Acute Tetrahydrobiopterin Improves Endothelial Function in Patients With COPD.

Background: Cardiovascular diseases represent a hallmark characteristic in COPD, and endothelial dysfunction has been observed in these patients. Tetrahydrobiopterin (BH) is an essential cofactor for nitric oxide (NO) synthesis and a regulator of endothelial function. The goal of this study was to test the hypothesis that a single dose of BH would improve endothelial function in patients with COPD via an increase in NO bioavailability.

BH4 improves postprandial endothelial function after a high-fat meal in men and postmenopausal women.

Objective: The timing and duration of menopause is important when evaluating the risk for cardiovascular disease in postmenopausal women, likely related in part to nitric oxide (NO) bioavailability. The flow-mediated dilation (FMD) test is a noninvasive assessment of NO bioavailability in humans, and tetrahydrobiopterin (BH4) is essential for NO synthesis. A high-fat meal (HFM) has been used to increase lipemia and reduce NO bioavailability.

Assessments of endothelial function and arterial stiffness are reproducible in patients with COPD.

Background: Elevated cardiovascular disease risk is observed in patients with COPD. Non-invasive assessments of endothelial dysfunction and arterial stiffness have recently emerged to provide mechanistic insight into cardiovascular disease risk in COPD; however, the reproducibility of endothelial function and arterial stiffness has yet to be investigated in this patient population.

Objectives: This study sought to examine the within-day and between-day reproducibility of endothelial function and arterial stiffness in patients with COPD.

An unusual cause of massive pleural effusion.

Pleural effusions in ovarian hyperstimulation syndrome, whether transudative or exudative, can occur in up to 30% of cases. This disorder is always reversible but may have various clinical presentations and degrees of severity. Although assessing for risk factors to predict clinical severity is helpful, it is rare for ovarian hyperstimulation syndrome to present as a massive pleural effusion requiring emergent intervention.