Effects of GH replacement on 24-h ambulatory blood pressure and its circadian rhythm in adult GH deficiency

OBJECTIVE: Increased prevalence of hypertension and cardiovascular mortality have been reported in hypopituitary patients who had been appropriately replaced with conventional pituitary hormones except GH. Growth hormone replacement (GHR) results in improvement of surrogate markers of cardiovascular function. Data on effects of GHR on blood pressure (BP) in adult growth hormone deficiency (AGHD), however, remain contradictory. There are as yet no reports on BP circadian rhythms in untreated or treated AGHD. Therefore, in a 12-month follow-up study, we evaluated the effects of GHR on ambulatory blood pressure (ABP) in AGHD patients. STUDY DESIGN: A prospective, open treatment design study to determine the effects of GHR on ABP and heart rate in AGHD patients. GH was commenced at a daily dose of 0.5 IU, and titrated up by increments of 0.25 IU at 4-weekly intervals to achieve and maintain IGF-I standard deviation score (IGF-I SD) between the median and upper end of the age-related reference range. PATIENTS: Twenty-two, post-pituitary surgery, severe AGHD patients (11 men), defined as peak GH response < 9 mU/l to provocative testing were recruited. The mean age +/- SEM was 48.8 +/- 2.5 years. Twenty-one patients required additional pituitary replacement hormones following pituitary surgery and were on optimal doses at recruitment. MEASUREMENTS: Twenty-four-hour ABP and heart rate (HR), body mass index (BMI), waist hip ratio (WHR) and total body water (TBW) were measured before and after 12 months on GHR. Cosinor analysis was used to analyse BP and HR circadian rhythm parameter estimates. RESULTS: Target IGF-I SD was achieved within 3 months of commencement of GHR in all patients (-3.5 +/- 0.4 at baseline vs. 0.8 +/- 0.2 at 3 months, P < 0.001) and remained within range at 12 months (1.1 +/- 0.2, P < 0.001 compared to baseline). A significant increase in TBW (45.8 +/- 1.2 vs. 47.8 +/- 1.5 kg, P < 0.05) but no significant change in BMI (30.7 +/- 2.2 vs. 31.8 +/- 2.7, P = NS) or WHR (0.95 +/- 0.02 vs. 0.93 +/- 0.02, P = NS) was observed after 12 months on GHR. The 24-h mean systolic ABP (SBP; 126.2 +/- 2.8 vs. 120.1 +/- 2.7 mmHg, P < 0.001) and diastolic ABP (DBP; 78.2 +/- 1.6 vs. 71.4 +/- 1.8 mmHg, P < 0.001) significantly decreased following GHR with a parallel increase in 24-h mean HR (69.6 +/- 2.5 vs. 73.8 +/- 2.5 beats/min; P < 0.001). A significant nocturnal decrease in SBP and DBP was observed both before (SBP; daytime, 129.1 +/- 2.8 vs. night time, 115.9 +/- 3.0 mmHg, P < 0.001 and DBP; daytime, 80.7 +/- 1.6 vs. night time, 69.2 +/- 1.8 mmHg, P < 0.001) and following GHR (SBP; daytime, 122.8 +/- 2.6 vs. night time, 110.0 +/- 3.6 mmHg, P < 0.001 and DBP; daytime, 73.9 +/- 1.8 vs. night time, 62.0 +/- 2.3 mmHg, P < 0.001). Individual and population-mean cosinor analysis demonstrated significant circadian rhythms for SBP, DBP and HR before and after 12 months on GHR (P < 0.001), suggesting that SBP, DBP and HR circadian rhythms were not altered by GHR. There was, however, a significant reduction in SBP (124.2 +/- 2.8 vs. 118.4 +/- 2.8 mmHg, P < 0.001) and DBP (77.0 +/- 1.6 vs. 70.2 +/- 1.8 mmHg, P < 0.001) MESOR with an increase in HR MESOR (68.9 +/- 2.5 vs. 72.2 +/- 2.4 beats/min, P < 0.01) following GHR. CONCLUSIONS: Systolic and diastolic BP and HR circadian rhythms are preserved in AGHD following 12 months of GHR. However, there is a significant decrease in 24-h mean SBP and DBP and increase in 24-h mean HR after 12 months on GHR. We postulate that this decrease in 24-h mean SBP and DBP may result in a reduction of cardiovascular morbidity and mortality and may explain the beneficial effects of GHR on cardiovascular system previously reported in AGHD patients.     

