Hypertension (HTN) is a major risk factor for cardiovascular disease and the single most important risk factor for stroke. Diurnal blood pressure (BP) variations assessed by 24-hour ambulatory BP (ABP) monitoring have been shown to be closely associated with increased cardiovascular risk in hypertensives. The objective of this study is to evaluate the relationship between morning blood pressure surge (MBPS) and the development of target organ damage (TOD) in hypertensive subjects.Design and method:
Subjects with office BP (OBP) >140/90 mmHg, under treatment with at least one antihypertensive medication were included in the study. Exclusion criteria were severe renal (eGFR<25 ml/min/1.73m2), cardiac (left ventricular ejection fraction<30%) or other systematic disease, or evidence of secondary HTN. A complete medical history was obtained from all participants. OBP was measured by a digital oscillometric BP electronic device (MicrolifeWatchBP Office). ABP and office measurements were taken on the same non-dominant arm using a validated MicrolifeWatchBP 03 device. MBPS was calculated as the difference between mean BP two hours after awakening and the mean BP two hours before awakening. Transthoracic echocardiogram for assessment of left ventricular mass index (LVMI), left ventricular hypertrophy (LVH), left atrial enlargement, diastolic dysfunction, and interventricular septum thickness, were performed in all patients. Urine albumin excretion (UAE) was measured by an immunoturbidimetric assay. Microalbuminuria was defined as a value of UAE of 30–300 mg/24 h.Results:
A total of 37 hypertensives (age 60 ± 14 years, 22 men) were studied. Morning surge in both systolic and diastolic BP was correlated with LVMI, with r = -0.42, p = 0.01 and r = -0.33, p = 0.04 respectively. Patients with concentric hypertrophy had lower systolic MBPS (5 ± 11 vs 16 ± 13 mmHg, p = 0.01), as well as diastolic MBPS (7 ± 8 vs 14 ± 6 mmHg, p = 0.01) than those without. Moreover, patients with microalbuminuria had lower systolic MBPS (3 ± 21 vs 12 ± 11 mmHg, p = 0.03); diastolic MBPS tended also to be lower (6 ± 14 vs 11 ± 7 mmHg, p = 0.4) in those patients, albeit not reaching statistical significance.Conclusions:
Early MBPS systolic and diastolic assessed by 24-hour ABPM is inversely associated with LVMI and microalbuminuria, further supporting the need for assessing MBPS in clinical practice.