Nocturnal blood pressure predicts left ventricular mass index in normotensive elderly

Blood pressure (BP) predictors of left ventricular mass index (LVMI) were Studied in 40 healthy normotensive (71.4 +/- 4.4 years) and 31 hypertensive (73.5 +/- 4.8 years) elderly community-dwelling Subjects using short-axis cardiac cine magnetic resonance imaging and 24-h ambulator BP monitoring, Mean night-time BPs were calculated from the average of readings during sleep and mean daytime BPs were calculated from the remaining recordings. The hypertensive subjects were all receiving antihypertensive therapy with angiotensin-converting enzyme (ACE) inhibitors, calcium-channel blockers, beta-blockers or diuretics. Nocturnal systolic BP was a strong predictor of LVMI in both normotensive (beta = 0.38. p = 0.02) and treated hypertensive (beta = 0.39, p = 0.03) subjects. By contrast, daytime systolic BP was a weaker predictor of LVMI in the treated hypertensives (beta = 0.36, p = 0.04) and did not predict LVMI in the normal subjects (beta = 0.27 NS). Nocturnal BP may partly explain the increase in LVMI with ageing in subjects thought to be non-notensive on the basis of daytime clinic BP recordings.