Within-visit variability of blood pressure and all-cause and cardiovascular mortality among US adults

Hypertension in the first blood pressure reading and the risk of cardiovascular disease mortality in the general population: findings from the prospective KORA study

BACKGROUND

The risk of cardiovascular disease (CVD) mortality in individuals with an alerting reaction, assessed by hypertension in the first blood pressure (BP) reading but normal BP in further readings, remains unknown in the general population.

METHODS AND RESULTS

In a sample of 11 146 adults (51.5% men and 48.5% women) with a mean age of 47.1 years (SD ± 12.3) from a German population-based cohort, we analyzed risk factors and CVD mortality risk associated with an alerting reaction. An alerting reaction was prevalent in 10.2% of the population and associated with sociodemographic, lifestyle, and somatic CVD risk factors. Within a mean follow-up period of 22.7 years (SD ± 7.05 years; max: 32 years; 253 201 person years), 1420 (12.7%) CVD mortality cases were observed. The CVD mortality rate associated with an alerting reaction was significantly higher than in normotension (64 vs. 32 cases/10 000 person-years), but lower than hypertension (118 cases/10 000 person-years). Correspondingly, the alerting reaction was associated with a 23% higher hazard ratio of CVD mortality than normal blood pressure [hazard ratio 1.23 (95% confidence interval 1.02-1.49), P  = 0.04]. However, adjustment for antihypertensive medication use attenuated this association [1.19 (0.99-1.44), P  = 0.06].

CONCLUSION

The results may warrant monitoring of an alerting reaction as a preventive measure of CVD mortality in untreated individuals with elevated first BP readings, as well as optimized treatment in treated individuals.

Inter-arm systolic blood pressure difference: non-persistence and association with incident cardiovascular disease in the Multi-ethnic Study of Atherosclerosis

We investigated inter-arm systolic blood pressure (sIAD) difference, reproducibility, and incident cardiovascular disease (CVD). We hypothesized that higher sIAD values have low prevalence and nonpersistence over years, but that CVD risk is higher starting from the time of first high absolute sIAD. In Multi-Ethnic Study of Atherosclerosis participants (n = 6725, 53% female, 45-84 years old), Doppler systolic blood pressure (SBP) measurements were made in both arms (10-minute interval) thrice over 9.5 years. Proportional hazards for CVD (coronary heart disease, heart failure, stroke, peripheral arterial disease (PAD)) over 16.4 years were tested according to time-varying absolute inter-arm difference with covariates: (1) age, gender, race, and clinic; (2) model 1 plus height, heart rate, BP, antihypertensives, BMI, smoking status, lipids, lipid lowering medication, and diabetes. High sIAD was not persistent across exams. Maximum absolute sIAD ≥ 15 mmHg was found at least once in 815 persons. Maximum absolute sIAD had a graded relationship with incident stroke or PAD: 6.2% events; model 2 hazard ratio per 10 mmHg 1.34 (95% CI, 1.15-1.56) and this risk was approximately doubled for maximum absolute sIAD ≥ 15 mmHg vs 0-4 mmHg. Total CVD risk (18.4% events) was increased only for maximum absolute sIAD ≥25 mmHg. Associations with incident CVD did not differ for higher SBP in left vs right arm. A higher maximum absolute sIAD at any exam was associated with greater risk for stroke and PAD especially for values ≥ 15 mmHg, and ≥25 mmHg for other CVD. Measuring SBP between arms may help identify individuals at risk for CVD.

Variabilidade da Pressão Arterial em Única Visita e Risco Cardiovascular em Participantes do ELSA-Brasil

Fundamento

A variabilidade da pressão arterial (VPA) tem valor prognóstico para desfechos cardiovasculares fatais e não fatais.

Objetivos

Este estudo teve como objetivo avaliar a associação entre a VPA em uma única visita e o risco cardiovascular em participantes do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil).

Métodos

O presente estudo transversal foi conduzido com dados basais (2008-2010) de 14.357 participantes do ELSA-Brasil, sem história de doença cardiovascular. A VPA foi quantificada pelo coeficiente de variação de três medidas padronizadas da pressão arterial sistólica (PAS) realizadas com um oscilômetro. Medidas antropométricas e exames laboratoriais também foram realizados. O risco cardiovascular foi avaliado pelo estimador de risco de doença cardiovascular aterosclerótica (ASCVD), e se empregou a análise de regressão logística multivariada com nível de significância de 5%.