White coat effect of alcohol

Numerous studies have shown a relationship between alcohol intake and elevated clinic blood pressures (BP). However, there have been few studies on the relationship between alcohol consumption and 24-h ambulatory BP monitoring. This study aimed to determine the relationship between alcohol intake, clinic BP, and 24-h ambulatory BP recordings to determine to what extent a white coat effect may contribute to the relationship between alcohol consumption and BP. Clinical BP and 24-h ambulatory BP were measured in 121 male volunteers aged 50.6 +/- 9.8 years (range, 30-70 years) who consumed between 0 and 2050 g of alcohol per week (mean, 394 +/- 342 g; median, 385 g/week). Supine clinical systolic BP (SBP) was significantly related to alcohol intake (beta = 0.242; P = .007). Alcohol consumption was not related to 24-h mean SBP or diastolic BP (DBP), daytime SBP or DBP, or nighttime SBP or DBP (daytime SBP: beta = 0.02, P = .802). Alcohol intake was significantly related to the difference between clinic SBP and mean daytime SBP (beta = 0.260, P = .004). Twenty-four-hour mean heart rate (HR), daytime mean and nighttime mean HR were strongly associated with alcohol intake (24-h HR: beta = 0.455, P < .001). These results suggest that the association between alcohol consumption and elevated BP is contributed to by a significant white coat effect and that excessive alcohol consumption may be a significant factor in explaining differences between clinic and ambulatory BP measurements.     

Comparison of the effects of cilnidipine and amlodipine on ambulatory blood pressure.

Cilnidipine is a novel and unique 1,4-dydropyridine derivative calcium antagonist that exerts potent inhibitory actions not only on L-type but also on N-type voltage-dependent calcium channels. Blockade of the neural N-type calcium channel inhibits the secretion of norepinephrine from peripheral neural terminals and depresses sympathetic nervous system activity. The purpose of this study was to assess the effect of cilnidipine and amlodipine on ambulatory blood pressure (BP) levels. We performed 24-h ambulatory BP monitoring before and after once-daily use of cilnidipine (n=55) and amlodipine (n=55) in 110 hypertensive patients. Both drugs significantly reduced clinic and 24-h systolic BP (SBP) and diastolic BP (DBP) (p < 0.005). However, the reductions of 24-h (-1.19+/-6.78 vs. 1.55+/-6.13 bpm, p=0.03), daytime (-1.58+/-6.72 vs. 1.68+/-7.34 bpm, p=0.02) and nighttime (-1.19+/-5.72 vs. 1.89+/-6.56 bpm, p=0.01) pulse rate (PR) were significantly greater in the cilnidipine group than the amlodipine group. There was no correlation between the degree of daytime SBP change and that of daytime PR change after amlodipine treatment (r=-0.08, n.s.), but there was a significant negative correlation between the degree of daytime SBP change and that of day-time PR change after cilnidipine treatment (r=-0.27, p<0.05). N-type calcium channel blockade by cilnidipine may not cause reflex tachycardia, and may be useful for hypertensive treatment.     

Predictors of controlled ambulatory blood pressure in treated hypertensive patients with uncontrolled office blood pressure.

Although some treated hypertensive patients have controlled 24-h ambulatory blood pressure (ABP) despite their uncontrolled office blood pressure (BP), the factors relating to the control of 24-h ABP remain unknown. We conducted a study to assess 24-h ABP and its association with other cardiovascular risk factors, including echocardiographic left ventricular hypertrophy (LVH), in elderly hypertensive patients (n =41) with uncontrolled office BP (>140/90 mmHg) during long-term medication. Although a majority of the patients had isolated elevation of office systolic BP (SBP), there was no significant relationship between office SBP and 24-h SBP, and about half of the patients had controlled 24-h ABP (125+/-8/69+/-6 mmHg). Patients with controlled 24-h ABP (125+/-8/69+/-6 mmHg) had similar office BP (150+/-6/77+/-5 vs. 150+/-7/79+/-7 mmHg), but lower left ventricular mass index (LVMI) (123+/-34 vs. 156+/-34 g/m(2)) and body mass index (BMI) (24.4+/-2.1 vs. 26.4+/-3.6 kg/m(2)) compared with those with uncontrolled 24-h ABP (149+/-13/78+/-7 mmHg). Multivariate analysis showed that LVMI and BMI were independently associated with controlled 24-h ABP, and the control status of 24-h ABP was highly dependent on the presence of LVH and obesity. Therefore, absence of LVH and obesity may be useful for predicting the level of control of 24-h ABP in treated patients whose office BP is uncontrolled without ABP measurements.     

Role of nocturnal blood pressure in the onset of diabetic nephropathy

The aim of this study was to assess the responsibility of night-time blood pressure in the onset of nephropathy in diabetic patients. PATIENTS AND METHODS: This study included 98 diabetic patients (mean age: 54 +/- 15 years, diabetes duration: 15 +/- 10 years). An evaluation of diabetes and a 24-h ambulatory blood pressure were performed at the initial evaluation (Y0) and about five years later (Y5). At Y0, all patients had normal urinary albumin excretion (UAE) (<30 mg/24h). They were separated into two groups according to urinary albumin excretion at Y5: group (N +): UAE>30 mg/24h and group (N-): UAE<30 mg/24h. Twenty four hours ambulatory blood pressure, clinical and biological parameters recorded at Y0 were compared in both. RESULTS: At Y5, there was 18 patients in group (N +) and 78 in group (N-). Patients of group (N +) were older than those of group (N-): 62.9 +/- 9.5 vs. 52.6 +/- 15.7 years, p<0.01, and their BMI was higher (28 +/- 5 vs. 25 +/- 4 kg/m2, p<0.03). Diabetes duration and Hb A1c levels did not differ from significant manner in both. At Y0, UAE was significantly higher in group (N +) than in group (N-): 13 +/- 7 vs. 8 +/- 6 mg/24h, p<0.01. At the initial evaluation, daytime systolic and diastolic blood pressures did not differ from significant manner in both. Systolic and diastolic BP night-time were higher in diabetic patients who developed microalbuminuria (SBP: 122 +/- 19 vs. 113 +/- 13 mmHg, p<0.05 and DBP: 70 +/- 6 vs. 65 +/- 10 mmHg, p<0.03). UAE collected at Y5 was correlated to night-time BP recorded at Y0 (SBP: r=0.381, p=0.001 and PAD: r=0.294, p=0.004) and night-time systolic BP explained 12.3% of the UAE variance. Progression of UAE between the two evaluations was found to be correlated to the night-time systolic BP recorded at Y0 (r=0.335, p=0.0008) and night-time systolic BP explained 11.7% of the progression variance. There was a negative correlation between UAE at A5 and the difference between daytime and night-time BP recorded during the same evaluation (r=- 0.230, p=0.024 with SBP and r=- 0.243, p=0.017 with DBP). CONCLUSION: The results underlign the resposability of night-time blood pressure, and more especially of nighttime systolic blood pressure, for the onset of nephropathy in diabetic patients.     

Genetic influence on blood pressure and lipid parameters in a sample of Polish twins

We studied 76 healthy monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs (mean age 35 +/- 8 years, body mass index, BMI, 23.6 +/- 3.9 kg/m2) to determine genetic and environmental contributions to systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR) and serum lipids [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-chol), high-density lipoprotein cholesterol (HDL-chol) and triglycerides (TG)I. SBP, DBP and HR were measured clinically and by ambulatory blood pressure monitoring (ABPM). Parameters of the genetic models for age-, sex- and BMI-adjusted data were estimated by model fitting and path analysis technique using LISREL 8. We found significant genetic effect on SBP and DBP for both clinical and ABP measurements, ranging from 37% for night-time ambulatory DBP to 79% for daytime ambulatory SBP. Estimates of genetic effects were higher for daytime than night-time ABP values, and higher for ambulatory 24-h SBP than office SBP measurements, with the reverse true for DBP. Significant genetic effect on HR ranged from 59% for office measurements to 69% for 24-h mean values. In summary, we also found genetic effect on TC, LDL-chol and HDL-chol with estimates ranging from 36% to 64%, but not on TG. Furthermore, a shared environmental component for TG was found, estimated at 36%. We showed significant genetic effect on both office and ambulatory BP and HR, with stronger genetic effect on daytime than night-time BP. We also found genetic effect on TC and lipoprotein fractions, but no significant genetic effect on TG. Environmental factors influencing serum TG, such as alcohol consumption, may explain the apparent lack of genetic effect in this healthy, non-obese population.     

Twenty-four-hour ambulatory BP in snoring children with obstructive sleep apnea syndrome

INTRODUCTION: Obstructive sleep apnea syndrome (OSAS) is a known risk factor for hypertension in adults. This relationship is less clear in childhood OSAS. OBJECTIVE: This study examined the relationship between OSAS and 24-h ambulatory BP (ABP), a more accurate assessment than casual BP, in children with snoring. METHODS: Snoring children aged 6 to 15 years who underwent polysomnography in the sleep laboratory were recruited. Measurement: Twenty-four-hour ABP monitoring was initiated a few hours before polysomnography. The children were classified into two groups: a high apnea-hypopnea index (AHI) group (obstructive AHI > 5/h), and a low-AHI group (AHI < or = 5/h). Mean sleep, wake, and 24-h systolic BP (SBP) and diastolic BP (DBP) were recorded. A child was considered a "nondipper" if his or her mean SBP and DBP did not decrease by >/= 10% during sleep. RESULTS: Ninety-six children (mean age +/- SD, 9.4 +/- 2.8 years) were recruited. Forty-one children were obese. When awake, the high-AHI group children had a significantly higher SBP. When asleep, both SBP and DBP were higher in the high-AHI group. Age, body mass index (BMI) z score, and desaturation index (DI) were significant predictors for elevated sleep DBP. BMI z score was the only significant predictor for wake and sleep SBP. Sixteen children (17%) had hypertension, and all were nondippers. Obese children in the high-AHI group had a significantly higher prevalence of hypertension than obese children in the low-AHI group. This relationship was not found in nonobese children. CONCLUSION: The current study shows that increased DI contributed to the elevation of sleep DBP elevation.     

Influence of blood pressure level on urinary albumin excretion rate and erythropoietin production in diabetic patients

The purpose of this study was to investigate blood pressure variations during diabetic incipient nephropathy and to evaluate theirs consequences for erythropoietin (EPO) production. PATIENTS AND METHODS: This study included 94 diabetic patients (mean age: 59.9 +/- 15.3 years, diabetes duration: 13.8 +/- 15.3 years). Patients were divided in two groups according to urinary albumin excretion rate (UAE): group 1: UAE <30 mg/24 hrs, N=64 and group 2: 30相似文献   

Rate of morning increase in blood pressure is elevated in hypertensives

BACKGROUND: We applied a new logistic curve fitting procedure to ambulatory blood pressure (ABP) recordings to determine whether the rate of increase in systolic (SBP), mean (MBP) and diastolic blood pressure (DBP) and heart rate (HR) in the morning is related to the level of BP in subjects. METHODS: The rate of transition in the morning and evening period was determined using a six-parameter double-logistic equation applied to 528 ABP recordings from a cardiovascular risk assessment clinic. Based on daytime BP (MBP, SBP, or DBP), the upper quartile (UQ, n = 132) and lower quartile (LQ) were compared. RESULTS: Subjects in the UQ of daytime MBP were hypertensive and showed greater day-night differences compared to normotensive subjects in the LQ (29 +/- 1 mm Hg for MBP compared to 20 +/- 1 mm Hg). The rate of morning increase in SBP and DBP was 42% and 30% greater in UQ subjects compared to the LQ subjects (P < .05). The rates of evening decrease in all BPs were 69% to 84% greater in the subjects in the UQ. Similar results were obtained if subjects were divided according to daytime SBP or DBP. The rate of morning increase in MBP was correlated with daytime BP, but not night-time or 24 h MBP. CONCLUSIONS: The rate of morning increase in BP is greater in those subjects with the highest daytime BP. The exaggerated rate of morning increase in BP in this group, which were all hypertensive, may also be important for greater cardiovascular risk.     

Ambulatory blood pressure monitoring in patients with hyperthyroidism before and after control of thyroid function

BACKGROUND AND OBJECTIVE: Thyroid hormones have pronounced effects on the cardiovascular system. Thyrotoxicosis affects blood pressure (BP), modifying both diastolic (DBP) and systolic (SBP) pressures. There are no studies examining BP with ambulatory blood pressure monitoring (ABPM) in hyperthyroidism before and after control of thyroid function. Our aims were (1) to analyse ABPM in a group of normotensive hyperthyroid patients before and after normalizing circulating thyroid hormones and (2) to compare these results with those obtained in a group of euthyroid subjects. PATIENTS AND MEASUREMENTS: We studied 20 normotensive hyperthyroid subjects [18 women; age (mean +/- SEM) 49.0 +/- 3.0 years] and 15 healthy subjects. Patients were evaluated by ABPM over 24 h, at diagnosis and after therapy (n = 18). RESULTS: The average 24-h, daytime and night-time SBP was significantly greater in hyperthyroid patients than in controls with no significant differences in DBP. Circadian BP rhythm, estimated by the difference between mean values of SBP, DBP and mean BP during daytime and night-time, was unchanged. The average 24-h and daytime SBP significantly decreased after normalizing thyroid function in the 18 hyperthyroid evaluated patients. Daytime SBP and DBP were higher than night-time values both before and after control of thyroid function. However, no differences in circadian BP rhythm were observed. CONCLUSIONS: Normotensive hyperthyroid patients exhibit higher ambulatory SBP throughout 24 h than normotensive euthyroid subjects. Control of hyperthyroidism decreases ambulatory SBP values. Mean nocturnal fall in BP is comparable in normotensive hyperthyroid patients and control subjects.     

24-hour ambulatory blood-pressure effects of valsartan and hydrochlorothiazide combinations compared with amlodipine in hypertensive patients at increased cardiovascular risk: a VAST sub-study

BACKGROUND: There is a lack of data on the effects of angiotensin-receptor blocker and diuretic combinations on ambulatory blood pressure (ABP) in hypertensive patients with additional cardiovascular risk factors. METHODS: In a randomized, double-blind trial, the effects on 24-h ABP of the combination valsartan 160 mg od and hydrochlorothiazide 25 or 12.5 mg during 24 weeks of therapy were compared with the effects of amlodipine 10 mg monotherapy (group A10) in 474 stage-II hypertensive patients with additional cardiovascular risk factors. After a two-week single-blind placebo run-in period, patients were randomized to receive valsartan 160 mg od or amlodipine 5 mg od. At week 4, HCTZ 12.5 mg (group V160/HCTZ12.5) and 25 mg (group V160/HCTZ25) were added to the valsartan groups and in the A10 patients the amlodipine dose was force-titrated to 10 mg od. RESULTS: All three treatments reduced 24-h BP as well as night-time and daytime BP levels from baseline. Twenty-four hour systolic blood pressure (SBP) was reduced by 15.9+/-1.0 mmHg (least-squares mean change+/-SE), 19.3+/-1.0 mmHg and 16.1+/-1.1 mmHg in the V160/HCTZ12.5, V160/HCTZ25 and A10 groups, respectively and 24-h diastolic blood pressure (DBP) was reduced by 9.3+/-0.6 mmHg, 11.4+/-0.6 mmHg and 9.6+/-0.7 mmHg in the three groups. The differences between the V160/HCTZ25 group and the A10 group were significant (p<0.05) for the changes in 24-h systolic BP as well as for changes in daytime systolic BP and night-time diastolic BP. Control rates defined as ABPM < or =130/80 mmHg were: 48.4%, 60.8% and 50.9% in the V160/HCTZ12.5, V160/25 and A10 groups, respectively. The differences in control rates between the V160/HCTZ25 group and the other two treatment groups were significant at p<0.05. CONCLUSIONS: The fixed-dose combination of valsartan 160 mg+HCTZ 25 mg od is an attractive therapeutic option measured on the effects on 24-h ABPM, night-time and daytime BP reduction and control rates in hypertensive patients at additional cardiovascular risk.     

Rosiglitazone reduces office and diastolic ambulatory blood pressure following 1-year treatment in non-diabetic subjects with insulin resistance

OBJECTIVE: Rosiglitazone (RSG) has been reported to reduce blood pressure (BP) in patients with type-2 diabetes, but similar effects in non-diabetic people with insulin resistance is less clear. Our aim was to test the long-term BP-lowering effects of RSG compared with placebo. METHODS: We recruited participants for BP evaluation of RSG treatment from a larger intervention trial. Office BP was recorded in 355 non-diabetic subjects with insulin resistance randomized to receive either RSG or placebo for 52 weeks. Ambulatory BP monitoring (ABPM; Spacelab 90207) was performed in a subgroup of 24 subjects (RSG: n = 11; placebo n = 13). RESULTS: After 1 year, the office BP decreased by -3.1 mmHg systolic (p<0.05) and -3.8 mmHg diastolic (p<0.001) in the RSG group versus placebo. In patients treated with RSG, at 1 year there was a trend for a reduction from baseline for mean 24-h diastolic BP (DBP), daytime DBP and night-time DBP (-4.39, -5.26 and -2.93 mmHg, respectively). However, only daytime DBP was significantly lower in the RSG group compared with control (adjusted mean difference: -4.41 mmHg, p = 0.007). There was also a non-significant trend for a reduction in mean 24-h systolic BP (SBP), daytime SBP and night-time SBP (-2.70, -2.51 and -3.35 mmHg, respectively). CONCLUSIONS: RSG treatment for 1 year was associated with a small but significant decrease in diastolic 24-h ambulatory diastolic BP, and both systolic and diastolic office BPs in non-diabetic people with insulin resistance.     

Impact of blood pressure variability on cardiac and cerebrovascular complications in hypertension

BACKGROUND: The independent prognostic value of daytime and night-time blood pressure (BP) variability estimated by noninvasive 24-h BP monitoring is unclear. METHODS: We followed 2649 initially untreated subjects with essential hypertension for up to 16 years (mean, 6). Variability of BP was estimated by the standard deviation of daytime or night-time systolic BP (SBP) and diastolic BP (DBP). A BP variability either less than or equal to the group median or greater than the group median (12.7/10.4 mm Hg for daytime SBP/DBP and 10.8 and 8.9 mm Hg for night-time SBP/DBP) identified subjects at low or high BP variability. RESULTS: During follow-up there were 167 new cardiac and 122 new cerebrovascular events. The rate of cardiac events (x100 person-years) was higher (all P < .05) in the subjects with high than in those with low BP variability (daytime SBP: 1.45 v 0.72, daytime DBP: 1.29 v 0.91; night-time SBP: 1.58 v 0.62; night-time DBP: 1.32 v 0.85). The rate of cerebrovascular events was also higher (all P < .05) in the subjects with high than in those with low BP variability. In a multivariate analysis, after adjustment for several confounders, a high night-time SBP variability was associated with a 51% (P = .024) excess risk of cardiac events. The relation of daytime BP variability to cardiac events and that of daytime and night-time BP variability to cerebrovascular events lost significance in the multivariate analysis. CONCLUSIONS: An enhanced variability in SBP during the night-time is an independent predictor of cardiac events in initially untreated hypertensive subjects.     

24-Hour ambulatory blood pressure control with triple-therapy amlodipine, valsartan and hydrochlorothiazide in patients with moderate to severe hypertension

To determine the effectiveness and safety of once-daily combination therapy with amlodipine, valsartan and hydrochlorothiazide for reducing ambulatory blood pressure (ABP) in patients with moderate to severe hypertension, a multicenter, double-blind study was performed (N=2271) that included ABP monitoring in a 283-patient subset. After a single-blind, placebo run-in period, patients were randomized to receive amlodipine/valsartan/hydrochlorothiazide (10/320/25?mg), valsartan/hydrochlorothiazide (320/25?mg), amlodipine/valsartan (10/320?mg) or amlodipine/hydrochlorothiazide (10/25?mg) each morning for 8 weeks. Efficacy assessments included change from baseline in 24-h, daytime and night time mean ambulatory systolic BP (SBP) and diastolic BP (DBP). Statistically significant and clinically relevant reductions from baseline in all these parameters occurred in all treatment groups (P<0.0001, all comparisons versus baseline). At week 8, least squares mean reductions from baseline in 24-h, daytime and night time mean ambulatory SBP/DBP were 30.3/19.7, 31.2/20.5 and 28.0/17.8?mm?Hg, respectively, with amlodipine/valsartan/hydrochlorothiazide; corresponding reductions with dual therapies ranged from 18.8-24.1/11.7-15.5, 19.0-25.1/12.0-16.0 and 18.3-22.6/11.1-14.3?mm?Hg (P≤0.01, all comparisons of triple versus dual therapy). Treatment with amlodipine/valsartan/hydrochlorothiazide maintained full 24-h effectiveness, including during the morning hours; all hourly mean ambulatory SBP and mean ambulatory DBP measurements were ≤130/85?mm?Hg at end point. Amlodipine/valsartan/hydrochlorothiazide combination therapy was well tolerated. Once-daily treatment with amlodipine/valsartan/hydrochlorothiazide (10/320/25?mg) reduces ABP to a significantly greater extent than component-based dual therapy and maintains its effectiveness over the entire 24-h dosing period.     

The impact of dipper and non-dipper characteristics in the fluctuation of arterial blood pressure. A study of a population of 484 diabetic patients

Abnormal pattern of circadian blood pressure variations carries a high risk of cardiovascular complications. The aim of this study was to assess the frequency of abnormal blood pressure rhythm in diabetes and its consequences on micro and macrovascular complications. 484 diabetes mellitus patients were submitted to 24-h ambulatory blood pressure monitoring. They were divided into two groups according to the absence (non-dipper: group 1; n = 167) or presence (dipper: group 2; n = 317) of nocturnal BP reduction = 10% of daytime BP. Following data were collected and compared between these two groups: body mass index, glycated haemoglobin, urinary albumin excretion, research of retinopathy by fundoscopy, tests for presence of a macrovascular disease. There were no significant differences among the two groups in sex, body mass index, type and duration of diabetes and glycemic control. Clinical SBP and DBP did not differ from significant manner between non-dipper and dipper (140 +/- 18/81 +/- 1 versus 138 +/- 19/81 +/- 10 mmHg). Non-dipper 24-h SBP and 24-h DBP were higher than those of dipper (129 +/- 16/76 +/- 9 versus 122 +/- 15/73 +/- 8 mmHg; p < 0.001). Non-dipper were older than dipper (59.9 +/- 13 versus 55.8 +/- 15 years; p < 0.001) and there was more hypertensive patients in group 1 than in group 2 (50% versus 39%; p < 0.01). Macro- and microvascular diabetes complications were more common in non-dipper. In conclusion high blood pressure is frequently observed in diabetic patients. Its association with a diminished nocturnal BP fall could explain a higher risk of complications, especially retinopathy, nephropathy and cardiac events.     

