Deleterious impact of obstructive sleep apnea on autonomic nervous system control during rapid-eye-movement sleep in adult type 1 diabetes.

Obstructive sleep apnea (OSA) with an apnea-hypopnea index (AHI) ≥ 15/h increases the cardiovascular disease (CVD) risk in type 1 diabetes (T1D). Cardiovascular autonomic neuropathy (CAN) is a key driver of CVD in diabetes and could be increased by autonomic nervous system (ANS) dysfunction related to OSA. We compared ANS control in T1D patients with AHI ≥ 15/h versus <15/h. T1D patients underwent polysomnography with heart rate variability analysis, cardiovascular reflex tests (CARTs), sudomotor function test, and urinary catecholamine analysis. Compared with patients with AHI < 15/h (n = 14), those with AHI ≥ 15/h (n = 7) showed a lower HFnu during REM sleep (12 ± 11 vs. 25 ± 14 nu, p < 0.05) and a higher heart rate (73 ± 8 vs. 64 ± 9 bpm; p < 0.05). A significantly higher urinary norepinephrine/epinephrine ratio was observed in patients with AHI ≥ 15/h. No significant group differences were observed regarding CAN. However, AHI correlated with systolic blood pressure at orthostatism (r = 0.54, p < 0.05). In T1D patients, OSA with AHI ≥ 15/h showed a lower parasympathetic activity and a sympathetic activation during sleep without any significant diurnal CAN proportion increase in patients with AHI ≥ 15/h. The potential impact of OSA on CAN and CVD risk in T1D patients should be assessed in further studies.