Change In 24-h Blood Pressure Research Articles

DIETARY SODIUM RESTRICTION REDUCES NOCTURNAL BLOOD PRESSURE IN PATIENTS WITH TREATMENT RESISTANT HYPERTENSION

Objective: Patients with treatment resistant hypertension (TRH) are characterised by lack of blood pressure (BP) control despite antihypertensive treatment. They are at particular risk of cardiovascular disease and more likely to experience BP increase as a response to sodium loading than other individuals. In this study, we aimed to analyse if self-performed dietary sodium restriction could be implemented in patients with TRH. Moreover, we aimed to analyse the effect of this on nocturnal and 24h BP, and how BP changes were correlated to changes in plasma levels of BNP, nitric oxide and body water content. Design and method: The study was conducted as an interventional cross-over study including patients with TRH from 20-70 years. Patients were screened with 24h ambulatory BP monitoring initiated after observed intake of usual antihypertensive medication. They were included if 24h systolic BP>130/80 mmHg. Study participation included two periods of 14 days; a standard period with usual diet and an interventional period with instructed dietary sodium restriction and handed-out sodium-free bread. At the end of each period, patients were examined with 24h BP monitoring, 24h urine collection (sodium excretion), blood samples (nitric oxide, BNP), and bioimpedance measurement (body water content). Results: Participation was completed by 15 patients with mean age 59 years and mean 24h BP 144/82 mmHg. Mean baseline urinary sodium excretion was 192(86) mmol/24h (11.2 grams of salt). As seen in Table 1, sodium excretion was reduced to 91 mmol/24h equalling 5.3 grams of salt. BP levels were reduced significantly. Plasma levels of nitric oxide increased significantly, and this was correlated to the change in 24h BP. Total body water content and plasma levels of BNP was reduced significantly. The changes in BP were not correlated to changes in sodium excretion, body water or BNP. Conclusions: Self-performed dietary sodium restriction could be implemented resulting in a significant reduction in BP levels. BP change was not related to changes in body water or sodium excretion. Increased levels of nitric oxide may be evidence of improved endothelial function and may be one of the involved mechanisms in BP decrease following sodium restriction

Renal nerve stimulation: complete versus incomplete renal sympathetic denervation

Purpose Blood pressure (BP) reduction after renal sympathetic denervation (RDN) is highly variable. Renal nerve stimulation (RNS) can localize sympathetic nerves. The RNS trial aimed to investigate the medium-term BP-lowering effects of the use of RNS during RDN, and explore if RNS can check the completeness of the denervation. Material and methods Forty-four treatment-resistant hypertensive patients were included in the prospective, single-center RNS trial. The primary study endpoint was change in 24-h BP at 6- to 12-month follow-up after RDN. The secondary study endpoints were the acute procedural RNS-induced BP response before and after RDN; number of antihypertensive drugs at follow-up; and the correlation between the RNS-induced BP increase before versus after RDN (delta [Δ] RNS-induced BP). Results Before RDN, the RNS-induced systolic BP rise was 43(±21) mmHg, and decreased to 9(±12) mmHg after RDN (p < 0.001). Mean 24-h systolic/diastolic BP decreased from 147(±12)/82(±11) mmHg at baseline to 135(±11)/76(±10) mmHg (p < 0.001/<0.001) at follow-up (10 [6–12] months), with 1 antihypertensive drug less compared to baseline. The Δ RNS-induced BP and the 24-h BP decrease at follow-up were correlated for systolic (R = 0.44, p = 0.004) and diastolic (R = 0.48, p = 0.003) BP. Patients with ≤0 mmHg residual RNS-induced BP response after RDN had a significant lower mean 24-h systolic BP at follow-up compared to the patients with >0 mmHg residual RNS-induced BP response (126 ± 4 mmHg versus 135 ± 10 mmHg, p = 0.04). 83% of the patients with ≤0 mmHg residual RNS-induced BP response had normal 24-h BP at follow-up, compared to 33% in the patients with >0 mmHg residual RNS-induced BP response (p = 0.023). Conclusion The use of RNS during RDN leads to clinically significant and sustained lowering of 24-h BP with fewer antihypertensive drugs at follow-up. RNS-induced BP changes were correlated with 24-h BP changes at follow-up. Moreover, patients with complete denervation had significant lower BP compared to the patients with incomplete denervation.

