Atherothrombosis, Vascular Function
Conditions
Keywords
firefighters, police officers, emergency service professionals, myocardial infarction, endothelial function, thrombosis
Brief summary
Emergency Service Professionals have an increased risk of death from heart attacks when compared to the general public. All the emergency professions share similar responsibilities such as emergency call-outs and shift work. Heart disease is the commonest cause of on-duty death amongst fire-fighters accounting for 45% and compared with 22% in police officers and 15% in the general population. The unique risk to fire-fighters is likely to reflect a combination of factors including extreme physical exertion, mental stress, heat and pollutant exposure. In this study the investigators will assess healthy career fire-fighters and age-matched healthy police officer control subjects following a sedentary period. The investigators will take blood samples to measure platelet activity (platelets are the particles in blood that help blood clot) and will examine how blood clots outside of the body. The investigators will then perform studies placing small needles in the arm to assess how the blood vessels respond following these duties. The investigators hypothesise that fire-fighters do not have pre-existing impairment of heart, blood or blood vessel function as a cumulative effect of their occupation, but rather these are acute and transitory effects following distinct fire-fighter duties. We therefore expect similar results in both occupational groups.
Interventions
Forearm venous occlusion plethysmography to measure forearm blood flow during intra-arterial infusion of the vasodilators Verapamil (10-100 µg/min), bradykinin (100-1000 pmol/min), sodium nitroprusside (2-8 µg/min) and Acetylcholine (5-20 µg/min).
Ex-vivo assessment of thrombus formation using the Badimon Chamber
Sponsors
Study design
Eligibility
Inclusion criteria
* Non-smoking healthy firefighters
Exclusion criteria
* Current smoker * History of lung or ischaemic heart disease * Malignant arrhythmia * Systolic blood pressure \>190mmHg or \<100mmHg * Renal or hepatic dysfunction * Previous history of blood dyscrasia * Unable to tolerate the supine position * Blood donation within the last 3 months * Recent respiratory tract infection within the past 4 weeks * Routine medication including aspirin and NSAIDs
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators | following 48 hours off duty |
Secondary
| Measure | Time frame |
|---|---|
| Ex-vivo thrombus formation using the Badimon chamber | following 48 hours off duty |
| Plasma t-PA and PAI concentrations following infusion of bradykinin | During forearm study, following 48 hours off duty |
Countries
United Kingdom