Table 4—

Plasma fasting insulin level according to quartiles of magnesium intake in 349 apparently healthy women from the WHS

Fasting insulin levels (pmol/l)Quartile of intake
P for trend
1 (lowest)234 (highest)
Total magnesium intake
Median intake (mg/day)259307356425
 Crude [median (interquartile range)]42.6 (29.9–59.3)47.4 (32.7–72.6)37.2 (26.0–57.0)36.4 (27.8–52.3)0.004
 Age adjusted44.3 (39.9–50.1)49.0 (43.6–54.8)38.5 (34.3–43.1)37.3 (33.3–41.9)0.005
 Age and BMI adjusted43.4 (39.3–47.8)47.0 (42.7–51.8)39.6 (36.0–43.7)38.9 (35.3–42.8)0.03
 Multivariate adjusted42.1 (37.7–47.0)45.2 (40.4–50.5)39.3 (35.1–43.9)38.5 (34.5–43.0)0.08
Dietary magnesium intake
Median intake (mg/day)255301339387
 Crude [median (interquartile range)]44.0 (28.8–63.1)43.5 (30.6–64.6)37.2 (29.5–57.4)36.6 (26.0–50.3)0.003
 Age adjusted44.7 (39.8–50.2)47.5 (42.3–53.2)40.9 (36.4–45.8)36.2 (32.3–40.7)0.004
 Age and BMI adjusted43.8 (39.2–48.9)46.5 (42.2–51.2)40.9 (37.1–45.0)38.1 (34.5–42.0)0.02
 Multivariate adjusted42.5 (38.1–47.5)45.2 (40.4–50.4)40.0 (35.9–44.7)37.8 (33.9–42.0)0.05
  • Data are expressed as geometric mean (95% CI, unless noted otherwise). All covariate values are according to the quartiles of magnesium intake. The multivariate linear model was adjusted for age (continuous), smoking (current, past, and never), BMI (continuous), exercise (rarely/never, <1 time/week, 1–3 times/week, and ≥4 times/week), alcohol use (rarely/never, 1–3 drinks/month, 1–6 drinks/week, and ≥1 drink/day), family history of diabetes (yes or no), and total calories (quintiles).