Effect of alcohol abstinence on blood pressure: assessment by 24-hour ambulatory blood pressure monitoring

Several studies have shown that cessation of alcohol drinking reduces blood pressure (BP). However, attempts to reproduce these findings by ambulatory BP monitoring (ABPM) have shown inconsistent results. The aim of the present study was to assess the effect of 1 month of proven abstinence from alcohol on the 24-hour BP profile in heavy alcohol drinkers. Forty-two men who were heavy drinkers (>100 g of pure ethanol per day) were consecutively admitted to a general ward for voluntary alcohol detoxification. On the day of admission, they received a total dose of 2 g/kg of ethanol diluted in orange juice in 5 divided doses, and a 24-hour ABPM was performed. A new 24-hour BP monitoring in the same environmental conditions was performed after 1 month of proven alcohol abstinence while the subjects were receiving the same amount of fluid but without the addition of alcohol. After 1 month of proven alcohol abstinence, BP and heart rate (HR) significantly decreased. The reduction was 7.2 mm Hg for 24-hour systolic BP (SBP) (95% CI, 4.5 to 9.9), 6.6 mm Hg for 24-hour diastolic BP (DBP) (95% CI, 4.2 to 9.0), and 7.9 bpm for HR (95% CI, 5.1 to 10.7). The proportion of alcoholic patients considered hypertensive on the basis of 24-hour BP criteria (daytime SBP >/=135 mm Hg or daytime DBP >/=85 mm Hg) fell from 42% during alcohol drinking to 12% after 1 month of complete abstinence. Abstinence did not modify either the long-term BP variability, assessed by SD of 24-hour BP, or its circadian profile. We conclude that abstinence in heavy alcohol drinkers significantly reduces BP assessed by 24-hour ABPM and that this reduction is clinically relevant. These results show that heavy alcohol consumption has an important effect on BP, and thus cessation of alcohol consumption must be recommended as a priority for hypertensive alcohol drinkers.     

Ambulatory blood pressure characteristics in normotensive and treated hypertensive older people

The objective of this study was to determine the normal values and characteristics of 24-h ambulatory blood pressure (ABP) and to describe the ABP level of treated hypertensive subjects in an older Finnish population. ABP was measured in 502 randomly selected subjects aged 64 years or over living in a Finnish municipality (mean age 70 years, range 64-87 years). A total of 211 subjects did not have blood pressure (BP) affecting medication. ABP measurements were taken every 30 min for 24 h, and the day- and night-time periods were diary-based. The results were that in untreated subjects, the average office BP was 134/82 +/- 16/9 (s.d.) mm Hg for men and 140/81 +/- 18/8 mm Hg for women. The 24-h average BP was 120/75 +/- 14/8 mm Hg (95th percentile upper limit 145/93 mm Hg) for men and 125/75 +/- 15/7 (95th = 154/89 mm Hg) for women. The daytime averages were 127/78 +/- 12/7 mm Hg (95th = 154/99 mm Hg) and 131/78 +/- 15/7 mm Hg (95th = 158/91 mm Hg) for men and women, respectively. The ABP daytime value of 130/83 mm Hg corresponded best to the office BP value of 140/90 mm Hg. All BP values were significantly higher in the treated hypertensive group compared to the normotensive group. Night-time BP was markedly lower than daytime BP, and no difference in circadian variability was found between the normotensive and hypertensive subjects. Both office and ambulatory BPs were significantly higher in women than in men. This study provides sex-specific normal values for ABP in a 64 to 87-year-old age group. The normal values of ABP were markedly lower than the office BP values. Hypertensives, even when treated, tended to have elevated values.     

老老年人群动态血压参数与动脉僵硬度的相关性

目的探讨老老年人群动态血压参数与动脉僵硬度的相关性。方法筛选年龄≥80岁的老老年人238例,以血压≥160/95 mm Hg(1 mm Hg=0.133 kPa)为标准,分为高血压组(134例)和对照组(104例),并进行臂-踝脉搏传导速度(baPWV)和24 h动态血压监测。用Pearson分析动态血压各参数与动脉僵硬度的相关性。结果高血压组baPWV高于对照组(P<0.05)。高血压组偶测收缩压,24 h、昼间和夜间收缩压、舒张压、脉压,收缩压负荷及舒张压负荷均高于对照组.夜间收缩压下降率、舒张压下降率低于对照组,差异有统计学意义(P<0.05,P<0.01)。baPWV与偶测血压;24 h收缩压、舒张压、脉压;昼间收缩压、舒张压、脉压、心率;夜间收缩压、舒张压、脉压;收缩压负荷、舒张压负荷呈正相关(P<0.05,P<0.01),而与夜间收缩压下降率呈负相关(P<0.01)。结论高血压是老老年人群动脉僵硬度增加的一个重要因素,动脉僵硬度与动态血压、脉压、心率及血压负荷相关。     

Sex, cardiac hypertrophy and diurnal blood pressure variations in essential hypertension.

