Is the absence of a normal nocturnal fall in blood pressure (nondipping) associated with cardiovascular target organ damage?

Abstract

Objective To determine whether the failure to decrease blood pressure normally during sleep is associated with more prominent target organ damage.Methods Cardiac and vascular structure and function were characterized in 183 asymptomatic, unmedicated hypertensive patients and compared with their ambulatory blood pressures. ResultsThe 104 patients with a normal (> 10%) nocturnal fall in systolic blood pressure (dippers) were similar to the 79 patients with an abnormal fall (nondippers) in sex, race, body size, smoking history, and average awake ambulatory blood pressure. Nondippers tended to be older (57 versus 54 years, P = 0.06). The supine blood pressure upon completion of the ultrasound studies was higher in the nondippers (156/93 versus 146/89 mmHg, P < 0.005) as was the variability of the awake diastolic blood pressure. There were no differences between dippers and nondippers in left ventricular mass (170 versus 172 g), mass index (90 versus 91 gm/m 2 ), prevalence of abnormal ventricular geometry, common carotid artery diameter (5.74 versus 5.75 mm), and vascular strain. Although nondippers were more likely to have carotid artery plaque (41 versus 27%, P = 0.053) and an increased intimal-medial thickness (0.84 versus 0.79 mm, P < 0.05), adjustment for age rendered the differences insignificant. There were no differences in the relation of awake and sleeping systolic pressures to the left ventricular mass (r = 0.36 and 0.35, respectively, both P < 0.005) or to the carotid wall thickness (r = 0.28 and 0.29, respectively, both P < 0.005). When the 114 men and 69 women were considered separately, similar findings were obtained. When the 109 whites and 56 blacks (African-Americans and Afro-Caribbeans) were considered separately, there were no differences in left ventricular structure in either group, and differences in vascular structure were confined to the white subgroup. ConclusionThe lack of a normal nocturnal fall in blood pressure is not associated with an increase in left ventricular mass or in arterial disease independently of age. Age-related changes in carotid artery wall thickness and plaque among nondippers may reflect a contribution of an altered baroreceptor function to the lack of normal nocturnal and supine blood pressure decreases.Journal of Hypertension 1997, 15:969-978

Night-time blood pressure patterns and target organ damage: A review

“…Many researchers have evaluated cardiac damage in untreated individuals with essential hypertension and found no significant differences between dippers and nondippers with respect to LV diameter (14,21), LV systolic and diastolic function (21), interventricular septum thickness, posterior wall thickness, relative wall thickness (14,45,56), LV concentric remodelling (45,56), LVH, LVM and LVMI (14,21,45,56), aortic distensibility (21) and atrial dimensions (56). However, in these studies, the classification of dipping status was based on a single ABPM session.…”

“…Several studies involving subjects with uncomplicated essential hypertension have revealed an association between a nondipper BP profile and an increased risk of target organ damage at the cardiac, renal, vascular and cerebrovascular levels (6,9,10,15,18,27,28,(42)(43)(44)(45). Target organ damage has also been found to be linked with two additional abnormal BP patterns: reverse dipping (nocturnal rise in night-time BP) and extreme dipping (nocturnal fall in night-time BP of greater than 20%) (46).…”

Reproducibility of nocturnal blood pressure fall in early phases of untreated essential hypertension: a prospective observational study

“…Some authors demonstrated that nondipping status was associated with greater cardiac and extracardiac TOD, [17][18][19] whereas other studies failed to demonstrate any significant difference in left ventricular and vascular structure among dippers and nondippers. 20,21 Contradictory results can be attributed to a variety of clinical and methodological problems. The classification into dippers and nondippers based on a single ABPM represents probably one of the major confounding factors because of the limited reproducibility of nocturnal BP fall over time.…”

Night time blood pressure and cardiovascular structure in a middle-aged general population in northern Italy: the Vobarno Study

“…In a larger group of unmedicated hypertensive patients, 20 non-dippers were more likely to have carotid plaque and an increased common carotid intima-media thickness, although adjustment for age rendered these differences insignificant and there-fore the lack of a nocturnal fall in BP was not associated with carotid arterial disease, independently of age. When Roman et al 20 analysed the data separately for men and women, results did not change substantially and the small differences observed between female dippers and non-dippers were again eliminated after controlling for age.…”

“…18 It has been recently observed that in hypertensive patients who did not show a decrease of BP during night time the intima media thickness of the common carotid artery was greater as compared with patients with a sleep reduction of BP. 19,20 In the present population-based cross-sectional study, designed to estimate the prevalence of structural changes both in the heart and in the carotid arteries in middle-aged subjects, the carotid intimamedia thickness and the presence of plaque, as well as the presence of LVH, were determined in relation to an altered diurnal BP rhythm, obtained by ambulatory monitoring, before and after correction for other traditional risk factors.…”