Response to Why Is Nondipping in Ambulatory Blood Pressure Monitoring Not Prognostic in Poor Sleepers?

Response to Why Is Nondipping in Ambulatory Blood Pressure Monitoring Not Prognostic in Poor Sleepers?We thank Martinez and Fuchs 1 for their interest in our study.Unfortunately, we could not cite their article, 2 because it was published almost contemporaneously to our own. 3 In their elegant study carried out in a sleep laboratory, these authors found that systolic and diastolic blood pressure (BP) values were 5 mm Hg lower during uninterrupted sleep than during brief awakenings induced by cuff inflations.In our study, nighttime systolic BP was 5 mm Hg higher and diastolic BP 4 mm Hg higher in the subjects who perceived a sleep deprivation Ͼ4 hours as compared with subjects who did not complain of sleep disturbances.Other studies carried out in sleep laboratories provided consistent results.For example, Pedulla `et al 4 found an association between number of microarousals and a blunted day-night BP rhythm.Portaluppi et al 5 found a higher number of episodes of sleep apnea and snoring in nondippers than in dippers.Nighttime BP could no longer be predictive of cardiovascular events in poor sleepers, because it was reset to randomly higher levels in these subjects, possibly as a result of compressive, tactile, and sonorous stimuli produced by cuff inflations.The true differences in nighttime BP between dippers and nondippers might turn into random differences during overnight BP monitoring in poor sleepers.However, contrary to interpretation by Martinez and Fuchs, we would be more cautious in extrapolating implications from the study by Kripke et al 6 on the relation between sleep duration and mortality.In that study, a J-shaped relation was observed between duration of sleep and risk of mortality, with the highest risk of death in people who slept Ͼ8 hours or Ͻ6 hours per night, and the best survival among those sleeping Ϸ7 hours per night. 6 The relevance of these data to episodic sleep alterations induced by overnight BP monitoring in one or a few more occasions during life looks virtually absent.