Catheter-based renal denervation in patients with uncontrolled hypertension in the absence of antihypertensive medications (SPYRAL HTN-OFF MED): a randomised, sham-controlled, proof-of-concept trial

Previous randomised renal denervation studies did not show consistent efficacy in reducing blood pressure. The objective of our study was to evaluate the effect of renal denervation on blood pressure in the absence of antihypertensive medications. SPYRAL HTN-OFF MED was a multicentre, international, single-blind, randomised, sham-controlled, proof-of-concept trial. Patients were enrolled at 21 centres in the USA, Europe, Japan, and Australia. Eligible patients were drug-naive or discontinued their antihypertensive medications. Patients with an office systolic blood pressure (SBP) of 150 mm Hg or greater and less than 180 mm Hg, office diastolic blood pressure (DBP) of 90 mm Hg or greater, and a mean 24-h ambulatory SBP of 140 mm Hg or greater and less than 170 mm Hg at second screening underwent renal angiography and were randomly assigned to renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were blinded to randomisation assignments. The primary endpoint, change in 24-h blood pressure at 3 months, was compared between groups. Drug surveillance was done to ensure patient compliance with absence of antihypertensive medication. The primary analysis was done in the intention-to-treat population. Safety events were assessed at 3 months. This study is registered with ClinicalTrials.gov, number NCT02439749. Between June 25, 2015, and Jan 30, 2017, 353 patients were screened. 80 patients were randomly assigned to renal denervation (n=38) or sham control (n=42) and followed up for 3 months. Office and 24-h ambulatory blood pressure decreased significantly from baseline to 3 months in the renal denervation group: 24-h SBP -5·5 mm Hg (95% CI -9·1 to -2·0; p=0·0031), 24-h DBP -4·8 mm Hg (-7·0 to -2·6; p<0·0001), office SBP -10·0 mm Hg (-15·1 to -4·9; p=0·0004), and office DBP -5·3 mm Hg (-7·8 to -2·7; p=0·0002). No significant changes were seen in the sham-control group: 24-h SBP -0·5 mm Hg (95% CI -3·9 to 2·9; p=0·7644), 24-h DBP -0·4 mm Hg (-2·2 to 1·4; p=0·6448), office SBP -2·3 mm Hg (-6·1 to 1·6; p=0·2381), and office DBP -0·3 mm Hg (-2·9 to 2·2; p=0·8052). The mean difference between the groups favoured renal denervation for 3-month change in both office and 24-h blood pressure from baseline: 24-h SBP -5·0 mm Hg (95% CI -9·9 to -0·2; p=0·0414), 24-h DBP -4·4 mm Hg (-7·2 to -1·6; p=0·0024), office SBP -7·7 mm Hg (-14·0 to -1·5; p=0·0155), and office DBP -4·9 mm Hg (-8·5 to -1·4; p=0·0077). Baseline-adjusted analyses showed similar findings. There were no major adverse events in either group. Results from SPYRAL HTN-OFF MED provide biological proof of principle for the blood-pressure-lowering efficacy of renal denervation. Medtronic.

Effects of daily walking on office, home and 24-h blood pressure in hypertensive patients

Aerobic exercise has been recommended in the management of hypertension. However, few studies have examined the effect of walking on ambulatory blood pressure (BP), and no studies have employed home BP monitoring. We investigated the effects of daily walking on office, home, and 24-h ambulatory BP in hypertensive patients. Sixty-five treated or untreated patients with essential hypertension (39 women and 26 men, 60 ± 9 years) were examined in a randomized cross-over design. The patients were asked to take a daily walk of 30–60 min to achieve 10 000 steps/d for 4 weeks, and to maintain usual activities for another 4 weeks. The number of steps taken and home BP were recorded everyday. Measurement of office and ambulatory BP, and sampling of blood and urine were performed at the end of each period. The average number of steps were 5349 ± 2267/d and 10 049 ± 3403/d in the control and walking period, respectively. Body weight and urinary sodium excretion did not change. Office, home, and 24-h BP in the walking period were lower compared to the control period by 2.6 ± 9.4/1.3 ± 4.9 mmHg (p < 0.05), 1.6 ± 6.8/1.5 ± 3.7 mmHg (p < 0.01), and 2.4 ± 7.6/1.8 ± 5.3 mmHg (p < 0.01), respectively. Average 24-h heart rate and serum triglyceride also decreased significantly. The changes in 24-h BP with walking significantly correlated with the average 24-h BP in the control period. In conclusion, daily walking lowered office, home, and 24-h BP, and improved 24-h heart rate and lipid metabolism in hypertensive patients. However, the small changes in BP may limit the value of walking as a non-pharmacologic therapy for hypertension.

