Publications

INTRODUCTION

Erectile dysfunction (ED) and cardiovascular disease (CVD) share pathophysiological mechanisms and often co-occur. Yet it is not known whether ED provides an early warning for increased CVD or other causes of mortality.

AIM

We sought to examine the association of ED with all-cause and cause-specific mortality.

METHODS

Prospective population-based study of 1,709 men (of 3,258 eligible) aged 40-70 years. ED was measured by self-report. Subjects were followed for a mean of 15 years. Hazard ratios (HR) were calculated using the Cox proportional hazards regression model.

MAIN OUTCOME MEASURES

Mortality due to all causes, CVD, malignant neoplasms, and other causes.

RESULTS

Of 1,709 men, 1,284 survived to the end of 2004 and had complete ED and age data. Of 403 men who died, 371 had complete data. After adjustment for age, body mass index, alcohol consumption, physical activity, cigarette smoking, self-assessed health, and self-reported heart disease, hypertension, and diabetes, ED was associated with HRs of 1.26 (95% confidence interval [CI] 1.01-1.57) for all-cause mortality, and 1.43 (95% CI 1.00-2.05) for CVD mortality. The HR for CVD mortality associated with ED is of comparable magnitude to HRs of some conventional CVD risk factors.

CONCLUSIONS

These findings demonstrate that ED is significantly associated with increased all-cause mortality, primarily through its association with CVD mortality.

BACKGROUND

Transplant coronary arteriosclerosis (TCA) is the principal long-term complication in cardiac transplant recipients. The mediators responsible for vascular proliferation and vasoconstriction typical of TCA remain largely unknown. We tested whether endothelin-1 (ET-1), a potent vasoconstrictor and mitogen, contributes to the pathogenesis and manifestations of TCA.

METHODS AND RESULTS

BQ-123, an ET-1 receptor-A antagonist, was infused into a coronary artery (40 nmol/min for 60 minutes) of 18 subjects, 6 + or - 4 years after transplantation. Vasomotor responses were measured in the infused artery and in a noninfused control artery in patients with (n=10) and without (n=8) advanced TCA (108 total coronary segments). Changes in diameters were compared at 15-minute intervals up to 60 minutes. Contribution of ET-1 to coronary constrictor tone was assessed by comparing vasodilation from BQ-123 with that of the maximal vasodilator nitroglycerin (200-microg intracoronary bolus). BQ-123 dilated coronary arteries of transplanted patients (8.4% at 60 minutes versus -0.4% in noninfused arteries, P<0.001). Dilation was greater for arteries with advanced TCA defined as diameter stenosis > or = 15% (dilation 15.2% with versus 0.6% without advanced TCA, P=0.004). Judged against the response to nitroglycerin, ET-1 accounted for 53.2% of coronary tone in advanced TCA but only 12.9% without advanced TCA.

CONCLUSIONS

This study shows for the first time in humans that ET-1 is an important mediator of coronary vasoconstriction in TCA and accounts for >50% of the increased vasomotor tone. Therapeutic targeting of ET-1 may retard the development of TCA.

IL-6 is a biological marker of ventilator-associated lung injury that may contribute to alveolar barrier dysfunction in acute respiratory distress syndrome. To determine whether IL-6 affects alveolar barrier disruption in a model of ventilator-induced lung injury, we examined alveolar barrier albumin flux in wild-type (WT) mice given an IL-6-blocking Ab (IL6AB) and mice deficient in IL-6 (IL6KO). Albumin flux was significantly higher in mice given IL6AB compared with mice given a control Ab. Unexpectedly, albumin flux was similar in WT and IL6KO mice. To examine the mechanisms for these findings, lung neutrophil accumulation (myeloperoxidase activity) was compared, revealing a correlation between lung neutrophil accumulation and albumin flux. IL6AB mice had significantly more lung neutrophils than WT and IL6KO mice, which were similar. Therefore, to determine whether the cellular source of IL-6 influences neutrophil accumulation and alveolar barrier function, chimeric mice were compared. WT/KO chimeras (WT mice with IL6KO hematopoietic cells) showed significantly greater albumin flux and neutrophil accumulation with mechanical ventilation than WT/WT mice. Neutrophil depletion decreased albumin flux in WT and WT/KO mice. IL6KO neutrophils were more adherent in an in vitro assay compared with WT neutrophils. IL-6 from a hematopoietic cell source limits alveolar barrier disruption potentially by reducing neutrophil contact with the endothelium. Modulation of IL-6 signaling in a cell type-specific fashion may be a therapeutic target for patients with acute lung injury.