ObjectiveTo determine whether the use of patients' individual awake/asleep patterns instead of fixed day/night intervals would influence the correlations between blood pressure values and left ventricular morpho-functional characteristics.MethodsWe enrolled 167 never-treated hypertensives (clinic blood pressures > 160 mmHg systolic or 90 mmHg diastolic, or both): 32 had 24 h blood pressures < 130/80 mmHg [white-coat hypertensives (WCH)] and 135 had 24 h blood pressures > 130 mmHg systolic or 80 mmHg diastolic, or both (hypertensives). Each patient underwent left ventricular echocardiographic examination and 24 h ambulatory blood pressure monitoring, evaluated twice, using standard day/night intervals (daytime 0700–2200 h, nighttime 2200–0700 h) and using the patient's individual awake/asleep pattern (an individualized scheme).ResultsDaytime and night-time blood pressures in WCH and daytime and night-time diastolic blood pressures in hypertensives were not affected by choice of using individualized or standard intervals; daytime systolic blood pressure in hypertensives was significantly higher and night-time systolic blood pressure lower with individualized intervals. The non-dippers (nocturnal decrease in blood pressure < 10% of daytime blood pressure) were 31 hypertensives and six WCH with standard day/night intervals and 25 hypertensives and four WCH with individualized intervals; nocturnal falls in systolic and diastolic blood pressures were significantly greater with individualized intervals for both groups. Left ventricular hypertrophy was present in 68 hypertensives and seven WCH; left ventricular systolic function was normal in all and left ventricular diastolic function was impaired in 53 hypertensives and seven WCH. Left ventricular characteristics of WCH were not correlated to blood pressure parameters; left ventricular mass index of hypertensives was directly correlated to 24 h, daytime and night-time systolic blood pressures, whereas left ventricular diastolic function was inversely correlated to night-time systolic and diastolic blood pressures. The correlations were not affected by choice of using individual awake/asleep patternsConclusionsTiming day and night in an individualized way seems to improve the evaluation of nocturnal fall in blood pressure, but does not improve the ability to predict the left ventricle's involvement with ambulatory blood pressure monitoring