Risk stratification by 24-hour ambulatory blood pressure and estimated glomerular filtration rate in 5322 subjects from 11 populations

Ambulatory blood pressure monitoring over 24 h: A Latin American Society of Hypertension position paper-accessibility, clinical use and cost effectiveness of ABPM in Latin America in year 2020

Accurate office blood pressure measurement remains crucial in the diagnosis and management of hypertension worldwide, including Latin America (LA). Office blood pressure (OBP) measurement is still the leading technique in LA for screening and diagnosis of hypertension, monitoring of treatment, and long-term follow-up. Despite this, due to the increasing awareness of the limitations affecting OBP and to the accumulating evidence on the importance of ambulatory BP monitoring (ABPM), as a complement of OBP in the clinical approach to the hypertensive patient, a progressively greater attention has been paid worldwide to the information on daytime and nighttime BP patterns offered by 24-h ABPM in the diagnostic, prognostic, and therapeutic management of hypertension. In LA countries, most of the Scientific Societies of Hypertension and/or Cardiology have issued guidelines for hypertension care, and most of them include a special section on ABPM. Also, full guidelines on ABPM are available. However, despite the available evidence on the advantages of ABPM for the diagnosis and management of hypertension in LA, availability of ABPM is often restricted to cities with large population, and access to this technology by lower-income patients is sometimes limited by its excessive cost. The authors hope that this document might stimulate health authorities in each LA Country, as well as in other countries in the world, to regulate ABPM access and to widen the range of patients able to access the benefits of this technique.

Association of kidney function and albuminuria with prevalent and incident hypertension: the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

Decreased kidney function and kidney damage may predate hypertension, but only a few studies have investigated both types of markers simultaneously, and these studies have obtained conflicting results.

STUDY DESIGN

Cross-sectional for prevalent and prospective observational study for incident hypertension.

SETTING & PARTICIPANTS

9,593 participants from the ARIC (Atherosclerosis Risk in Communities) Study, aged 53-75 years in 1996-1998.

PREDICTORS

Several markers of kidney function (estimated glomerular filtration rate using serum creatinine and/or cystatin C and 2 novel markers [β-trace protein and β2-microglobulin]) and 1 marker of kidney damage (urinary albumin-creatinine ratio [ACR]). Every kidney marker was categorized by its quintiles (top quintile as a reference for estimated glomerular filtration rates and bottom quintile for the rest).

OUTCOMES

Prevalent and incident hypertension.

MEASUREMENTS

Prevalence ratios and HRs of hypertension based on modified Poisson regression and Cox proportional hazards models, respectively.

RESULTS

There were 4,378 participants (45.6%) with prevalent hypertension at baseline and 2,175 incident hypertension cases during a median follow-up of 9.8 years. Although all 5 kidney function markers were associated significantly with prevalent hypertension, prevalent hypertension was associated most notably with higher ACR (adjusted prevalence ratio, 1.60 [95% CI, 1.50-1.71] for the highest vs lowest ACR quintile). Similarly, ACR was associated consistently with incident hypertension in all models tested (adjusted HR, 1.28 [95% CI, 1.10-1.49] for top quintile), while kidney function markers demonstrated significant associations in some, but not all, models. Even mildly increased ACR (9.14-14.0mg/g) was associated significantly with incident hypertension.

LIMITATIONS

Self-reported use of antihypertensive medication for defining incident hypertension, single assessment of kidney markers, and relatively narrow age range.

CONCLUSIONS

Although all kidney markers were associated with prevalent hypertension, only elevated albuminuria was associated consistently with incident hypertension, suggesting that kidney damage is related more closely to hypertension than moderate reduction in overall kidney function.

Ambulatory hypertension subtypes and 24-hour systolic and diastolic blood pressure as distinct outcome predictors in 8341 untreated people recruited from 12 populations

BACKGROUND

Data on risk associated with 24-hour ambulatory diastolic (DBP24) versus systolic (SBP24) blood pressure are scarce.

