Low Serum Magnesium Levels and Its Association with High Blood Pressure in Children

Objective To evaluate the association of hypomagnesemia with prehypertension (preHTN) and hypertension in children. Study design A total of 3954 apparently healthy Mexican children were enrolled in a cross-sectional study. Exclusion criteria were type 2 diabetes; hepatic, renal, or endocrine disease; impaired fasting glucose; chronic diarrhea; and intake of vitamins or magnesium supplements in the previous 6 months. preHTN was defined by systolic and/or diastolic blood pressure >= 90th to < 95th percentile and hypertension by systolic and/or diastolic blood pressure >= 95th percentile, according to age, sex, and height percentile. Hypomagnesemia was defined by serum magnesium concentration < 1.8 mg/dL (< 0.74 mmol/L). To control for potential sources of bias related to age, participants were allocated into 2 groups, aged 6-10 years and 11-15 years. Results The prevalence of preHTN and hypertension was 12.2% and 6.4%, respectively, in children aged 6-10 years and 13.9% and 10.6% in those aged 11-15 years. Hypomagnesemia was identified in 59 children with preHTN (27.3%) and 52 (45.6%) with hypertension in the 6-10 year age group, and in 115 children with preHTN (36.0%) and 109 (49.6%) with hypertension in the 11-15 year age group. Adjusted multiple logistic regression analysis showed that in children in both age groups, hypomagnesemia was associated with both preHTN (6-10 years: OR, 2.18, P <.0005; 11-15 years: OR, 1.38, P =.018) and hypertension (6-10 years: OR, 4.87, P <.0005; 11-15 years: OR, 1.83, P =.0002). Conclusion Our results indicate that serum magnesium level < 1.8 mg/dL is significantly associated with preHTN and hypertension in apparently healthy children.