Abstract
Background: Cardiac autonomic neuropathy (CAN) is a complication of diabetes mellitus (DM) that is associated with increased mortality. Exercise-based assessment of autonomic function has identified diminished parasympathetic reactivation after exercise in type 2 DM. It is postulated herein, that this would be more prominent among those with type 1 DM. Methods: Sixteen subjects with type 1 DM (age 32.9 ± 10.1 years), 18 subjects with type 2 DM (55.4 ± ± 8.0 years) and 30 controls (44.0 ± 11.6 years) underwent exercise-based assessment of autonomic function. Two 16-min submaximal bicycle tests were performed followed by 45 min of recovery. On the second test, atropine (0.04 mg/kg) was administered near end-exercise so that all of the recovery occurred under parasympathetic blockade. Plasma epinephrine and norepinephrine levels were measured at rest, during exercise, and during recovery. Results: There were no differences in resting or end-exercise heart rates in the three groups. Para-sympathetic effect on RR-intervals during recovery (p < 0.03) and heart rate recovery (p = 0.02) were blunted in type 2 DM. Type 1 DM had higher baseline epinephrine and norepinephrine levels (p < 0.03), and exhibited persistent sympathoexcitation during recovery. Conclusions: Despite a longer duration of DM in the study patients with type 1 versus type 2 DM, diminished parasympathetic reactivation was not noted in type 1 DM. Instead, elevation in resting plasma catecholamines was noted compared to type 2 DM and controls. The variable pathophysiology for exercise-induced autonomic abnormalities in type 1 versus type 2 DM may impact prognosis.
Original language | English (US) |
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Pages (from-to) | 272-283 |
Number of pages | 12 |
Journal | Cardiology Journal |
Volume | 29 |
Issue number | 2 |
DOIs | |
State | Published - Apr 7 2022 |
Funding
This research was supported, in part, by the National Heart, Lung, and Blood Institute (Grant No. 1 RO1 HL 70179-01A2).
Keywords
- cardiac autonomic function
- cardiac autonomic neuropathy
- diabetes mellitus
- exercise testing
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine