KNES 360 Journal Article 3: Cardiovascular

Dettoni et al. Cardiovascular effects of partial sleep deprivation in healthy volunteers. Journal of Applied Physiology:113:232-236, 2012.

Definitions: be able to define these terms

1) endothelial function: 2) heart rate variability3) arterial oxygen saturation4) venodilation:

Questions on the article:

1. What was the purpose of the study? Did the authors have an hypothesis proposed before they conducted the study, if so what was it?To investigate the effects of five nights of sleep deprivation on cardiac autonomic balance, peripheral sympathetic activity, and on vascular reactivity among young subjects. Hypothesis: partial sleep deprivation will promote sig impairment on cardiac autonomic balance, peripheral sympathetic activity, and vascular reactivity.

2. Describe the subjects (how many, were they trained or untrained) and the study design of the experiment (how many times were they tested and when).Subjects: healthy male volunteersSleep monitoring: monitored by wrist actigraphy device; study period: 12 nights; randomized to 5 nights of extended sleep (control)/ 5 nights sleep dep (3 1/2 – 5 hrs) Blood samples and BP, HR, autonomic measurements between 8-10AM. 3. Summarize the methods for measuring endothelial function that were performed ; what is pulse oximetry? What were the blood samples used for? What CV variables were measured and compared in the control and partial sleep deprivation arms of the experiment?Needle inserted into vein, vasodilator response calculated using variable differential transformer. CV variables measured: BP waveforms, BP: systolic/diastolic, CO, peripheral vascular resistance 4. What was the single major finding from the study; what other results did the authors report? Was there a novel finding from the experiment?Sleep deprivation caused sig increase in sympathetic activity and reduction in maximum endothelial dependent venodilation 5. Explain 2 major discussion points from the article.

-increased levels of norepinephrine, increased HR and BP variability, vein endothelial dysfunction, decrease bioavailability of nitric oxide.

6. Can you ascribe a real world/practical message from this sleep deprivation experiment……………….what is it?