"circadian rhythm", " sleep", "high blood pressure"

PURPOSE OF REVIEW: The failure to lower systolic blood pressure at night (called non-dipping) and sleep apnea are both associated with adverse cardiovascular outcomes. Sleep apnea is a common cause of non-dipping blood pressure. RECENT FINDINGS: Sleep apnea increases night time blood pressure through enhanced cardiac pre-load, sleep disturbance and hypoxia. Hypoxia elicits increased levels of norepinephrine, endothelin and erythropoetin. Patients with sleep apnea tend to be elderly and obese, so they have poor endothelial nitric oxide release and blunted baroreflexes...

No abstract text is available yet for this article.

The antihypertensive effects of four different antihypertensive medications (beta-blocking agent, atenolol 50 mg; calcium-antagonist, isradipine SRO [slow release] 2.5 mg; diuretic, hydrochlorothiazide [HCTZ] 25 mg; and angiotension converting enzyme-inhibitor, spirapril 6 mg) on obese patients with sleep disordered breathing and hypertension were compared by the ambulatory blood pressure measurement (ABPM). Eighteen patients were randomized in a double-blind, crossover fashion to receive each of the four different medications for 8 weeks...

UNLABELLED: To establish the normal values for Ambulatory Blood Pressure Monitoring (ABPM) in normotensive, non-obese, male adolescents without family history of High Blood Pressure (HBP), a 24 hours ABPM study using oscillometric method (Space Lab 90207) was preformed on 102 subjects, 10-18 years of age, classified in 3 age groups: Group 1: 10-12, group 2: 13-15 and group 3: 16-18. RESULTS: Systolic and Diastolic Blood Pressure (SBP, DBP) mean values (+/- standard deviation), during 24 hours were: 109/64 (7...

The number of patients undergoing ambulatory blood pressure monitoring (ABPM) and the number of publications using this technique to evaluate the risks and effects of high blood pressure on target organs has been increasing, and dramatically so, in the last 5 years. Much of this growth has centered on the role of the blood pressure load (the percentage of systolic or diastolic readings above a preset value during a specific time period) and the changes in blood pressures levels that occur, with sleep. Although many studies are focused on the interaction between blood pressure (as assessed by ABPM) and the heart, interest is growing in the application of ABPM to the practice of nephrology...

Circadian blood pressure rhythms were examined in subjects exhibiting various forms of secondary and essential hypertension and in normotensive subjects with and without renal disease. Indirect ambulatory blood pressure recordings were performed in 284 subjects for 24 h. In contrast to patients with essential hypertension and to normotensive healthy subjects, the circadian fluctuations of blood pressure were reduced in secondary hypertensives and in normotensive renal patients. In renal hypertensives, these alterations in the diurnal blood pressure variations were dependent on the degree of renal failure...

Noninvasive ambulatory blood pressure monitoring (NABPM) has been playing an increasing role in the diagnosis of hypertension and in the evaluation of antihypertensive drugs. NABPM data for the normal Chinese population has not yet been established. However, data obtained from 25 young male Chinese adults has been analysed. Average ambulatory blood pressure was 120 +/- 8/74 +/- 7 mmHg for the whole-day monitoring. There was an evident diurnal change of blood pressure during the 24-hour monitoring period with higher blood pressure levels being recorded during the daytime, rather than during the nighttime (7...

Clinical studies with non-invasive ambulatory blood pressure monitoring have shown that some cardiovascular complications of essential hypertension (left ventricular hypertrophy, stroke) tend to be more frequent in patients whose 24-h blood pressure profile is flattened (non-dippers) and, consequently, suffer a longer duration of exposure to high blood pressure levels over the 24 h. The distribution of patients between dippers and non-dippers is conditioned by the limits of the blood pressure changes from day to night that are arbitrarily chosen to define these two groups, and by the time intervals defining daytime and night-time hours...

An association between chronic high blood pressure and obstructive sleep apnea has been described. We hypothesized that repetitive episodic hypoxia patterned after the hypoxia seen in sleep apnea could contribute to diurnal elevation of blood pressure. Using 12-second infusions of nitrogen into daytime sleeping chambers, four groups of male rats (250-375 g) were subjected to intermittent hypoxia (3-5% nadir ambient oxygen) every 30 seconds, 7 hours per day for up to 35 days. In one group, blood pressure was measured weekly by the tail-cuff method in conscious animals during 5 weeks of episodic hypoxia...