Gender differences in the handling of biologically‐active magnesium (Mg2+) and calcium (Ca2+) in short‐term (S‐T) dietary magnesium deficiency (MD); Implications for cardiovascular diseases (CVD)

Abstract

There has been a steady decline in the dietary intake of Mg in the USA. Is there a gender difference in the handling of Mg2+? To test this hypothesis, we induced S‐T MD (10% normal intake)in young ,mature male and female Wistar rats and used ISEs to measure, precisely, serum levels of Mg2+, Ca2+, Ca2+/Mg2+ ratios and total Mg (tMg).The MD‐animals were allowed to drink triply‐distilled water containing one of five different levels of Mg ,while control animals received a normal Mg‐containing diet The data indicate that male and female rats, on normal Mg diets ,exhibit identical serum levels of Mg2+(0.64 +/− 0.02 vs.0.63 +/− 0.3 mM),Ca2+(1.47 +/− 0.08 vs 1.43 +/− 0.03 mM),and Ca2+/Mg2+ ratios (2.30 vs.2.17). The MD‐male and female rats exhibited different Mg2+(0.26+/−0.04 vs. 0.36+/−0.06 mM),tMg and Ca2+/Mg2+ ratios ( 6.19 vs 4.3) from one another and the controls ( p< 0.01). Feeding water‐borne Mg failed to restore Mg2+ or tMg to normal serum levels in male animals ,but the higher water‐borne levels of Mg in females were able to restore serum Mg2+ and tMg to normal.We demonstrate ,for the first time, that ;1) mature male MD‐ rats do not have an ability to mobilize biologically‐active Mg2+ as do female mature MD‐ rats; 2) male rats exhibit high serum Ca2+/Mg2+ ratios in a S‐T MD state, which would result in increased risk for the development of CVD.