Fatigue is a common symptom in patients with pulmonary arterial hypertension (PAH); however, the impact of fatigue on daily physical activity in PAH is unknown. Accelerometry is a validated measure for assessing physical activity. We hypothesized that patients with PAH reporting higher levels of fatigue would have lower daily physical activity measured by accelerometry.METHODS:
We performed a prospective cohort study of 15 women with PAH. On day 1, subjects completed the Multidimensional Fatigue Inventory (MFI), the United States Cambridge Pulmonary Hypertension Outcome Review (US CAMPHOR), and a 6-min walk test. Subjects wore the accelerometer on their dominant hip and completed an activity diary for 7 days. On day 15, subjects repeated the MFI and the US CAMPHOR, and then wore the accelerometer and completed an activity diary for an additional 7 days. All multivariate analyses were adjusted for age, BMI, and PAH type.RESULTS:
The mean age was 50.5 years, and 53% had idiopathic or heritable PAH. During the 2 weeks, subjects were mostly sedentary (85% of the time), although 10% of their time was spent performing low-level activity. Lower average daily counts were associated with worse self-reported energy levels, whereas less day-to-day physical activity variability was associated with more self-reported mental fatigue, physical fatigue, and total activity. Higher percentage of activity bouts was also associated with worse energy.CONCLUSIONS:
Women with PAH may spend most of their time being sedentary, and lower self-reported energy levels are associated with less daily activity. Interventions to improve symptoms such as fatigue may also increase physical activity levels in PAH.