Estimation of sleep disturbances using wrist actigraphy in patients with postural tachycardia syndrome

Abstract

Study objectives: Patients with postural tachycardia syndrome (POTS) commonly complain of fatigue, unrefreshing sleep, daytime sleepiness and diminished quality of life. The study objective was to assess sleep quality in POTS patients using wrist actigraphy.

Design: Prospective study with control group.

Methods: Patients with POTS (n = 36) and healthy subjects (n = 36) completed a detailed sleep log and actigraphy for 7 days.

Results: Compared with healthy subjects, POTS patients have more self-reported problems including days with restless sleep (53 ± 30% vs. 21 ± 20%; P<0.001) and tiredness (75 ± 23% vs. 39 ± 27%; P<0.001). Using actigraphy, POTS patients have lower sleep efficiency (73 ± 13% vs. 79 ± 6%; P = 0.01). Actigraphy determined sleep onset latency (SOL) did not vary significantly in the two groups, but subjective SOL was higher in POTS patient (56 ± 66 min vs. 1 3 ± 9 min; P = 0.001). In POTS patients, there was a significant correlation between subjective complaints of tiredness and actigraphic sleep efficiency (Rs = -0.36; R(2) = 0.15; P = 0.01), significant correlations between actigraphic SOL and upright norepinephrine levels (P = 0.040), and between wake after sleep onset and standing heart rate (P = 0.02).

Conclusions: POTS patients have more sleep-related symptoms and poor sleep efficiency. The pattern of subjective vs. objective SOL mismatch is suggestive of sleep-state misperception. High norepinephrine correlated with actigraphic SOL, and this activation of the stress system may contribute significantly to a hyperarousal state with consequent insomnia, poor mental and physical health in POTS patients.

Keywords: Actigraphy; Autonomic; Human; Orthostatic tachycardia; Sleep.

Figure 1

Sleep Log Parameters in Postural Tachycardia Syndrome (POTS) patients and healthy controls subjects, including subjective sleep complaints of restless sleep and tiredness in morning (top panel), and Spearman correlations between subjective complaints of restless sleep and tiredness (bottom panel).

Figure 2

Actigraphic Parameters in Postural Tachycardia Syndrome (POTS) patients and healthy controls subjects including sleep efficiency and wake after sleep onset (WASO) (top panel), and Spearman correlations between subjective complaints of tiredness and actigraphic sleep efficiency, and tiredness and WASO (bottom panel). Data are presented as mean±SEM, and were analyzed using the Student’s t-test.

Figure 3

Sleep log based subjective time to sleep in Postural Tachycardia Syndrome (POTS) patients and healthy controls subjects, and Spearman correlations between subjective complaints of tiredness and subjective time to sleep (top panel). Actigraphic sleep onset latency in POTS patients and healthy controls subjects, and Spearman correlations between subjective tiredness and actigraphic sleep onset latency (bottom panel).

Figure 4

Spearman correlations (Rs) are presented for actigraphic sleep onset latency (SOL) versus standing norepinephrine (NE) levels (top panel) and actigraphic wake after sleep onset (WASO) and standing heart rate (HR; bottom panel).