Low correlation between visit-to-visit variability and 24-h variability of blood pressure.
ABSTRACT: visit-to-visit variability (VVV) of clinic systolic blood pressure (SBP) has been associated with cardiovascular disease risk. Given the need for obtaining blood pressure (BP) at multiple visits to calculate VVV, substituting BP variability from ambulatory blood pressure monitoring (ABPM) may be a practical alternative. We assessed the correlation between VVV of BP and BP variability from ABPM using data from 146 untreated, mostly normotensive participants (mean age 47.9 years), in a substudy of the ongoing Masked Hypertension Study. VVV of SBP and diastolic blood pressure (DBP) was estimated by the standard deviation (s.d.vvv) and average real variability (ARVvvv) from six study visits over a median of 216 days. ABPM data were used to calculate the day-night s.d. (s.d.dn), and the ARV of SBP and DBP over 24 h (ARV24). For SBP, the mean s.d.vvv and s.d.dn were 6.3 (s.d.=2.5) and 8.8 mm Hg (s.d.=1.8), respectively, and mean ARVvvv and ARV24 were 7.2 (s.d.=3.2) and 8.4 mm Hg (s.d.=2.1), respectively. Spearman's correlation coefficient between s.d.vvv and s.d.dn of SBP was rs=0.25, and between ARVvvv and ARV24 was rs=0.17. Participants in the highest quartile of s.d.dn of SBP were 1.66 (95% CI: 0.93-2.75) times more likely to be in the highest quartile of s.d.vvv of SBP. The observed-to-expected ratio between the highest quartiles of ARVvvv and ARV24 of SBP was 0.89 (95% CI: 0.41-1.69). The correlations for s.d.vvv and s.d.dn, and ARVvvv and ARV24 of DBP were minimal. These data suggest VVV and 24-h variability are weakly correlated and not interchangeable.
Project description:BACKGROUND:Increasing evidence has shown that visit-to-visit variability (VVV) of blood pressure (BP) is associated with an increased risk of cardiovascular disease (CVD). The objective of this study was to evaluate the impact of VVV of systolic blood pressure (SBP) and diastolic blood pressure (DBP) on the risk of CVD among patients with type 2 diabetes mellitus (T2DM) in China. METHODS:We conducted a retrospective cohort study of 10,163 T2DM patients who were not previously diagnosed with CVD from January 2008 to December 2012 in Ningbo, China. The VVV of BP was calculated using five metrics, including standard deviation (SD), coefficient of variation (CV), variation independent of mean, average real variability, and successive variability (SV) of measurements, obtained over a 24-month measurement period. Hazard ratios and 95% confidence intervals (CIs) were estimated by Cox proportional hazards regression models for the associations of variability in BP with risk of CVD. RESULTS:A total of 894 CVD events were observed during a median follow-up of 49.5 months. The hazard ratio in the highest quintile of SD of SBP was 1.24 (95% CI, 1.01 to 1.52) compared with patients in the lowest quintile. The association between higher VVV of DBP and risk of CVD was not consistent across different metrics and sensitivity analyses. CONCLUSION:Higher VVV of SBP was associated with an increased risk of CVD, irrespective of the mean SBP level. Future studies are needed to confirm these findings.
Project description:As evidence suggests visit-to-visit variability (VVV) of blood pressure (BP) is associated with cardiovascular events and mortality, there is increasing interest in identifying interventions that reduce VVV of BP. We investigated the effects of weight loss and sodium reduction, alone or in combination, on VVV of BP in participants enrolled in phase II of the Trials of Hypertension Prevention.BP readings were taken at 6-month intervals for 36 months in 1820 participants with high-normal DBP who were randomized to weight loss, sodium reduction, combination (weight loss and sodium reduction), or usual care groups. VVV of BP was defined as the SD of BP across six follow-up visits.VVV of SBP was not significantly different between participants randomized to the weight loss (7.2?±?3.1 ?mmHg), sodium reduction (7.1?±?3.0? mmHg), or combined (6.9?±?2.9 ?mmHg) intervention groups vs. the usual care group (6.9?±?2.9 ?mmHg). In a fully adjusted model, no difference (0.0?±?0.2 ?mmHg) in VVV of SBP was present between individuals who successfully maintained their weight loss vs. individuals who did not lose weight during follow-up (P?=?0.93). Also, those who maintained a reduced sodium intake throughout follow-up did not have lower VVV of SBP compared to those who did not reduce their sodium intake (0.1?±?0.3? mmHg; P?=?0.77). Results were similar for VVV of DBP.These findings suggest that weight loss and sodium reduction may not be effective interventions for lowering VVV of BP in individuals with high-normal DBP.
