Different definitions of awake-asleep periods and BP indices significantly affected the classification of nocturnal BP dipping (kappa 0.323-0.459) and its relation with target-organ damage.
Cross-Sectional (n=150)
How do different definitions of awake/asleep periods and BP indices affect the classification of nocturnal BP dipping and its relation to target-organ damage in hypertensive patients?
The method used to define awake and asleep periods during 24-hour ambulatory BP monitoring significantly alters the classification of nocturnal dipping and its association with target-organ damage.
OBJECTIVE: We assessed how different definitions of the awake and asleep periods and use of various blood pressure (BP) indices affect the extent of the nocturnal BP dip, the prevalence of dippers and nondippers, their respective reproducibilities and the relation of nondipping with target-organ damage. METHODS: We performed 24-h ambulatory BP monitoring twice and determined the left ventricular mass index and urinary albumin excretion as indices of target-organ damage in 150 hypertensive patients (off-medication). Awake and asleep periods were assessed using fixed and diary time methods, covering all readings available (wide) or excluding morning and evening transition hours (narrow). Nondipping (BP dip < 10%) was established for systolic BP and diastolic BP, their combinations (and/or), and mean arterial pressure. RESULTS: The different awake-asleep definitions caused significant variation in both the extent of the BP dip and the number of dippers and nondippers in comparison with the wide diary definition (i.e. use of actual awake and sleep periods). The prevalences of dippers and nondippers also varied significantly with the BP index. Reproducibility analyses of the BP dip and the dipping status yielded repeatability coefficients (expressed as percentages of nearly maximal variation) between 42.39 and 48.71%, and kappa values between 0.323 and 0.459, respectively. Some classifications, but not all, discriminated significantly between consistent dippers and nondippers in terms of left ventricular mass index or urinary albumin excretion. CONCLUSIONS: Use of different definitions of awake-asleep and BP indices affects significantly the classification of nocturnal BP dipping and its relation with hypertensive target-organ damage.
Henskens et al. (Tue,) conducted a cross-sectional in Hypertension (n=150). Different definitions of awake and asleep periods and BP indices vs. Wide diary definition (actual awake and sleep periods) was evaluated on Classification of nocturnal BP dipping and relation with target-organ damage (left ventricular mass index and urinary albumin excretion). Different definitions of awake-asleep periods and BP indices significantly affected the classification of nocturnal BP dipping (kappa 0.323-0.459) and its relation with target-organ damage.