Extreme dipping: is the cardiovascular risk increased? An unsolved issue

Nocturnal systolic blood pressure dipping among people living with HIV and people without HIV: a cross-sectional study in Rural Uganda

Background

In this study, we investigated sleep quality, depression and stress symptoms as hypothesized factors affecting the association between HIV status and nocturnal blood pressure dipping status in rural Uganda.

Methods

Individuals living with HIV (PLHIV) and people without HIV (PwoHIV) underwent 24-hour ambulatory blood pressure monitoring (ABPM) and classified as extreme dippers, dippers and non-dippers based on a percentage nocturnal drop in mean systolic and diastolic blood pressure. Ordinal logistic regression models were used to assess the effect of different exposure variables (HIV status, sleep quality and other covariates) on the outcome (dipping status).

Results

The median age was 45 years (IQR: 35-54) and 80% of the participants were female. 24% of PwoHIV and 16% of PLHIV were overweight, 10% of HIV negative and 3% of the HIV positive individuals were obese. Depression was prevalent in both PLHIV and PwoHIV. Additionally, poor sleep quality was more prevalent in PLHIV compared to PwoHIV (70% versus 58%, P= 0.046). The study found that 53% of participants had normal dipping, while 35.1% were non-dippers, with non-dipping being more prevalent in PwoHIV individuals (34.9% vs 29.7%, P<0.001). PLHIV had 3.6 times the odds of being extreme dippers compared to PwoHIV (OR 3.64, 95% CI: 1.40 - 9.44).

Conclusion

This study identified high proportions of non-dipping BP profiles among both PLHIV and PwoHIV. However, the odds of being extreme dippers were higher among PLHIV compared to PwoHIV. Further research is needed to understand the underlying mechanisms contributing to extreme dipping patterns in PLHIV.

Food consumption by degree of processing is associated with nocturnal dipping and blood pressure variability: The ELSA-Brasil study

BACKGROUND AND AIMS

Ambulatory blood pressure monitoring (ABPM) allows the assessment of cardiovascular risk markers that cannot be obtained by casual measurements; however, the evidence on the association between food consumption and blood pressure (BP) assessed by ABPM is scarce. We aimed to evaluate the association between food consumption by degree of processing and ambulatory BP.

METHODS AND RESULTS

Cross-sectional analysis (2012-2014) of data from a subsample (n = 815) of ELSA-Brasil cohort participants who performed 24-h ABPM was conducted. Systolic (SBP) and diastolic (DBP) BP means and variability during the 24 h and subperiods (sleep and wake), nocturnal dipping, and morning surge were evaluated. Food consumption was classified according to NOVA. Associations were tested by generalized linear models. The consumption of unprocessed, minimally processed foods, and culinary ingredients (U/MPF&CI) was 63.1% of daily caloric intake, 10.8% of processed (PF), and 24.8% of ultraprocessed (UPF). A negative association was found between U/MPF&CI consumption and extreme dipping (T2: odds ratio [OR] = 0.56, 95% confidence interval [CI] = 0.55-0.58; T3: OR = 0.55; 95% CI = 0.54-0.57); and between UPF consumption and nondipping (T2: OR = 0.68, 95% CI = 0.55-0.85) and extreme dipping (T2: OR = 0.63, 95% CI = 0.61-0.65; T3: OR = 0.95, 95% CI = 0.91-0.99). There was a positive association between PF consumption and extreme dipping (T2: OR = 1.22, 95% CI = 1.18-1.27; T3: OR = 1.34, 95% CI = 1.29-1.39) and sleep SBP variability (T3: Coef = 0.56, 95% CI = 0.03-1.10).

CONCLUSIONS

The high consumption of PF was associated with greater BP variability and extreme dipping, while the U/MPF&CI and UPF consumption were negatively associated with alterations in nocturnal dipping.

Association between ambulatory blood pressure monitoring patterns with cognitive function and risk of dementia: a systematic review and meta-analysis

BACKGROUND

The objective of this systematic review and meta-analysis is to investigate whether nocturnal blood pressure fall, expressed by dipping patterns according to 24 h ambulatory blood pressure monitoring (ABPM), is associated with abnormal cognitive function (cognitive impairment or dementia).

METHODS

We systematically searched PubMed, Embase, and Cochrane databases to identify original articles through December 2022. We included any study with at least ten participants reporting on all-cause dementia or cognitive impairment incidence (primary outcome) or validated cognitive tests (secondary outcome) among ABPM patterns. We assessed risk of bias using Newcastle-Ottawa Quality Assessment Scale. We pooled odds ratios (OR) and standardized mean differences (SMD) using random-effect models for primary and secondary outcome, respectively.

