Objectives: This study sought to clarify the relationship between the degree of intracellular magnesium deficiency and the frequency of anginal attacks in women with variant angina.
Patients and methods: We evaluated the intracellular and extracellular magnesium status of twelve women with variant angina: group A (> or = 4 attacks/week, n = 5) and group B (< 4 attacks/week, n = 7). Magnesium levels were determined in serum, urine, and erythrocytes, and the 24-h magnesium retention rate was calculated by magnesium loading test.
Results: Group A showed a higher 24-h magnesium retention rate (58.2 +/- 9.1% vs. 31.3 +/- 4.4%; p < 0.01) and a lower intracellular concentration of magnesium in erythrocytes than group B (3.1 +/- 1.1 vs. 5.0 +/- 0.8 fg/cell; p < 0.05), demonstrating the presence of magnesium deficiency in group A. The 24-h magnesium retention rate and intracellular concentrations of magnesium in erythrocytes correlated well with the activity of variant angina (r = 0.61, p < 0.01; and r = -0.74, p < 0.01, respectively) for these patients.
Conclusion: This study demonstrates that the degree of intracellular magnesium deficiency in women with variant angina is closely related to the frequency of chest pain.