Sleep disturbances and diminished quality of life in 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. This study's objective was to assess the sleep quality and health-related quality of life in patients with POTS as compared with healthy control subjects.

Methods: Patients with POTS (n = 44) and healthy control subjects (n = 46) completed a battery of questionnaires including Medical Outcomes Study (MOS) Sleep Survey and the Epworth Sleepiness Scale to assess sleep, fatigue visual analogue scale (VAS) to assess fatigue, and the RAND-36 and EuroQol (EQ-5D) surveys to assess health-related quality of life.

Results: Compared with healthy control subjects, patients with POTS have more sleep problems (58 ± 18 vs. 20 ± 13; p < 0.0001) and excessive daytime sleepiness (10.2 ± 5.7 vs. 6.2 ± 3.2; p < 0.0001), higher fatigue levels (7.5 ± 2.0 vs. 2.8 ± 2.5; p < 0.0001), and poor health-related quality of life (EQ-5D health thermometer 53 ± 17 vs. 89 ± 7; p < 0.0001). There were strong correlations between MOS Sleep Survey index and the fatigue VAS (Rs = 0.73; R(2) = 0.53; p < 0.0001) and the RAND-36 physical health composite scores (Rs = -0.70; R(2) = 0.53; p < 0.0001)

Conclusions: Patients with POTS have higher subjective daytime sleepiness, fatigue, and worse sleep and health related quality of life. The sleep problems contribute significantly to the diminished quality of life: ∼ 50% of the variability in HRQL can be explained by the variability in sleep problems. Further objective studies are needed to delineate the specific nature of the sleep problems in patients with POTS.

Keywords: Postural tachycardia syndrome; fatigue; quality of life; sleepiness.

Figure 1

Sleep and fatigue in patients with postural tachycardia syndrome (POTS) and healthy control subjects Box and whisker plots showing the medians, interquartile ranges (IQR), and confidence intervals from 5% to 95% for the MOS Sleep Problems index (A), the Epworth Sleepiness Scale (B), and the fatigue visual analogue scale (C). The horizontal line in Panel B represents the commonly used threshold for “excessive daytime sleepiness.” Outliers are represented with black dots.

Figure 2

Health-related quality of life in patients with postural tachycardia syndrome (POTS) and healthy control subjects Box and whisker plots show the medians, interquartile ranges (IQR), and confidence intervals from 5% to 95%. Panel A shows the RAND-36 physical health composite score (left) and the mental health composite scores (right). Panel B shows results for the EuroQol health thermometer. Outliers are represented with black dots.

Figure 3

Scatterplots with linear regression line showing the relationship between the MOS Sleep Problems Index and the RAND-36 physical health composite score (A), the RAND-36 mental health composite score (B), and the fatigue visual analogue scale (VAS) (C) Each panel shows individual data points for POTS patients (plus signs) and control subjects (open circles).