Exosomal miRNAs in urine associated with children's cardiorenal parameters: a cross-sectional study.

Aims: The authors sought to examine associations between urinary exosomal miRNAs (exo-miRs), emerging biomarkers of renal health, and cardiorenal outcomes in early childhood. Materials & methods: The authors extracted exo-miRs in urine from 88 healthy Mexican children aged 4-6 years. The authors measured associations between 193 exo-miRs and cardiorenal outcomes: systolic/diastolic blood pressure, estimated glomerular filtration rate and urinary sodium and potassium levels. The authors adjusted for age, sex, BMI, socioeconomic status, indoor tobacco smoke exposure and urine specific gravity. Results: Multiple exo-miRs were identified meeting a false discovery rate threshold of q < 0.1. Specifically, three exo-miRs had increased expression with urinary sodium, 17 with urinary sodium-to-potassium ratio and one with decreased estimated glomerular filtration rate. Conclusions: These results highlight urinary exo-miRs as early-life biomarkers of children's cardiorenal health.

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.