Resultados

Um risco cardiovascular significativamente maior foi determinado por uma VPA elevada para ambos os sexos. Uma prevalência significativamente maior de alto risco foi observada mais em homens que em mulheres em todos os quartis, com a maior diferença observada no quarto quartil de variabilidade (48,3% vs. 17,1%). Comparações entre quartis por sexo revelaram um risco significativamente mais alto para homens no terceiro (OR=1,20; IC95%: 1,02 - 1,40) e no quarto quartis OR=1,46; IC95%: 1,25 -1,71), e para mulheres no quarto quartil (OR=1,27; IC95%: 1,03 - 1,57).

Conclusão

Análises de dados basais de participantes do ELSA-Brasil revelaram que a variabilidade da pressão arterial se associou com risco cardiovascular aumentado, especialmente nos homens.

Predictive value of within-visit and visit-to-visit blood pressure variability for all-cause mortality: the Minhang Study

BACKGROUND

Blood pressure variability is a common physiological phenomenon; however, the association between within-visit and visit-to-visit variability in blood pressure and all-cause mortality remains uncertain.

METHODS

We conducted a retrospective analysis of blood pressure variability among 11 721 adults who underwent blood pressure measurement on three occasions within a period of 6 months. Within-visit and visit-to-visit variability was quantified using the standard deviation and maximum--minimum difference between measures. The predictive effect of this variability on all-cause mortality was evaluated using Kaplan--Meier survival curves and Cox regression analysis.

RESULTS

The incidence of all-cause mortality was significantly higher for participants in the top quintile of within-visit and visit-to-visit blood pressure variability and for those with sustained high within-visit variability. Within-visit variability was not retained as a risk factor after adjustment in Cox regression models. The hazard ratio for mortality increased from 48 to 55% for the top quintile of visit-to-visit blood pressure variability and from 56 to 61% for sustained high within-visit variability. The risk of mortality remained statistically higher even if visit-to-visit blood pressure variability was added to the model, including consistency of within-visit blood pressure variability and vice versa.

CONCLUSION

Visit-to-visit and sustained high within-visit blood pressure variability were significant positive prognostic factors for all-cause mortality. Our findings underlined the clinical significance of achieving stable blood pressure in an effective plan of hypertension management.

Within-visit and between-visit intra-individual blood pressure variability in an unselected adult population from rural China

OBJECTIVE

To assess the association between the variability of blood pressure (BP) readings within an initial clinic visit, the variability within subsequent visits and the variability between visits over 1 week in a general population.

METHODS

This study included 1401 adult residents, who were not taking antihypertensive drugs, having BP measurements at three visits over 1 week. The difference between maximal and minimal BP readings (ΔBP), ΔBP/BPm (the mean BP value in a visit), the standard deviation (SD) and coefficient of variation (coefficient of variation = SD × 100/mean) of three BP values in each visit were used to estimate the within-visit BP variability (BPV). The SD and coefficient of variation of all nine BP readings over the three visits were calculated as SD9 or CV9 to reflect the overall BPV during the study visits. The SD and coefficient of variation on the mean BP values (BPm) of three visits were computed as SD-3 or CV-3, whereas the difference between maximal and minimal BP in three visits was computed as ΔBP-3 to estimate visit-to-visit BPV. The average BP or HR was the mean values of nine BP or HR readings over three visits.

RESULTS

The systolic and diastolic mean BP (SBP and DBP) decreased from the first to the third visit. The ΔBP, SD and coefficient of variation for both SBP and DBP at the first visit were positively and significantly correlated with the corresponding variables computed at the second and third visits, as well as with overall BPV (ΔBP9, SD9 and CV9). A positive correlation was also found between overall BPV and visit-to visit BPV (SD-3, CV-3 and ΔBP9). Multivariate analysis showed: no association between average SBP and systolic coefficient of variation or ΔBP/BPm but a negative association between average DBP and coefficient of variation or ΔBP/BPm for DBP at the first visit, DBP-3 and DBP9. Age was positively correlated with coefficient of variation or ΔBP/BPm for SBP at the first visit, SBP-3 and SBP9, and correlated with coefficient of variation and ΔBP/BPm for DBP only at the first visit.

CONCLUSION

In a general population, within-visit BPV at an initial visit is associated with within-visit BPV at subsequent visits and with visit-to-visit BPV over three visits within 1 week.

Within-visit SBP variability from childhood to adulthood and markers of cardiovascular end-organ damage in mid-life

BACKGROUND

Within-visit SBP variability is associated with age and SBP, but its long-term clinical significance is unknown. We examined the association between child, adult, and life-time within-visit SBP variability with markers of end-organ damage using data from a 31-year longitudinal study.

METHODS

Within-visit SBP variability was calculated as the standard deviation of three sitting SBP readings among up to 3010 participants aged 6-18 years (childhood) who were re-measured up to seven times to mid-adulthood. Markers of cardiovascular end-organ damage in adulthood were carotid intima--media thickness, brachial flow-mediated dilatation, carotid distensibility, pulse wave velocity, left ventricular mass index, carotid plaque, and coronary artery calcification.

RESULTS

The mean (standard deviation) cumulative within-visit SBP variability was 2.7 (1.5) mmHg in childhood, 3.9 (1.9) mmHg in adulthood and 3.7 (1.5) mmHg across the observed life-time. Childhood within-visit SBP variability was not correlated with its subsequent values measured from 3 to 31 years later. With adjustment for age, sex, cumulative SBP, BMI and serum lipids, neither child, adult, or life-time cumulative within-visit SBP variability associated with markers of cardiovascular end-organ damage. However, higher child, adult, and life-time cumulative SBP significantly associated with higher carotid intima--media thickness, higher pulse wave velocity, lower brachial flow-mediated dilatation, lower carotid distensibility in adulthood.

CONCLUSION

Within-visit SBP variability from childhood to adulthood does not provide additional predictive utility over SBP over the same period of the life course.

Relation between Blood Pressure Variability within a Single Visit and Stroke

Blood pressure variability (BPV) has been identified as an important risk factor for cardiovascular events. The white coat effect (WCE), which is measured as the first systolic blood pressure (SBP) measurement minus the mean of the second and third measurements, is a BPV indicator within a single visit. In total, 2,972 participants who had three measurements of BP within a single visit were included. The participants were divided into three groups based on their WCE percentiles: Group 1 (WCE_2.5-97.5, 2.5–97.5th percentiles of WCE), Group 2 (WCE_2.5, 0–2.4th percentiles of WCE), and Group 3 (WCE_97.5, 97.6–100th percentiles of WCE). A multiple logistic regression model was used to analyze the relationship between WCE and stroke after adjusting for cardiovascular disease risk factors. Compared with the WCE_2.5-97.5 group, the OR for stroke in the WCE_2.5 group was 2.78 (95% CI: 1.22, 6.36, p=0.015). After adjusting for cardiovascular factors, OR increased to 3.12 (95% CI: 1.22, 7.96, p=0.017). The OR of WCE for stroke was 0.93 (95%CI: 0.87, 0.99, p=0.036). BPV within a single visit is associated with stroke. The value and direction of the change may be important as well.

A cohort-based comprehensive characterization of different patterns of very short-term, within-visit, blood pressure variability

AIM

To characterize different patterns of variability of three repeated within-visit blood pressure (BP) readings and to determine the prevalence of specific variation trends in systolic (SBP), diastolic (DBP) blood pressure and pulse pressure (PP).

METHODS

Data from 53 737 subjects from the National Health and Nutrition Examination Survey were analyzed. In each subject, three consecutive BP measurements were performed with a minimum time-interval of at least 30 s. We propose three patterns of within-visit BP variability (separately for SBP, DBP and PP): (1) increasing trend (BP3 > BP2 > BP1); (2) decreasing trend (BP1 > BP2 > BP3) and (3) no trend (BP3 ≈ BP2 ≈ BP1). A threshold of minimum change (ΔP > 3 mmHg) between BP1-BP2 and BP2-BP3 was also applied as a prerequisite for the definition of these trends.

RESULTS

An increasing trend was observed among three consecutive measurements of SBP, DBP and PP in 7.4, 10.4 and 10.2%, respectively. When a minimum threshold of 3 mmHg was set the respective increasing trends were observed in 1.8, 2.9 and 4.4%, respectively. There was a higher prevalence of decreasing trend within three consecutive SBP, DBP and PP readings: 17, 13.1 and 16.2%, respectively, whereas using a threshold of ΔP >3 mmHg the respective prevalence was 6.3, 4.1 and 7.7%. A maximum absolute difference >10 mmHg within triplicate of SBP/DBP/PP readings was observed in 12.9, 13 and 29.4%, respectively. In the era of personalized medicine, these patterns are well worth further investigation concerning their pathophysiologic and clinical relevance.

