Gender-related differences of urinary magnesium excretion: implications for chemotherapy in cancer patients

Aim and methods. Hypomagnesemia is a frequent adverse effect of chemotherapy in cancer patients. Its gender-dependent peculiarities are unknown. The aim of the current work was to define peculiarities of urinary magnesium (Mg) excretion in healthy adolescents; to elucidate gender-related differences in Mg urinary excretion; to determine a correlation between urinary Mg excretion and arterial blood pressure (BP) in healthy adolescents. Mg was examined in diurnal and nocturnal urine of adolescent boys (n = 27) and girls (n = 42) aged 13 - 17 years. Urinary Mg (both during day and night) was monitored 24-h concomitantly with BP (hourly) in 44 adolescents (22 girls and 22 boys). Additionally, of the same girls 15 were examined during different phases of their menstrual cycle (follicular, ovulation and luteal). Results. 24-h urinary Mg excretion was significantly higher in boys than in girls (2.66 +/- 0.9 mmol vs. 2.1 +/- 0.9 mmol; p < 0.05). Nocturnal systolic BP was significantly higher (p < 0.05) in boys than in girls in all phases of their menstrual cycle. Diurnal systolic BP in boys was significantly higher than in girls during the follicular phase. It revealed a significant positive correlation between Mg excretion and BP in boys at night (p < 0.05). Girls exhibited a significant inverse correlation between Mg nocturnal excretion and BP (p < 0.05) during the luteal phase of their menstrual cycle, as well as a significant negative correlation between diurnal Mg excretion and BP (p < 0.05) during the ovulation phase. Urine Mg was negatively related to height in girls (p < 0.05). Conclusion. Mg urinary excretion is related to gender, height, circadian rhythm, and blood pressure. The further preclinical and clinical studies of gender-related risks of hypomagnesemia under chemotherapeutic treatment could contribute to improving the efficacy of anticancer treatment.