Plasma Magnesium Concentrations Research Articles

Low thiamine status in adults following low-carbohydrate / ketogenic diets: a cross-sectional comparative study of micronutrient intake and status.

Low-carbohydrate diets (LCD) are popular for weight loss but lack evidence about micronutrient sufficiency in real-life use. This study assessed the intake and biochemical status of selected micronutrients in people voluntarily following LCDs. A cross-sectional study was conducted (2018-20) among 98 adults recruited as self-reporting either LCD (n = 49) or diets not restricting carbohydrates (controls; n = 49). Diets were assessed using the 130-item EPIC-Norfolk food-frequency questionnaire. Red-blood-cell thiamine diphosphate (TDP) was measured for thiamine status using HPLC. Plasma magnesium, zinc, copper, and selenium were measured using inductively coupled plasma mass spectrometry. Between-group biomarker comparisons were conducted using ANCOVA and adjusted for age, sex, body mass index (BMI), and diabetes status. LCD-followers (26% male, median age 36 years, median BMI 24.2 kg/m2) reported adhering to LCDs for a median duration of 9 months (IQR 4-36). The most followed LCD type was 'their own variations of LCD' (30%), followed by ketogenic (23%), 'palaeolithic' (15%), and Atkins diets (8%). Among controls, 41% were male (median age 27 years, median BMI 23kg/m2). Median macronutrient intakes for LCD vs control groups were carbohydrate 16%Energy (E) vs. 50%E; protein 25%E vs. 19%E; and fat 55%E vs 34%E (saturated fat 18%E vs. 11%E). Two-thirds of LCD followers (32/49) and half of the controls (24/49) reported some use of dietary supplements (p = 0.19). Among LCD-followers, assessing from food data only, 21 (43%) failed to meet the reference nutrient intake (RNI) for thiamine (vs.14% controls, p = 0.002). When thiamine from supplementation (single- or multivitamin) was included, there appeared to be no difference in thiamine intake between groups. Still, red-blood-cell TDP was lower in LCD-followers than controls (407 ± 91 vs. 633 ± 234 ng/gHb, p < 0.001). Three LCD-followers were thiamine-deficient (RBC thiamine < 275 ng/gHb) vs. one control. There were no significant differences in dietary intakes or plasma concentrations of magnesium, zinc, copper, and selenium between groups. Following LCDs is associated with lower thiamine intake and TDP status than diets without carbohydrate restriction, incompletely corrected by supplement use. These data, coupled with a lack of RCT evidence on body weight control, do not support recommending LCDs for weight management without appropriate guidance and diet supplementation.

Significance of correcting magnesium deficiency in different groups of women in surgical menopause

Background. In the 21st century, there is a clear trend towards an increase in the proportion of women with climacteric syndrome (CS) and surgical menopause. Medical care for such patients usually includes menopausal hormone therapy (MHT), which often causes changes in magnesium and pyridoxine metabolism and their deficiency, leading to the development of adverse reactions. Therefore, it is necessary to improve rehabilitation programs designed to increаse the quality of life (QoL) for this category of gynecological patients.Objective: to assess the profile of women with CS and surgical menopause receiving and not receiving MHT and to identify the significance of magnesium deficiency (MD) effect on the recovery process.Material and methods. The observational non-interventional study included a total of 9168 women, of which 1528 patiеnts with CS and surgical menopause were taking MHT (Group 1), and 1528 patients with CS and surgical menopause were not taking MHT (Group 2). The Magnesium Deficiency Questionnaire (MDQ) was used to determine the number of participants with MD. A biochemical blood test was also performed, including determination of plasma magnesium concentration. The patients’ profile was analyzed for general somatic pathologies, obstetric and gynecological history, complaints, and MD symptoms using visual analogue scale. To assess QoL before the start of 4-week MD replenishing course and at the end of therapy, the World Health Organization Quality of Life Questionnaire (WHOQL-26) was applied.Results. The MDQ data showed that the prevalence of DM in Group 1 was higher compared to Group 2. In both groups, women with hypomagnesemia had a higher incidence of viral infections, vegetative-vascular dystonia, osteochondrosis and arterial hypertension, more pronounced sleep disorders, irritability, back pain, rapid fatigue, and higher MDQ scores. After completion of the course of therapy with magnesium citrate and pyridoxine combination, the MDQ scores in patients with DM decreased along with an increase in plasma magnesium concentration. Besides, women's satisfaction with their physical, psychological, social wellbeing and microsocial support increased, and self-perception improved. A decrease in the severity of DM and a significant improvement in QoL according to WHOQOL-26 were demonstrated in patients with CS and surgical menopause after therapy.Conclusion. The profile of patients with CS and surgical menopause, regardless of MHT, is often characterized by DM and decreased QoL. It seems reasonable to include blood magnesium level monitoring and DM correction in the comprehensive rehabilitation program for such patients.