Obesity is a strong determinant of hypertensive target organ damage in young-to-middle-age patients

To examine the impact of overweight and obesity on development of target organ damage in the early stage of hypertension. Participants were 727 young-to-middle-age subjects screened for stage 1 hypertension and followed for 8 years. Ambulatory blood pressure (BP), albumin excretion rate and echocardiographic data were obtained at entry, every 5 years and/or before starting antihypertensive treatment. During the follow-up, hypertension needing treatment was developed by 54.7% of the subjects with normal weight, 66.6% of those with overweight and 73.0% of those with obesity (P<0.001). Kaplan-Meier curves showed that patients with obesity or overweight progressed to sustained hypertension earlier than those with normal weight (P<0.001). At study end, rate of organ damage was 10.7% in the normal weight, 16.4% in the overweight and 30.1% in the obese subjects (P<0.001). In a multivariable logistic regression analysis, overweight (P=0.008) and obesity (P<0.001) were significant predictors of final organ damage. Inclusion of changes in 24-h BP and body mass index, and of baseline organ damage did not virtually modify these associations (P=0.002 and <0.001, respectively). Obesity was a significant predictor of both left ventricular hypertrophy (P<0.001) and microalbuminuria (P=0.015) with an odds ratio (95% confidence interval) of 8.5 (2.7-26.8) and 3.5 (1.3-9.6), respectively. These data indicate that in hypertensive subjects obesity has deleterious effects on the cardiovascular system already at an early age. Preventive strategies addressed to achieve weight reduction should be implemented at a very early stage in young people with excess adiposity and high BP.

Renal Effects of Aliskiren Compared With and in Combination With Irbesartan in Patients With Type 2 Diabetes, Hypertension, and Albuminuria

OBJECTIVEWe investigated whether the antiproteinuric effect of the direct renin inhibitor aliskiren is comparable to that of irbesartan and the effect of the combination.RESEARCH DESIGN AND METHODSThis was a double-blind, randomized, crossover trial. After a 1-month washout period, 26 patients with type 2 diabetes, hypertension, and albuminuria (>100 mg/day) were randomly assigned to four 2-month treatment periods in random order with placebo, 300 mg aliskiren once daily, 300 mg irbesartan once daily, or the combination using identical doses. Patients received furosemide in a stable dose throughout the study. The primary end point was a change in albuminuria. Secondary measures included change in 24-h blood pressure and glomerular filtration rate (GFR).RESULTSPlacebo geometric mean albuminuria was 258 mg/day (range 84–2,361), mean ± SD 24-h blood pressure was 140/73 ± 15/8 mmHg, and GFR was 89 ± 27 ml/min per 1.73 m2. Aliskiren treatment reduced albuminuria by 48% (95% CI 27–62) compared with placebo (P < 0.001), not significantly different from the 58% (42–79) reduction with irbesartan treatment (P < 0.001 vs. placebo). Combination treatment reduced albuminuria by 71% (59–79), more than either monotherapy (P < 0.001 and P = 0.028). Fractional clearances of albumin were significantly reduced (46, 56, and 67% reduction vs. placebo). Twenty-four-hour blood pressure was reduced 3/4 mmHg by aliskiren (NS/P = 0.009), 12/5 mmHg by irbesartan (P < 0.001/P = 0.002), and 10/6 mmHg by the combination (P = 0.001/P < 0.001). GFR was significantly reduced 4.6 (95% CI 0.3–8.8) ml/min per 1.73 m2 by aliskiren, 8.0 (3.6–12.3) ml/min per 1.73 m2 by irbesartan, and 11.7 (7.4–15.9) ml/min per 1.73 m2 by the combination.CONCLUSIONSThe combination of aliskiren and irbesartan is more antiproteinuric in type 2 diabetic patients with albuminuria than monotherapy.

Effect of body weight changes on 24-hour blood pressure and left ventricular mass in hypertension: a 4-year follow-up

Background Few data are available on the long-term effects of weight loss on 24-h blood pressure (BP) and left ventricular mass in overweight hypertensive patients. Methods A total of 181 never-treated overweight hypertensive subjects (body mass index, 25 to 39 kg/m 2, office BP 145/94 ± 12/7 mm Hg) had 24-h BP monitoring and echocardiography twice, at baseline and after 3.8 ± 2 years (minimum 1 year). None of the subjects received antihypertensive drugs during the follow-up. Main outcome measures were changes in 24-h BP and in left ventricular mass. Results Percent change in body weight had a direct relationship with 24-h BP changes ( r = 0.35 and 0.31 for systolic and diastolic BP, respectively; both P < .001). The associations with office BP changes ( r = 0.13, P = .10 for systolic BP; r = 0.15, P = .06 for diastolic BP) were significantly weaker (both P < .01, z test). The patients who lost weight during follow-up ( n = 106) had a significantly lower increase in 24-h BP (+0.6 ± 9/ +0.2 ± 6 v +4.9 ± 9/ +2.7 ± 7 mm Hg for systolic/diastolic BP, both P < .01) and in left ventricular mass (−3 ± 30 g v +9 ± 32 g, P < .02) than the remaining subjects. In a multiple linear regression, a 10% weight loss independently predicted a 4.3/3.8 mm Hg decrease in 24-h systolic/diastolic BP. Conclusions Long-term weight loss determines a sustained BP reduction during the 24 h and a decrease in left ventricular mass in overweight hypertensive subjects. The relation of weight loss with ambulatory BP changes is closer than that with office BP.

