Clinical Implications of White Coat Hypertension

Objective: To determine the clinical implications of mild white coat hypertension (WCH).

Subjects and methods: We studied 102 subjects (54 men, 48 women). 51 of whom were normotensive and 51 slightly hypertensive. None had ever received antihypertensive therapy. An ambulatory blood pressure (ABP) record (Accutracker II), a 24-h electrocardiogram and an echocardiogram were obtained from each, and each was examined by funduscopy. WCH subjects were compared with sustained hypertension (SH) subjects and with normotensives.

Results: Fifty-three percent of the hypertensives qualified as WCH. The ultrasonographic characteristics and the ABP variables of the WCH group differed significantly from those of normotensives, but not from those of the SH group. The prevalence of left ventricilar hypertrophy (LVH) in the SH group (62.5%) did not differ significantly from its prevalence in the WCH group (40.7%). but the prevalence among normotensives (17.6%) was significantly lower than in either of the other two groups. The WCH and SH groups did not differ significantly as regards the prevalence of hypertensive retinopathy (33.3%) in the former, 58.3% in the latter). For no non-LVH, nonretinopathic subject, whether norniotensive or hypertensive, were more than 18% of daytime diastolic ABP measurements ≥90mmHg. Ultrasonographic findings were no better correlated with ABP than with in-clinic BP measurements. Fundus findings correlated well with in-clinic BP and with numerous ABP parameters. Retinopathy, with or without LVH, was efficiently predictable among hypertensives on the basis of body mass index and the 24-h maximum of systolic BP.

Conclusions: Myocardiac remodelling and vascular retinopathy develop early and in parallel in hypertensives, and both developments appear to involve determinants including body mass index and 24-h maximum systolic BP. WCH subjects, as defined by current ABP-based criteria, have cardiac and retinovascular Characteristics different to normotensive subjects. Stricter criteria are needed to discriminate between hypertensives with and without the systemic developments that constitute the immediate source of risk to the hypertensive individual.     

Association of office and ambulatory blood pressure with blood lead in workers before occupational exposure

In view of decreasing lead exposure and guidelines endorsing ambulatory above office blood pressure (BP) measurement, we reassessed association of BP with blood lead (BL) in 236 newly employed men (mean age, 28.6 years) without previous lead exposure not treated for hypertension. Office BP was the mean of five auscultatory readings at one visit. Twenty-four-hour BP was recorded at 15- and 30-minute intervals during wakefulness and sleep. BL was determined by inductively coupled plasma mass spectrometry. Systolic/diastolic office BP averaged 120.0/80.7 mm Hg, and the 24-hour, awake, and asleep BP 125.5/73.6, 129.3/77.9, and 117.6/65.0 mm Hg, respectively. The geometric mean of blood lead was 4.5 μg/dL (interquartile range, 2.60–9.15 μg/dL). In multivariable-adjusted analyses, effect sizes associated with BL doubling were 0.79/0.87 mm Hg (P = .11/.043) for office BP and 0.29/?0.25, 0.60/?0.10, and ?0.40/?0.43 mm Hg for 24-hour, awake, and asleep BP (P ≥ .33). Neither office nor 24-hour ambulatory hypertension was related to BL (P ≥ .14). A clinically relevant white coat effect (WCE; office minus awake BP, ≥20/≥10 mm Hg) was attributable to exceeding the systolic or diastolic threshold in 1 and 45 workers, respectively. With BL doubling, the systolic/diastolic WCE increased by 0.20/0.97 mm Hg (P = .57/.046). Accounting for the presence of a diastolic WCE, reduced the association size of office diastolic BP with BL to 0.39 mm Hg (95% confidence interval, ?0.20 to 1.33; P = .15). In conclusion, a cross-sectional analysis of newly hired workers before lead exposure identified the WCE as confounder of the association between office BP and BL and did not reveal any association between ambulatory BP and BL.     