Blood Pressure–Lowering Profiles and Clinical Effects of Angiotensin Receptor Blockers Versus Calcium Channel Blockers

Blood pressure–lowering drugs have different blood pressure–lowering profiles. We studied if differences in blood pressure mean and variability can explain the differences in risks of cardiovascular events and death among 15 245 high-risk hypertensive patients randomized to valsartan or amlodipine and followed for 4.2 years in the VALUE trial (Valsartan Antihypertensive Long-Term Use Evaluation). We selected patients with ≥3 visits and performed Cox regression analyses, defining mean blood pressure as a time-dependent covariate and visit-to-visit and within-visit blood pressure variability as the SD. Of 14 996 eligible patients, participants in the valsartan group had higher systolic mean blood pressure by 2.2 mm Hg, higher visit-to-visit systolic variability by 1.4 mm Hg, and higher within-visit systolic variability by 0.2 mm Hg ( P values <0.0001). The higher risks of myocardial infarction and stroke in the valsartan group was attenuated after adjustment for mean and variability of systolic blood pressure, from HR 1.19 (95% CI, 1.02–1.39) to 1.11 (0.96–1.30) and from HR 1.13 (0.96–1.33) to 1.00 (0.85–1.18), respectively. The lower risk of congestive heart failure in the valsartan group was accentuated after adjustment, from HR 0.86 (0.74–1.00) to 0.76 (0.65–0.89). A smaller effect was seen on risk of death, from 1.01 (0.92–1.12) to 0.94 (0.85–1.04). In conclusion, the higher risks of myocardial infarction and stroke in patients randomized to valsartan versus amlodipine were related to the drugs’ different blood pressure modulating profiles. The risk of congestive heart failure with valsartan was lower, independent of the less favorable blood pressure modulating profile.

Measurement of Blood Pressure in Humans: A Scientific Statement From the American Heart Association

The accurate measurement of blood pressure (BP) is essential for the diagnosis and management of hypertension. This article provides an updated American Heart Association scientific statement on BP measurement in humans. In the office setting, many oscillometric devices have been validated that allow accurate BP measurement while reducing human errors associated with the auscultatory approach. Fully automated oscillometric devices capable of taking multiple readings even without an observer being present may provide a more accurate measurement of BP than auscultation. Studies have shown substantial differences in BP when measured outside versus in the office setting. Ambulatory BP monitoring is considered the reference standard for out-of-office BP assessment, with home BP monitoring being an alternative when ambulatory BP monitoring is not available or tolerated. Compared with their counterparts with sustained normotension (ie, nonhypertensive BP levels in and outside the office setting), it is unclear whether adults with white-coat hypertension (ie, hypertensive BP levels in the office but not outside the office) have increased cardiovascular disease risk, whereas those with masked hypertension (ie, hypertensive BP levels outside the office but not in the office) are at substantially increased risk. In addition, high nighttime BP on ambulatory BP monitoring is associated with increased cardiovascular disease risk. Both oscillometric and auscultatory methods are considered acceptable for measuring BP in children and adolescents. Regardless of the method used to measure BP, initial and ongoing training of technicians and healthcare providers and the use of validated and calibrated devices are critical for obtaining accurate BP measurements.

Association between B-type natriuretic peptide and within-visit blood pressure variability

BACKGROUND

Blood pressure variability (BPV) has been shown to predict cardiovascular events. Within-visit BPV is the simplest and easiest measure of BPV, but previous studies have shown conflicts as to whether within-visit BPV correlates with target organ damage. We aimed to evaluate whether within-visit BPV correlates with B-type natriuretic peptide (BNP) in a general population.

HYPOTHESIS

Within-visit BPV correlates with BNP in a general population.

METHODS

This was a cross-sectional study that included 633 individuals, randomly selected, age 45 to 99 years, registered in the primary care program from an urban medium-sized town. Patients were scheduled for a single-day visit that consisted of clinical evaluation and laboratory tests. Three blood pressure (BP) readings, 1 minute apart, were done, and within-visit BPV was determined as the coefficient of variation (CV) of the 3 BP measures. Our main outcome was to correlate BNP and within-visit BPV. A multivariable model was estimated using a generalized linear model to evaluate the independent effects of different variables on BNP levels.

RESULTS

The median age was 57 years. Median BNP was 16 pg/mL, and the median systolic and diastolic BP-CV were, respectively, 3.9% and 3.5%. There was a weak but positive correlation between BNP and both systolic BP-CV and diastolic BP-CV (r = 0.107 and P = 0.007 and r = 0.092 and P = 0.019, respectively). In multiple regression equation, systolic BP, diastolic BP-CV, body mass index, and estimated glomerular filtration rate were associated with BNP.

CONCLUSIONS

In the present study, there was a positive, albeit weak, correlation between within-visit BPV and BNP. In addition, diastolic BPV was associated with BNP even after adjustment for multiple confounders.

Correlation of Blood Pressure Variability as Measured By Clinic, Self-measurement at Home, and Ambulatory Blood Pressure Monitoring

BACKGROUND

Blood pressure variability (BPV) has been postulated as a potential predictor of cardiovascular outcomes. No agreement exists as to which measurement method is best for BPV estimation. We attempt to assess the correlation between BPV obtained at the doctor's office, self-measurement at home (SMBP) and ambulatory BP monitoring (ABPM).

METHODS

Eight weekly clinic BP measurements, 2 SMBP series, and 1 24-hour ABPM recording were carried out in a sample of treated hypertensive patients. BPV was calculated using the SD, the "coefficient of variation" and the "average real variability." Determinants of short-, mid-, and long-term BPV (within each measurement method) were also calculated. The different BPV determinants were correlated "intramethod" and "intermethod" by linear regression test.

RESULTS

For the 104 patients (66.5 ± 7.7 years, 58.7% males), the ABPM BPV (SD, systolic/diastolic: 14.5 ± 3.1/9.8 ± 2.5 mm Hg) was higher than the SMBP (12.2 ± 9.8/7.4 ± 5.8 mm Hg; P < 0.001) and clinic BPV (10 ± 8.9/5.9 ± 4.9 mm Hg; P = 0.001). The main BPV correlation between methods was weak, with a maximum R2 = 0.17 (P < 0.001) between clinic and SMBP systolic BPV. The "intramethod" correlation of BPV yielded a maximum R2 = 0.21 (P < 0.001) between morning diastolic SMBP intershift/intermeans variability. The "intermethod" correlation of short-, mid-, and long-term BPV determinants was weak (maximum R2 = 0.22, P < 0.001, between clinic intraday variability/SMBP morning intershift variability).

CONCLUSIONS

The "intramethod" and "intermethod" correlation between BPV determinants was weak or nonexistent, even when comparing determinants reflecting the same type of temporal BPV. Our data suggest that BPV reflects a heterogeneous phenomenon that strongly depends on the estimation method and the time period evaluated.

Regional Fat Distribution and Blood Pressure Level and Variability: The Dallas Heart Study

Our aim was to investigate the associations of regional fat distribution with home and office blood pressure (BP) levels and variability. Participants in the Dallas Heart Study, a multiethnic cohort, underwent 5 BP measurements on 3 occasions during 5 months (2 in home and 1 in office) and quantification of visceral adipose tissue, abdominal subcutaneous adipose tissue, and liver fat by magnetic resonance imaging, and lower body subcutaneous fat by dual x-ray absorptiometry. The relation of regional adiposity with short-term (within-visit) and long-term (overall visits) mean BP and average real variability was assessed with multivariable linear regression. We have included 2595 participants with a mean age of 44 years (54% women; 48% black), and mean body mass index was 29 kg/m(2) Mean systolic BP/diastolic BP was 127/79 mm Hg and average real variability systolic BP was 9.8 mm Hg during 3 visits. In multivariable-adjusted models, higher amount of visceral adipose tissue was associated with higher short-term (both home and office) and long-term mean systolic BP (β[SE]: 1.9[0.5], 2.7[0.5], and 2.1[0.5], respectively; all P<0.001) and with lower long-term average real variability systolic BP (β[SE]: -0.5[0.2]; P<0.05). In contrast, lower body fat was associated with lower short-term home and long-term mean BP (β[SE]: -0.30[0.13] and -0.24[0.1], respectively; both P<0.05). Neither subcutaneous adipose tissue or liver fat was associated with BP levels or variability. In conclusion, excess visceral fat was associated with persistently higher short- and long-term mean BP levels and with lower long-term BP variability, whereas lower body fat was associated with lower short- and long-term mean BP. Persistently elevated BP, coupled with lower variability, may partially explain increased risk for cardiac hypertrophy and failure related to visceral adiposity.

Within-Home Blood Pressure Variability on a Single Occasion Has Clinical Significance

There is growing evidence that diversely defined blood pressure variability (BPV) is an independent predictor of hypertensive target organ damage (TOD) and cardiovascular events. Several mechanisms have been speculated to underlie episodes of increased BPV, including the impairment of autonomic or hormonal regulation, renal dysfunction, and increased arterial stiffness. Within-home BPV, defined as differences in BP values obtained on a single occasion at home, could have prognostic significance for hypertensive TOD. It is typically thought that BP values are decreased with repeated measurements on a single occasion at home, but in the present subanalysis of 4,149 J-HOP (Japan Morning Surge-Home Blood Pressure) study patients, approximately 20% of the patients' home BP values were increased or unchanged by repeated measurements on a single occasion. In addition, those patients were likely to have hypertensive TOD. Thus, home BP measurement should be taken twice or more to detect the increase trend in home BP, which has been defined as within-home BPV.

Target organ complications and prognostic significance of alerting reaction: analysis from the Dallas Heart Study

OBJECTIVE

Noninvasive blood pressure (BP) measurement often triggers a transient rise in BP, known as an alerting reaction. However, the prevalence and prognostic significance of the alerting reaction has never been assessed in the general population.

METHODS

We evaluated the association between the alerting reaction and left ventricular mass by MRI and urinary albumin-to-creatinine ratio in the Dallas Heart Study, a large population sample of 3069 individuals. Participants were categorized into four groups based on levels of consecutive BP: first, normal first BP and average third to fifth (avg3-5) BP of less than 140/90 mmHg (control group); second, high first BP of at least 140/90 mmHg and normal (avg3-5) BP (alerting reaction group); third, normal first BP and high (avg3-5) BP; and fourth, high first to fifth BP. Then, associations between BP categories with incident cardiovascular outcomes (coronary heart disease, stroke, atrial fibrillation, heart failure, and cardiovascular death) over a median follow-up period of 9.4 years were assessed.

RESULTS

The sample-weighted prevalence of isolated hypertension during the first BP measurement was 9.6%. Presence of an alerting reaction was independently associated with increased left ventricular mass, urinary albumin-to-creatinine ratio, cardiovascular events after adjustment for traditional cardiovascular risk factors, and baseline BP (adjusted hazard ratio 1.24, 95% confidence interval 1.07-1.43).

CONCLUSION

Our study indicated that the alerting reaction is independently associated with increased cardiovascular and renal complications.

Individual 6-year systolic blood pressure change and impact on cardiovascular mortality in a French general population

Impact of blood pressure (BP) visit-to-visit variability remains controversial for untreated hypertensives and for normotensive subjects. Association between 6-year systolic BP change and all-cause and cardiovascular (CVD) mortality was studied in general primary care population including untreated hypertensive and normotensive subjects. Normotensive individuals and untreated high BP patients (40,926 and 14,283, respectively) had two check-ups (interval: 5.8±2.2 years) at the IPC center (Paris). Follow-up was 6.1±3.2 years: 1131 people died, 114 from CVD causes. Systolic BP (SBP) change was assessed by tertiles of absolute differences between V1 and V2, and the relationship with mortality was analysed with multivariate Cox models (hazard ratio (HR), 95% confidence interval (CI)) including V1 or V2 parameters notably SBP. Adjusting for V1 variables, mortality was associated with SBP change, for the entire population (all-cause: HR=1.15 (95%: 1.01-1.30) and CVD: HR=1.95 (95%: 1.25-3.05)) and in hypertensive individuals: (HR=1.31 (95%: 1.08-1.59) and HR=2.51 (95%: 1.34-4.72), respectively). Adjustments for V2 variables gave similar results. For those who were normotensive at V1, the associations were not significant. In this primary care population, individual long-term visit-to-visit change of BP is an independent predictor of all-cause mortality in hypertensive individuals but not in those with normal BP.

Within-visit blood pressure variability is associated with prediabetes and diabetes

We investigated the associations between within-visit blood pressure variability (BPV) and risk factors for cardiovascular disease (CVD). The study subjects included 17,795 people aged 40–74 years who underwent health check-ups in Aichi Prefecture, Japan, and completed two blood pressure measurements. Subjects were categorized into three groups according to the difference of systolic blood pressure (ΔSBP), namely, low-BPV (≤10 mmHg), moderate-BPV (11–20 mmHg), and high-BPV (>20 mmHg). Subjects were also divided into three categories as those without prediabetes (glycosylated hemoglobin A_1c [HbA_1c] < 5.7%), prediabetes (HbA_1c 5.7–6.4%) and diabetes (HbA_1c ≥ 6.5% or under treatment for diabetes). The proportion of prediabetes and diabetes were significantly higher in subjects with high-BPV than in those with low-BPV after adjusting for age, sex, and mean SBP (odds ratio [95% confidence interval] was 1.16 [1.01–1.33] for prediabetes and 1.33 [1.06–1.66] for diabetes). Other CVD risk factors were not associated with high-BPV after the adjustment. In conclusion, increased within-visit BPV was significantly associated with the prevalence of prediabetes and diabetes, independent of mean SBP, in a large general population. Therefore, assessing BPV in a single visit may help to identify subjects at increased risk of impaired glycemic control.