OBJECTIVE: To test the hypothesis of a difference between men and women in the left ventricular hypertrophic response to diurnal variations of ambulatory blood pressure in essential hypertension. DESIGN: Non-invasive ambulatory blood pressure monitoring and echocardiography in untreated hypertensive patients and healthy normotensive subjects. SETTING: Community-based ambulatory population in tertiary care centers. PATIENTS: Two hundred and sixty hypertensive patients and sixty-three healthy normotensive subjects. MAIN OUTCOME MEASURE: Patients with average daytime systolic blood pressure (SBP) and diastolic blood pressure (DBP) falling by less than 10% during the night were defined as non-dippers, the others as dippers. RESULTS: In the hypertensive group, dippers and non-dippers did not differ, in either gender, in several covariates possibly affecting left ventricular structure, including daytime ambulatory blood pressure, prevalence of white coat hypertension, age, body mass index, family history and known duration of hypertension, funduscopic changes, diabetes, alcohol consumption and renal function. Left ventricular mass (LVM) did not differ between dippers and non-dippers in hypertensive men whilst in hypertensive women it was significantly lower in dippers than in non-dippers. This sex difference held for all quartiles of the distribution of mean daytime blood pressure. In hypertensive women there was an inverse correlation between LVM and the per cent reduction of SBP and DBP from day to night, but this relationship was absent in hypertensive men. Other indices of left ventricular structure differed between dippers and non-dippers in both genders, as did LVM. CONCLUSIONS: For any level of daytime ambulatory blood pressure, a reduction of SBP and DBP by less than 10% from day to night identifies a subset of hypertensive patients at increased risk of left ventricular hypertrophy only in the female gender. These data suggest that, compared with men, hypertensive women require a longer duration of exposure to high blood pressure levels during the 24 h to develop left ventricular hypertrophy.     

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.     

Effects of the renin inhibitor MK-8141 (ACT-077825) in patients with hypertension

The renin inhibitor MK-8141 (ACT-077825) demonstrates substantial immunoreactive active renin (ir-AR) increase (sevenfold) without a persistent plasma renin activity (PRA) decrease. The present study assessed the antihypertensive efficacy of MK-8141 in hypertensive patients. In this double-blind, placebo- and active comparator-controlled study, 195 patients with hypertension (trough sitting diastolic blood pressure ≥92 to <105 mm Hg, trough sitting systolic blood pressure <170 mm Hg, and 24-hour mean diastolic blood pressure [DBP] ≥80 mm Hg) were randomized to one of four treatments (stratified by race, black versus others): MK-8141 250 mg, MK-8141 500 mg, enalapril 20 mg, or placebo. Blood pressure was measured at trough and as 24-hour ambulatory blood pressure monitoring. The primary end point was change from baseline in 24-hour mean ambulatory DBP measured after 4 weeks. At week 4, the change from baseline in 24-hour mean (95% CI) ambulatory DBP compared with placebo was ?1.6 mm Hg (?4.2, 1.1), ?1.1 mm Hg (?3.9, 1.6), and ?4.9 (?7.5, ?2.2) for MK-8141 250 mg, MK-8141 500 mg, and enalapril 20 mg, respectively. Only mean ambulatory DBP-lowering with enalapril 20 mg was statistically significant. Enalapril, but not MK-8141, also significantly lowered 24-hour mean ambulatory systolic blood pressure (SBP) compared with placebo (?6.7 mm Hg [?10.5, ?2.8]). Neither enalapril nor MK-8141 significantly lowered trough DBP and SBP compared with placebo. MK-8141 was generally well tolerated. In patients with hypertension, MK-8141 (ACT-077825) did not produce significant blood pressure–lowering efficacy despite a demonstrated effect of the drug on ir-AR, in the absence of durable PRA suppression.     