Orienting-Defense Responses and Psychophysiological Reactivity in Isolated Clinic versus Sustained Hypertension

This study sought to determine whether patients with white-coat or isolated clinic hypertension (ICH) show, in comparison to patients with sustained hypertension (SH), a defense response pattern to novel stimuli and an enhanced psychophysiological reactivity to stress. Forty-three patients with essential hypertension were divided into two groups after 16 days of self-monitoring blood pressure (BP): ICH (24 men; self-measured BP < 135/85 mmHg) and SH (19 men; self-measured BP ≥ 135/85 mmHg). Defense responses were measured as the cardiac changes to phasic non-aversive auditory stimuli. Psychophysiological reactivity (heart and breath rate, blood volume pulse, electromyography, and skin conductance) was measured during mental arithmetic and video game tasks. The standard deviation of self-measured BPs and the difference between mean BPs at work and at home were used as indicators of cardiovascular reactivity to daily stress. No significant differences were seen in defense responses or psychophysiological reactivity to laboratory or naturally occurring stressors. These results do not support the hypothesis that ICH can be explained in terms of a generalized hyperreactivity to novel or stressful stimuli.     

Atrial Electromechanical Coupling Interval and P-Wave Dispersion in Patients With White Coat Hypertension

Background. The aim of our study was to investigate the effect of white coat hypertension (WCH) to atrial conduction abnormalities by electrocardiographic P-wave analysis and echocardiographic electromechanical coupling (EMC) interval measurement. Methods. The study consisted of sex-, age-, and body mass index-matched 24 patients with WCH, 24 patients with sustained hypertension (SH), and 24 subjects with normotension (NT). The difference between the maximum (Pmax) and minimum P-wave durations on 12-lead electrocardiography was defined as P-wave dispersion (PD). Intra- and inter-atrial EMC were measured by tissue Doppler imaging. Results. Pmax and PD of subjects with WCH were significantly higher than those of normotensives and lower than those of patients with SH. Inter-atrial EMC and left atrial EMC values of WCH group were intermediate between NT and SH groups. There was a significant correlation between left atrial diameter, PD, Pmax, left ventricle mass index, left atrial EMC, and inter-atrial EMC. Conclusion. White coat hypertension is an intermediate group between SH and NT in terms of atrial electromechanical abnormalities which may be associated with the risk of atrial fibrillation.     

Role of Prolactin in Pregnancy Hypertension

In 51 patients with pregnancy hypertension (H) and 51 normotensive gravid women (N), matched for age of gestation, plasma prolactin was measured at 8.30 am (PRL1) and 9.30 am (PRL2) in basal conditions and after 10 minutes of upright posture (PRL3). While in N there was a fall from PRL1 to PRL2 which was nonsignificant, in H there was a significant fall from PRL1 to PRL2. With upright posture there was a further decrease in prolactin in N and a significant increase in H. With multiple regression analysis, systolic and diastolic blood pressure did not show any independent relations with PRLl, PRL2 and PRL3, while serum proteins and proteinuria showed a significant relation with PFU1, as did serum proteins, serum potassium and serum urate with PRL2 and serum urate with PRL3. As has been suggested in primary hypertension, a certain increase in peripheral sympathetic tone, dependent on a decreased central dopaminergic activity, may be present in patients who develop pregnancy hypertension compared to normotensive pregnant controls and may be involved in the pathogenesis of pregnancy hypertension.

Preliminary results have been presented at the “16th Congress of the Society for the Study of Pathophysiology of Pregnancy-Organisation Gestosis”-Aachen, Germany, June 1984.     

白大衣高血压患者的血小板功能

目的:探讨白大衣高血压(WCH)患者的血小板功能.方法:选初诊的原发性高血压(EH)患者、 WCH 患者、正常血压(NT)者各35例,通过诊室血压测量和24 h动态血压监测,同时测定并比较3组血小板最大聚集率(PAGTmax)、血浆血小板α-颗粒膜蛋白(GMP-140)含量、平均血小板容积(MPV) 、血小板数量的变化.结果:和NT对照组相比,EH组和WCH组 PAGTmax、血浆血小板GMP-140含量、MPV均明显增加(P<0.05)而三组血小板计数无统计学差异,同时EH组的PAGTmax、血浆血小板GMP-140含量、MPV均高于WCH组(P<0.05).EH组和WCH组MPV与24 h平均舒张压、GMP-140含量均正相关( P<0.05).结论:WCH存在血小板活化,可能和心血管事件发生率增加有关.     

