Prevalence of hypo- and hypermagnesemia in an Iranian urban population

Background: Magnesium (Mg) plays an important role in metabolic processes and its deficiency or excess could adversely affect metabolism. Although magnesium deficiency and excess is associated with a variety of medical conditions, the prevalence of hypo- and hypermagnesemia have not been reported in an Iranian urban population.

Subjects and methods: This cross-sectional study was performed on 1558 subjects (754 males and 804 females), randomly selected from among participants of the Tehran Lipid and Glucose Study (TLGS). Serum Mg level was measured by flame atomic absorption spectrophotometry. Hypo- and hypermagnesemia were defined by serum Mg < 0.75 mmol/L and Mg>1.04 mmol/L, respectively, and sub-optimal serum Mg concentrations were defined by serum Mg < 0.8 mmol/L.

Results: The prevalence of hypomagnesemia was 4.6% in the total population, being more prevalent in females (6.0%) compared to males (3.2%) (p < 0.05). The overall prevalence of hypermagnesemia was 3.0% and it was more prevalent in males (3.2%) than females (2.7%) (p < 0.05). Sub-optimal Mg levels were found in 14.6% of the total population.

Conclusions: The data show a relatively high prevalence of abnormal levels of serum Mg, among a general population; levels which may contribute to the pathophysiology of several diseases.     

镁离子和钙离子对实验性家兔心肌毒性作用的研究

目的通过观察钙剂对高镁血症家兔血压、呼吸和心电的影响,进一步探讨钙离子和镁离子对心肌的毒性作用。方法常规麻醉,手术插管,实验分为正常对照组、模型组和实验组。采用10%MgCl2溶液,按1.8 ml/kg静推方法复制家兔高镁血症模型,造模成功后将实验组分成小、低、中、高4个钙剂处理组,每组钙（5%CaCl2溶液）的计量分别为：1.1 ml/kg、1.5 ml/kg、1.9 ml/kg、2.3 ml/kg,通过静推进行抢救,观察记录血压、呼吸和心电各项指标处理前后的变化。结果小剂量组呼吸恢复慢,血压不能恢复正常,心肌传导阻滞得不到改善;低剂量组呼吸恢复正常,血压接近正常值,心肌传导阻滞有改善;中剂量组呼吸、血压恢复正常,心肌传导阻滞明显改善;高剂量组呼吸恢复正常,血压接近正常值,出现钙离子心肌中毒症状,其中一只家兔出现室扑、室颤后死亡。结论 1.9 ml/kg 5%CaCl2溶液缓慢静脉推注抢救实验性家兔高镁血症效果最佳。     

Electrolyte disturbances in chronic heart failure: Metabolic and clinical aspects

The pathophysiology of congestive heart failure (CHF) includes conditions (e.g., activation of the renin-angiotensin-aldosterone system) which, when combined with CHF therapies, make patients afflicted with this syndrome quite susceptible to electrolyte disturbances. The most commonly encountered are hyponatremia, hypokalemia, and hypomagnesemia. These derangements are of vast clinical importance; their development not only represents an immediate threat to the CHF patient (e.g., dysrhythmias secondary to hypokalemia), but are also indicative of underlying pathophysiologic events, an unfavorable clinical course, and occasionally an adverse therapeutic response. The optimal care of the CHF patient includes the recognition and management of these electrolyte disturbances.     

Magnesium: An Overlooked Electrolyte

Background

Hypermagnesemia is rare and usually iatrogenic. Due to decreased renal function, older patients are generally more susceptible to hypermagnesemia than are younger patients. Because it is not one of the commonly assessed electrolytes in the blood work panel of patients, high levels are usually missed.

