Habitual sleep duration is associated with heightened muscle sympathetic nerve activation and blood pressure reactivity in response to the cold pressor test.

The link between short sleep duration and cardiovascular disease may be related to exaggerated neurocardiovascular reactivity. Purpose: We examined the association of actigraphy-measured habitual sleep duration (HSD) with muscle sympathetic nerve activity (MSNA) and blood pressure (BP) at rest and in response to a cold pressor test (CPT). Methods: Thirteen adults (5M/8F; 30±9 y; 26.9±5.8 kg/m 2 , 117±13 / 76±6 mmHg) were instrumented for measurement of beat-to-beat BP, forearm vascular resistance, and MSNA at rest and during a 2-min CPT. HSD was measured using wrist actigraphy across 6-7 days. Partial correlations (r XY·Z ) described the relation between HSD with sympathetic and cardiovascular activity at rest and in response to the CPT (Δ), accounting for sex, age, and relative body fat. Results: The CPT induced increases in systolic (+8.1±7 mmHg; p=0.002), diastolic (+6.4±4; p0.14). However, HSD was strongly associated with the CPT-induced changes in MSNA burst frequency (r XY·Z =−0.69; p=0.028), diastolic (r XY·Z = −0.69; p=0.028) and mean BP (r XY·Z = −0.77; p=0.009). Conclusions: Whereas HSD is not strongly associated with resting sympathetic neural activity or BP, it is associated with sympathetic and BP reactivity to physiological stress. These findings support an important role for MSNA and BP reactivity in the described association of sleep duration with CVD risk.