Pre-awakening diastolic hypotension in treated hypertensive patients: prevalence and predictors

In the pre-awakening hours, diastolic blood pressure (dbp) is normally at its lowest, and diastolic hypotension is a risk factor for cardiac ischemia. we investigated pre-awakening dbp values and its predictors in treated hypertensive patients who underwent ambulatory blood pressure monitoring. the pre-awakening period was defined as the 3-h period ending 1 h before awakening (most frequently 03:00–06:00). in 269 included subjects, office dbp was 86.4±12.0 mm hg, 24-h dbp was 78.6±9.6 mm hg, mean pre-awakening dbp was 70.3±10.9 mm hg, and trough pre-awakening dbp was 62.5±11.2 mm hg. half of the patients (51%) had a mean pre-awakening dbp <70 mm hg, and 14% had <60 mm hg. trough pre-awakening dbp <60 mm hg was seen in 36% and <50 mm hg in 12% of patients. office dbp was the most important predictor of mean and trough pre-awakening dbp (both beta=0.4; p<0.001), and of pre-awakening dbp <70 mm hg and <60 mm hg (both p⩽0.001). diabetes mellitus was associated with a lower trough pre-awakening dbp (beta=−3.2; p=0.02). among variables that failed to independently predict low pre-awakening dbp were age, a history of vascular disease, and classes and number of antihypertensive drugs. we found that many hypertensive patients have low dbp in the pre-awakening period. office dbp is the main predictor of low pre-awakening dbp. further studies are needed to define the prognostic relevance and potential risks of low pre-awakening dbp.