血清镁对老年男性急性肾损伤患者短期预后的影响

目的对老年急性肾损伤(AKI)患者进行随访观察,探讨AKI患者血清镁紊乱发生情况及血清镁水平对老年AKI患者短期生存的影响。方法选择2007年1月至2015年12月就诊于解放军总医院老年病房≥75岁的住院男性AKI患者为研究对象。根据AKI后28 d时和60 d时患者的生存情况,将患者病历资料分为死亡组和存活组进行分析。以血清镁0.7 mmol/L为低镁血症,1.1 mmol/L为高镁血症。采用SPSS 17.0软件进行统计分析。Kaplan-Meier乘积法估计生存曲线,并通过对数秩检验进行比较,多因素Cox回归模型分析血清镁对老年患者短期生存的影响。结果 623例老年男性AKI患者,中位年龄87(84,91)岁。正常血镁者473例(75.9%),低镁血症患者72例(11.6%),高镁血症患者78例(12.5%)。发生AKI后28 d内死亡160例,60 d内共死亡194例。采用Kaplan-Meier生存曲线比较显示高镁血症患者28 d生存状况明显较差(log-rank检验:P=0.001)。多因素Cox回归分析显示AKI诊断时间(HR=0.865,95%CI 0.799~0.937;P0.001)、平均动脉压(HR=0.970,95%CI 0.958~0.981;P0.001)、血清前白蛋白(HR=0.924,95%CI 0.894~0.955;P0.001)、少尿(HR=2.261,95%CI 1.424~3.590;P=0.001)、机械通气(HR=1.492,95%CI 1.047~2.124;P=0.027)、血尿素氮(HR=1.037,95%CI 1.025~1.049;P0.001)、血镁水平(HR=2.512,95%CI 1.243~5.076;P=0.010)、AKI分期(2期:HR=3.709,95%CI 1.926~7.141,P0.001;3期:HR=5.660,95%CI 2.990~10.717,P0.001)是老年AKI患者28 d生存的影响因素。血清镁对患者29~60 d的生存影响无统计学意义。结论老年AKI患者镁离子紊乱发生率高达24.1%(150/623),高血镁与老年男性AKI患者28 d病死率密切相关,监测及适当纠正血镁紊乱可能会延长其生存时间。     

THE HYPOCALCEMIA ASSOCIATED WITH MAGNESIUM INFUSION IS MEDIATED THROUGH PARATHYROID HORMONE

Pregnant women receiving intravenous magnesium sulfate to suppress premature labor developed nontetanic hypocalcemia in a temporal association with suppressed parathyroid hormone secretion.     

Admission hypomagnesemia linked to septic shock in patients with systemic inflammatory response syndrome

Abstract

Background: The association between admission serum magnesium (Mg) levels and risk of developing septic shock in patients with systemic inflammatory response syndrome (SIRS) is limited. The aim of this study was to assess the risk of developing septic shock in hospitalized patients with SIRS with various admission Mg levels. Methods: This is a single-center retrospective study conducted at a tertiary referral hospital. All hospitalized adult patients with SIRS at admission who had admission Mg available from January 2009 to December 2013 were analyzed in this study. Admission Mg was categorized based on its distribution into six groups (<1.5, 1.5–1.7, 1.7–1.9, 1.9–2.1, 2.1–2.3, and >2.3?mg/dL). The primary outcome was septic shock occurring after hospital admission. Logistic regression analysis was performed to obtain the odds ratio (OR) of septic shock of various admission Mg levels using Mg with lowest incidence of shock, 2.1–2.3?mg/dL as the reference group. Results: Of 2589 patients with SIRS enrolled, septic shock occurred in 236 patients (9.1%). The lowest incidence of septic shock was when serum Mg was within 2.1–2.3?mg/dL. A reverse-checkmark curve emerged demonstrating higher incidences of septic shock associated with both hypoMg (<2.1) and hyperMg (>2.3). After adjusting for potential confounders, hypoMg (<1.5?mg/dL) was associated with an increased risk of developing septic shock with ORs of 1.86 (95% CI 1.07–3.27). Conclusion: Patients with SIRS and hypoMg (<1.5?mg/dL) at the time of admission had increased risk of developing septic shock during hospitalization.