Factors influencing white-coat effect

BACKGROUND: The transient blood pressure (BP) rise during clinical visits is usually referred to as white-coat effect (WCE). The aim of the present study was to investigate factors that may influence the WCE. METHODS: A total of 2004 subjects underwent office BP measurements and 24-h ambulatory BP monitoring (ABPM) on the same day. The WCE was estimated as the difference between office and average daytime ambulatory BP (ABP). According to the office and daytime BP values, the study population was divided into normotensives (NTs), white-coat hypertensives (WCHs), masked hypertensives (MHTs), and sustained hypertensives (SHTs). Statistical analyses were performed using one-way analysis of variance and multiple linear regression models. RESULTS: The mean systolic and diastolic WCE was 9 +/- 16 and 7 +/- 12 mm Hg, respectively. In the entire group of patients, multiple linear regression models revealed independent determinants of systolic WCE in the following rank order: office systolic BP (SBP) (beta = 0.727; P < 0.001), female gender (beta = 0.166; P < 0.001), daytime SBP variability (beta = 0.128; P < 0.001), age (beta = 0.039, P = 0.020), and smoking (beta = 0.031, P = 0.048). A 1.0 mm Hg increase in daytime SBP variability correlated with an increment of 0.589 mm Hg (95% confidence intervals, 0.437-0.741) in the systolic WCE. The regression analyses for diastolic WCE revealed the same factors as independent determinants. A 1.0 mm Hg increase in daytime diastolic BP (DBP) variability was independently associated with an increment of 0.418 mm Hg (95% confidence intervals, 0.121-0.715) in the diastolic WCE. CONCLUSIONS: Factors such as gender, age, smoking, office BPV and daytime BPV may exert an important influence on the magnitude of the WCE.     

Evaluation of the activity of the autonomic nervous system in "dipper" and "non dipper" essential hypertensives. Gender differences]

OBJECTIVES: 1) To compare the autonomic nervous system activity parameters obtained from a photoplethysmographic recording in dipper and non dipper hypertensive. 2) To look for an interaction between dipper/non dipper status and gender. METHODS: Prospective study involving 245 untreated hypertensives (51 +/- 13 years, 146 men, 99 women). All of the patients underwent a 24-hour ambulatory blood pressure measurement (ABPM) as well as an echocardiography for left ventricular mass index determination (LVMI) and a photoplethysmographic recording of blood pressure (BP). Nondippers were defined as those whose nocturnal decrease in systolic BP (SBP) and/or diastolic BP (DBP) was < 10% of daytime BP. Spectral powers were obtained from the photoplethysmographic recording using a fast Fourier transform over the low frequency band (LF) and the high frequency band (HF). Baroreflex sensitivity (BRS) was evaluated by the sequences method. RESULTS: Of the 245 patients, 159 were dippers (98 men, 61 women) and 86 were non dippers (48 men and 38 women). Clinic BP was significantly higher in non dippers than in dippers (168/101 vs 161/98 mmHg; p < 0.01 for SBP and p < 0.05 for DBP) whereas daytime ABPM and LVMI were not different, whatever the gender. LF spectral powers were significantly lower in non dippers than in dippers for SBP (respectively 25 +/- 11% vs 30 +/- 13%; p < 0.01) for DBP (respectively 35 +/- 14% vs 41 +/- 15%; p < 0.01) and for HR (respectively 34 +/- 15% vs 38 +/- 15%; p = 0.03). They showed a positive correlation with the nocturnal SBP fall (r = 0.21, p < 0.001 for SBP and DBP spectral powers, r = 0.19; p < 0.005 for HR spectral power) and with the nocturnal DBP fall, too (r = 0.19; p < 0.005 for SBP spectral power, r = 0.20; p < 0.002 for DBP spectral power, r = 0.19; p < 0.005 for HR spectral power). HF spectral powers tended to be higher in non dippers than in dippers but in a non significative way. BRS was roughly the same in dippers and non dippers (7.5 +/- 2.7 vs 7.0 +/- 3.1 ms/mmHg, NS). The interaction between non dipper/dipper status and sex was non significant whatever the LF spectral power. CONCLUSIONS: 1) The greater the nocturnal BP fall, the higher the sympathetic activity indexes. 2) This relationship was found both in males and females.     

Circadian rhythm of blood pressure in patients with obstructive sleep apnea.

