A prospective evaluation of thiamine and magnesium status in relation to clinicopathological characteristics and 1-year mortality in patients with alcohol withdrawal syndrome.

BACKGROUND: Alcohol withdrawal syndrome (AWS) is routinely treated with B-vitamins. However, the relationship between thiamine status and outcome is rarely examined. The aim of the present study was to examine the relationship between thiamine and magnesium status in patients with AWS. METHODS: Patients (n = 127) presenting to the Emergency Department with AWS were recruited to a prospective observational study. Blood samples were drawn to measure whole blood thiamine diphosphate (TDP) and serum magnesium concentrations. Routine biochemistry and haematology assays were also conducted. The Glasgow Modified Alcohol Withdrawal Score (GMAWS) measured severity of AWS. Seizure history and current medications were also recorded. RESULTS: The majority of patients (99%) had whole blood TDP concentration within/above the reference interval (275-675 ng/gHb) and had been prescribed thiamine (70%). In contrast, the majority of patients (60%) had low serum magnesium concentrations (< 0.75 mmol/L) and had not been prescribed magnesium (93%). The majority of patients (66%) had plasma lactate concentrations above 2.0 mmol/L. At 1 year, 13 patients with AWS had died giving a mortality rate of 11%. Male gender (p < 0.05), BMI < 20 kg/m2 (p < 0.01), GMAWS max ≥ 4 (p < 0.05), elevated plasma lactate (p < 0.01), low albumin (p < 0.05) and elevated serum CRP (p < 0.05) were associated with greater 1-year mortality. Also, low serum magnesium at time of recruitment to study and low serum magnesium at next admission were associated with higher 1-year mortality rates, (84% and 100% respectively; both p < 0.05). CONCLUSION: The prevalence of low circulating thiamine concentrations were rare and it was regularly prescribed in patients with AWS. In contrast, low serum magnesium concentrations were common and not prescribed. Low serum magnesium was associated more severe AWS and increased 1-year mortality.

Serum Magnesium and Mortality in Hemodialysis Patients in the United States: A Cohort Study.

BACKGROUND: Low serum magnesium levels in patients with kidney disease have been linked to increased mortality. This study investigated whether similar associations existed in maintenance hemodialysis (HD) patients. STUDY DESIGN: Cohort study. SETTING & PARTICIPANTS: All Fresenius Medical Care North America in-center HD patients with available serum magnesium measurements were studied. The initial exploratory study in 21,534 HD patients evaluated associations among serum magnesium level, dialysate magnesium concentration, and mortality from April 2007 through June 2008. The follow-up study in 27,544 HD patients evaluated associations between serum magnesium levels and mortality over 1 year (January through December 2008). PREDICTORS: The primary predictor was serum magnesium level, with adjustment for case-mix (age, sex, race, diabetes, and dialysis vintage and additionally for follow-up study: body surface area and vascular access) and laboratory variables (albumin, hemoglobin, phosphorus, equilibrated Kt/V, potassium, calcium, and intact parathyroid hormone values). OUTCOME: Primary outcome variable was 1-year mortality risk, evaluated using Cox proportional hazards models. RESULTS: Among 21,534 HD patients in the exploratory study, there were 3,682 deaths. Higher dialysate magnesium level was associated with higher serum magnesium level (R=0.22; P<0.001). Patients with the lowest serum magnesium levels (<1.30 mEq/L) were at highest risk for death (HR, 1.63; 95% CI, 1.30-1.96; reference serum magnesium, 1.60-<1.90 mEq/L). Among 27,544 HD patients in the follow-up study, there were 4,531 deaths. In Cox proportional hazards models, there was a linear decline in death risk from the lowest to the highest serum magnesium category, with the best survival at serum magnesium levels ≥ 2.50 mEq/L (HR, 0.68; 95% CI, 0.56-0.82). However, risk estimates were attenuated with case-mix and lab adjustment. This pattern was consistent within diabetes subgroups and for cardiovascular or noncardiovascular causes of death. LIMITATIONS: Observational study with cross-sectional serum magnesium measurements and no information for oral magnesium intake. CONCLUSIONS: Elevated serum magnesium levels > 2.10 mEq/L were associated with better survival than low serum magnesium levels < 1.30 mEq/L in HD patients. Prospective studies may determine whether manipulation of low serum magnesium levels affects survival.

