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document
Direct renin inhibition improves parasympathetic function in diabetes . AIM The renin-angiotensin-aldosterone system ( RAAS ) and autonomic nervous system regulate the cardiovascular system . Blockade of the RAAS may slow the progression of end-organ damage . Direct renin inhibition offers a means for blocking the RAAS . The objective of this study was to examine the effect of direct renin inhibition on cardiovascular autonomic function . METHODS In this double-blind , placebo-controlled trial , 60 individuals with diabetes were randomly assigned to 300 mg of aliskiren or placebo once daily for 6 weeks . The primary end point was a change in tests of cardiovascular autonomic function . Autonomic function was assessed by power spectral analysis and RR-variation during deep breathing [ i.e . mean circular resultant ( MCR ) , expiration/inspiration ( E/I ) ratio ] . The MCR and E/I ratio assess parasympathetic function . Secondary measures included change in biochemical parameters [ e.g . plasma renin activity , leptin and interleukin-6 ] . Change in cardiovascular autonomic function and blood analytes were analysed by a mixed effects model for repeated measures . RESULTS Baseline characteristics were similar between treatment groups . In response to aliskiren compared with placebo , blood pressure was reduced as well as plasma renin activity [ from 2.4 ± 3.8 ( mean ± standard deviation ) to 0.5 ± 0.4 µg/l/h , p < 0.001 ] . There was a significant interaction ( aliskiren × visit ) for MCR ( p = 0.003 ) and E/I ratio ( p = 0.003 ) indicating improvement in MCR and E/I ratio for those on aliskiren . MCR means , baseline vs. follow-up , were 41.8 ± 19.7 vs. 50.8 ± 26.1 ( aliskiren ) and 38.2 ± 23.6 vs. 37.5 ± 24.1 ( placebo ) . CONCLUSIONS Parasympathetic function ( i.e . MCR and E/I ratio ) was enhanced by downregulation of the RAAS .
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Intervention_Control
placebo-controlled
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Intervention_Pharmacological
aliskiren
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Intervention_Pharmacological
placebo
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Intervention_Pharmacological
aliskiren
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Intervention_Control
placebo
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Outcome_Physical
change in tests of cardiovascular autonomic function
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Outcome_Physical
Autonomic function
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Outcome_Physical
change in biochemical parameters
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Outcome_Physical
plasma renin activity , leptin and interleukin-6
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Outcome_Physical
Change in cardiovascular autonomic function and blood analytes
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Outcome_Physical
blood pressure
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Participant_Condition
diabetes
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Participant_Sample-size
60
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Participant_Condition
diabetes