Background: Leptin is considered to play an important role in the development of hypertension in obesity. The excessive synthesis of aldosterone contributes to the development and progression of metabolic and cardiovascular dysfunctions. Leptin is a newly described regulator of aldosterone synthesis that acts directly on adrenal glomerulosa cells to increase CYP11B2 expression and enhance aldosterone production in human adrenal cells lines and in animal models.
Objective: To analyze if there is association between leptin with serum aldosterone (SA), as well as with blood pressure (BP), plasma renin activity (PRA), trans-tubular potassium gradient (TTKG), fractional excretion of sodium (FENa) and 24 h-Na/K urine ratio.
Design: Cross sectional study.
Subject and methods: We studied 79 subjects between 6.1 and 18 years old (mean, 13.2 years; 42 females); 37 were normal weight, 18 were overweight, and 24 were obese. After overnight fasting: anthropometric parameters, SA, PRA, plasma and 24-h-urine electrolytes were measured and TTKG, FENa and 24 h-Na:K urine ratio were calculated. For variables without normal distribution Spearman correlation was used, and log transformation was calculated previously to partial correlation analyses.
Results: Leptin was directly associated with SA (ρ=0.275; P=0.016). None association was found between leptin with systolic and diastolic BP (P=0.657 and P=0.869, respectively) and PRA (P=0.197). Moreover, after controlling by age, body mass index z-score (BMI-z), log10 PRA and log10 24 h-Na:K urine ratio, the association between log10 leptin and log10 SA increase (partial correlation=0.367; P=0.002). In other hand, SA was associated with PRA (ρ=0.400; P<0.001) and TTKG (ρ=0.330; P=0.037); and negative associated with FENa (ρ=−0.246; P=0.035) and 24 h-Na:K urine ratio (ρ=−0.276; P=0.014).
Conclusion: In paediatric subjects, leptin was associated with SA. This association was independently of the effect of age, BMI-z, PRA and BP. Our clinical results agree with the recently described effect between of leptin upon aldosterone secretion in human adrenal cells lines and in animal models.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology