Daniele Longo

Prevalence and Clinical Significance of Isolated Ambulatory Hypertension in Young Subjects Screened for Stage 1 Hypertension

Little is known about the clinical significance of isolated ambulatory hypertension, a condition characterized by low office but elevated ambulatory blood pressure. This study aimed to investigate the prevalence and the predictive value of isolated ambulatory hypertension diagnosed after 3 months of observation for the development of sustained hypertension within a cohort of 871 never-treated stage-1 hypertensive subjects. The study end point was progression to more severe hypertension and need of antihypertensive medication. In 244 subjects (28%), clinic blood pressure declined to <140/90 mm Hg after 3 months. Of these, 124 (14.2% of total) had low clinic and ambulatory blood pressures after 3 months (nonhypertensive subjects), whereas 120 subjects (13.8% of total) showed low clinic but elevated ambulatory blood pressure (isolated ambulatory hypertension). During the 6 years of observation, the number of end points based on multiple clinic blood pressure readings progressively increased from the nonhypertensive subjects (19%) to the subjects with isolated ambulatory hypertension (35%) and to the subjects with high clinic and high ambulatory blood pressures (65%, P <0.0001). In an adjusted proportional hazard model, isolated ambulatory hypertension status was associated with a 2.2 (P <0.02) increase in the risk of reaching the end point in comparison with the nonhypertensive subjects. Final ambulatory systolic blood pressure was also higher in the former than the latter (P =0.03). Our results indicate that among subjects screened for stage 1 hypertension, individuals with isolated ambulatory hypertension after 3 months of observation have increased risk of developing sustained hypertension in later life compared with subjects in whom both clinic and ambulatory blood pressures are normal.

Evolution of blood pressure and cholesterol in stage 1 hypertension: role of autonomic nervous system activity

Objective Controversy remains concerning the pathogenetic mechanisms for the relationship between sympathetic activity, hypertension and lipid abnormalities. We tested the hypothesis that a condition characterized by sympathetic predominance may affect the evolution of blood pressure and lipids in the early stage of hypertension. Methods We prospectively studied 163 young stage 1 hypertensive individuals and 28 normotensive control individuals. The hypertensive subjects were divided by cluster analysis into two groups according to low frequency and high frequency components of heart rate variability. Large artery and small artery compliance was assessed at the end of the follow-up. Results Fifty-nine subjects showed reduced total power and signs of sympathetic predominance in the resting condition, on standing and during mental stress (group 1). At baseline, they had similar blood pressure and metabolic data to the rest of the group (n = 104, group 2) and a greater white-coat effect (P = 0.03). During a 6-year follow-up, 23.7% of group 1 subjects versus 9.6% of group 2 subjects developed sustained hypertension requiring antihypertensive treatment (P = 0.02). In group 1 subjects, there was also a greater increase in total cholesterol (P = 0.01) than in group 2. In addition, at the end of follow-up group 1 subjects had impaired large artery compliance (P < 0.001 versus group 2). Conclusions These data indicate that a condition characterized by sympathetic predominance may favour the development of sustained hypertension and hypercholesterolemia early in life, and lead to increased susceptibility to vascular complications. They further indicate that the increased white-coat effect is not an innocent phenomenon.

Microalbuminuria, renal function and development of sustained hypertension: a longitudinal study in the early stage of hypertension.

Objective Microalbuminuria (MA) is a marker of adverse outcome in hypertension. The aim of this study was to investigate the association of MA with cardiovascular risk factors and glomerular hyperfiltration in the early stage of hypertension and to assess its predictive value for the development of sustained hypertension requiring antihypertensive treatment. Design and participants We studied 1041 young stage 1 hypertensive subjects. Study variables were 24-h ambulatory blood pressure and heart rate, anthropometric measures, metabolic variables, creatinine clearance and lifestyle factors analyzed as a function of ascending urinary albumin measured from 24-h collections. Subjects were followed until they developed sustained hypertension and were eligible for antihypertensive medication according to current guidelines. Setting Seventeen outpatient clinics in Italy. Results Eighty-five percent of the subjects were normoalbuminuric, 9% had borderline MA, and 6% had overt MA. No between-group differences were found for age, body mass index, heart rate, lifestyle factors and biochemistry in both genders. Creatinine clearance was greater in the subjects with overt MA and borderline MA than in the normoalbuminuric subjects (P = 0.003 and 0.011, respectively). In a two-way ANCOVA, microalbuminuric subjects both with hyperfiltration (P < 0.001) and with normal filtration (P = 0.04) had higher 24-h systolic blood pressure than subjects with normoalbuminuria and normal filtration. In a Cox analysis, neither MA nor hyperfiltration were significant predictors of development of sustained hypertension. Conclusion MA is not associated with an adverse metabolic risk profile in the early stage of hypertension. MA is associated with greater hemodynamic load and with glomerular hyperfiltration in this clinical setting, but does not help in predicting those subjects destined to develop sustained hypertension requiring antihypertensive therapy.

Physical Activity and Angiotensin-Converting Enzyme Gene Polymorphism in Mild Hypertensives

It has been suggested that the insertion(I) allele of the I/deletion(D) polymorphism of the angiotensin converting enzyme (ACE) gene is associated with endurance exercise and increased physical conditioning in response to this type of exercise. To investigate the association between the ACE I/D polymorphism and physical activity status in 355 never treated, stage I hypertensives (265 men, 90 women, mean age: 33 ± 9 years), in whom power exercise is contraindicated, participants of the HARVEST study. Physical activity was assessed using a standardized questionnaire. BMI and age did not vary among genotypes. None of active subjects performed power oriented exercises. ACE I/D frequencies (II‐18%, ID‐55%, DD‐27%) were in Hardy–Weinberg equilibrium. Sedentary lifestyle was more common among DD than II hypertensives (76% in DD, and 48% in II, Chi2 = 13.9, P = 0.001). In stepwise MANOVA using age, marital status, profession, sex, and ACE genotype as predictors of physical activity, marital status (F = 24.4, P < 0.0001) and ACE genotype (F = 16.03, P < 0.0001) contributed to more than 50% of the variance in physical activity status of the population. Our results suggest that the ACE I/D polymorphism may be a specific genetic factor associated with physical activity levels in free‐living borderline and mild hypertensive subjects.

Lifestyle, family history and progression of hypertension.

Background Unhealthy lifestyle practices are risk factors for future hypertension. Objectives The aim of this study was to investigate the association between lifestyle changes over a 6-year period and the risk of developing sustained hypertension in a cohort of young hypertensive individuals, and to identify the predictors of lifestyle impairment over time. Methods Seven-hundred and eighty never-treated hypertensive HARVEST participants, 18–45 years old, were studied. Results Only modest mean behavioral changes were observed during follow-up. This, however, was the net result of many participants improving and others worsening their lifestyle. Participants with a family history of hypertension (FH+, n = 459) had more undesirable lifestyles (P = 0.004) and higher clinic and ambulatory blood pressures (P = 0.03) at baseline than participants without a family history of hypertension (FH−). During the 6-year follow-up, FH− individuals strikingly worsened their lifestyle while FH+ participants exhibited impressive improvements (P < 0.00001). Other predictors of lifestyle impairment were male gender (P = 0.003) and age (P = 0.02). Adoption of an unfavorable lifestyle was accompanied by an increased risk of developing sustained hypertension (P = 0.04). Initiation of drug therapy for hypertension was significantly higher among FH− than FH+ individuals (53 versus 45%, respectively; P = 0.045). Conclusions ‘Lower risk’ FH− stage 1 hypertensive individuals may initially be at higher risk of developing more severe hypertension in comparison with their FH+ counterparts. This increased risk may be attributed to worsening of their lifestyle profiles over time. Healthy lifestyles should be emphasized to all hypertensive individuals including patients with favorable lifestyle profiles.

Masked hypertension in adults.

A body of evidence indicates that masked hypertension is a significant predictor of cardiovascular disease, but how to identify these patients is still a matter of dispute. Data obtained in several cross-sectional studies have demonstrated that masked hypertension is associated with increased left ventricular mass index and carotid intima–media thickness, and impaired large artery distensibility. Furthermore, in longitudinal studies, masked hypertension was a strong predictor of cardiovascular morbidity and mortality. Several factors that can selectively raise ambulatory blood pressure increase the likelihood of having masked hypertension. These include younger age, smoking, alcohol use, contraceptive use in women, sedentary habits and central obesity. In addition, masked hypertension is more common in individuals with high-normal clinic blood pressure or transiently elevated blood pressure. Increased reactivity to daily life stressors and behavioural factors are other important predictors of masked hypertension. In clinical practice, masked hypertension should be searched for in individuals who are more likely to have this condition or are at increased risk of cardiovascular events including those with coronary, cerebrovascular or kidney disease, patients with diabetes and individuals with a high cardiovascular risk profile. To determine whether the use of ambulatory blood pressure monitoring is cost-effective in these individuals, further research is needed.