High plasma magnesium and phosphorus levels and their correlation with struvite urolithiasis in buffaloes

BackgroundUrolithiasis is a common urinary tract disease in buffaloes, almost exclusively affects young males, and has significant economic and production impacts. We have investigated hemato-biochemical and urinary changes in an attempt to deduce their correlation with struvite urolithiasis in buffaloes. MethodsTen male buffalo calves with obstructive urolithiasis were used. Blood samples were used for hematology and elemental analysis. Urine samples were used for physico-chemical examination, microscopy, and elemental analysis. Uroliths were subjected to chemical functional group determination using the FTIR spectroscopy. ResultsThe mean neutrophil, leukocyte, and neutrophil-to-lymphocyte ratio was significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. The mean blood calcium and magnesium concentrations were significantly (p < 0.05) lower and higher in urolithic buffaloes than in healthy controls, respectively. Mean blood phosphorus concentration and calcium-phosphorus ratio were found to be non-significantly (p > 0.05) higher and lower in urolithic buffaloes than in healthy controls, respectively. The urine pH was highly alkaline. Multiple prismatic lid-shaped crystals, along with erythrocytes, leukocytes, and epithelial cells, were found in urine. The mean urinary magnesium and phosphorus concentrations were non-significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. A positive correlation of magnesium (r = 0.864, p = 0.001) and phosphorus (r = 0.849, p = 0.002) concentrations between the blood and urine was observed in urolithic buffaloes. The FTIR spectra of uroliths were similar to those of magnesium ammonium phosphate hexahydrate, MgNH4PO4·6H2O or struvite. ConclusionThe findings suggest that high plasma magnesium and phosphorus concentrations have a positive correlation with struvite urolithiasis in buffaloes.

Associations between plasma metal elements and risk of cognitive impairment among Chinese older adults.

The relationship between plasma metal elements and cognitive function is unclear, especially in extremely older individuals. This present study aimed to explore the association between plasma metal concentrations and the risk of cognitive impairment (CI) in Chinese extremely older adults. Individuals aged ≥90 years with plasm metal concentration data from the fifth wave of the 2008 Chinese Longitudinal Healthy Longevity Survey were included. Plasma selenium (Se), manganese (Mn), magnesium (Mg), calcium (Ca), iron (Fe), copper (Cu), and zinc (Zn) concentrations were measured using inductively coupled plasma optical emission spectroscopy. Cognitive function was assessed by the Chinese version of the mini-mental state examination. The study enrolled 408 participants. Participants with CI had significantly lower plasma Se, Mn, and Fe levels and higher Ca levels than those with normal cognitive function (p < 0.05). Plasma Se, Mn, Ca, and Fe concentrations were significantly associated with CI risk in both single- and multiple-element logistic regression models. Additionally, the multiple-element model results showed that the adjusted odds ratios for CI were 0.042 (95% confidence interval 0.016-0.109), 0.106 (0.044-0.255), 7.629 (3.211-18.124) and 0.092 (0.036-0.233) for the highest quartiles compared to the lowest quartiles of Se, Mn, Ca, and Fe, respectively. Moreover, subgroup analyses by age, sex, and body mass index suggested a consistent significant correlation (p < 0.05). Therefore, decreased plasma Se, Mn, and Fe and increased plasma Ca levels were associated with CI risk in Chinese older adults. These findings are of great significance for the development of programs to delay cognitive decline in the elderly.

Analysis of the toxic effects of fluoroquinolones in laboratory rabbit models

Introduction. Fluoroquinolones are antibacterials for which the development of cardiotoxicity, hepatotoxicity, nephrotoxicity and connective tissue damage has been noted. The likely mechanism for the development of these reactions is magnesium metabolism disorder. An available method to detect fluoroquinolones toxicity in animal experiments is a blood biochemical test.The aim of the work was to identify the biochemical signs of the toxic effects of fluoroquinolones in laboratory rabbit models.Materials and methods. Twenty male rabbits randomised into three groups were included in the study: 6 control animals; 7 rabbits treated with ciprofloxacin 150 mg/kg 14 days; 7 rabbits treated with levofloxacin 150 mg/kg 14 days. Serum levels of albumin, alanine aminotransferase (liver damage marker), creatinine (nephrotoxicity marker), creatine kinase MB (cardiotoxicity marker), matrix metalloproteinase 9 (connective tissue damage marker), serum and plasma magnesium content were studied in this work. Data are presented as mean (standard deviation).Results. Serum levels of albumin, alanine aminotransferase and creatinine did not change during the experiment. Rabbits treated with levofloxacin had 2.0–2.5 times lower values of CF creatine kinase activity than control animals. There was double increase of serum concentration of matrix metalloproteinase 9 in ciprofloxacin group in comparison with control (70,17 (20,88) and 38,10 (16,04) ng/ ml, p = 0,019). Magnesium content was unchanged with both fluoroquinolones.Discussion. The absence of signs of hepatotoxicity and nephrotoxicity is consistent with their low frequency of detection in clinical and experimental studies. A decrease in the activity of creatine kinase MB in animals treated with levofloxacin has not been described in the literature. An increase in the concentration of metalloproteinase 9 is evidence of destruction of connective tissue structures. The absence of changes in serum and plasma concentrations of magnesium is explained by the functioning of the systems maintaining the constancy of its content in blood.Conclusion. No biochemical evidence of hepato-, nephro- and cardiotoxic effects of ciprofloxacin and levofloxacin at the doses of 150 mg/kg for 14 days was shown in rabbits; no magnesium metabolism disorders were shown, and the ability of ciprofloxacin to increase the serum content of matrix metalloproteinase type 9 was demonstrated. The proposed model can be used to investigate ways to prevent the toxic effects of fluoroquinolones on connective tissue structures.

Sleep quality, fatigue, societal participation and health-related quality of life in kidney transplant recipients: a cross-sectional and longitudinal cohort study.

Fatigue and impaired health-related quality of life (HRQoL) are common among kidney transplant recipients (KTR). We hypothesized that both may partially be attributable to poor sleep. Cross-sectional and longitudinal data of KTR enrolled in the TransplantLines Biobank and Cohort Study were used. Sleep quality was assessed using the Pittsburgh Sleep Quality Index questionnaire. Individual strength (i.e. a composite of fatigue, concentration, motivation and physical activity), societal participation and HRQoL were assessed using validated questionnaires. We included 872 KTR (39% female, age 56±13 years) and 335 healthy controls. In total, 33% of male KTR and 49% of female KTR reported poor sleep quality, which was higher compared with male and female healthy controls (19% and 28%, respectively, P<.001 for both). In logistic regression analyses, female sex, anxiety, active smoking, low protein intake, physically inactive lifestyle, low plasma magnesium concentration, using calcineurin inhibitors, not using mTOR inhibitors and using benzodiazepine agonists were associated with poor sleep quality. In adjusted linear regression analyses, poor sleep was strongly and independently associated with lower individual strength [standardized β (st.β) = 0.59, 95% confidence interval (CI) 0.45 to 0.74, P<.001], poorer societal participation (frequency: st.β = -0.17, 95% CI -0.32 to -0.01, P=.04; restrictions: st.β = -0.36, 95% CI -0.51 to -0.21, P<.001; satisfaction: st.β = -0.44, 95% CI -0.59 to -0.28, P<.001) and lower HRQoL (physical: st.β = -0.53, 95% CI -0.68 to -0.38, P<.001; mental: st.β = -0.64, 95% CI -0.78 to -0.50, P<.001). The associations with poorer societal participation and lower HRQoL were strongly mediated by individual strength (P<.001 for all), yet the suggested direct effects of poor sleep quality on HRQoL remained significant (Pphysical=.03, Pmental=.002). Longitudinal data of 292 KTR showed that sleep quality improves after kidney transplantation in males (P<.001), but not in females (P=.9). Poor sleep quality is common among KTR, and may be a potential target to improve fatigue, societal participation and HRQoL among KTR.

Fibroblast growth factor 23 is independently associated with renal magnesium handling in patients with chronic kidney disease.

Disturbances in magnesium homeostasis are common in patients with chronic kidney disease (CKD) and are associated with increased mortality. The kidney is a key organ in maintaining normal serum magnesium concentrations. To this end, fractional excretion of magnesium (FEMg) increases as renal function declines. Despite recent progress, the hormonal regulation of renal magnesium handling is incompletely understood. Fibroblast Growth Factor 23 (FGF23) is a phosphaturic hormone that has been linked to renal magnesium handling. However, it has not yet been reported whether FGF23 is associated with renal magnesium handling in CKD patients. The associations between plasma FGF23 levels, plasma and urine magnesium concentrations and FEMg was investigated in a cross-sectional cohort of 198 non-dialysis CKD patients undergoing renal biopsy. FGF23 was significantly correlated with FEMg (Pearson's correlation coefficient = 0.37, p<0.001) and urinary magnesium (-0.14, p=0.04), but not with plasma magnesium. The association between FGF23 and FEMg remained significant after adjusting for potential confounders, including estimated glomerular filtration rate (eGFR), parathyroid hormone and 25-hydroxyvitamin D. We report that plasma FGF23 is independently associated with measures of renal magnesium handling in a cohort of non-dialysis CKD patients. A potential causal relationship should be investigated in future studies.

