The effect of sleep deprivation on endothelial function and inflammation

Epidemiological studies demonstrated an association between sleep deprivation (SD) and ischemic heart disease, heart failure, hypertension, new onset type 2 diabetes mellitus and metabolic syndrome. Our aim was to find the effect of SD on endothelial function and on the inflammatory profile of young men following SD. Methods: Fourteen healthy (31.3 ± 2.4 years old) men, smokers, took part. All work in the hospital and are doing moon shifts twice a week for more than 12 months. Measurements of the endothelial function were done (fasting) early in the morning (8:00-8:30 AM), using a linear array high resolution ultrasound (12-15 MHz). Cytokines (interleukin 1 [IL-1] and interleukin 6 [IL-6]) were measured in saliva. Saliva was collected in 50 ml tubes, frozen and stored at – 800C until biochemical analysis. IL-1 and IL-6 in saliva were measured using a commercial ELISA kit. Results: All the parameters that were monitored after SD were compared to the baseline measurements. Basic FMD% was 6.7 ± 6.8%, and the post SD FMD% was 1.7± 3.3% (p=0.009). There was a 5.0 ± 6.1% decrease in endothelial function. IL-1 levels increased after SD from 36 ± 21 pg/mL to 47 ± 24 pg/mL (p=0.004), and IL-6 levels increased from 22 ± 07 pg/mL to 36 ± 11 pg/mL (p=0.0005). A negative correlation was found between the decrease in FMD% and the increase in IL-1 level (r=-0.813; p=0.001). A negative correlation was also found between the decrease in FMD% and the increase in IL-6 level (r=-0.735; p=0.003). Discussion: SD caused endothelial dysfunction with increase in markers of inflammation (IL-1 and IL-6), with an inverse correlation between the change (decrease) in endothelial function and the change (increase) in IL-1 and in IL-6. We suggest that SD enhances the inflammatory system, and the activated inflammatory system leads to impaired endothelial function.