Leptin and aldosterone in 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.


OBJECTIVE
As aldosterone also increases sympathetic activity, we aimed to assess the relationship between sympathetic overactivity and plasma leptin and aldosterone levels in resistant hypertension (RHTN), comparing the groups with and without T2D.


METHODS
Twenty-five RHTN patients underwent ambulatory electrocardiography to analyze heart rate variability (HRV) in time and frequency domains, which were stratified into two periods: 24 hours and daytime (DT), comprising the records between 2:00 p.m to 6:00 p.m (time domain) and one hour at 3:00 p.m (frequency domain).


RESULTS
T2D group (n=10) had higher serum aldosterone and plasma leptin levels than the non-T2D (n=15) (26.0 ± 11.5 vs. 16.9 ± 7.0 ng/dL - p=0.021; 81.368.7 ± 47.086.1 vs 41.228.1 ± 24.523.1 pg/mL - p=0.048, respectively). Both groups had aldosterone correlated with HRV in frequency domain. Non-T2D had aldosterone correlated with DT low frequency in normalized units (LF nu) (r=0.6 [0.12-0.85] p=0.018) and DT high frequency in normalized units (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). However, despite of the importance of leptin in sympathetic overactivity in hypertension, leptin did not correlate with HRV.


CONCLUSIONS
Aldosterone seems to overdrive sympathetic activity in RHTN with and without T2D. This information combined with the clinical efficacy of mineralocorticoid receptor blocker in RHTN may reinforce that aldosterone is a major player to be a therapeutic target in RHTN.
Cardiovascular Pharmacology Laboratory, Faculty of Medical Sciences and Teaching Hospital, University of Campinas, Campinas, São Paulo - Brazil .
Leandro
L
Boer-Martins
Valéria Nasser
VN
Figueiredo
Caroline
C
Demacq
Luiz Cláudio
LC
Martins
Ana Paula Cabral de
AP
Faria
Carolina de Haro
Cde H
Moraes
Heitor
H
Moreno
D000328:Adult; D000450:Aldosterone / Q000097:blood* / Q000502:physiology; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D004351:Drug Resistance; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*; D020738:Leptin / Q000097:blood* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D013564:Sympathetic Nervous System / Q000503:physiopathology*
D000959:Antihypertensive Agents; D020738:Leptin; D000450:Aldosterone