| Variables | Cases No (%) | Controls No (%) | Total | P value | |
| Serum Magnesium | Low (<1.8) mg/dL | 34 (48.6%) | 3 (4.3%) | 37 (26.4%) | 0.001* |
| Normal (1.8 - 2.3) mg/dL | 31 (44.3%) | 21 (30.0%) | 52 (37.1%) | ||
| High (>2.3) mg/dL | 5 (7.1%) | 46 (65.7%) | 51 (36.4%) | ||
| Total | 70 (100%) | 70 (100%) | 140 (100%) | ||