Medical rehabilitation of patients with menopausal syndrome and surgical menopause: contribution of magnesium deficiency correction

Background. The increase in the proportion of patients with menopausal syndrome (MS) and surgical menopause, including women in the recovery phase after radical surgical treatment of the reproductive system cancer, is a characteristic trend of the 21st century. Part of them receive menopausal hormone therapy (MHT). This determines the relevance of the analysis of the specified cohort of patients to enhance rehabilitation programs designed to improve the quality of life (QoL) in this category of gynecological patients.Objective: subanalysis of primary data from the MAGYN study cohort of MHT treated women with MS and surgical menopause.Material and methods. The MAGYN observational non-interventional study of the real clinical practice included 9168 women, of whom 1528 represented a group of previously not characterized MHT treated women with MS and surgical menopause. To determine the number of patients with magnesium deficiency (MD), a Magnesium Deficiency Questionnaire (MDQ) was used, a biochemical blood test with an indicator of serum magnesium concentration was evaluated. The profile of the participants was analyzed by the presence of general somatic pathologies, obstetric, gynecological history, complaints, symptoms of MD on a visual-analog scale. The QoL was assessed with the help of The World Health Organization Quality of Life Brief Version (WHOQOL-BREF) before the start of a 4-week course of MD supplementation and after treatment.Results. According to the MDQ results, the prevalence of DM was 79.4%, which exceeded the results of all other groups in the study. Women with MD had a higher incidence of viral infections (19.2% vs. 22.7%; p=0.028), vegetative-vascular dystonia (26.2% vs. 29.7%; p=0.0466) and osteochondrosis (42.9% vs. 46.8%; p=0.0453). A subgroup of participants with verified MD demonstrated significantly more pronounced symptoms, such as irritability (4.9±3.5 vs. 4.6±3.4 points in the general group; p=0.0437), sleep disorders (4.4±2.3 vs. 4.2±2.3 points; p=0.0491), back pain (3.9±2.0 vs. 3.7±2.0; p=0.0405), and increased fatigue (4.6±2.3 vs. 4.4±2.3 points; p=0.0444). After the end of the course of therapy with fixed dose combination of magnesium citrate and pyridoxine, the sum of MDQ scores decreased from 46.0±12.7 to 29.2±15.1 points (p&lt;0.001) in combination with an increase in the plasma concentration of magnesium to 0.79±0.23 mmol/l; women's satisfaction with their physical, psychological, social well-being increased (from 21.1±4.5 to 26.2±3.5 points; from 24.8±4.9 to 28.1±4.4 points, and from 9.3±2.7 to 11.0±2.8 points, respectively; p&lt;0.001); self-perception increased from 18.2±3.7 to 22.2±3.6 points. Thus, there was a significant decrease in the severity of MD and a significant improvement in QoL according to WHOQOL-BREF, which is important in the rehabilitation of such patients.Conclusion. The profile of patients with MS and surgical menopause receiving MHT, including the period of recovery after radical surgical treatment of reproductive cancer, is characterized by MD and decreased QoL. It seems effective to introduce MD correction into the complex rehabilitation program of such patients. It is necessary to conduct further studies to improve the rehabilitation measures in this cohort of patients.

Effect of supplementing magnesium oxide or brucite on plasma magnesium, rumen pH, rumen protozoa and plasma glucose levels in dairy goats

This study determined the effect of supplementing magnesium oxide (MgO) or brucite on plasma magnesium, rumen pH, rumen protozoa and plasma glucose levels in dairy goats. Fifteen Alpine goats were used and assigned to three treatments: control (CON) = Rolled corn, cottonseed hulls, soybean meal, molasses, alfalfa hay and calcium carbonate; MgO = CON + 0.5 % MgO; and brucite = CON + 2 % brucite. The study lasted for 16 days with 10 days for diet adaptation and 6 days for sample collection. Samples of blood, urine, feces, milk, and ruminal fluid were taken. Concentration of magnesium in plasma from brucite was 22.3 % higher compared to the control. In addition, MgO and brucite had higher Mg values in feces (28.9 % and 95.5 %, respectively) and urine (58.3 % and 45 %, respectively). Brucite decreased rumen pH, ruminal protozoan population and dry matter intake compared to other treatments. Milk production and milk fat and protein were not affected by Mg treatments, but blood glucose was increased with MgO. Overall, results showed that at least in a relatively short-term, MgO can be used in goat diets as compared to the control treatment and brucite, kept dry matter intake without reducing rumen pH and rumen protozoa.