Effect of Magnesium Status on Microalbuminuria in Type 2 Diabetic Patients.

BACKGROUND: There are several controversies regarding the association between serum magnesium depletion and microalbuminuria in type 2 diabetic patients. OBJECTIVE: Therefore, this study aimed to assess serum magnesium concentrations in Type 2 diabetic patients with microalbuminuria and normoalbuminuria in Birjand, Iran, in 2019. METHODS: In this cross-sectional study, 25 type 2 diabetes patients with microalbuminuria were enrolled as the case group and 25 type 2 diabetes patients with normoalbuminuria as the control group. Both groups were matched for age, sex, hypertension, and dyslipidemia. Blood samples were obtained for serum magnesium measurement. RESULTS: Our findings showed no significant difference between serum magnesium concentration in the case and control groups (mean serum magnesium concentration for case group: 2.34 ± 0.35 mg/dl and control group: 2.27 ± 0.33 mg/dl). Pearson correlation coefficient analysis did not show any correlation between serum magnesium levels and urine albumin levels in patients with microalbuminuria versus patients with normoalbuminuria (r = 0.06, p = 0.67). CONCLUSION: This study did not indicate a correlation between serum magnesium concentrations and microalbuminuria in Type 2 diabetic patients.

Serum Magnesium Concentrations in the Canadian Population and Associations with Diabetes, Glycemic Regulation, and Insulin Resistance.

Total serum magnesium (Mg) concentration (SMC) is commonly used to assess Mg status. This study reports current SMCs of Canadians and their associations with demographic factors, diabetes, and measures of glycemic control and insulin resistance using results from the Canadian Health Measures Survey cycle 3 (2012-2013). Associations were examined in adults aged 20-79 years using linear mixed models. Mean SMCs and percentile distributions for 11 sex-age groups between 3 and 79 years (n = 5561) are reported. SMCs were normally distributed and differences (p < 0.05) among sex and age groups were small. Between 9.5% and 16.6% of adult sex-age groups had a SMC below the lower cut-off of a population-based reference interval (0.75-0.955 mmol·L-1) established in the United States population as part of the NHANES I conducted in 1971-1974. Having diabetes was associated with 0.04 to 0.07 mmol·L-1 lower SMC compared to not having diabetes in the various models. Body mass index, glycated hemoglobin, serum glucose and insulin concentrations, and homeostatic model assessment of insulin resistance were negatively associated with SMC. This is the first study to report SMCs in a nationally representative sample of the Canadian population. A substantial proportion of Canadians are hypomagnesaemic in relation to a population-based reference interval, and SMC was negatively associated with diabetes and indices of glycemic control and insulin resistance.

Relationship between renal function and serum magnesium concentration in elderly outpatients treated with magnesium oxide.

AIMS: We investigated the relationship between renal function and serum magnesium concentration in elderly patients treated with magnesium oxide (MgO) in an outpatient setting of an urban hospital in Japan. METHODS: In the present study, 44 elderly outpatients (23 patients with constipation treated with daily oral MgO and 21 untreated patients in the control group) who visited Kameyama municipal medical center were enrolled. Variables were age, sex, weight, height, serum magnesium concentration, serum blood urea nitrogen level, serum creatinine level, use of other magnesium-containing supplements and symptoms associated with hypermagnesemia. We calculated the estimated glomerular filtration rate (eGFR) and classified patients based on eGFR category. RESULTS: Compared with the control group, the MgO group showed a significantly higher concentration of serum magnesium (median 2.2 mg/dL [interquartile range 2.1-2.3] vs 2.4 mg/dL [2.2-2.6], P < 0.001). Hypermagnesemia (>2.6 mg/dL) was noted only in the MgO group. However, symptoms associated with hypermagnesemia occurred in patients from both groups, with no significant difference between groups. In the MgO group, significant difference was seen in the median serum magnesium concentration between eGFR categories (P < 0.05). The category G4 (eGFR 15-29 mL/min/1.73 m(2) ) group had the highest serum magnesium concentration in the MgO group (3.0 mg/L [2.9-3.1]). CONCLUSIONS: Elderly patients treated with MgO have higher serum magnesium levels compared with the control group. MgO should be prescribed with caution in patients with low renal function as shown by a GFR category G3b or less (eGFR < 30 mL/min/1.73 m(2) ). Geriatr Gerontol Int 2016; 16: 600-605.