Project description:Secondary analysis of clinical trial data suggests visit-to-visit variability (VVV) of blood pressure is strongly associated with the incidence of cardiovascular disease. Measurement of blood pressure in usual practice settings may be subject to substantial error, calling into question the value of VVV in real-world settings.We analyzed data on adults of at least 65 years of age with diagnosed hypertension who were taking antihypertensive medication from the Cohort Study of Medication Adherence among Older Adults (n?=?772 with 14 or more blood pressure measurements). All blood pressure measurements, taken as part of routine outpatient care over a median of 2.8 years, were abstracted from patients' medical charts.Using each participant's first seven SBP measurements, the mean intraindividual standard deviation was 13.5?mmHg. The intraclass correlation coefficient for the standard deviation based on the first seven and second seven SBP measurements was 0.28 [95% confidence interval (CI) 0.20-0.34]. Individuals in the highest quintile of standard deviation of SBP based on their first seven measurements were more likely to be in the highest quintile of VVV using their second seven measurements (observed/expected ratio?=?1.71, 95% CI 1.29-2.22). Results were similar for other metrics of VVV. The intraclass correlation coefficient was lower for DBP than SBP.These data suggest VVV of SBP measured in a real-world setting is not random. Future studies are needed to assess the prognostic value of VVV of SBP assessed in routine clinical practice.
Project description:Variability of blood pressure (BP) across outpatient visits is frequently dismissed as random fluctuation around a patient's underlying BP.To examine the association of visit-to-visit variability (VVV) of systolic BP (SBP) and diastolic BP with cardiovascular disease (CVD) and mortality outcomes.Prospective cohort study.Post hoc analysis of ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial).25 814 ALLHAT participants.The VVV of SBP was defined as the SD across SBP measurements obtained at 7 visits conducted from 6 to 28 months after ALLHAT enrollment. Participants without CVD events during the first 28 months of follow-up were followed from the 28-month visit through the end of active ALLHAT follow-up. Outcomes included fatal coronary heart disease (CHD) or nonfatal myocardial infarction, all-cause mortality, stroke, and heart failure.During follow-up, 1194 fatal CHD or nonfatal MI events, 1948 deaths, 606 strokes, and 921 heart failure events occurred. After multivariable adjustment, including for mean SBP, the hazard ratio comparing participants in the highest versus lowest quintile of SD of SBP (?14.4 mm Hg vs. <6.5 mm Hg) was 1.30 (95% CI, 1.06 to 1.59) for fatal CHD or nonfatal MI, 1.58 (CI, 1.32 to 1.90) for all-cause mortality, 1.46 (CI, 1.06 to 2.01) for stroke, and 1.25 (CI, 0.97 to 1.61) for heart failure. Higher VVV of diastolic BP was also associated with CVD events and mortality.Long-term outcomes were not available.Higher VVV of SBP is associated with an increased risk for CVD and mortality. Future studies should examine whether reducing VVV of BP lowers this risk.National Institutes of Health.