Magnesium deficiency as a contributing factor to type 2 diabetes: a review of the literature

Magnesium deficiency is a vital contributing factor to the happening and arising of insulin resistance, metabolic syndrome, and type 2 diabetes mellitus. Magnesium has a critical function in controlling the level of glucose in the blood and insulin sensitivity, acting as a cofactor for various enzymes such as enzymes involved in carbohydrate oxidation, glucose transport mechanisms of the cell membrane, cell replication, and lipid metabolism. Studies have indicated that reduced magnesium levels in the blood are connected with a significant decline in insulin-mediated glucose uptake which is a vital part of the cell’s metabolism. In people with type 2 diabetes, plasma magnesium concentration was inversely associated with markers of insulin resistance. This means as magnesium levels in plasma decrease, the risk of insulin resistance increases. Additionally, magnesium deficiency can play a role in the development of diabetes by affecting the activity of the Na/K-ATPase enzyme, pancreas inflammation, reactive oxygen species (ROS) modification, lipid metabolism, and causing genetic instability, as the main contributors to type 2 diabetes. Therefore, early detection of magnesium deficiency can help prevent further complications. Physicians should be aware of the connection between magnesium deficiency and diabetes and monitor patients with magnesium deficiency for diabetes symptoms and make sure that the patient is getting adequate amounts of magnesium from their diet. Further research is needed to reveal the exact mechanisms underlying magnesium deficiency-induced type 2 diabetes and the curative effects of magnesium supplementation.

Дефицит магния у женщин после лечения злокачественных новообразований репродуктивной системы. Клиническое значение и пути решения

Objective. Clinical evaluation of magnesium deficiency (MD) in women in the recovery period after treatment of reproductive cancers. Patients and methods. Data from a multicenter observational study of MD in women with hormone-dependent disorders were analyzed. In a cohort of 9168 patients, women with a history of reproductive cancers (endometrial cancer, cervical cancer, ovarian cancer, vaginal cancer, breast cancer) were identified. Plasma magnesium concentrations were determined by a biochemical blood test. The clinical presentation of MD was evaluated using the Magnesium Deficiency Questionnaire (MDQ). Quality of life (QoL) was assessed using the World Health Organization Quality of Life-Brief Version (WHOQOL-BREF). In a part of women with MD, the dynamics of the studied parameters was evaluated after one month of magnesium supplementation. Results. A total of 70 (0.76%) patients in the recovery period after treatment of reproductive cancers were identified. High probability of MD according to MDQ was revealed in 57.1% of patients, intermediate risk – in 37.1%. Only 5.7% of women had no MD. Serum MD was present in 76.9% of patients. After one month of magnesium supplementation, 16.7% of patients had a high probability of MD according to MDQ, 66.7% had an intermediate risk of MD, and 16.7% had no MD. The number of patients with plasma MD was 33.3%. These women showed a significant reduction in the prevalence of symptoms such as cramps, nervousness, and muscle weakness. There was also a trend towards a reduction in irritability, and there was a significant improvement in the WHOQOL-BREF scores in terms of QoL (physical, psychological, and social domains). Conclusion. The obtained results emphasize the importance of magnesium level monitoring in women after treatment of reproductive cancers. Early detection and correction of MD is needed to prevent the development of MD-related symptoms, improve well-being and QoL. It is necessary to continue larger prospective studies of the clinical significance of MD in women undergoing rehabilitation after radical treatment of reproductive cancers. Key words: malignant neoplasms, cancer, reproductive system, magnesium deficiency, quality of life

Magnesium in chronic haemodialysis (MAGIC-HD): a study protocol for a randomised controlled trial to determine feasibility and safety of using increased dialysate magnesium concentrations to increase plasma magnesium concentrations in people treated with haemodialysis

IntroductionPeople treated with haemodialysis are at increased risk for all-cause and cardiovascular mortality. Plasma magnesium concentration has been inversely associated with these risks. Therefore, plasma magnesium may be a new...