Should the first blood pressure reading be discarded?

We evaluated the consequences of excluding the first of three blood pressure (BP) readings in different settings: a random population sample (POS, n=1525), a general practice office (GPO, n=942) and a specialized hypertension center (SHC, n=462). Differences between systolic and diastolic BP (SBP and DBP) estimates obtained including and excluding the first reading were compared and their correlation with ambulatory BP monitoring (ABPM) was estimated. The samples were divided into quartiles according to the difference between the third and the first SBP (3-1ΔSBP). SBP decreased through sequential readings, 3-1ΔSBP was -5.5 ± 9.7 mm Hg (P<0.001), -5.1 ± 10.4 mm Hg (P<0.001) and -6.1 ± 9.3 mm Hg (P<0.001) for POS, GPO and SHC, respectively. However, individuals included in the top quartile of 3-1ΔSBP showed their highest values on the third reading. The mean SBP estimate was significantly higher excluding the first reading (P<0.001), but the differences among both approaches were small (1.5-1.6 mm g). Moreover, the correlation between SBP values including and excluding the first reading and daytime ABPM were comparable (r = 0.69 and 0.68, respectively). Similar results were observed for DBP. In conclusion, our study does not support the notion of discarding the first BP measurement and suggests that it should be measured repeatedly, regardless the first value.

The association between within-visit blood pressure variability and carotid artery atherosclerosis in general population

Objectives

To determine whether within-visit blood pressure (BP) variability based on three measurements over minutes is associated with increased carotid intima-media thickness (IMT) and plaque in a general population.

Methods

A cross-sectional survey was performed in 2007, and a total of 1222 Beijing community residents aged 50–79 years belonging to part of the Chinese Multi-Provincial Cohort Study (CMCS) were recruited in this study. BP was measured three times at 5-minute intervals during a single visit, and the maximum absolute difference (MAD) between any two readings of three measurements was used to indicate within-visit BP variability. Carotid IMT and plaque scanned by B-mode ultrasound were identified as the surrogate end points in the intermediate stage of atherosclerosis.

Results

After adjustment for established cardiovascular risk factors, the odds ratio (OR) (95% confidence interval (CI)) for increased carotid IMT and internal carotid plaque associated with the highest within-visit diastolic BP (DBP) variability (MAD > mean + standard deviation (SD)) compared with participants in the lowest within-visit DBP variability (MAD ≤ mean −SD) was 4.92 (1.48–16.42) and 6.07 (1.31–28.10), respectively, in the normotensives (P = 0.01; P = 0.02). The OR (95% CI) for internal carotid plaque associated with the highest within-visit systolic BP (SBP) variability (MAD >mean +SD) compared with participants in the lowest within-visit SBP variability (MAD ≤ mean −SD) was 3.54 (1.26–10.00) in the hypertensives on antihypertensive therapy (P = 0.02).

Conclusions

Within-visit DBP variability was associated with increased carotid IMT and internal carotid plaque in the normotensive population, and within-visit SBP variability was associated with internal carotid plaque in hypertensive patients undergoing antihypertensive therapy.