METHODS AND RESULTS

We recorded 24-hour blood pressure and health outcomes in 8341 untreated people (mean age, 50.8 years; 46.6% women) randomly recruited from 12 populations. We computed hazard ratios (HRs) using multivariable-adjusted Cox regression. Over 11.2 years (median), 927 (11.1%) participants died, 356 (4.3%) from cardiovascular causes, and 744 (8.9%) experienced a fatal or nonfatal cardiovascular event. Isolated diastolic hypertension (DBP24≥80 mm Hg) did not increase the risk of total mortality, cardiovascular mortality, or stroke (HRs≤1.54; P≥0.18), but was associated with a higher risk of fatal combined with nonfatal cardiovascular, cardiac, or coronary events (HRs≥1.75; P≤0.0054). Isolated systolic hypertension (SBP24≥130 mm Hg) and mixed diastolic plus systolic hypertension were associated with increased risks of all aforementioned end points (P≤0.0012). Below age 50, DBP24 was the main driver of risk, reaching significance for total (HR for 1-SD increase, 2.05; P=0.0039) and cardiovascular mortality (HR, 4.07; P=0.0032) and for all cardiovascular end points combined (HR, 1.74; P=0.039) with a nonsignificant contribution of SBP24 (HR≤0.92; P≥0.068); above age 50, SBP24 predicted all end points (HR≥1.19; P≤0.0002) with a nonsignificant contribution of DBP24 (0.96≤HR≤1.14; P≥0.10). The interactions of age with SBP24 and DBP24 were significant for all cardiovascular and coronary events (P≤0.043).

CONCLUSIONS

The risks conferred by DBP24 and SBP24 are age dependent. DBP24 and isolated diastolic hypertension drive coronary complications below age 50, whereas above age 50 SBP24 and isolated systolic and mixed hypertension are the predominant risk factors.

Significance of white-coat and masked hypertension in chronic kidney disease and end-stage renal disease

Hypertension is a frequent and modifiable cardiovascular risk factor with a cyclic relationship with chronic kidney disease (CKD). The diagnosis, treatment, monitoring and control of high blood pressure are all mandatory not only in CKD but also in end-stage renal disease (ESRD). As demonstrated by studies using population and hypertensive patients, white-coat hypertension (WCHT) and masked hypertension (MHT) carry a particular degree of risk. The advantages of ambulatory techniques in the management and prognostic stratification of patients with CKD and ESRD have also been recognized. However, most of the evidence underlines the importance of nocturnal hypertension and neglects WCHT and MHT. The absence of specific reports involving untreated and treated patients hinders the ability to significantly discriminate WCHT from the white-coat effect and MHT from masked uncontrolled hypertension. The heterogeneous definitions that are used add additional difficulty in translating experimental evidence into clinical practice. Reaching a consensus in definitions is mandatory for designing future research. Cross-sectional studies underscore the frequency of misdiagnosis, potentially leading to undertreatment (MHT) and overtreatment (WCHT) in renal disease. The divergent prevalence of WCHT and MHT reported in CKD could be related to the diverse definitions of hypertension and the heterogeneity of the pathologies pooled under the CKD definition. Even in the absence of randomized clinical trials specifically addressing this issue, the scarce longitudinal studies confirm that WCHT carries a risk close to that of sustained normotension, whereas MHT is associated with a risk close or identical to that of sustained hypertension.

Ambulatory blood pressure in chronic kidney disease

Chronic kidney disease (CKD) affects approximately 20 million adults in the United States. Patients with CKD have an increased risk of cardiovascular (CV) disease. Ambulatory blood pressure monitoring (ABPM) provides superior BP measurements when compared to office BP measurements in normotensive, hypertensive and CKD patients. ABPM measurements are often abnormal in CKD, with CKD patients frequently showing an altered circadian rhythm with an increased rate of non-dipping and reverse dipping. The prevalence of non-dippers and reverse-dippers increases progressively as stage of CKD progresses. ABPM has been shown to be a better tool for predicting CV risk, CKD progression, end stage renal disease (ESRD) or death than office-based pressures. ABPM is also additive and adds prognostic value for predicting CKD and CV outcomes when added to estimated glomerular filtration rate (eGFR). Although ABPM is time consuming, it is worth considering, as the data demonstrates that information from ABPM can potentially impact future CV and renal outcomes in patients with CKD.

