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Exaggerated blood pressure and sympathetic reactivity in patients with Type 2 Diabetes
Author(s) -
Vranish Jennifer R,
Holwerda Seth W,
Keller David M,
Fadel Paul J
Publication year - 2016
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.30.1_supplement.1004.1
Subject(s) - isometric exercise , cold pressor test , medicine , blood pressure , microneurography , heart rate , diabetes mellitus , type 2 diabetes , cardiology , baroreflex , endocrinology
Although greater blood pressure (BP) responses to exercise have been observed in Type 2 Diabetes (T2D) patients, our understanding of the time course and mechanisms involved remains limited. Herein, we focused on the immediate onset of isometric handgrip (i.e., first 30 seconds) and tested the hypothesis that T2D patients would exhibit an augmented increase in BP and muscle sympathetic nerve activity (MSNA) relative to age and bodyweight‐matched, healthy controls. T2D patients (n=14) and controls (n=8) performed isometric handgrip at 40% of maximal voluntary contraction while BP, MSNA, and heart rate (HR) were continuously recorded. A cold pressor test (CPT) was also performed as a generalized, central sympatho‐excitatory stimulus. Data were averaged over 10s intervals for the initial 30s of handgrip and CPT. HR increased at exercise onset (first 10s; P < 0.001) with no differences between groups (8±1.9 vs. 11±1.7; P = 0.655). However, mean BP (9±1.2 vs. 4±1.9 mmHg; P = 0.019) and systolic BP (12±1.7 vs. 3±2.5 mmHg; P = 0.003) were significantly greater for the first 10s of handgrip in T2D patients than controls. These differences were maintained over the entire 30s onset of exercise. Likewise, MSNA was also greater for T2D patients (10±2.1 vs. 1±2.6 bursts per minute; P = 0.031) at the onset of exercise. Interestingly, T2D patients also exhibited a greater mean BP (11±2.4 vs. 3±1.4 mmHg; P = 0.013) and MSNA (17±3.6 vs. 7±2.4 bursts per minute; P = 0.042) response to the first 30s of CPT. Collectively, these data suggest that T2D patients exhibit heightened pressor and sympathetic responsiveness at the onset of isometric handgrip that may be mediated by greater central reactivity, although a role for the muscle mechanoreflex also warrants consideration. Support or Funding Information Supported by AHA‐20160072 (P.J.F.).