A Smooth Blood Pressure Control is obtained over 24 h by Delapril in Mild to Moderate Essential Hypertensives

Objective: To assess the homogeneity of the antihypertensive effect of delapril over 24 h. Design and methods: After 2 weeks of placebo 50 mild to moderate essential hypertensives (age 54 - 5 years) were subjected to 8 weeks of treatment with delapril 30 mg once daily. At the end of each period, blood pressure (BP) was assessed by conventional sphygmomanometry (clinic or CBP) and ambulatory (A) BP monitoring. Twenty-four-hour means, trough-to-peak ratio (T/P) and smoothness index (SI, the ratio between the average of the 24-h BP changes after T and its standard deviation) were calculated for systolic (S) and diastolic (D) BP. Results: CBP and ABP were significantly reduced by treatment. Pulse pressure (PP, the SBP-DBP difference) was also significantly ( p < 0.01) reduced by delapril (5.7 - 6.2 and 3.3 - 3.8 mmHg, CPP and APP). The median T/P was higher (0.51 and 0.62, SBP and DBP) in the 43 responders at trough than in the whole group (0.44 and 0.51). The SI was similarly high in the whole group (1.3 - 0.6 and 1.4 - 0.6, SBP and DBP) and in the responders (1.4 - 0.5 and 1.5 - 0.6). Conclusions: Delapril effectively and smoothly reduces BP over 24 h, this effect being evident also on PP, a parameter with a relevant prognostic value.

How to evaluate the duration of blood pressure control: the trough:peak ratio and 24-hour monitoring.

Recently published data provide confirming evidence to support existing epidemiologic data showing that treatment-induced changes in 24-h blood pressure are more closely correlated with treatment-induced changes in left ventricular mass index than corresponding changes in clinic blood pressure. This provides definitive support for the aim of achieving blood pressure control based on a smooth and consistent antihypertensive effect over a full 24-h period. With the plethora of agents now available for once-daily administration in the treatment of hypertension, it would be of value to have a validated index that defines duration of effect and that discriminates between alternative treatments and treatment regimens. The trough:peak ratio of blood pressure response has been proposed as such as index and has in part been validated in this role. Evidence suggests that many existing agents have suboptimal trough:peak ratios or, alternatively, that achieving a high ratio is dependent on utilizing inappropriately high doses of drug. Where a drug has a high trough:peak ratio that is associated with its intrinsic long duration of action and is independent of dose over the therapeutic range, the evidence indicates that the drug may offer the additional benefit of sustained blood pressure control after a missed dose. Finally, theoretic and experimental evidence supports the concept that rational drug combinations will produce enhanced trough:peak ratios compared to the individual drug components.

Circadian Variation of Hemodynamics and Baroreflex Functions in Patients with Essential Hypertension.

It is well known that cardiovascular accidents such as myocardial infarction frequently occur in the morning, but their triggering mechanisms are not clear. The present study investigated circadian variations of hemodynamics and baroreflex functions. Twenty-three patients with essential hypertension were studied. Direct blood pressure (BP) and ECG were recorded by telemeter over 24 h, and then computer-analyzed. The pulse-contour method was used to measure cardiac output (CO) and total peripheral vascular resistance (TPR). The ratio of low to high frequency components (LF/HF) of the RR-interval on ECG was calculated by power spectral analysis. The baroreflex sensitivity index (BRI) was measured on the basis of the ratio delta RR/delta Ps (delta Ps = spontaneous decrease in systolic BP, delta RR = change in RR). Furthermore, 24-h BP changes were transformed algebraically into positive load component (PC) and negative load component (NC) by using a Windkessel model. The circadian variation of hematocrit (Ht) was also measured. The least squares method was used to determine the time at which the maximum and minimum value of each measurement occurred. Whereas the maximum values for BP and CO occurred in the evening (18:30, 17:00), the maximum values for TPR and LF/HF occurred between 06:30 and 08:00, and the minimum value for BRI occurred at 08:00. PC significantly correlated with Ps, heart rate, and CO (r = 0.81, 0.92, 0.67), and NC significantly correlated with BRI and LF/HF (r = 0.71, 0.64). PC (related to cardiovascular function) reached a maximum and NC (related to baroreflex function) reached a minimum in the late morning (11:00). Ht was highest immediately after the subjects got out of bed. These hemodynamic imbalances may negatively influence coronary blood flow in the morning.