Blood pressure control and primary prevention of stroke: summary of the recent clinical trial data and meta-analyses

Stroke is the second most common cause of death worldwide and of adult disability, but in the near future the global burden of cerebrovascular diseases will rise due to ageing and adverse lifestyle changes in populations worldwide. The risk of stroke increases at blood pressure levels above 115/75 mm Hg and high blood pressure (BP) is the most important modifiable risk factor for stroke, associated with 54 % episodes of stroke worldwide. There is strong evidence from clinical trials that antihypertensive therapy reduces substantially the risk of any type of stroke, as well as stroke-related death and disability. The risk attributed to BP is associated not only with absolute values but also with certain parameters describing BP diurnal pattern as well as short-term and long-term variability. Many studies reported that certain features of BP like nocturnal hypertension, morning surge or increased variability predict an increased stroke risk. However, there is no accepted effective modality for correction of these disturbances (chronotherapy, certain classes of antihypertensive drugs). In the elderly, who are mostly affected by stroke, the primary prevention guidelines recommend treatment with diuretics and calcium channel blockers to lower blood pressure to the standard level.

Progression of glomerular filtration rate reduction determined in conscious Dahl salt-sensitive hypertensive rats

Sequential changes in glomerular filtration rate during development of hypertension in the conscious Dahl salt-sensitive rats were determined using a new method for measurement. Using a miniaturized device, disappearance curves of fluorescein isothiocyanate-sinistrin were measured by transcutaneous excitation and real-time detection of the emitted light through the skin. Rats with implanted femoral venous catheters (dye injection and sampling) and carotid catheters (mean arterial pressure by telemetry) were studied, while maintained on a 0.4% NaCl diet and on days 2, 5, 7, 14, and 21 after switching to 4.0% (high-salt [HS]) diet. A separate group of rats were maintained on 0.4% for 21 days as a time control. Mean arterial pressure rose progressively from the last day of 0.4% (130±2 mm Hg) reaching significance by day 5 of HS and averaged 162±7 mm Hg by day 21. Urine albumin excretion was significantly elevated (×3) by day 7 of HS in Dahl salt-sensitive rats. Glomerular filtration rate reduced on day 14 of HS falling from 1.53±0.06 mL/min per 100 g body weight to 1.27±0.04. By day 21, glomerular filtration rate had fallen 28% to 1.1±0.04 mL/min per 100 g (t(1/2) 28.4±1.1 minute.) No significant reductions of creatinine clearance were observed throughout the study in response to HS demonstrating the insensitivity of creatinine clearance measurements even with creatinine measured using mass spectrometry. We conclude that the observed reduction of glomerular filtration rate was a consequence and not a cause of the hypertension and that this noninvasive approach could be used in these conscious Dahl salt-sensitive rats for a longitudinal assessment of renal function.

Both chronic kidney disease and nocturnal blood pressure associate with strokes in the elderly

BACKGROUND

Among elderly hypertensive patients, we aimed to assess the association of nocturnal blood pressure (BP) pattern on stroke; interaction of dipping pattern with kidney disease was explored.

METHODS

We retrospectively analyzed the records of 1,276 elderly (≥60 years) hypertensive Japanese patients (mean 74 years; 40% were men) who had measurements of estimated glomerular filtration rate and ambulatory BP.

RESULTS

Stroke events occurred in 73 people over an average of 3.2 years (4,026 person-years). Chronic kidney disease (CKD) at baseline (n = 634, 50%) was more prevalent in people with strokes (71%) than those without strokes (48%; p < 0.01). Both CKD and nocturnal systolic BP (SBP) increase (10 mm Hg) were independently associated with increased risk for stroke [hazard ratio (HR), 1.9; 95% confidence interval (CI), 1.1-3.1 for CKD and HR 1.2; 1.1-1.4 for SBP]. After adjustment for office SBP, a 10-mm Hg increase in nocturnal SBP was similarly associated with strokes in patients with CKD (HR 1.2; 95% CI 1.0-1.3) and those without CKD (HR 1.2; 95% CI 0.97-1.5). Although reverse dipping (nocturnal SBP ≥ daytime SBP) was associated with stroke only in patients with CKD (HR 2.1; 95% CI 1.1-4.1) and not those without CKD (HR 1.1; 95% CI 0.3-3.8), the interaction effect was not significant (p = 0.30).

CONCLUSION

In elderly hypertensive patients, both high nocturnal SBP and CKD are independent risk factors for stroke.