Background: Cardiovascular autonomic neuropathy (CAN) can affect daily activities and patients'
quality of life and evoke potentially life-threatening outcomes in diabetes mellitus
(DM). Objectives: We aimed to identify and characterize CAN and associated disorders in Libyan patients
with DM at National Diabetes Hospital. Patients and Methods: Ninety-nine patients with DM seen in the outpatient clinics from October 2017 to
April 2018 at National Diabetes Hospital were prospectively evaluated. Assessments
for CAN were made by clinical symptoms and signs, cardiovascular autonomic reflex
tests, and echocardiogram. Patients with potentially confounding concomitant medical
conditions were excluded. CAN is defined as possible (one abnormal cardiovagal test),
confirmed (two abnormal such tests), and severe (with concomitant orthostatic hypotension
and heart rate abnormality). Results: Sixty-two percent of the studied patients (mean age: 52 ± 1.5 years, 53% – female)
with DM had CAN. CAN diagnosis was possible in 18% of these patients, confirmed in
6%, and severe in 38%. The presence of severe CAN was associated with hypoglycemic
unawareness (P = 0.01), dyslipidemia (P = 0.012), and microvascular diabetic complications
(P = 0.04). Conclusions: In this cohort of relatively old and high-risk cardiovascular disease, patients with
diabetes, uncontrolled blood pressure, associated dyslipidemia, presence of microvascular
complication of diabetes, and history of hypoglycemic unawareness were strongly associated
with a severe form of cardiac autonomic neuropathy with potentially serious clinical
consequences. Larger and more detailed studies are needed to elucidate further the
complex association between hypoglycemia and cardiac autonomic dysfunction.
Key-words:
Cardiovascular autonomic neuropathy - diabetes mellitus - heart rate variability -
orthostatic hypotension - resting tachycardia
