Predictive Role of the Nighttime Blood Pressure Hansen, Tine W; Li, Yan; Boggia, José ...
Hypertension (Dallas, Tex. 1979),
2011-January, 2011, 2011-Jan, 2011-01-00, 20110101, Letnik:
57, Številka:
1
Journal Article
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Numerous studies addressed the predictive value of the nighttime blood pressure (BP) as captured by ambulatory monitoring. However, arbitrary cutoff limits in dichotomized analyses of continuous ...variables, data dredging across selected subgroups, extrapolation of cross-sectional studies to prospective outcomes, and lack of comprehensive adjustments for confounders make interpretation of the literature difficult. We reviewed prospective studies with total mortality or a composite cardiovascular end point as an outcome in relation to the level and the circadian profile of systolic BP. We analyzed studies in hypertensive patients (n=23 856) separately from those in individuals randomly recruited from populations (n=9641). We pooled summary statistics and individual subject data, respectively. In both patients and populations, in analyses in which nighttime BP was additionally adjusted for daytime BP and vice versa, nighttime BP was a stronger predictor than daytime BP. With adjustment for the 24-hour BP, both the night-to-day BP ratio and dipping status remained significant predictors of outcome but added little prognostic value over and beyond the 24-hour BP level. In the absence of conclusive evidence proving that nondipping is a reversible risk factor, the option whether or not to restore the diurnal blood pressure profile to a normal pattern should be left to the clinical judgment of doctors and should be individualized for each patient. Current guidelines on the interpretation of ambulatory BP recording need to be updated.
This review portrays how ambulatory blood pressure (BP) monitoring was established and recommended as the method of choice for the assessment of BP and for the rational use of antihypertensive drugs. ...To establish much-needed diagnostic ambulatory BP thresholds, initial statistical approaches evolved into longitudinal studies of patients and populations, which demonstrated that cardiovascular complications are more closely associated with 24-hour and nighttime BP than with office BP. Studies cross-classifying individuals based on ambulatory and office BP thresholds identified white-coat hypertension, an elevated office BP in the presence of ambulatory normotension as a low-risk condition, whereas its counterpart, masked hypertension, carries a hazard almost as high as ambulatory combined with office hypertension. What clinically matters most is the level of the 24-hour and the nighttime BP, while other BP indexes derived from 24-hour ambulatory BP recordings, on top of the 24-hour and nighttime BP level, add little to risk stratification or hypertension management. Ambulatory BP monitoring is cost-effective. Ambulatory and home BP monitoring are complimentary approaches. Their interchangeability provides great versatility in the clinical implementation of out-of-office BP measurement. We are still waiting for evidence from randomized clinical trials to prove that out-of-office BP monitoring is superior to office BP in adjusting antihypertensive drug treatment and in the prevention of cardiovascular complications. A starting research line, the development of a standardized validation protocol for wearable BP monitoring devices, might facilitate the clinical applicability of ambulatory BP monitoring.
Hypertension guidelines recommend blood pressure self-measurement at home (HBP), but no previous trial has assessed cardiovascular outcomes in hypertensive patients treated according to HBP. The ...multicenter Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP; 2001-2010) trial involved 3518 patients (50% women; mean age 59.6 years) with an untreated systolic/diastolic HBP of 135-179/85-119 mm Hg. In a 2 × 3 design, patients were randomized to usual control (125-134/80-84 mm Hg (UC)) vs. tight control (<125/<80 mm Hg (TC)) of HBP and to initiation of drug treatment with angiotensin converting enzyme inhibitors, angiotensin receptor blockers or calcium channel blockers. During follow-up, a computer algorithm automatically generated treatment recommendations based on HBP. At the last follow-up (median 5.3 years), TC patients used more antihypertensive drugs than UC patients (1.82 vs. 1.74 defined daily doses, P=0.045) and had a greater HBP reduction (21.3/13.1 mm Hg vs. 22.7/13.9 mm Hg, P=0.018/0.020), but they less frequently achieved the lower HBP targets (37.4 vs. 63.5%, P<0.0001). The primary end point, cardiovascular death plus stroke and myocardial infarction, occurred in 25 UC and 26 TC patients (hazard ratio, 1.02; 95% confidence interval, 0.59-1.77; P=0.94). Rates were similar (P≥0.13) in the three drug groups. In all patients combined, the risk of the primary end point independently increased by 41% (6-89%; P=0.019) and 47% (15-87%; P=0.0020) for a 1-s.d. increase in baseline (12.5 mm Hg) and follow-up (13.2 mm Hg) systolic HBP. The 5-year risk was minimal (≤1%) if on-treatment systolic HBP was 131.6 mm Hg or less. HOMED-BP proved the feasibility of adjusting antihypertensive drug treatment based on HBP and suggests that a systolic HBP level of 130 mm Hg should be an achievable and safe target.
We assessed, in a double-blind, placebo-controlled trial, whether lowering blood pressure (BP) prevents the recurrence of stroke in Chinese patients with cerebrovascular disease. Patients were ...randomized into two groups: 2825 patients received a placebo and 2840 patients received 2.5 mg of indapamide daily. The primary and secondary outcomes were the recurrence of fatal or nonfatal stroke and major fatal and nonfatal cardiovascular events, respectively. The average systolic/diastolic BP at randomization was 153.8/92.8 mm Hg. At median follow-up (2 years), BP was, on an average, 6.8/3.3 mm Hg lower in patients on active treatment. In total, 143 patients on indapamide and 219 patients on placebo had recurrent strokes (hazard ratio for indapamide, 0.69; 95% confidence interval (CI): 0.54-0.89; P<0.001). In addition, 199 patients on indapamide and 258 patients on placebo had a cardiovascular event (hazard ratio, 0.75; 95% CI: 0.89-0.62; P=0.002). We performed a systematic review of literature that included our new results. Across 10 trials, the odds ratio for the prevention of stroke recurrence by BP lowering was 0.78 (95% CI: 0.68-0.90; P=0.0007). The pooled odds ratio was 0.63 (95% CI: 0.54-0.73; P<0.0001) for trials involving diuretics as a component of therapy and 0.93 (95% CI: 0.87-1.01; P=0.086) for trials in which treatment included renin system inhibitors (P<0.0001 for heterogeneity). The weighted correlation between the odds for stroke recurrence and the reduction in systolic BP was -0.57 (P=0.067). In conclusion, BP lowering by indapamide treatment reduced the recurrence of stroke and the incidence of cardiovascular events in Chinese patients with cerebrovascular disease. Whether prevention of stroke recurrence depends on drug class, degree of BP lowering or both requires further investigation.
Summary Background Few studies have formally compared the predictive value of the blood pressure at night over and beyond the daytime value. We investigated the prognostic significance of the ...ambulatory blood pressure during night and day and of the night-to-day blood pressure ratio. Methods We did 24-h blood pressure monitoring in 7458 people (mean age 56·8 years SD 13·9) enrolled in prospective population studies in Denmark, Belgium, Japan, Sweden, Uruguay, and China. We calculated multivariate-adjusted hazard ratios for daytime and night-time blood pressure and the systolic night-to-day ratio, while adjusting for cohort and cardiovascular risk factors. Findings Median follow-up was 9·6 years (5th to 95th percentile 2·5–13·7). Adjusted for daytime blood pressure, night-time blood pressure predicted total (n=983; p<0·0001), cardiovascular (n=387; p<0·01), and non-cardiovascular (n=560; p<0·001) mortality. Conversely, adjusted for night-time blood pressure, daytime blood pressure predicted only non-cardiovascular mortality (p<0·05), with lower blood pressure levels being associated with increased risk. Both daytime and night-time blood pressure consistently predicted all cardiovascular events (n=943; p<0·05) and stroke (n=420; p<0·01). Adjusted for night-time blood pressure, daytime blood pressure lost prognostic significance only for cardiac events (n=525; p≥0·07). Adjusted for the 24-h blood pressure, night-to-day ratio predicted mortality, but not fatal combined with non-fatal events. Antihypertensive drug treatment removed the significant association between cardiovascular events and the daytime blood pressure. Participants with systolic night-to-day ratio value of 1 or more were older, at higher risk of death, and died at an older age than those whose night-to-day ratio was normal (≥0·80 to <0·90). Interpretation In contrast to commonly held views, daytime blood pressure adjusted for night-time blood pressure predicts fatal combined with non-fatal cardiovascular events, except in treated patients, in whom antihypertensive drugs might reduce blood pressure during the day, but not at night. The increased mortality in patients with higher night-time than daytime blood pressure probably indicates reverse causality. Our findings support recording the ambulatory blood pressure during the whole day.
Few population studies addressed the prognostic significance of aortic pulse wave velocity (APWV) above and beyond other cardiovascular risk factors.
We studied a sex- and age-stratified random ...sample of 1678 Danes aged 40 to 70 years. We used Cox regression to investigate the prognostic value of APWV, office pulse pressure (PP), and 24-hour ambulatory PP while adjusting for mean arterial pressure (MAP) and other covariates. Over a median follow-up of 9.4 years, the incidence of fatal and nonfatal cardiovascular end points, cardiovascular mortality, and fatal and nonfatal coronary heart disease amounted to 154, 62, and 101 cases, respectively. We adjusted for sex, age, body mass index, MAP measured in the office (conventional PP and APWV) or by ambulatory monitoring (24-hour PP), smoking, and alcohol intake. With these adjustments, APWV maintained its prognostic significance in relation to each end point (P<0.05), whereas office and 24-hour PP lost their predictive value (P>0.19), except for office PP in relation to coronary heart disease (P=0.02). For each 1-SD increment in APWV (3.4 m/s), the risk of an event increased by 16% to 20%. In sensitivity analyses, APWV still predicted all cardiovascular events after standardization to a heart rate of 60 beats per minute, after adjustment for 24-hour MAP instead of office MAP, and/or after additional adjustment for the ratio of total to HDL serum cholesterol and diabetes mellitus at baseline.
In a general Danish population, APWV predicted a composite of cardiovascular outcomes above and beyond traditional cardiovascular risk factors, including 24-hour MAP.
Accumulation of mitochondrial DNA (mtDNA) mutations leads to alterations of mitochondrial biogenesis and function that might produce a decrease in mtDNA content within cells. This implies that mtDNA ...content might be a potential biomarker associated with oxidative stress and inflammation. However, data on correlates of mtDNA content in a general population are sparse. Our goal in the present study was to describe in a randomly recruited population sample the distribution and determinants of peripheral blood mtDNA content. From 2009 to 2013, we examined 689 persons (50.4% women; mean age = 54.4 years) randomly selected from a Flemish population (Flemish Study on Environment, Genes, and Health Outcomes). Relative mtDNA copy number as compared with nuclear DNA was measured by quantitative real-time polymerase chain reaction in peripheral blood. There was a curvilinear relationship between relative mtDNA copy number and age. mtDNA content slightly increased until the fifth decade of life and declined in older subjects (Page (2) = 0.0002). mtDNA content was significantly higher in women (P = 0.007) and increased with platelet count (P < 0.0001), whereas it was inversely associated with white blood cell count (P < 0.0001). We also observed lower mtDNA content in women using estroprogestogens (P = 0.044). This study demonstrated in a general population that peripheral blood mtDNA content is significantly associated with sex and age. Blood mtDNA content is also influenced by platelet and white blood cell counts and estroprogestogen intake. Further studies are required to clarify the impact of chronic inflammation and hormone therapy on mitochondrial function.
Our aim was to assess the prognostic significance of nighttime and daytime ambulatory blood pressure and their ratio for mortality and cause-specific cardiovascular events in hypertensive patients ...without major cardiovascular disease at baseline. We performed a meta-analysis on individual data of 3468 patients from 4 prospective studies performed in Europe. Age of the subjects averaged 61±13 years, 45% were men, 13.7% smoked, 8.4% had diabetes, and 61% were under antihypertensive treatment at the time of ambulatory blood pressure monitoring. Office, daytime, and nighttime blood pressure averaged 159±20/91±12, 143±17/87±12, and 130±18/75±12 mm Hg. Total follow-up amounted to 23 164 patient-years. We used multivariable Cox regression analysis to assess the hazard ratios associated with 1 standard deviation higher blood pressure. Daytime and nighttime systolic blood pressure predicted all-cause and cardiovascular mortality, coronary heart disease, and stroke, independently from office blood pressure and confounding variables. When these blood pressures were entered simultaneously into the models, nighttime blood pressure predicted all outcomes, whereas daytime blood pressure did not add prognostic precision to nighttime pressure. Appropriate interaction terms indicated that the results were similar in men and women, in younger and older patients, and in treated and untreated patients The systolic night–day blood pressure ratio predicted all outcomes, which only persisted for all-cause mortality after adjustment for 24-hour blood pressure. In conclusion, nighttime blood pressure is in general a better predictor of outcome than daytime pressure in hypertensive patients, and the night–day blood pressure ratio predicts mortality, even after adjustment for 24-hour blood pressure.
