Background: Magnesium is an essential intracellular cation. Magnesium deficiency is common in the general population and its prevalence among patients with cirrhosis is even higher. Correlation between serum levels and total body content is poor because most magnesium is intracellular. Minimal hepatic encephalopathy is a subclinical phase of hepatic encephalopathy with no overt symptoms. Cognitive exams can reveal minor changes in coordination, attention, and visuomotor function, whereas language and verbal intelligence are usually relatively spared.
Objectives: To assess the correlation between intracellular and serum magnesium levels and minimal hepatic encephalopathy.
Methods: Outpatients with a diagnosis of compensated liver cirrhosis were enrolled in this randomized, double-blinded study. Patients were recruited for the study from November 2013 to January 2014, and were randomly assigned to a control (placebo) or an interventional (treated with magnesium oxide) group. Serum and intracellular magnesium levels were measured at enrollment and at the end of the study. Cognitive function was assessed by a specialized occupational therapist.
Results: Forty-two patients met the inclusion criteria, 29 of whom were included in this study. Among these, 83% had abnormal cognitive exam results compatible with minimal hepatic encephalopathy. While only 10% had hypomagnesemia, 33.3% had low levels of intracellular magnesium. Initial intracellular and serum magnesium levels positively correlated with cognitive performance.
Conclusions: Magnesium deficiency is common among patients with compensated liver cirrhosis. We found an association between magnesium deficiency and impairment in several cognitive function tests. This finding suggests involvement of magnesium in the pathophysiology of minimal hepatic encephalopathy.