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Arterial baroreflex control of heart rate and sympathetic nerve activity in patients with type II diabetes
Author(s) -
Young Colin N.,
Deo Shekhar H.,
Fisher James P.,
LeMaster Joseph W.,
HannaMoussa Abdullah,
Khan Uzma Z.,
Fadel Paul J.
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.786.7
Subject(s) - baroreflex , medicine , blood pressure , heart rate , microneurography , diabetes mellitus , cardiology , phenylephrine , sodium nitroprusside , sympathetic nervous system , anesthesia , endocrinology , nitric oxide
Previous studies have indicated that diabetes is associated with postural hypotension and greater arterial blood pressure (BP) reactivity to acute cardiovascular stressors. However, whether impairments in arterial baroreflex (ABR) function contribute to alterations in BP control in diabetes remains unclear. To begin to address this question, muscle sympathetic nerve activity (MSNA), heart rate, and BP were continuously recorded in 8 type II diabetic patients and 4 healthy age‐matched control subjects during intravenous bolus injections of sodium nitroprusside followed 60s later by phenylephrine hydrochloride. The sensitivity (i.e., gain) of ABR‐cardiac and ABR‐MSNA control were identified from the linear relationships between RR‐interval and systolic BP and total MSNA and diastolic BP, respectively. ABR‐cardiac gain tended to be lower in diabetic patients compared to healthy controls [4.95±0.67 diabetics (n=8) vs. 9.25±3.90 controls, ms/mmHg; P=0.18]. In contrast, the ABR‐MSNA gain was similar between the two groups [‐8.32±3.03 diabetics (n=5) vs. ‐9.67±1.40 controls, units/beat/mmHg; P=0.72]. These preliminary data suggest that type II diabetic patients exhibit differential alterations in ABR function demonstrating ∼46% reductions in ABR‐cardiac control, whereas ABR‐MSNA control appears to be better preserved (∼14% reduction vs. controls).