Diagnosis of hypertension: Ambulatory pediatric American Heart Association/European Society of Hypertension versus blood pressure load thresholds

The agreement between the traditionally‐used ambulatory blood pressure (ABP)‐load thresholds in children and recently‐recommended pediatric American Heart Association (AHA)/European Society of Hypertension (ESH) ABP thresholds for diagnosing ambulatory hypertension (AH), white coat hypertension (WCH), and masked hypertension (MH) has not been evaluated. In this cross‐sectional study on 450 outpatient participants, the authors evaluated the agreement between previously used ABP‐load 25%, 30%, 40%, 50% thresholds and the AHA/ESH thresholds for diagnosing AH, WCH, and MH. The American Academy of Pediatrics thresholds were used to diagnose office hypertension. The AHA threshold diagnosed ambulatory normotension/hypertension closest to ABP load 50% in 88% (95% CI 0.79, 0.96) participants (k 0.67, 95% CI 0.59, 0.75) and the ESH threshold diagnosed ambulatory normotension/hypertension closest to ABP load 40% in 86% (95% CI 0.77, 0.94) participants (k 0.66, 95% CI 0.59, 0.74). In contrast, the AHA/ESH thresholds had a relatively weaker agreement with ABP load 25%/30%. Therefore, the diagnosis of AH was closest between the AHA threshold and ABP load 50% (difference 3%, 95% CI ‐2.6%, 8.6%, p = .29) and between the ESH threshold and ABP load 40% (difference 4%, 95% CI ‐2.1%, 10.1%, p = .19) than between the AHA/ESH and ABP load 25%/30% thresholds. A similar agreement pattern persisted between the AHA/ESH and various ABP load thresholds for diagnosing WCH and MH. The AHA and ESH thresholds diagnosed AH, WCH, and MH closest to ABP load 40%/50% than ABP load 25%/30%. Future outcome‐based studies are needed to guide the optimal use of these ABP thresholds in clinical practice.     

Investigation of Major Genetic Polymorphisms in the Renin-Angiotensin-Aldosterone System in Subjects with Young-Onset Hypertension Selected by a Targeted-Screening System at University

Although polymorphisms in renin-angiotensin-aldosterone (RAA) system genes for angiotensinogen (AGT M235T), angiotensin-converting enzyme (ACE I/D), angiotensin II type 1 receptor (AT1 A/C¹¹⁶⁶), and aldosterone synthase (CYP11B2–344T/C) have been major targets for genetic investigation in association with essential hypertension (EH), the influence of these genetic factors is still to be determined. Because patients with young-onset EH are thought to possess a stronger genetic background than EH patients who show elevated BP relatively late in life, the targeted screening of hypertensive students in Tohoku University was completed for the selection of subjects for genetic investigation. Out of 16,434 students (12,794 males and 3,670 females) younger than 30, 22 students showed a high blood pressure (BP) (systolic and diastolic BP of 140 and/or 90 mmHg or greater, respectively, on two occasions and more than 135 and/or 85 mmHg, respectively, at a third measurement during casual BP measurements at the Tohoku University Health Center. These 22 students were asked to measure their BP at home (HBP). Six of the students had a systolic HBP of more than 135 mmHg and/or a diastolic HBP of more than 85 mmHg, and these students subsequently received medical examinations at Tohoku University Hospital and were diagnosed with EH. Genotyping for the four major genetic polymorphisms mentioned above was performed on the six students with EH and on 12 of the remaining 16 students whose HBP was within the normal range (white coat hypertension: WCH). Neither the EH nor the WCH students showed a different distribution of genotypes and allelic frequencies, compared to those found in the general Japanese population. Hence, the present study suggests that none of the major genetic polymorphisms in the RAA system strongly influence the onset of EH.     

Effects of β1-Adrenoceptor Blockade in the Treatment of Hypertension during Pregnancy in Diabetic Women

ABSTRACT The effects of β₁-blockade were investigated in 18 hypertensive pregnant diabetic women. The same women served as controls, covering a period just before therapy. The blood pressure was reduced in 14 women (p<0.01). The change in blood glucose homeostasis was statistically not different from the control period. Insulin doses were not affected. The fetal heart rate was affected by therapy, causing a decrease in baseline rate (p<0.05) and in acceleration amplitude (p<0.05). Although the incidence of suspect fetal distress, intrauterine growth retardation and preterm delivery was high, all surviving infants had normal Apgar scores at 5 and 10 min. Perinatal mortality consisted of one stillbirth. Except for respiratory problems, the incidence of neonatal complications was low. All survivors were healthy at follow-up. We found β₁-blockade to be effective and safe in this group of high-risk pregnancies, and suggest it as an alternative for anti-hypertensive therapy in diabetic pregnancy.     