Effects of water temperature on the gut microbiome and physiology of Chinook salmon (Oncorhynchus tshawytscha) reared in a freshwater recirculating system

Climate change and global warming pose particular concerns to the aquaculture industry as water temperature is one of the most important influences of health and growth performance in poikilotherms. Despite increased recognition of the importance of the gut microbiome in fish health, knowledge of temperature effects on the holobiont and implications for aquaculture performance are still limited. We assessed the effect of water temperature in a freshwater recirculating aquaculture system on the gut microbiome and the physiology, health and growth of New Zealand's most important farmed fish, the Chinook Salmon (Oncorhynchus tshawytscha). Fish were reared at four temperatures (8, 12, 16, 20 °C) for 41 to 49 days. Health, growth and feed intake were assessed at the beginning and end of the experiment. Haematology, plasma biochemistry, histology and tissue composition (e.g. fatty acids, amino acids, chemical composition) and gut microbiota (faeces and hindgut wall mucosa) were characterized. We found that increased temperature resulted in an increase in feed intake and growth (plateauing as it approached 20 °C) but did not impact feed conversion efficiency. Gut microbiome community composition assessed from both sample types changed with increasing temperature, with the dominance of Vibrionaceae (Photobacterium phosphoreum and/or pisciola) being gradually replaced by Fusobacteriaceae (Cetobacterium somerae) and Brevenemataceae (Brevinema). A significant effect of temperature was also observed on fish histology, fatty acids, chemical composition, haematology, plasma biochemistry and several internal biometrics, with significant correlation of most of these data layers with the gut microbiota. Notably, glucose, lactate and magnesium concentration in plasma, whole-body palmitic and the sum of the saturated fatty acids, and Cetobacterium were positively associated with increased temperature. This study provides further knowledge on how the Chinook salmon holobiont is influenced by water temperature and how the changes observed relate to fish growth performance and health. These results will help make more informed decisions for monitoring fish gut microbiota and tailoring dietary requirements to rearing water temperature.

The effect of magnesium sulfate on maternal serum electrolytes and parathyroid hormone in pre-eclampsia.

To evaluate possible interactions of magnesium sulfate-the drug of choice in the management of pre-eclampsia/eclampsia-in response to a few case reports that revealed maternal electrolyte disturbances, especially symptomatic changes, following magnesium sulfate administration in pre-eclampsia. Prospectively, women with pre-eclampsia were given 4g of intravenous magnesium sulfate followed by a 2g/h infusion up to 24 h after delivery. Sequential blood samples were drawn from each patient and used to measure the serum levels of sodium, potassium, calcium, phosphorus, magnesium, and parathyroid hormone. A total of 30 pregnant women with pre-eclampsia were evaluated. They were aged between 20 and 41 years with median gestational age of 37.6 (interquartile range 35.4-38.9) weeks. Only five patients reached the therapeutic window of magnesium in at least one of our measuring intervals during magnesium sulfate infusion. Plasma magnesium concentrations increased significantly during magnesium sulfate administration and dropped during the next 12 and 24 h after infusion discontinuation (P< 0.05). Fifteen of 30 (50%) patients developed asymptomatic hypocalcemia, mainly at hour 24 of infusion. Negative moderate correlations were detected between the calcium and magnesium concentrations at 12 and 24 hours of infusion (ρ=-0.390, P= 0.044 and ρ=0.315, P= 0.096, respectively). None of the patients with hypocalcemia reached the therapeutic level of magnesium or experienced parallel hyperphosphatemia. Eleven of 30 (36.6%) patients developed hyperphosphatemia mainly at 2 and 12 h of magnesium sulfate infusion. Our study implies that magnesium sulfate could cause hypermagnesemia-induced hypocalcemia in women with pre-eclampsia, independent from parathyroid hormone. The negative correlations between calcium and magnesium concentrations could be indicative of dose-dependent associations between serum magnesium level and degree of hypocalcemia in our study.

The Relationship Between Plasma Magnesium Concentration and Hepatic Encephalopathy in Liver Cirrhosis Patients: A Preliminary Result of a Referral Center in Iran

Background: The present study aimed to assess the relationship between hepatic encephalopathy (HE) and serum magnesium concentration in patients with liver cirrhosis. Methods: The study population consisted of 90 cirrhotic patients admitted to the internal ward of Shariati Hospital, Isfahan, Iran. The patients were divided into two groups: with or without HE. Demographic data, cirrhosis aetiology, plasma concentration of magnesium, model end-stage liver disease (MELD) score, and Child-Pugh-Turcotte (CTP) class were recorded. Results: Thirty-one patients (34.4%) had hypomagnesaemia. Age and sex had no significant effects on plasma magnesium concentration (P-value = 0.134 and 0.212, respectively). The distribution of cirrhosis aetiologies was significantly different between patients with and without hypomagnesaemia (P-value = 0.005). Most patients with hypomagnesaemia were in groups B and C of CTP class (P = 0.027) and had a mean MELD score of 16.5 ± 5.8 versus 14.3 ± 5.4 in patients without hypomagnesaemia (P-value = 0.08). Hepatic encephalopathy was diagnosed in 45 (50.0%) patients. Mean serum levels of magnesium in patients with or without HE were 1.6 ± 0.2 and 1.9 ± 0.2 mEq/L, respectively (P-value &lt; 0.001). There was no significant association between encephalopathy grade and serum magnesium concentration (P-value = 0.377). Conclusions: We demonstrated a relatively high prevalence of hypomagnesaemia among cirrhotic patients with HE. Hypomagnesaemia was associated with the severity of liver cirrhosis based on the Child-Pugh score. Prescription of magnesium supplements in cirrhotic patients may be helpful in preventing disease progression; however, further studies are needed.