Predialysis systolic BP variability and outcomes in hemodialysis patients

BP variability (BPV) is an important predictor of outcomes in the general population, but its association with clinical outcomes in hemodialysis patients is not clear. We identified 11,291 patients starting dialysis in 2003-2008 and followed them through December 31, 2008 (median=22 months). Predialysis systolic BPV was assessed over monthly intervals. Outcomes included factors associated with BPV, mortality (all-cause and cardiovascular), and first cardiovascular event (cardiovascular death or hospitalization). Patients' mean age was 62 years, 55% of patients were men, and 58% of patients were white. Modifiable factors associated with higher BPV included obesity, higher calcium-phosphate product levels, and lower hemoglobin concentration; factors associated with lower BPV included greater fluid removal, achievement of prescribed dry weight during dialysis, higher hemoglobin concentration, and antihypertensive regimens without β-blockers or renin-angiotensin system blocking agents. In total, 3200 deaths occurred, including 1592 cardiovascular deaths. After adjustment for demographics, comorbidities, and clinical factors, higher predialysis BPV was associated with increased risk of all-cause mortality (hazard ratio [HR], 1.18; 95% confidence interval [95% CI] per 1 SD increase in BPV, 1.13 to 1.22), cardiovascular mortality (HR, 1.18; 95% CI, 1.12 to 1.24), and first cardiovascular event (HR, 1.11; 95% CI, 1.07 to 1.15). Results were similar when BPV was categorized in tertiles and patients were stratified by baseline systolic BP. In summary, predialysis systolic BPV is an important, potentially modifiable risk factor for death and cardiovascular outcomes in incident hemodialysis patients. Studies of BP management in dialysis patients should focus on both absolute BP and BPV.

Visit-to-visit blood pressure variability and risk for progression of cardiovascular and renal diseases

PURPOSE OF REVIEW

Recent data have highlighted the shortcomings of the usual blood pressure hypothesis in posthoc analyses of randomized controlled trials led in populations at high cardiovascular risk and have emphasized the importance of an increased visit-to-visit variability of blood pressure in predicting cardiovascular events.

RECENT FINDINGS

Over the last 2 years, the prognostic value of visit-to-visit blood pressure variability has been substantially confirmed in a wide spectrum of clinical populations, in studies investigating both cardiovascular outcomes and target organ damage.

SUMMARY

There is an obvious need to design studies to prospectively determine the causes of increased visit-to-visit blood pressure variability, its best estimate and whether or not treatments that reduce blood pressure variability (and to what extent/target) improve clinical outcome.

Assessment and management of blood-pressure variability

Blood pressure (BP) is characterized by marked short-term fluctuations occurring within a 24 h period (beat-to-beat, minute-to-minute, hour-to-hour, and day-to-night changes) and also by long-term fluctuations occurring over more-prolonged periods of time (days, weeks, months, seasons, and even years). Rather than representing 'background noise' or a randomly occurring phenomenon, these variations have been shown to be the result of complex interactions between extrinsic environmental and behavioural factors and intrinsic cardiovascular regulatory mechanisms. Although the adverse cardiovascular consequences of hypertension largely depend on absolute BP values, evidence from observational studies and post-hoc analyses of data from clinical trials have indicated that these outcomes might also depend on increased BP variability (BPV). Increased short-term and long-term BPV are associated with the development, progression, and severity of cardiac, vascular, and renal damage and with an increased risk of cardiovascular events and mortality. Of particular interest are the findings from post-hoc analyses of large intervention trials in hypertension, showing that within-patient visit-to-visit BPV is strongly prognostic for cardiovascular morbidity and mortality. This result has prompted discussion on whether antihypertensive treatment should be targeted not only towards reducing mean BP levels but also to stabilizing BPV with the aim of achieving consistent BP control over time, which might favour cardiovascular protection.

Within-visit blood pressure variability: relevant factors in the general population

The objective of this study was to use a nationwide epidemiological survey to investigate the factors that affect within-visit blood pressure (BP) variability. We analyzed the Korean National Health and Nutrition Examination Survey (KNHNES) data for 2005 (n=5488). We examined three within-visit BP variability parameters that include the following: the alarm reaction (AR), defined as the first BP reading minus the third BP reading; the BP discrepancy, defined as the maximal BP reading minus the minimal BP reading (ΔBPmax); and the s.d. (BPSD). Age, fasting glucose, eGFR, total cholesterol, LDL cholesterol, and the metabolic syndrome (MetS) score were the relevant factors that affected the systolic AR, ΔSBPmax and SBPSD. Multiple linear regression models revealed that age (P<0.0001), the office systolic BP (SBP) level (P<0.0001), the MetS score (P<0.0001), the female gender (P=0.007) and the eGFR (P=0.049) were independently associated with the systolic AR, whereas age (P<0.0001), the office SBP level (P<0.0001), and the female gender (P=0.024 and 0.022) were independently associated with ΔSBPmax and SBPSD, respectively. Within-visit BP variability, especially the variability associated with the SBP, was significantly associated with increased age, female gender and cardiovascular risk factors, such as hypertension, low eGFR and adverse glucose and lipid profiles. In addition, increased age, female gender, the eGFR and the MetS score were independently relevant factors that affected the systolic AR. Systolic within-visit BP variability and systolic AR are associated with cardiovascular risk factors.