终止高血压膳食干预糖尿病的研究进展

终止高血压膳食是对于高血压人群有降低血压和降低心血管疾病风险的饮食模式。近年来的研究显示终止高血压膳食同样能使糖尿病人群获益。对于有糖尿病风险的人群,该膳食模式能降低2型糖尿病和妊娠糖尿病的风险,改善胰岛素抵抗及合并糖尿病的高血压患者的血压控制。但目前部分研究的结果还存在一定的争议,需要更多的研究。     

The Concept of The Natriuretic Hormone And Its Relation To Hypertension

Acute volume expansion increases the intrathoracic blood volume thus endowing the plasma with an increased capacity to cause a natriuresis, to inhibit Na-K-ATPase and stimulate vascular reactivity. It is not known whether these changes, which stem from a common stimulus are due to a change in the concentration of one substance or several. It is proposed that in essential hypertension a genetic abnormality of the kidney causes a difficulty in excreting sodium. This leads to an initial blood volume expansion which causes the observed rise in the plasma's capacity to inhibit sodium transport, and to the increased vascular tone. Eventually the increase in tone of the arterial smooth muscle causes the blood pressure to rise, while the increase in tone of the smooth muscle of the veins diminishes venous compliance thus causing a shift of blood from the periphery to the chest thus providing the stimulus for the persistent rise in the plasma's capacity to increase vascular reactivity, even though total blood volume may have returned to normal.     

Relation of maternal blood pressure during pregnancy to birth weight and blood pressure in children. The Hypertension in Pregnancy Offspring Study

Objective . To evaluate the importance of perinatal factors, e.g. low birth weight, reduced gestational period and elevated maternal blood pressure during pregnancy, as well as high maternal blood pressure at follow-up 7–12 years after pregnancy, on blood pressure in children born after normotensive and hypertensive pregnancies. Design . Follow-up study in children from hypertensive pregnancies and a control group of children born after normotensive pregnancies. Setting . University Hospital, Göteborg, Sweden. Subjects . Thirty-six children born after hypertensive pregnancies and a control group of 17 children born after normotensive pregnancies were studied at a mean age of 12.5 years. Main outcome measure . Blood pressure. Results . Systolic blood pressure was higher in children born after hypertensive pregnancies. They also had lower birth weight and a shorter gestational period. There was a negative correlation between the highest recorded maternal blood pressure during pregnancy and birth weight of the child and a positive correlation between maternal blood pressure and blood pressure in their offspring. No correlation was found between birth weight and blood pressure in these children. Conclusions . Children born after hypertensive pregnancies have higher blood pressure compared to children born after normotensive pregnancies. There is a positive relationship between childhood blood pressure and maternal blood pressure during pregnancy.     

The impact of apelin and relaxin plasma levels in masked hypertension and white coat hypertension

Masked hypertension (HTN) and white coat hypertension represent two reverse forms of clinical HTN with questionable prognostic significance. Recent evidence supports that low apelin and relaxin plasma levels contribute to vascular damage accelerating atherogenesis and predisposing to HTN and cardiovascular (CV) events. The aim of this study was to compare apelin and relaxin plasma levels between patients with masked hypertension (MH) and those with white coat HTN (WCH). Overall, 130 patients not receiving antihypertensive therapy were studied. All patients underwent 24‐hour ambulatory BP monitoring (ABPM) and office BP measurements. Plasma apelin and relaxin levels were measured by ELISA method. According to BP recordings, 24 subjects had MH (group A) and 32 had WCH (group B). Apelin (200 ± 111 pg/mL vs 305 ± 127 pg/mL, P < 0.01) and relaxin (35.2 ± 6.7 pg/mL vs 46.8 ± 23.6 pg/mL, P < 0.01) plasma levels were significantly lower in patients with MH compared to those with WCH, respectively. In conclusion, our findings showed that patients with MH had significantly lower apelin and relaxin levels compared to those with WCH. This observation implies an additional prognostic role for adipokines supporting the concept that MH is closer to essential HTN whereas WCH is a more benign condition.     