Leptin and its relationship with magnesium biomarkers in women with obesity

Some studies have demonstrated the participation of leptin in magnesium metabolism. On the other hand, there is evidence of the role of magnesium in the leptin intracellular signaling pathway. Therefore, the aim of this study was to investigate the existence of a relationship between serum leptin concentrations and magnesium biomarkers in women with obesity. Case-control study involving 108 women aged between 20 and 50years, divided into two groups: obese (n = 52) and control (n = 56). Body weight, height and waist circumference, body mass index, dietary magnesium intake, magnesium biomarkers and serum leptin concentrations were measured. Serum leptin concentrations showed a statistically significant difference between groups (p < 0.001). Mean values of magnesium intake were lower than intake recommended, and with no statistically significant difference between two groups (p > 0.05). Women with obesity had lower plasma and erythrocyte magnesium concentrations than control group did (p < 0.001). Magnesium concentrations found in the urine of women with obesity were higher than the control group was, with a statistically significant difference (p < 0.001). There was a correlation between serum leptin and magnesium biomarkers (p < 0.001). Women with obesity show an inadequate magnesium nutritional status characterized by low plasma and erythrocyte concentrations and high concentrations in urine, and they also have high serum leptin concentrations. Thus, it was possible to observe a correlation between hyperleptinemia and magnesium biomarkers, requiring further studies to determine whether the dysfunction of this hormone can influence the compartmentalization of the mineral in obese organisms.

Dietary 25-hydroxyvitamin D3 effects on vitamin D status, plasma metabolites and urine mineral excretion in adult cats.

The study aimed to evaluate the safety and effectiveness of vitamin D supplementation with dietary 25-hydroxyvitamin D3 (25[OH]D3) in adult cats. Three levels of dietary 25(OH)D3 concentrations (4.9, 8.4, 11.8 µg/kg as fed) were received by five adult cats for 9 weeks, each in a randomized complete block design. Effects were determined on plasma or serum concentrations of 25(OH)D3, 24,25-dihydroxyvitamin D3, calcitriol, parathyroid hormone, ionized calcium, urinary excretions of phosphorus, calcium and magnesium, and clinical hematology and chemistry panels. The lowest concentration of dietary 25(OH)D3 supported elevation of vitamin D status, with no adverse effects. Supplementation of 8.4 µg/kg 25(OH)D3 had significant effects on the urinary magnesium: creatinine ratio. Increasing supplementation up to 11.8 µg/kg 25(OH)D3 had significant effects on plasma concentrations of calcium and magnesium, and vitamin D metabolites. Dietary supplementation with approximately 5.0 µg/kg of 25(OH)D3 or the ingested equivalence of 0.09 µg of 25(OH)D3 per metabolic body weight (kg0.67) is a safe, potent and effective means for raising vitamin D status in cats. A higher dose with approximately 11.8 µg/kg of 25(OH)D3 resulted in elevation in C-3 epimers of 25(OH)D3 and slight elevation in plasma magnesium and calcium concentrations above their respective reference intervals.

Plasma and erythrocyte magnesium levels: from validation of the method to analysis in volunteers diagnosed to migraine

Deficiency of serum magnesium is associated with the incidence of migraine attacks. The present study aimed to evaluate plasma and erythrocyte magnesium levels in a group of patients diagnosed with migraine. Human donors were selected from basic health units (migraine, n = 25) and from a collection and transfusion unit (control, n = 25), both located in the city of Sinop, Brazil. Plasma and erythrocyte magnesium were assessed using flame atomic absorption. Plasma magnesium concentration was significantly lower in the migraine group (0.172 ± 0.018) compared to the control group (0.197 ± 0.020 mg/L), and erythrocyte magnesium concentration was also lower in the migraine group (0.393 ± 0.053 mg/L) compared to the control group (0.432 ± 0.056 mg/L). The method for analysis of magnesium in human plasma and erythrocytes by flame atomic absorption was shown to be in accordance with validation guidelines. This study shows that plasma and erythrocyte magnesium levels were significantly lower in volunteers diagnosed with migraine compared to healthy volunteers. Furthermore, erythrocyte magnesium proved to be a better marker than plasma magnesium for patients with migraine.