We undertook a quantitative literature review to search for evidence underpinning current guidelines proposing a reduction of sodium intake to less than 2.4 g/d for the management of chronic kidney ...disease. We searched PubMed for peer-reviewed articles published from January 1980 through May 2016. Two investigators screened 5072 publications and extracted data from 36, including 11 cross-sectional and 5 longitudinal observational studies and 20 intervention trials. Within-study effect sizes were pooled and standardized to a sodium gradient of 100 mmol/d by using inverse-variance weighted random effects models. Among cross-sectional studies, the pooled odds ratio for albuminuria was 1.23 (95% confidence interval CI, 0.92–1.64, P = 0.16), and the pooled mean difference in glomerular filtration rate amounted to 8.5 ml/min (CI, -2.3 to 19.2 ml/min; P = 0.12). In the cohort studies, the pooled relative risk of a renal endpoint was 1.08 (CI, 0.92–1.29; P = 0.35). In the intervention trials (median duration, 14 days range, 4–186 days), the mean differences in estimated glomerular filtration rate and albuminuria (high vs. low sodium intake) averaged 4.6 ml/min (CI, 3.4–5.8 ml/min; P < 0.0001) and 53% (CI, 21–84; P = 0.001), respectively. Cochran’s Q statistic indicated significant heterogeneity among cross-sectional studies for both estimated glomerular filtration rate and albuminuria (P < 0.0001) and among intervention trials for albuminuria (P = 0.04). In conclusion, there is no robust evidence suggesting that long-term reduction of salt intake would prevent chronic kidney disease or delay its progression. However, our current findings, which were mainly obtained in people with slight renal impairment, cannot be extrapolated to patients with moderate or severe chronic kidney disease.
In previous studies, of which several were underpowered, the relation between cardiovascular outcome and blood pressure (BP) variability was inconsistent. We followed health outcomes in 8938 subjects ...(mean age53.0 years; 46.8% women) randomly recruited from 11 populations. At baseline, we assessed BP variability from the SD and average real variability in 24-hour ambulatory BP recordings. We computed standardized hazard ratios (HRs) while stratifying by cohort and adjusting for 24-hour BP and other risk factors. Over 11.3 years (median), 1242 deaths (487 cardiovascular) occurred, and 1049, 577, 421, and 457 participants experienced a fatal or nonfatal cardiovascular, cardiac, or coronary event or a stroke. Higher diastolic average real variability in 24-hour ambulatory BP recordings predicted (P≤0.03) total (HR1.14) and cardiovascular (HR1.21) mortality and all types of fatal combined with nonfatal end points (HR≥1.07) with the exception of cardiac and coronary events (HR≤1.02; P≥0.58). Higher systolic average real variability in 24-hour ambulatory BP recordings predicted (P<0.05) total (HR1.11) and cardiovascular (HR1.16) mortality and all fatal combined with nonfatal end points (HR≥1.07), with the exception of cardiac and coronary events (HR≤1.03; P≥0.54). SD predicted only total and cardiovascular mortality. While accounting for the 24-hour BP level, average real variability in 24-hour ambulatory BP recordings added <1% to the prediction of a cardiovascular event. Sensitivity analyses considering ethnicity, sex, age, previous cardiovascular disease, antihypertensive treatment, number of BP readings per recording, or the night:day BP ratio were confirmatory. In conclusion, in a large population cohort, which provided sufficient statistical power, BP variability assessed from 24-hour ambulatory recordings did not contribute much to risk stratification over and beyond 24-hour BP.
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