Assessment of salt sensitivity in essential hypertension by 24-h ambulatory blood pressure monitoring

We used ambulatory blood pressure monitoring (ABPM) in the assessment of salt sensitivity in 40 essential hypertensive patients, comparing 24-h mean blood pressure during 7 days of low salt (20 mmol NaCl/day) and high salt (260 mmol NaCl/day) intake. Salt sensitivity was diagnosed in 18 essential hypertensive patients (45%), each of them showing a significant increase in mean blood pressure (P < .05) from low to high salt diet. Salt-sensitive patients exhibited a high-salt-dependent increase in all blood pressure parameters including 24-h systolic, mean, diastolic blood pressure, blood pressure load, area under the curve, and awake and asleep blood pressure values. These patients exhibited a nondipper profile on both low-salt and high-salt diets. Salt-resistant patients (55%) showed a decrease in awake, and an increase in asleep blood pressure values after high salt intake, thus tending to flatten the circadian blood pressure profile. We conclude that ABPM is a useful method to assess salt sensitivity. In salt-resistant patients high salt intake induces a significant increase in asleep blood pressure with no significant changes in 24-h blood pressure, promoting a flattened blood pressure curve and tending to transform a dipper into a nondipper profile, which could have important implications in end-organ damage.

The changes in blood pressure after acute stroke: abolishing the ‘white coat effect’ with 24‐h ambulatory monitoring

To assess the changes in 24-h and casual blood pressure (BP) levels following hospitalization for acute stroke. Prospective study of patients admitted with acute hemispheric stroke and hospitalized controls using casual and 24-h BP monitoring. Medical wards in a large teaching hospital. Thirty-three patients (median age 77 years, 17 male) and 21 control subjects admitted non-acutely. All subjects underwent 24-h BP monitoring within 24 h of stroke onset (patients) or admission (controls) and again at 1 week. Casual BPs were recorded over the same period. The change in BP over the first week in each group. Eleven stroke subjects had 24-h BP monitoring repeated at 6 months. In the stroke group, 24-h systolic BP (SBP) fell by 7 mmHg (95% CI, 0 to 14 mmHg; P < 0.05) and diastolic BP (DBP) by 3 mmHg (95% CI, 0 to 6 mmHg; P < 0.02) over the first week. Mean 24-h BP levels in the control group did not change during this period. However, casual BP recordings fell in both stroke (18/12 mmHg) and control (19/9 mmHg) groups. Stroke subjects followed to 6 months showed no further change in 24-h BP (day 7: 137 +/- 17/79 +/- 13 mmHg; month 6: 138 +/- 16/78 +/- 11 mmHg). Although there was a large fall in causal BPs seen in both groups there was only a small, but a significant fall in mean 24-h BP over the first week following hemispheric stroke that was not seen in control subjects. Although the 'white coat effect' and admission to hospital play an important part in the high casual BP observed in the days following acute stroke they are unlikely to be the sole factors.

Augmentation of the renal tubular dopaminergic activity by oral calcium supplementation in patients with essential hypertension.

We studied the effect of oral calcium supplementation on renal tubular dopaminergic activity in patients with mild to moderate essential hypertension. Fifteen patients aged 45 to 68 years (nine men and six women, mean age 59 +/- 7 [SD]) participated in the study. We orally administered calcium (1.0 g per day for 1 week) during hospitalization. The change in 24-h blood pressure (BP), measured by ambulatory BP monitoring, and excretions of electrolytes and catecholamines were investigated before and after 1 week of oral calcium supplementation. The mean values of 24-h systolic and diastolic BP showed no significant changes by calcium loading. Daily urinary excretion of free dopamine, sodium clearance (CNa), fractional excretion of sodium (FENa), and urinary volume were significantly increased by oral calcium supplementation. Urinary excretions of epinephrine and norepinephrine and creatinine clearance showed no significant changes by oral calcium treatment. CNa and FENa showed significant correlations with urinary excretion of free dopamine. These results suggest that oral calcium supplementation induces natriuresis partly through augmentation of renal tubular dopaminergic activity.