Researcher(s)
- Raina Lakhani, Biological Sciences, University of Delaware
Faculty Mentor(s)
- Melissa Witman, Kinesiology and Applied Physiology, University of Delaware
Abstract
Cardiovascular diseases (CVD) are a leading cause of morbidity and mortality in first responders. A lack of sleep and irregular sleep schedules in first responders are major contributing factors to CVD. Insufficient sleep contributes to endothelial dysfunction, an independent risk factor for CVD, by reducing nitric oxide bioavailability and increasing oxidative stress. While CVD prevention in first responders historically focused on objective sleep duration, the impact of subjective sleep quality on endothelial function remains unexplored in this population.
PURPOSE: To determine the effect of sleep quality on macrovascular and microvascular function in young-to-middle-aged first responders. It was hypothesized that poor sleep quality would be correlated with lower macrovascular function, as assessed by flow-mediated dilation (FMD), and microvascular function, as assessed during passive leg movement (PLM).
METHODS: Participants (n=25) were Emergency Medical Technicians, paramedics, and police officers with a mean age of 28±9 yrs. Sleep quality was subjectively assessed with the Pittsburgh Sleep Quality Index (PSQI), where higher scores indicate greater sleep disturbance. Macrovascular function was assessed using FMD of the brachial artery, while microvascular function was assessed using continuous PLM. Pearson correlation coefficients were used to evaluate the relation between variables.
RESULTS: PSQI scores were not correlated to FMD percent (r=-.13, p=0.58) or FMD absolute diameter change (r=-0.15, p=0.51). The blood flow (BF) area under the curve during PLM was negatively correlated with PSQI score (r=-.53, p=.019). The BF change during PLM also trended to be negatively correlated with PSQI score (r=-.44, p=.061).
CONCLUSIONS: Our findings suggest that increased PSQI score has no relationship with macrovascular function, but may be associated with reduced microvascular function in first responders. Poor sleep quality may be a key player in first responders’ elevated CVD risk, although future work is warranted.