a "Forgotten cation". Like other cations, maintenance of the normal physiological level of Mg²⁺ is important. Its deficiency is associated with various diseases, which point out to the importance of Mg²⁺ as a drug. The roles of Mg²⁺ such as natural calcium antagonist, glutamate NMDA receptor blocker, vasodilator, antioxidant and anti-inflammatory agent are responsible for its therapeutic benefits. Various salts of Mg²⁺ are currently in clinical use, but their application is limited. This review collates all the possible mechanisms behind the behavior of magnesium as a drug at different disease conditions with clinical shreds of evidence.

Lower Serum Magnesium Concentrations are associated With Specific Heavy Drinking Markers, Pro-Inflammatory Response and Early-Stage Alcohol-associated Liver Injury§

AIM

Chronic heavy alcohol intake frequently causes liver inflammation/injury, and altered mineral metabolism may be involved in this liver pathology. In this study, we evaluated the association of heavy drinking, changes in serum magnesium levels and biochemical evidence of liver injury in alcohol-use-disorder (AUD) patients who had no clinical signs or symptoms of liver injury. We also aimed to identify any sex-based differences in patients with mild or no biochemical evidence of liver injury induced by heavy drinking.

METHODS

114 heavy drinking alcohol-dependent (AD) female and male patients aged 21-65 years without clinical manifestations of liver injury, who were admitted to an alcohol treatment program, were grouped by alanine aminotransaminase (ALT) levels: ≤ 40 IU/L, as no liver injury (GR.1), and ALT>40 IU/L as mild liver injury (GR.2). Patients were actively drinking until the day of admission. Comprehensive metabolic biochemistry results, fatty acid panel, serum magnesium and drinking history data were collected at admission; and study-specific measures were evaluated.

RESULTS

In all AD patients, lower magnesium was significantly associated with the heavy drinking marker and heavy drinking days past 90 days (HDD90). A lower serum magnesium concentration was observed in AD patients with mild liver injury. Females of both groups had mean levels of magnesium in the deficient range. A clinically significant drop in magnesium levels was observed only in the GR.2 (mild liver injury) male AD patients. Females showed a significant association between low magnesium levels and the ω6:ω3 polyunsaturated fatty acids (PUFAs) ratio.

CONCLUSIONS

Specific heavy drinking markers showed an association with lower magnesium levels. Low serum magnesium levels are common in subjects with AUD and appear to be associated with the onset of liver injury.

Cross-sectional analysis of the health profile and dietary intake of a sample of Canadian adults diagnosed with non-alcoholic fatty liver disease

Background

Dietary intake is an important factor in the development and management of non-alcoholic fatty liver disease (NAFLD); however, optimal dietary composition remains unclear. Moreover, there is minimal evidence on the relationship between dietary intake and markers of liver health in Canadian adults diagnosed with NAFLD.

Objective

The aim of this study is to characterize the dietary intake of a sample of Canadian adults diagnosed with NAFLD and examine the correlations with markers of liver health.

Design

Forty-two adults recruited from the community and hepatology clinics in Calgary, Canada from 2016 to 2019 completed a 3-day food record. Anthropometrics, blood biomarkers, liver stiffness (FibroScan), and liver fat (magnetic resonance imaging) were measured. Nutrient intake was compared with the data from the 2004 and 2015 Canadian Community Health Surveys. Relationships were assessed using Pearson’s correlation and regression analysis.