Quantitative study of circadian variations of ambulatory blood pressure in Chinese healthy, hypertensive, and diabetes subjects

Ambulatory blood pressure monitoring (ABPM) recorded abundant data of BP and heart rate (HR) variations with even more derived parameters for evaluation of BP. Using our ABP database system established recently, we studied quantitatively the data of 24-hr ABP in Chinese. First, 155 Chinese were divided into three groups: 50 healthy subjects (C) of 20 men and 30 women, aged 60.0 +/- 10.3 (SD) years; 58 hypertensive patients (H, mild or moderate hypertension) of 33 men and 25 women, aged 59.4 +/- 8.0 years; 47 diabetes patients (D, type 2 diabetes, all were normotensive and with no insulin treatment) with 28 men and 19 women, aged 61.0 +/- 8.5 years. Then 24-hr ABP was monitored by TM-2421 Monitor and data were analyzed by ABP database, cosinor method, and conventional statistics. Our results were 4-fold: 1) systolic BP (SBP), diastolic BP (DBP), HR, rate-pressure product (HR x SBP) showed circadian variations, and significant circadian rhythms were confirmed by cosinor method in all groups. MESOR (midline estimate statistic of rhythm) differed significantly among three groups (H had the highest and C had the lowest values); 2) BP means (SBP, DBP, pulse pressure [PP], and HR x SBP) and BP loads (SBP, DBP, and PP) showed significant differences among the groups (H and D had higher values than that of C); 3) there were no significant differences of BP variability (BPV) of SBP, DBP, and PP among the groups; 4) areas under curve of BP (SBP, DBP, and PP) in H were significantly higher than in C and there was no significant difference between H and D. We concluded that ABPM can offer abundant information on BP evaluation by its direct recording data and derived parameters. The computerized way of treating the large numbers of ABPM values supplies a useful tool in evaluation of BP. Our results suggest that clinically normotensive diabetes patients had some pathological alterations in their BP systems.     

Quantitative Study of Circadian Variations of Ambulatory Blood Pressure in Chinese Healthy,Hypertensive, and Diabetes Subjects

Ambulatory blood pressure monitoring (ABPM) recorded abundant data of BP and heart rate (HR) variations with even more derived parameters for evaluation of BP. Using our ABP database system established recently, we studied quantitatively the data of 24-hr ABP in Chinese. First, 155 Chinese were divided into three groups: 50 healthy subjects (C) of 20 men and 30 women, aged 60.0 ± 10.3 (SD) years; 58 hypertensive patients (H, mild or moderate hypertension) of 33 men and 25 women, aged 59.4 ± 8.0 years; 47 diabetes patients (D, type 2 diabetes, all were normotensive and with no insulin treatment) with 28 men and 19 women, aged 61.0 ± 8.5 years. Then 24-hr ABP was monitored by TM-2421 Monitor and data were analyzed by ABP database, cosinor method, and conventional statistics. Our results were 4-fold: 1) systolic BP (SBP), diastolic BP (DBP), HR, rate-pressure product (HR × SBP) showed circadian variations, and significant circadian rhythms were confirmed by cosinor method in all groups. MESOR (midline estimate statistic of rhythm) differed significantly among three groups (H had the highest and C had the lowest values); 2) BP means (SBP, DBP, pulse pressure [PP], and HR × SBP) and BP loads (SBP, DBP, and PP) showed significant differences among the groups (H and D had higher values than that of C); 3) there were no significant differences of BP variability (BPV) of SBP, DBP, and PP among the groups; 4) areas under curve of BP (SBP, DBP, and PP) in H were significantly higher than in C and there was no significant difference between H and D. We concluded that ABPM can offer abundant information on BP evaluation by its direct recording data and derived parameters. The computerized way of treating the large numbers of ABPM values supplies a useful tool in evaluation of BP. Our results suggest that clinically normotensive diabetes patients had some pathological alterations in their BP systems.     

High heritability of ambulatory blood pressure in families of East African descent

We estimated the heritability of ambulatory systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP) in east African families with at least 2 hypertensive siblings and living in the Seychelles islands (Indian Ocean). The sample consisted of 314 individuals (147 men and 167 women), both normotensive and hypertensive, from 76 pedigrees (mean+/-SD of 4.1+/-2.8 persons per pedigree). After a 2-week off-treatment period, daytime and nighttime ambulatory blood pressure (BP) was monitored. Office BP was measured with a standard mercury sphygmomanometer. We estimated by maximum likelihood the age- and sex-adjusted heritabilities from the additive polygenic component of the variance of the traits allowing for the presence of other familial correlations. We also adjusted for ascertainment (ie, for the fact that 2 siblings had to be hypertensive) and examined the effect of adjusting for body mass index, 24-hour urinary excretion of sodium and potassium, plasma renin activity, and plasma aldosterone concentration. Heritability estimates (+/-SE) for ambulatory SBP, DBP, and PP were, respectively, 0.37+/-0.12/0.24+/-0.12/0.54+/-0.12 for daytime and 0.34+/-0.13/ 0.37+/-0.15/0.47+/-0.12 for nighttime measurements (P<0.05 for all estimates). Heritability estimates for office SBP, DBP, and PP were, respectively, 0.20+/-0.11, 0.05+/-0.09, and 0.37+/-0.12. Heritability estimates for SBP varied markedly according to whether participants were treated for hypertension at baseline. The present data show that ambulatory BP and PP have a high heritability in families of African descent. They also demonstrate that antihypertensive treatment and the number of BP measurements have a major influence on the heritability estimates.     

动态血压均值及脉压在评估原发性高血压早期肾损害中的临床研究

目的探讨动态血压均值及动态脉压与微量蛋白尿的关系,以期为动态血压监测(ABPM)应用于早期诊断和评价高血压性肾损害提供科学依据。方法将原发性高血压患者125例按动态脉压(24 h PP)≤40 mm Hg(1mm Hg=0.133 kPa)、41～55 mm Hg、56～70 mm Hg、>70 mm Hg分为Ⅰ、Ⅱ、Ⅲ、Ⅳ组,测量24 h 平均收缩压(24h SBP)、24 h 平均舒张压(24 h DBP)、24 h PP、尿微量白蛋白(mA1b)及尿 N-乙酰-β-D-氨基葡萄糖苷酶(NAG),比较各组的尿 mA1b、NAG 检测值及其阳性率,进行24 h SBP、24 h DBP、24 h PP 与尿 mA1b、NAG 的相关回归分析。结果 (1)Ⅰ组与Ⅱ组之间,尿 mA1b、NAG 及微量蛋白尿阳性率差异无统计学意义(P>0.05),Ⅱ组、Ⅲ组与Ⅳ组随24 h PP 的增高,尿 mA1b、NAG 及微量蛋白尿阳性率均依次明显增高,各组间差异有统计学意义(P<0.05);(2)24 h PP、24 h SBP 与尿 mA1b、NAG 呈正相关(r=0.79、0.78、0.78、0.76,P<0.05),24 h DBP 与mA1b、NAG 呈负相关(r=0.64、-0.65,P<0.05);建立多元回归方程得出高血压早期肾损害时对应的24 hSBP、24 h DBP 及24 h PP 值分别为150 mm Hg、91 mm Hg、58 mm Hg。结论动态血压均值及动态脉压可为原发性高血压患者早期肾损害的检测评价指标,24 h SBP 高于150 mm Hg、24 h PP 高于58 mm Hg,24 h DBP 过度下降的患者为高血压性肾损害高危患者。     

Stroke risk in systolic and combined systolic and diastolic hypertension determined using ambulatory blood pressure. The Ohasama study

BACKGROUND: To investigate the risk of stroke in subjects with isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and combined systolic and diastolic hypertension (SDH) in a Japanese general population, we used 24-h ambulatory blood pressure (ABP) and casual-screening blood-pressure (CBP) readings. METHODS: Subtypes of hypertension were defined based on systolic blood pressure (SBP) >135 mm Hg or diastolic blood pressure (DBP) >80 mm Hg for 24-h ABP, and SBP >140 mm Hg or DBP >90 mm Hg for CBP. We obtained 24-h ABP and CBP data for 1271 (40% male) subjects aged > or =40 years (mean age, 61 years) without a history of symptomatic stroke; their stroke-free survival was then determined. The prognostic significance of each subtype of hypertension was determined by Cox proportional hazard analysis. RESULTS: There were 113 symptomatic strokes during follow-up (mean time, 11 years). Compared with normotension, among the hypertension subtypes determined by 24-h ABP, the adjusted relative hazards (RHs) of stroke were 2.24 for ISH (P = .002) and 2.39 for SDH (P = .0004). The association was less marked among subtypes determined by CBP (RH = 1.40 and P = .13 for ISH; RH = 2.07 and P = .017 for SDH). The IDH group was excluded from the Cox analysis because both the prevalence and the number of events were low in this group. CONCLUSIONS: Isolated systolic hypertension, as determined by 24-h ABP measurements, was associated with a high risk of stroke, similar to that found in SDH subjects; this suggests that the prognosis of hypertensive patients would be improved by focusing treatment on 24-h systolic ABP.     

