DESCRIPTION (provided by applicant): Mounting epidemiological evidence links short sleep with an increase in hypertension of 60% or more, and a strong relationship has been reported between cardiovascular disease and short sleep in women. We hypothesize that chronic sleep deficiency is causally related to the development of hypertension and cardiovascular disease via effects on the mechanisms supporting autonomic control. This study addresses the important question of whether reversing the sleep deficit can improve blood pressure (BP) control, and if so, what mechanisms are involved? To address this question, the current study uses a randomized clinical trial to test the efficacy of an individualized sleep extension (increased duration of nocturnal sleep) intervention in the treatment of pre-hypertension and stage 1 hypertension (BP>120/80, up to 160/100). This study compares sleep extension in men and women, with a within-subject wait list control group and an active control group targeting daily habits, "sleep hygiene", that are known to impact sleep. The project includes 3 in-hospital physiological monitoring stays to evaluate the underlying mechanisms associated with BP lowering effects of sleep extension. These mechanisms include autonomic function tests (heart rate variability and estimated baroreflex sensitivity), plasma catecholamines, inflammatory mediators, and sleep electrophysiology. This project tests the predictive relationship of these mechanisms with the primary endpoint of 24 hour BP outcome, as a function of increased sleep. It predicts that women are more vulnerable to the heart health impact of insufficient sleep, and that women will benefit more from the behavioral sleep extension intervention.