Results

Relative to Canadian dietary recommendations, participants consumed lower magnesium, fiber, calcium, vitamin D, and vitamin E, and higher cholesterol, saturated fat, total fat, fructose, iron, vitamin B12, selenium, phosphorus, and sodium. Compared with the national average, participants consumed more energy, fiber, sodium, total fat, and saturated fat. Systolic blood pressure (P = 0.012), serum α-2 macroglobulin (P = 0.008), carbohydrate (P = 0.022), total fat (P = 0.029), and saturated fat intakes (P = 0.029) were associated with FibroScan scores. Liver fat was correlated with serum triglycerides (P < 0.001), trunk fat (P = 0.029), added sugar (P = 0.042), phosphorus (P = 0.017), and magnesium intake (P = 0.013). In females, selenium intake was associated with liver fat (P = 0.015) and FibroScan score (P = 0.05), while in males, liver fat was associated with trunk fat (P = 0.004), body weight (P = 0.004), high-density lipoprotein (P < 0.001), and fructose intake (P = 0.037). Regression analysis showed that increasing magnesium intake corresponds to a decrease in liver fat.

Conclusion

Despite the higher energy intake of participants, overall nutrient intake is low, suggesting lower diet quality. Associations between select micronutrients and liver health markers warrant further investigation.

Experimental rat model for acute tubular injury induced by high water hardness and high water fluoride: efficacy of primary preventive intervention by distilled water administration

Background

High water hardness associated with high water fluoride and the geographical distribution of Chronic Kidney Disease of unknown etiology (CKDu) in Sri Lanka are well correlated. We undertook this study to observe the effects of high water hardness with high fluoride on kidney and liver in rats and efficacy of distilled water in reducing the effects.

Methods

Test water sample with high water hardness and high fluoride was collected from Mihinthale region and normal water samples were collected from Kandy region. Twenty-four rats were randomly divided into 8 groups and water samples were introduced as follows as daily water supply. Four groups received normal water for 60 (N1) and 90 (N2) days and test water for 60 (T1) and 90 (T2) days. Other four groups received normal (N3) and test (T3) water for 60 days and followed by distilled water for additional 60 days and normal (N4) and test (T4) water for 90 days followed by distilled water for another 90 days. The rats were sacrificed following treatment. Serum samples were subjected to biochemical tests; serum creatinine, urea, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and elemental analysis. Histopathological examinations were carried out using kidney and liver samples.

Results

Test water treated groups were associated with acute tubular injury with loss of brush border and test water followed with distilled water treated groups maintained a better morphology with minimal loss of brush border. Serum creatinine levels in T1 and T2 groups and urea level in T2 group were significantly (p < 0.05) increased compared to control groups. After administration of distilled water, both parameters were significantly reduced in T4 group (p < 0.05) compared to T2. Serum AST activity was increased in T4 group (p < 0.05) compared to control group with no histopathological changes in liver tissues. The serum sodium levels were found to be much higher compared to the other electrolytes in test groups.

Conclusion

Hard water with high fluoride content resulted in acute tubular injury with a significant increase in serum levels of creatinine, urea and AST activity. These alterations were minimized by administering distilled water.

Magnesium intake and primary liver cancer incidence and mortality in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial

Epidemiological studies on magnesium intake and primary liver cancer (PLC) are scarce, and no prospective studies have examined the associations of magnesium intake with PLC incidence and mortality. We sought to clarify whether higher magnesium intake from diet and supplements was associated with lower risks of PLC incidence and mortality in the US population. Magnesium intake from diet and supplements was evaluated through a food frequency questionnaire in a cohort of 104,025 participants. Cox regression was employed to calculate hazard ratios for PLC incidence and competing risk regression was employed to calculate subdistribution hazard ratios for PLC mortality. Restricted cubic spline regression was employed to test nonlinearity. We documented 116 PLC cases during 1,193,513.5 person-years of follow-up and 100 PLC deaths during 1,198,021.3 person-years of follow-up. Total (diet + supplements) magnesium intake was found to be inversely associated with risks of PLC incidence (hazard ratio_{tertile 3 vs. 1} : 0.44; 95% confidence interval: 0.24, 0.80; p_trend = 0.0065) and mortality (subdistribution hazard ratio_{tertile 3 vs. 1} : 0.37; 95% confidence interval: 0.19, 0.71; p_trend = 0.0008). Similar results were obtained for dietary magnesium intake. Nonlinear inverse dose-response associations with PLC incidence and mortality were observed for both total and dietary magnesium intakes (all p_nonlinearity  < 0.05). In summary, in the US population, a high magnesium intake is associated with decreased risks of PLC incidence and mortality in a nonlinear dose-response manner. These findings support that increasing the consumption of foods rich in magnesium may be beneficial in reducing PLC incidence and mortality.