Project description:Accumulating evidence suggests that increased visit-to-visit variability (VVV) of blood pressure is associated with stroke. No study has examined the association between VVV of blood pressure and stroke in postmenopausal women, and scarce data exist as to whether this relation is independent of the temporal trend of blood pressure. We examined the association of VVV of blood pressure with stroke in 58,228 postmenopausal women enrolled in the Women's Health Initiative. Duplicate blood pressure readings, which were averaged, were taken at baseline and at each annual visit. VVV was defined as the SD for the participant's mean systolic blood pressure (SBP) across visits (SD) and about the participant's regression line with SBP regressed across visits (SDreg). Over a median follow-up of 5.4 years, 997 strokes occurred. In an adjusted model including mean SBP over time, the hazard ratios (95% CI) of stroke for higher quartiles of SD of SBP compared with the lowest quartile (referent) were 1.39 (1.03-1.89) for quartile 2, 1.52 (1.13-2.03) for quartile 3, and 1.72 (1.28-2.32) for quartile 4 (P trend <0.001). The relation was similar for SDreg of SBP quartiles in a model that additionally adjusted for the temporal trend in SBP (P trend <0.001). The associations did not differ by stroke type (ischemic versus hemorrhagic). There was a significant interaction between mean SBP and SDreg on stroke with the strongest association seen below 120 mmHg. In postmenopausal women, greater VVV of SBP was associated with increased risk of stroke, particularly in the lowest range of mean SBP.
Project description:Mean and visit-to-visit variability (VVV) of blood pressure (BP) are associated with an increased cardiovascular disease risk. We examined the effect of hormone therapy on mean and VVV of BP in postmenopausal women from the Women's Health Initiative (WHI) randomized controlled trials.BP was measured at baseline and annually in the two WHI hormone therapy trials, in which 10?739 and 16?608 postmenopausal women were randomized to conjugated equine estrogens (CEEs, 0.625?mg/day) or placebo, and CEEs and medroxyprogesterone acetate (MPA, 2.5?mg/day) or placebo, respectively.At the first annual visit (year 1), mean SBP was 1.04?mmHg [95% confidence interval (CI) 0.58, 1.50] and 1.35?mmHg (95% CI 0.99, 1.72) higher in the CEEs and CEEs and MPA arms, respectively, compared with the corresponding placebos. These effects remained stable after year 1. CEEs also increased the VVV of SBP (ratio of VVV in CEEs vs. placebo, 1.03; P?<?0.001), whereas CEEs and MPA did not (ratio of VVV in CEEs and MPA vs. placebo, 1.01; P?=?0.20). After accounting for study drug adherence, the effects of CEEs and CEEs and MPA on mean SBP increased at year 1, and the differences in the CEEs and CEEs and MPA arms vs. placebos also continued to increase after year 1. Further, both CEEs and CEEs and MPA significantly increased the VVV of SBP (ratio of VVV in CEEs vs. placebo, 1.04; P?<?0.001; ratio of VVV in CEEs and MPA vs. placebo, 1.05; P?<?0.001).Among postmenopausal women, CEEs and CEEs and MPA at conventional doses increased mean and VVV of SBP.
Project description:Visit-to-visit variability of blood pressure (VVV of BP) is an important independent risk factor for premature death and cardiovascular events, but relatively little is known about this phenomenon in patients with chronic kidney disease (CKD) not yet on dialysis.We conducted a retrospective study in a community-based cohort of 114?900 adults with CKD stages 3-4 (estimated glomerular filtration rate 15-59?ml/min per 1.73?m). We hypothesized that VVV of BP would be independently associated with higher risks of death, incident treated end-stage renal disease, and cardiovascular events. We defined systolic VVV of BP using three metrics: coefficient of variation, standard deviation of the mean SBP, and average real variability.The highest versus the lowest quintile of the coefficient of variation was associated with higher adjusted rates of death (hazard ratio 1.22; 95% confidence interval 1.11-1.34) and hemorrhagic stroke (hazard ratio 1.91; confidence interval 1.36-2.68). VVV of BP was inconsistently associated with heart failure, and was not significantly associated with acute coronary syndrome and ischemic stroke. Results were similar when using the other two metrics of VVV of BP. VVV of BP had inconsistent associations with end-stage renal disease, perhaps because of the relatively low incidences of this outcome.Higher VVV of BP is independently associated with higher rates of death and hemorrhagic stroke in patients with moderate to advanced CKD not yet on dialysis.