Total plasma magnesium, zinc, copper and selenium concentrations in obese patients before and after bariatric surgery

Obesity enhances the risk of type-2 diabetes, cardiovascular disease and inflammatory conditions and often leads to metal dyshomeostasis, which contributes to the negative health aspects associated with the disease. In severe cases, bariatric surgery can be recommended to achieve sustained weight loss and improvement in health. Here, magnesium, zinc, copper and selenium concentrations were examined in 24 obese patients (7 males; 17 females) before and 9 months after undergoing Roux-en-Y gastric bypass surgery. All patients lost weight over this period, with the mean BMI reducing from 51.2±7.1 kg/m2 to 37.2±5.5 kg/m2. Moreover, whole-blood glycated haemoglobin (HbA1c), as a marker of average glycaemia, was also measured and a correlative analysis of this parameter with metal concentrations performed. Significant alterations in the plasma concentrations of magnesium, zinc (both increased by 13.2% and 25.2% respectively) and copper (decreased by 7.9%) were observed over this period (plasma selenium concentration was unchanged), with BMI values correlating with plasma magnesium (p = 0.004) and zinc (p = 0.022) concentrations. At 9 months post-surgery, an increase in mean zinc/copper ratio was observed (0.86±0.29 compared to 0.63±0.14 pre-surgery). Comparison of whole-blood HbA1c concentrations pre- and post-surgery revealed a reduction from 6.50±1.28% pre-surgery to 5.51±0.49% post-surgery. Differences in plasma HbA1c and magnesium at either pre- and post-surgery correlated significantly, as did HbA1c and magnesium levels when pre- and post-surgery values were analysed together. Collectively, this work reveals that bariatric surgery, in conjunction with lifestyle/dietary changes, lead to improvements in the nutritional status of magnesium, zinc and copper. Furthermore, the observed improvements in magnesium and zinc were associated with weight loss and in the case of magnesium, to better glycaemic control.

Supplementing a blend of magnesium oxide to feedlot cattle: effects on ruminal, physiological, and productive responses.

This experiment evaluated ruminal, physiological, and productive responses of feedlot cattle consuming a corn-based finishing diet that included different levels of a magnesium oxide (MG) blend. Yearling cattle (58 heifers and 62 steers) were ranked by sex and initial body weight (BW; 407±3.1kg), and allocated to 4 groups of 30 animals each. Groups were housed in one of four drylot pens (30×12 m) equipped with GrowSafe automated feeding systems (Model 6000E, 4 bunks/pen) during the experiment (days -14 to 117). On day 0, groups were randomly assigned to receive a total-mixed ration without (CON; n = 30) or with the inclusion (as-fed basis) of MG at 0.25% (MG25; n = 30), 0.50% (MG50; n = 30), or 0.75% (MG75; n = 30) until slaughter on day 118. Individual feed intake was recorded daily, and BW was recorded every 14 d and prior to slaughter (day 117). Blood samples were collected on days 0, 28, 56, 84, and 112, and hair samples were collected on days 0, 56, and 112 from the tail-switch. On day 42, eight rumen-cannulated steers (BW = 492±8.0kg) were housed with yearling cattle (1 pair/pen). Pairs rotated among groups every 14 d, resulting in a replicated 4×4 Latin square design (n = 8/treatment; days 42 to 98). Rumen pH was measured on days 7 and 14 of each period (0800, 1200, 1600, and 2000h). Orthogonal contrasts were used to determine if inclusion of MG (0%, 0.25%, 0.50%, or 0.75% of the diet) yielded linear or quadratic effects, and to explore overall effect of MG supplementation (CON vs. MG25 + MG50 + MG75). No treatment differences were noted (P ≥ 0.31) for BW gain, feed intake, or feed efficiency. Cattle supplemented with MG tended to have less carcass marbling (P = 0.07) compared with CON. Inclusion of MG linearly increased (P < 0.01) mean plasma concentrations of magnesium and tended to linearly decrease (P = 0.09) mean plasma concentrations of haptoglobin. Cattle supplemented with MG had greater (P < 0.01) mean plasma concentrations of cortisol compared with CON. Hair cortisol concentration did not differ between treatments on day 56 (P ≥ 0.25) and linearly decreased (P < 0.01) with MG inclusion on day 112 (treatment × day; P = 0.02). Inclusion of MG linearly increased (P = 0.03) mean rumen pH, but these outcomes were mostly noted during the last two sampling of the day (treatment × hour; P = 0.02). Collectively, supplemental MG was effective in controlling rumen pH in cattle receiving a corn-based finishing diet, but without improvements in feedlot performance and carcass merit.