Nutrition in Chronic Liver Disease: A Point-of-Care Review

Patients with chronic liver disease have a very high lifetime risk of malnourishment. It has been increasingly identified in literature that the severity of liver disease affects severity of malnutrition and vice versa. The objective of this review article is to recognize the severity of complications associated with malnutrition in patients with cirrhosis and ways to overcome these obstacles.

Are Circulating Mg2+ Levels Associated with Glucose Tolerance Profiles and Incident Type 2 Diabetes?

Magnesium (Mg²⁺) is an enzyme co-factor that plays a key role in many biochemical reactions, as well as in glucose metabolism. Clinical evidences have demonstrated that depletion of serum Mg²⁺ increases exponentially with the duration of type 2 diabetes mellitus (T2DM). Diabetes is associated with low Mg²⁺, and hypomagnesemia is associated with insulin resistance, inflammation, and increased risk for cardiovascular disease. In subjects at high risk of inflammation and insulin resistance, supplementation of Mg²⁺ alone ameliorates both phenotypes, slowing the development and progression of hepatic steatosis. We analyze the relationship between serum Mg²⁺ levels and the onset of T2DM in a large cohort of well-characterized adult white individuals participating in the CATAMERI study, who were reexamined after a mean follow-up of 5.6 ± 0.9 years. In our analysis we acquired a significant negative correlation between Mg²⁺ levels, fasting glucose, and 2h-post load glucose in subjects who underwent an OGTT. Moreover, Mg²⁺ levels correlated negatively with fasting insulin levels, and positively with the lipid profile. As for the detrimental effect of lower circulating Mg²⁺ levels, our data revealed a significant reduction of T2DM risk of about 20% for each 1 mg/dL increase of circulating Mg²⁺. The present results are consistent with the theory that Mg²⁺ supplementation could ameliorate insulin sensitivity reducing the risk to develop T2DM.

Magnesium and liver disease

Magnesium is a vital cation that takes part in many cellular processes. Magnesium balance can be disturbed in multiple conditions, and differences in magnesium concentration can be responsible for numerous physiological and pathological processes. Magnesium deficiency is commonly associated with liver diseases, and may result from low nutrient uptake, greater urinary secretion, low serum albumin concentration, or hormone inactivation. In turn, low magnesium content in serum and liver tissue can lead to the progression of these diseases, due to a disruption in mitochondrial function, defective protein kinase C (PKC) translocation, inflammatory responses, oxidative stress, or metabolic disorders. Furthermore, magnesium supplementation can improve liver function in certain liver diseases. This paper comprehensively reviews the changes in magnesium concentrations associated with liver cirrhosis, alcoholic liver disease (ALD), liver cancer, and viral hepatitis, and explains how such changes may in turn impact these disease processes.

Low serum magnesium and 1-year mortality in alcohol withdrawal syndrome

BACKGROUND

In 2014, the WHO reported that 6% of all deaths were attributable to excess alcohol consumption. The aim of the present study was to examine the relationship between serum magnesium concentrations and mortality in patients with alcohol withdrawal syndrome (AWS).

MATERIALS AND METHODS

A retrospective review of 700 patients with documented evidence of previous AWS indicating a requirement for benzodiazepine prophylaxis or evidence of alcohol withdrawal syndrome between November 2014 and March 2015.

