Hyperpolarized 129Xe magnetic resonance imaging: tolerability in healthy volunteers and subjects with pulmonary disease.

Rationale And Objectives: The objective of this study was to evaluate the tolerability of hyperpolarized (129)Xe gas inhaled from functional residual capacity and magnetic resonance imaging in healthy subjects and those with pulmonary disease.

Materials And Methods: Twelve healthy volunteers (mean age, 59 ± 17 years), seven subjects with asthma (mean age, 47 ± 7 years), 10 subjects with chronic obstructive pulmonary disease (mean age, 74 ± 4 years), three subjects with cystic fibrosis (mean age, 27 ± 10 years), and a single subject with radiation-induced lung injury (age, 66 years) were enrolled and evaluated over 43 visits with 136 anoxic inhalations of 500 mL (129)Xe gas mixed with 500 mL (4)He gas. Oxygen saturation and heart rate were monitored during the breath-hold and imaging; subjects were queried for adverse events (AEs) before and immediately following gas inhalation and for 24 hours after the last dose.

Relationship between self-reported sleep duration and changes in circadian blood pressure.

Background: Abnormalities in sleep duration and circadian blood pressure (BP) rhythm are both independently associated with increased risk of death and cardiovascular disease. The relationship, however, between these two entities remains unclear. This study was undertaken to determine whether abnormal sleep duration is associated with nondipping status and elevated morning surge.