Table 4 shows the results of multiple linear regression analysis to examine the associations of time awake after sleep onset and awake physical activity with nocturnal SBP fall, which were fully adjusted for clinical factors including potential candidate causal factors for nocturnal hypertension (age, presence of medical hypertension treatment, renal function, sleep apnea and hypopnea, urinary sodium, rennin-angiotensin system, serum cortisol, insulin resistance, plasma BDNF, cardiac autonomic function). The gene discussed is BDNF; the disease is sleep apnea syndrome.