Abstract 12732: Aldosterone, Not Leptin, is Correlated With High Sympathetic Activity in Resistant Hypertension With or Without Type 2 Diabetes
Background: The finding of adipocyte-derived hormone leptin as an overstimulator of sympathetic activity brought a new perspective to the pathophysiological mechanisms of obesity-hypertension. However, considering that aldosterone also increases sympathetic activity, we aimed to assess the relationship between sympathetic overactivity and plasma leptin levels and aldosterone in resistant hypertension (RHTN), comparing the groups with and without T2D.
Methods: Twenty-five RHTN patients (15 non-T2D and 10 T2D, 15 males, 10 females; aged 34-70 years) underwent echocardiogram and ambulatory electrocardiography to analyze heart rate variability (HRV) in time and frequency domains, which were stratified into two periods: 24 hours and daytime (DT). Plasma leptin levels were measured by ELISA. In addition, patients were divided into non-obese and obese groups, independently of T2D, for exploratory evaluation.
Results: T2D group had higher values of serum aldosterone, plasma leptin and urinary sodium excretion than the non-T2D. Both groups (non-T2D and T2D) separately also had aldosterone correlated with HRV in frequency domain. Non-T2D had aldosterone correlated with DT normalized low frequency (LF nu) (r=0.6 [0.12 - 0.85] p=0.018) and DT normalized high frequency (HF nu) (r=-0.6 [-0.85 - -0.12] p=0.018). Type-2-diabetes group had aldosterone correlated with DT LF nu (r=0.72 [0.16 - 0.93] p=0.019) and DT HF nu (r=-0.72 [-0.93 - -0.16] p=0.019). Obese and non-obese subgroups also had aldosterone correlated with HRV in frequency domain. Non-obese subgroup had aldosterone correlated with DT LF nu (r=0.56 [0.08 - 1.0] p=0.029) and DT HF nu (r=-0.56 [-1.00 - -0.08) p=0.029). Obese subgroup had aldosterone correlated with DT LF nu (r=0.77 [0.38 - 0.93] p=0.002) and DT HF nu (r=-0.77 [-0.93 - -0.38] p=0.002). However, leptin did not correlate with HRV (frequency domain) neither in non-obese nor in obese patients.
Conclusion: Despite of the importance of leptin in sympathetic overactivity in RHTN, aldosterone may surpass the importance of leptin in sympathetic overstimulation. This information combined with the clinical efficacy of mineralocorticoid receptor blocker in RHTN reinforces that aldosterone is a major player to be a therapeutic target in RHTN.
- © 2011 by American Heart Association, Inc.