Associations between nondipping of nocturnal blood pressure decrease and cardiovascular target organ damage in strictly selected community-dwelling normotensives

Abstract Background In hypertensives, nondippers are more likely than dippers to suffer silent, as well as overt, hypertensive target organ damage. In this study, we investigated whether a nondipper status was associated with target organ damage in normotensives. Methods We performed ambulatory blood pressure (BP) monitoring, echocardiography, and carotid ultrasonography and measured natriuretic peptides and urinary albumin (UAE) in 74 normotensive subjects with the following criteria: 1) clinical BP <140/90 mm Hg; 2) average 24-h ambulatory BP <125/80 mm Hg. Results The left ventricular mass index (LVMI) and the relative wall thickness (RWT) measured by echocardiography, were greater in nondippers than dippers (LVMI: 103 ± 26 v 118 ± 34 g/m2, P< .05; RWT: 0.38 ± 0.07 v 0.43 ± 0.09, P< .01). Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were higher in nondippers than dippers (ANP: 14 ± 10 v 36 ± 63 pg/mL, P< .01; BNP: 16 ± 12 v 62 ± 153 pg/mL, P< .05). There were no significant differences in UAE and intima–media thickness measured by carotid ultrasonography. Conclusions Normotensive nondipping may not reflect renal damage, but may have a predominant effect on cardiac damage. Nondipping of nocturnal BP seems to be a determinant of cardiac hypertrophy and remodeling, and may result in a cardiovascular risk independent of ambulatory BP levels in normotensives.