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.     

Comparison between casual blood pressure and ambulatory blood pressure monitoring parameters in healthy and hypertensive adolescents

Casual blood pressure measurements were compared with mean ambulatory blood pressure values during wakefulness and sleep in 45 normotensive and 30 hypertensive adolescents of both sexes aged 10-18 years. Two sets of auscultatory casual blood pressure were obtained, one in a pediatric office setting (office blood pressure), performed by the physician, and one in the ambulatory blood pressure monitoring (ABPM) unit, performed by a trained nurse, prior to the initiation of ABPM (pre-ABPM blood pressure). In normotensive and hypertensive subjects of both sexes, the mean office systolic blood pressure (SBP) was lower than the mean pre-ABPM SBP, and the mean office diastolic blood pressure (DBP) was lower than the mean pre-ABPM DBP. In normotensive participants, the mean pre-ABPM SBP/DBP was lower than the mean ABPM SBP/DBP while awake, the mean ABPM SBP/DBP during sleep being lower than the mean ABPM SBP/DBP values while awake and the mean pre-ABPM SBP/DBP. No statistical difference was demonstrated between the mean office SBP and the mean ABPM SBP during sleep, the mean ABPM DBP during sleep being lower than the mean office DBP. The hypertensive adolescents presented a blood pressure profile similar to that of the normotensive group, albeit shifted upwards, with no significant difference between the mean pre-ABPM SBP and the mean ABPM SBP while awake but a higher mean pre-ABPM DBP than mean ABPM DBP while awake. This study suggests that, by evaluating the casual blood pressure in different environment/observer situations, the power of casual blood pressure to predict inadequate blood pressure control, manifested as abnormal ABPM parameters, can be enhanced. Our data indicate ABPM to be the method of choice for the early diagnosis and adequate follow-up of adolescent hypertension.     

Effect of dietary patterns on ambulatory blood pressure : results from the Dietary Approaches to Stop Hypertension (DASH) Trial. DASH Collaborative Research Group.

We measured ambulatory blood pressure (ABP) in 354 participants in the Dietary Approaches to Stop Hypertension (DASH) Trial to determine the effect of dietary treatment on ABP (24-hour, day and night) and to assess participants' acceptance of and compliance with the ABP monitoring (ABPM) technique. After a 3-week run-in period on a control "typical" American diet, subjects (diastolic blood pressure [BP], 80 to 95 mm Hg; systolic BP, <160 mm Hg; mean age, 45 years) were randomly assigned to 1 of 3 diets for an 8-week intervention period: a continuation of the control diet; a diet rich in fruits and vegetables; and a "combination" diet that emphasized fruits, vegetables, and low-fat dairy products. We measured ABP at the end of the run-in and intervention periods. Both the fruit/vegetable and combination diets lowered 24-hour ABP significantly compared with the control diet (P<0. 0001 for systolic and diastolic pressures on both diets: control diet, -0.2/+0.1 mm Hg; fruit/vegetable diet, -3.2/-1.9 mm Hg; combination diet, -4.6/-2. 6 mm Hg). The combination diet lowered pressure during both day and night. Hypertensive subjects had a significantly greater response than normotensives to the combination diet (24-hour ABP, -10.1/-5.5 versus -2.3/-1.6 mm Hg, respectively). After correction for the control diet responses, the magnitude of BP lowering was not significantly different whether measured by ABPM or random-zero sphygmomanometry. Participant acceptance of ABPM was excellent: only 1 participant refused to wear the ABP monitor, and 7 subjects (2%) provided incomplete recordings. These results demonstrate that the DASH combination diet provides significant round-the-clock reduction in BP, especially in hypertensive participants.     

