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ABSTRACT: An exaggerated elevation in blood pressure around waking potentially increases the risk of cardiovascular events, even in individuals with normal blood pressure at other-fold of day. The impact of such a transient blood pressure elevation is disproportionate to its short duration, and the reason has not been elucidated. We hypothesize that individuals with such a blood pressure abnormality receive a cardiovascular overload, even from slight physical activities that are frequently undertaken in daily life.
A total of 16 patients with essential hypertension (52±15 years) staying at hospital for lifestyle education participated in this study. Morning blood pressure elevation was assessed with 24 h ambulatory blood pressure monitoring. Cardiovascular responses to unloaded pedaling, including blood pressure changes, were assessed in a limited maximum exercise test using an electronically braked bicycle ergometer.
Changes in the systolic blood pressure caused by unloaded pedaling correlated positively with the elevation in systolic blood pressure around waking (r=0.52, P=0.05). Moreover, waking elevation of the systolic blood pressure correlated with changes in all of the following cardiovascular variables during unloaded pedaling: heart rate (r=0.69, P=0.003), oxygen consumption (r=0.73, P=0.001), oxygen pulse (r=0.62, P=0.001), and rate pressure product (r=0.64, P=0.008), respectively.
These observations indicate that individuals with prominent blood pressure elevation upon awakening also experience cardiovascular overload from slight physical activities.
Blood pressure monitoring 10/2012; 17(5):198-203. · 1.62 Impact Factor
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ABSTRACT: Endothelial damage is an early component of atherosclerosis; however, the impact of cardiovascular risk factors on endothelial function is not clearly understood. We investigated the impact of lipid profiles and high blood pressure on damage.
Japanese male outpatients with grade I or II hypertension, along with gender and age-matched normotensive subjects (both n = 25), were enrolled. Subjects with severe cardiovascular risk factors or illness or those taking medications were excluded. Blood was sampled for laboratory analysis and endothelial function was assessed by flow-mediated dilation (FMD).
Total cholesterol to high-density lipoprotein cholesterol ratio (total-C/HDL-C) was inversely correlated with the FMD value and positively correlated with both malondialdehyde-modified low-density lipoprotein and high-sensitivity C-reactive protein values. Stepwise regression analysis revealed total-C/HDL-C and systolic blood pressure were significant determinants of FMD. Hypertensive subjects had lower FMD values and similar lipid profiles to normotensive subjects. Grouping subjects according to total-C/HDL-C levels showed that those with high values had lower FMD values. Hypertensive subjects with low total-C/HDL-C had similar endothelial index values to those in normotensive subjects with high total-C/HDL-C. Logistic regression indicated hypertension and high total-C/HDL-C were significantly associated with low FMD values.
Impaired endothelial function was associated with increased total-C/HDL-C values, possibly as the result of increased vascular oxidative stress and inflammation. In the early stages of atherosclerosis, the impact of both total-C/HDL-C and BP may be similar in terms of endothelial damage.
Journal of Clinical Lipidology 11/2011; 5(6):460-6. · 1.58 Impact Factor
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International journal of cardiology 02/2011; 147(3):461-3. · 7.08 Impact Factor
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ABSTRACT: Some cardiovascular disorders disturb circadian variation of endothelial function. We investigated whether deterioration of renal function alters circadian variation of endothelial function in patients with hypertension. Endothelial function was assessed by the peak forearm blood flow (FBF) response to reactive hyperemia, and 24-hour ambulatory blood pressure monitoring was performed in 25 patients with essential hypertension (61 ± 17 years). Relationships among renal function, 24-hour blood pressure, and endothelial function were analyzed. The ratio of nighttime to daytime mean arterial pressure was inversely correlated with estimated glomerular filtration rate (eGFR) (r = -0.43, P = .03). The FBF response to reactive hyperemia examined at 21:00, but not at 6:30 or 11:30, was significantly correlated with eGFR (r = 0.44, P = .03). Furthermore, the ratio of FBF response measured at 21:00 to that measured at 6:30 was independently correlated with eGFR (β = 0.47, P = .02). Renal dysfunction is associated with the derangement of circadian variation of both endothelial function and blood pressure. Nocturnal blood pressure is elevated, and evening endothelial function deteriorates in parallel with a decline in renal function in hypertensive patients.
Journal of the American Society of Hypertension 10/2010; 4(6):265-71. · 2.12 Impact Factor