AIMS: The aims of this study were to examine the circadian variation in blood pressure (BP) in obstructive sleep apnea (OSA) and to compare this between normotensive and hypertensive subjects. METHODS: We measured 24-hour ambulatory BP (ABP) in 72 men (mean age 51 +/- 8 years), with OSA diagnosed on overnight sleep study. Measurements of BP were made at 15 min intervals for 24 h using either an Oxford Medilog ABP or Spacelabs 90207 recorder. All recordings were performed after > or = 3 week washout of anti-hypertensive drugs. The day-time monitoring period was defined as 07:00 hrs to 22:00 and night-time 22:00 to 07:00. The ratio of night:day systolic and diastolic BP was calculated. RESULTS: The patients were obese (mean body mass index 33 +/- 5 kg/m2) with a central pattern of obesity (waist:hip ratio 0.99 +/- 0.14, normal < 0.94). The mean 24-h ABP (systolic/diastolic) was 138 +/- 18/88 +/- 12 mmHg. The mean daytime ABP was 143 +/- 18/93 +/- 12 and night-time ABP 128 +/- 20/80 +/- 12 Hg. The night:day BP ratio was 0.90 +/- 0.07 (systolic) and 0.87 +/- 0.09 (diastolic) indicating that average BP was lower during the night. This pattern was similar in normotensive and hypertensive subjects. In contrast there was a significant relationship between increasing BMI and night:day blood pressure ratio (r = 0.56, p < 0.001) independent of the effects of OSA. CONCLUSION: In contrast to previous studies, men with OSA have a normal diurnal pattern of blood pressure levels. These findings suggest that any influence of OSA on BP is manifested throughout the 24-h period.     

Prognostic significance of 24-h ambulatory blood pressure characteristics for cardiovascular morbidity in a population of elderly men

OBJECTIVE: This study aimed to investigate the prognostic significance of 24-h ambulatory systolic (SBP), diastolic (DBP) and pulse pressure (PP), and blood pressure (BP) variability for cardiovascular morbidity in elderly men. DESIGN AND METHODS: Twenty-four hour ABP monitoring was performed in 70-year-old men (n = 872) participating in a longitudinal population-based study. The population was followed for up to 9.5 years, and the relationship between different blood pressure components and cardiovascular (CV) morbidity was assessed by Cox proportional hazard analysis. RESULTS: During follow-up, 172 CV events occurred (2.97 per 100 person-years). SBP and PP, both office and ambulatory, were significant predictors of CV morbidity. Twenty-four hour ambulatory PP [hazard ratio (HR) for 1 SD increase in BP 1.32, 95% confidence interval (CI) 1.15-1.52] and daytime ambulatory PP (HR 1.29, 95% CI 1.13-1.48) predicted CV morbidity independently of office PP and other established CV risk factors. Addition of night-time PP to a regression model with daytime PP and covariates did not increase the predictive value. However, the variability of daytime SBP (adjusted HR 1.24, 95% CI 1.07-1.42) provided additional prognostic power, independently of the 24-h SBP level. CONCLUSIONS: Ambulatory PP was a powerful predictor of CV morbidity in elderly men, independently of office PP and other established cardiovascular risk factors. Moreover, variability of daytime SBP added important prognostic information, suggesting that 24-h ambulatory BP monitoring may contribute to an improved risk assessment in elderly subjects.     

The magnitude and duration of ambulatory blood pressure reduction following acute exercise.

The purpose of this study was to observe the magnitude and duration of the ambulatory blood pressure (BP) reduction following exercise and to identify the peak intervals of BP reduction throughout the 24-h diurnal period. Subjects were 25 normo- (N = 116.7/ 78.2+/-10.0/7.2 mm Hg) and 21 hypertensive (H = 140.8/96.9+/-13.9/9.6 mm Hg) adults. Twenty-four hour ambulatory blood pressures (SBP = systolic and DBP = diastolic) were recorded following exercise (E = 50 min @ 50% VO2 max) and during a non-exercise control day (C). The 24-h pressures were compared between the E and C days for (1) duration and magnitude of the BP reduction following exercise, and for (2) the time of day for the diurnal patterns to exhibit reductions in BP. No BP differences were found for N between E and C days. Significant reductions in BP were found for 24-h average SBP (decrease 6.8 mm Hg) and DBP (decrease 4.1 mm Hg), daytime (06.00-22.00 hrs) SBP (decrease 6.9 mm Hg) and DBP (decrease 3.3 mm Hg), and sleep (22.00-06.00) SBP (decrease 5.1 mm Hg) and DBP (decrease 4.4 mm Hg) for H subjects only. H also demonstrated an 11 h reduction in SBP (chi = decrease 8.3+/-2.2 mm Hg) and 4h reduction in DBP (chi = decrease 6.0+/-1.7 mm Hg) following exercise. For the diurnal variation, the peak interval of reduction in SBP (chi = 17.0+/-2.6 mm Hg) was for 11 h; from 11.00-21.00 hrs. For DBP, a significant reduction (chi = decrease 5.7+/-0.7 mm Hg) was found for 5 h; from 11.00-15.00 h. Thus, exercise reduces both systolic and diastolic BP for a significant length of time postexercise as well as reduces pressures during the time of day that typically exhibits higher diurnal pressures.