Associations between reactive oxygen species, blood pressure and arterial stiffness in black South Africans: the SABPA study

Many mechanisms, including oxidative stress, contribute to hypertension. This study investigated the possible associations between oxidative stress, blood pressure and arterial stiffness in black South Africans. Ambulatory blood pressure measurements were taken for 101 black South African men and 99 women. The stiffness indices included ambulatory arterial stiffness index (AASI) and pulse pressure (PP). Reactive oxygen species (ROS) levels (P<0.0001) were higher in the African women compared with men. ROS levels were also higher in hypertensive compared with normotensive men. The 24?h systolic blood pressure (SBP; P<0.01), 24?h diastolic blood pressure (DBP; P<0.0001) and pulse wave velocity (PWV; P<0.01) were significantly higher in African men compared with women. There were unadjusted positive associations of 24?h SBP (r=0.33; P=0.001), 24?h DBP (r=0.26; P=0.008) and 24?h PP (r=0.29; P=0.003) with ROS in African men only. A positive association between AASI and ROS existed only in hypertensive men (r=0.27; P=0.035), but became nonsignificant (B=0.0014; P=0.14) after adjustments. Adjusted, positive associations of 24?h SBP (B=0.181; P=0.018) and 24?h PP (B=0.086; P=0.050) with ROS were again only evident in African men. ROS is positively associated with SBP and PP in African men, suggesting that increased ROS levels may contribute to hypertension in this population group.     

Determinants of blood pressure response to low-salt intake in a healthy adult population

Although the beneficial effects of lowering salt intake in hypertensive patients are widely appreciated, the impact of promoting dietary salt restriction for blood pressure (BP) reduction at the population level remains controversial. The authors used 24-hour ambulatory BP monitoring to characterize the determinants of systolic BP (SBP) response to low-salt intake in a large, relatively healthy Amish population. Patients received a high- and low-sodium diet for 6 days each, separated by a 6- to 14-day washout period. Variance component analysis was used to assess the association of several variables with SBP response to low-salt diet. Mean SBP was 0.7 ± 5.8 mm Hg and 1.3 ± 6.1 mm Hg lower on the low-salt compared with the high-salt diet during daytime (P=.008) and nighttime (P<.0001), respectively. SBP response to a low-salt diet was significantly associated with increasing age and pre-intervention SBP, in both daytime and nighttime, while the association with female sex and SBP response to cold pressor test (CPT) was significant only during nighttime. Our results suggest that salt reduction may have greater BP-lowering effects on women, older individuals, individuals with higher SBP, and individuals with higher SBP response to CPT.     

Trends in the prevalence of isolated systolic hypertension in the middle-aged population in 1972-1992.

We described the trends in the prevalence of isolated systolic hypertension during 1972 to 1992 in five independent population-based cross-sectional random samples in eastern Finland. A total of 15,155 men and 16,126 women aged 30-59 in 1972 and 30-64 years during 1977 to 1992 were included in this study. Standardised methods and measurements of the first screening blood pressure value were used, the size of the cuff bladder changed between 1977 and 1982. We defined isolated systolic hypertension as systolic blood pressure (SBP) > or =160 mm Hg and diastolic blood pressure (DBP) <95 mm Hg and diastolic hypertension as DBP > or =95 mm Hg. The normotensive group comprised subjects whose SBP <160 mm Hg and DBP <95 mm Hg. Subjects on antihypertensive medication were classified as having diastolic hypertension. The prevalence of isolated systolic hypertension increased in both sexes and in all age groups except among the youngest women, whereas the prevalence of diastolic hypertension decreased. The proportion of subjects with isolated systolic hypertension out of all hypertensive subjects increased from 11% in 1972 to 24% in 1992 among men and from 15% to 27% among women. The overall decrease in blood pressure, particularly the disproportionate decrease in diastolic over systolic blood in mean pressure may have resulted in the increase in the prevalence of isolated systolic hypertension.     

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.     

Rapid left ventricular filling in untreated hypertensive subjects with or without left ventricular hypertrophy.

In this study, independent contribution of age, HR, BMI, casual and ambulatory blood pressure, LVM and LVEF in evaluating diastolic filling have been investigated in 34 never-treated hypertensive patients and in 15 healthy normotensive subjects. All the subjects were free from coronary artery disease, valvular disease, heart failure, renal disease and psychiatric problems. All the hypertensive subjects (never treated) were subgrouped according to presence or absence of LVH. The PFR decreased significantly and tPFR increased significantly in hypertensive patients in comparison with normotensive subjects and they did not change in the presence vs absence of LVH. The PFR was inversely correlated with BMI, age, 24-h mean SBP and with 24-h DBP. In multiple regression analysis, PFR decreased with BMI, age, 24-h mean SBP and DBP but not with LVMI. These results suggest that BMI, age and 24-h mean blood pressure were the major determinants of PFR abnormalities in hypertensive patients.     

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.