RESULTS

Of 380 patients included in the sample analysis, 64 (17%) were dead at 1 year following the time of treatment for AWS. The majority of patients had been prescribed thiamine (77%) and a proton pump inhibitor (66%). In contrast, the majority of patients had low circulating magnesium concentrations (<0.75 mmol/L) (64%) and had not been prescribed magnesium (90%). The median age of death at one year was 55 years (P = 0.002). On univariate analysis, age (P < 0.05), GMAWS (P < 0.05), BDZ (P < 0.05), bilirubin (P < 0.001), alkaline phosphatase (P < 0.001), albumin (P < 0.001), CRP (P < 0.05), AST:ALT ratio >2 (P < 0.001), sodium (P < 0.05), magnesium (P < 0.001), platelets (P < 0.05) and the use of proton pump inhibitor medication (P < 0.001) were associated with death at 1 year. On multivariate binary logistic regression analysis, age > 50 years (OR 3.37, 95% CI 1.52-7.48, P < 0.01), AST:ALT ratio >2 (OR 3.10, 95% CI 1.38-6.94, P < 0.01) and magnesium < 0.75 mmol/L (OR 4.11, 95% CI 1.3-12.8, P < 0.05) remained independently associated with death at 1 year.

CONCLUSION

Overall, 1-year mortality was significantly higher among those patients who were magnesium deficient (<0.75 mmol/L) when compared to those who were replete (≥0.75 mmol/L; P < 0.001).

Dietary magnesium deficiency impaired intestinal structural integrity in grass carp (Ctenopharyngodon idella)

Grass carp (223.85–757.33 g) were fed diets supplemented with magnesium (73.54–1054.53 mg/kg) for 60 days to explore the impacts of magnesium deficiency on the growth and intestinal structural integrity of the fish. The results demonstrated that magnesium deficiency suppressed the growth and damaged the intestinal structural integrity of the fish. We first demonstrated that magnesium is partly involved in (1) attenuating antioxidant ability by suppressing Nrf2 signalling to decrease antioxidant enzyme mRNA levels and activities (except CuZnSOD mRNA levels and activities); (2) aggravating apoptosis by activating JNK (not p38MAPK) signalling to upregulate proapoptotic protein (Apaf-1, Bax and FasL) and caspase-2, -3, -7, -8 and -9 gene expression but downregulate antiapoptotic protein (Bcl-2, IAP and Mcl-1b) gene expression; (3) weakening the function of tight junctional complexes (TJs) by promoting myosin light chain kinase (MLCK) signalling to downregulate TJ gene expression [except claudin-7, ZO-2b and claudin-15 gene expression]. Additionally, based on percent weight gain (PWG), against reactive oxygen species (ROS), against caspase-9 and claudin-3c in grass carp, the optimal dietary magnesium levels were calculated to be 770.38, 839.86, 856.79 and 811.49 mg/kg, respectively.

Intakes of magnesium, calcium and risk of fatty liver disease and prediabetes

OBJECTIVE

Obesity and insulin resistance play important roles in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Mg intake is linked to a reduced risk of metabolic syndrome and insulin resistance; people with NAFLD or alcoholic liver disease are at high risk of Mg deficiency. The present study aimed to investigate whether Mg and Ca intakes were associated with risk of fatty liver disease and prediabetes by alcohol drinking status.

DESIGN

We analysed the association between Ca or Mg intake and fatty liver disease, prediabetes or both prediabetes and fatty liver disease in cross-sectional analyses.

SETTING

Third National Health and Nutrition Examination Survey (NHANES III) follow-up cohort of US adults.

SUBJECTS

Nationally representative sample of US adults in NHANES (n 13 489).

RESULTS

After adjusting for potential confounders, Mg intake was associated with approximately 30 % reduced odds of fatty liver disease and prediabetes, comparing the highest intake quartile v. the lowest. Mg intake may only be related to reduced odds of fatty liver disease and prediabetes in those whose Ca intake is less than 1200 mg/d. Mg intake may also only be associated with reduced odds of fatty liver disease among alcohol drinkers.

CONCLUSIONS

The study suggests that high intake of Mg may be associated with reduced risks of fatty liver disease and prediabetes. Further large studies, particularly prospective cohort studies, are warranted to confirm the findings.