Project description:Few randomized trials have compared visit-to-visit variability (VVV) of systolic blood pressure (SBP) across drug classes. The authors compared VVV of SBP among 24,004 participants randomized to chlorthalidone, amlodipine, or lisinopril in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). VVV of SBP was calculated across 5 to 7 visits occurring 6 to 28 months following randomization. The standard deviation (SD) of SBP was 10.6 (SD=5.0), 10.5 (SD=4.9), and 12.2 (SD=5.8) for participants randomized to chlorthalidone, amlodipine, and lisinopril, respectively. After multivariable adjustment including mean SBP across visits and compared with participants randomized to chlorthalidone, participants randomized to amlodipine had a 0.36 (standard error [SE]: 0.07) lower SD of SBP and participants randomized to lisinopril had a 0.77 (SE=0.08) higher SD of SBP. Results were consistent using other VVV of SBP metrics. These data suggest chlorthalidone and amlodipine are associated with lower VVV of SBP than lisinopril.
Project description:Visit-to-visit blood pressure (BP) variability is an important predictor of stroke. However, which antihypertensive drug combination is better at reducing visit-to-visit BP variability and therefore at reducing stroke incidence remains uncertain. We have previously reported that the dihydropyridine calcium channel blocker benidipine combined with a ?-blocker appeared to be less beneficial in reducing the risk of stroke than a combination of benidipine and thiazide. Here, we further compare the visit-to-visit BP variability among three benidipine-based regimens, namely angiotensin receptor blocker (ARB), ?-blocker and thiazide combinations. The present post hoc analysis included 2983 patients without cardiovascular events or death during the first 18 months after randomization. We compared the BP variability (defined as the s.d. and the coefficient of variation (CV)), maximum systolic BP (SBP) and diastolic BP (DBP) of the clinic mean on-treatment BPs obtained at 6-month intervals, starting 6 months after the treatment initiation, among the 3 treatments (ARB, n=1026; ?-blocker, n=966; thiazide, n=991). During the first 6-36 months after randomization, both the s.d. and CV-BPs were lower in the benidipine-thiazide group than in the benidipine-?-blocker group (s.d.-SBP, P=0.019; s.d.-DBP, P=0.030; CV-SBP, P=0.012; CV-DBP, P=0.022). The s.d. and CV in the ARB group did not reach statistical significance compared with the other two groups. The maximum BPs did not differ among the three treatments. These findings suggest that the benidipine-thiazide combination may reduce visit-to-visit BP variability more than the benidipine-?-blocker combination.
Project description:Physical exercise and isoflavone supplementation are potential strategies to prevent and treat cardiovascular diseases in postmenopausal women. The aim of this study was to investigate whether there are additive effects of isoflavone supplementation when associated with combined aerobic and resistance exercise on resting and ambulatory blood pressure monitoring (ABPM) and in blood pressure variability (BPV). Thirty-one non-obese postmenopausal women were randomly allocated into two groups: placebo and exercise (Placebo <i>n</i> = 19); and isoflavone supplementation (100 mg/day) and exercise (isoflavone <i>n</i> = 19). ABPM and BPV were evaluated before and after 10 weeks of moderate combined (aerobic and resistance) exercise training. Generalized Estimating Equation (GEE) with Bonferroni correction and intention-to-treat analysis was used to compare the effects of interventions on resting BP, ABPM and BPV. Combined exercise training decreased resting systolic (SBP) and diastolic blood pressure (DBP) and reduced 24 h and awake ambulatory SBP, DBP and mean blood pressure over time, with no additional effects of isoflavone supplementation. No changes were observed in sleep period, or in BPV indexes (Standard Deviation of 24 h (SD), daytime and nighttime interval (SDdn) and average real variability (ARV) in both groups. We conclude that isoflavone supplementation does not potentiate the effects of combined training on resting and ambulatorial systolic and diastolic blood pressure in non-obese postmenopausal women.