Validation of the SAW-102 wrist home blood pressure monitor according to the protocols of the British Hypertension Society, the Association for the Advancement of Medical Instrumentation, and the European Society of Hypertension.

ObjectiveTo determine the accuracy of the SAW-102 wrist oscillometric blood pressure monitor developed by the Sensacare Company according to the protocols of the European Society of Hypertension (ESH), the Association for the Advancement of Medical Instrumentation (AAMI), and the British Hypertension Society (BHS). MethodsSAW-102 was assessed on 33 participants according to ESH requirements, based on four zones of accuracy differing from the mercury standard by 5, 10, 15 mmHg or more. Then SAW-102 was tested on 85 participants according to AAMI criteria requiring mean device–observers discrepancy within 5±8 mmHg. Subsequently, SAW-102 was evaluated on 88 participants according to BHS requirements. Finally, 15 participants with wrist circumference greater than the manufacturers recommendation (19.5 cm) were studied (large wrist group). Efforts were made to secure a stable position of wrist and arm at the heart level. ResultsSAW-102 passed all phases of ESH international protocol for both systolic blood pressure (SBP) and diastolic blood pressure (DBP). SAW-102 passed AAMI criteria with mean differences between SAW-102 and observers of 3.8±7.5 and 1.5±6.0 mmHg, SBP and DPB, respectively. According to BHS protocol, the device achieved final grading of B/B for SBP and DBP, respectively. Large wrist group did not pass the first phase of ESH protocol. ConclusionThis study demonstrated that SAW-102 meets the BHS, ESH, and AAMI standards when measurements are done at the heart level and when the manufacturers specifications, regarding wrist circumference, are respected. Our data also indicate that exceeding 19.5 cm wrist circumference is accompanied by dramatic decrease of the accuracy of the device.

[BP.04.03] SHORT-TERM AND LONG TERM RELATIONSHIP BETWEEN HEART RATE AND AUGMENTATION INDEX IN YOUNG TO MIDDLE AGE SUBJECTS

Objective: Several studies have shown that the augmentation index (AIx), the primary outcome derived from pulse wave analysis, is negatively correlated with heart rate (HR). This led some authors to claim that the use of HR-lowering drugs may be detrimental in hypertension. The aim of this study was to assess the acute and chronic relationships of HR with AIx in a sample of normotensive and hypertensive adults younger than 45 years. Design and method: We studied 347 subjects (259 men) from the HARVEST study (mean age 37.3 ± 10.1 years). Central blood pressure and AIx were evaluated with Specaway DAT system and small artery compliance (SAC) with HDI Pulse Wave device. HR was measured at baseline in the office (mean of 6 readings) and with 24 h ambulatory recording. The arterial elasticity assessment was performed after a mean of 6.7 years from baseline. In multivariate regression analyses, AIx and central systolic BP were used as dependent variables and office HR or night-time HR as predictors adjusting for age, sex, BMI, height, mean BP, smoking, alcohol, physical activity habits, SAC, and pulse wave velocity. Results: Adjusted office HR measured at the time of arterial elasticity assessment was inversely correlated with AIx (p = 0.001) a relationship which was attenuated after physical activity (p = 0.004) and ejection duration (p = 0.015) were taken into account. In addition, office HR was inversely correlated with central BP (p = 0.039) a relationship which was no longer significant after physical activity (p = 0.14) or ejection duration (p = 0.58) were accounted for. In contrast, in fully adjusted models baseline average night-time HR was a significant positive predictor of AIx (p < 0.001) and central BP (p = 0.014) measured 6.7 years later. Adjusted AIx was 20.0 ± 3.0% in the top night-time HR quintile, 14.9 ± 1.4% in the 3 intermediate quintiles, and 6.5 ± 2.8% in the bottom quintile. Baseline office HR was unrelated to both AIx and central BP. Conclusions: These data confirm that HR is negatively related to AIx when measured at the time of arterial elasticity assessment. However, HR measured with ambulatory monitoring is an independent positive long-term predictor of AIx and central BP.