Evaluation of Once Daily Hydralazine in Inadequately Controlled Hypertension

ABSTRACT. Despite the short plasma half-life of hydralazine, once daily Slow Apresoline has been shown to maintain blood pressure control in well controlled hypertension. In the present investigation of 118 inadequately controlled hypertensives, we have shown that 50–150 mg Slow Apresoline once daily induces a significant blood pressure reduction and is well tolerated. Normotension, i.e. supine diastolic blood pressure <95 mmHg, was reached in 53 % of the patients. Normotension or a supine diastolic blood pressure reduction of ≥10 mmHg was achieved in 72% of the patients, the hydralazine responders. Sixteen patients discontinued treatment due to symptoms probably related to hydralazine. Acetylator phenotyping showed that slow acetylators predominated in the group of patients discontinuing hydralazine due to side-effects. In contrast, 90% of the phenotyped non-responders were rapid acetylators, which suggests a suboptimal use of hydralazine in some rapid acetylators.     

Characteristics of patients with hypertension in a population with type 2 diabetes mellitus. Results from the Turkish Nationwide SurvEy of Glycemic and Other Metabolic Parameters of Patients with Diabetes Mellitus (TEMD Hypertension Study)

BackgroundThe present survey aimed to find out the demographical and clinical characteristics of patients with hypertension in a population with type 2 diabetes mellitus (T2DM) in Turkey.MethodsPatients with T2DM who were followed-up in tertiary endocrine units for at least last one year were recruited. Demographic, clinical and biochemical data of the patients were collected. Hypertension was defined as taking anti-hypertensive medications or having office arterial blood pressure (ABP) ≥140/90 mmHg or home ABP ≥ 130/80 mmHg.ResultsA total of 4756 (58.9% women) diabetic patients were evaluated. The percentage of patients with hypertension was 67.5% (n = 3212). Although 87.4% (n = 2808) of hypertensive patients were under treatment, blood pressure was on target in 52.7% (n = 1479) of patients. Hypertension proportions were higher in woman (p = 0.001), older, more obese, and those who had longer diabetes duration, lower education levels, higher frequency of hypoglycemic events (all p < 0.001) and higher triglyceride levels (p = 0.003). LDL cholesterol level and the percentage of smokers were lower in hypertensive group than in non-hypertensive group (both p < 0.001). The percentage of macro and microvascular complications was higher in the hypertensive group than in the normotensive one (both p < 0.001). In multivariate logistic regression analysis, being a woman (OR: 1.26, 95% CI: 1.04–1.51, p = 0.016), smoking (OR: 1.38, 95% CI: 1.05–1.80, p = 0.020), regular physical activity (OR: 1.24, 95% CI: 1.01–1.53, p = 0.039) and the presence of macrovascular complications (OR: 1.38 95% CI: 1.15–1.65, p = 0.001) were the significant predictors of good ABP regulation. The ratios of masked and white coat hypertension were 41.2% and 5.7%, respectively.ConclusionOur findings indicate that two-thirds (67.5%) of adult patients with T2DM have hypertension. Co-existence of hypertension increases the frequency of macro and microvascular diabetic complications in these patients. Despite the critical role of hypertension in morbidity and mortality, only half of the patients have favorable ABP levels. Masked hypertension seems to be another important issue in this population.     

糖尿病病人中的降压治疗

高血压合并糖尿病是冠心病致死的最危险因素。有效的控制血压可以显著的降低糖尿病病人心血管事件的发病率与死亡率。高血压糖尿病病人的血压控制目标为 <13 0 /80mmHg(1mmHg =0 .13 3 3kPa)。为了达到这一血压水平 ,糖尿病病人的降压治疗包括合理的非药物治疗与药物治疗。在药物治疗中应选用血管紧张素转换酶抑制剂、血管紧张素受体拮抗剂、钙离子拮抗剂和小剂量利尿剂 ,并且注意联合用药     

白大衣高血压研究进展

白大衣高血压是高血压研究领域中的一种特殊现象 ,长期以来未引起足够的重视。随着对其发病机制和靶器官损害等方面研究的深入 ,发现白大衣高血压对机体已存在不良影响。本文就白大衣高血压的诊断标准、产生机制、对靶器官的损害等作一综述。