RESULTS

In the qualitative synthesis, 28 studies examining 7595 patients were included. The pooled analysis of 18 studies showed that dippers had a 51% [OR 0.49(0.35-0.69)] lower risk of abnormal cognitive function and a 63% [OR 0.37(0.23-0.61)] lower risk of dementia alone, compared to non-dippers. Reverse dippers presented an up to sixfold higher risk [OR 6.06(3.15-11.64)] of abnormal cognitive function compared to dippers and an almost twofold higher risk [OR 1.81(1.26-2.6)] compared to non-dippers. Reverse dippers performed worse in global function neuropsychological tests compared with both dippers [SMD - 0.66(- 0.93 to - 0.39)] and non-dippers [SMD - 0.35(- 0.53 to - 0.16)].

CONCLUSION

Dysregulation of the normal circadian BP rhythm, specifically non-dipping and reverse dipping is associated with abnormal cognitive function. Further studies are required to determine potential underlying mechanisms and possible prognostic or therapeutic implications.

PROTOCOL REGISTRATION

PROSPERO database (ID: CRD42022310384).

Pathophysiology of the Nondipping Blood Pressure Pattern

The nondipping blood pressure (BP) pattern corresponds to a disruption in the circadian BP rhythm with an insufficient decrease in BP levels during nighttime sleep as observed using 24-hour ambulatory BP monitoring. Patients with nondipping BP pattern have poorer renal and cardiovascular outcomes, independent of their average 24-hour BP levels. The pathophysiology of nondipping BP is complex and involves numerous mechanisms: perturbations of (1) the circadian rhythm, (2) the autonomic nervous system, and (3) water and sodium regulation. This review provides an outline of the pathways potentially involved in the nondipping BP profile in different conditions. A recent hypothesis is also discussed involving the role of gut microbiota in the dipping/nondipping patterns, via the fecal diet-derived short chain fatty acids.

Controlled-release oral melatonin supplementation for hypertension and nocturnal hypertension: A systematic review and meta-analysis

Oral melatonin is a potential alternative treatment for hypertension and nocturnal hypertension. However, high-quality and relevant meta-analyses are lacking. This meta-analysis aimed to investigate whether oral melatonin supplementation reduces daytime/asleep blood pressure and cardiovascular risk, improves sleep quality, and is well-tolerated compared with placebo. Relevant articles were searched in multiple databases, including MEDLINE, EMBASE, CINAHL Complete, and the Cochrane Library, from their inception to June 2021. The included studies were randomized controlled trials recruiting patients with hypertension, using oral melatonin as the sole intervention, and investigating its effect on blood pressure. The mean out-of-office (including 24-h, daytime, and asleep) systolic and diastolic blood pressures, sleep quality, and side effects were compared between the melatonin and placebo arms using pairwise random-effect meta-analyses. A risk of bias assessment was performed using the Cochrane risk-of-bias tool. Four studies were included in the analysis and only one study was considered to have a low risk of bias. No study reported on cardiovascular risk or outcomes. Only controlled-release melatonin (not an immediate-release preparation) reduced asleep systolic blood pressure by 3.57 mm Hg (95% confidence interval: -7.88 to .73; I2  = 0%). It also reduced asleep and awake diastolic blood pressure, but these differences were not statistically significant. Melatonin improves sleep efficacy and total sleep time and is safe and well-tolerated. Due to the limited number of high-quality trials, the quality of evidence was low to very low. Therefore, adequately powered randomized controlled trials on melatonin are warranted.

Is there any true distinction in extreme dipping versus nondipping or dipping phenotype regarding hypertension-mediated organ damage in newly diagnosed and never-treated hypertensive patients?

Dipping phenomena is defined as nocturnal BP fall >10% during 24-h ambulatory blood pressure (BP) monitoring (ABPM) which carries a favorable cardiovascular risk (CVR) prognosis due to reduced 24-h hypertension burden. To date, extreme dipping phenotype (defined as BP decrease ≥20%) has led to controversial prognostic results regarding CVR. We aimed to explore hypertension-mediated organ damage (HMOD) in extreme dippers compared to the other dipping phenotypes (nondipping, dipping). From 490 consecutive patients with newly diagnosed never-treated arterial hypertension (mean age 51 ± 11 years, 294 males) subjected to 24-h ABPM, we studied 52 extreme dippers, 52 age- and gender-matched nondippers, and 52 age- and gender-matched dippers. All patients were subjected to arterial stiffness (PWV), 24-h microalbumin levels, carotid intima-media thickness (cIMT), diastolic dysfunction (E/Ea), and left ventricular mass index (LVMI) evaluation. ANOVA analysis found no differences regarding HMOD between groups. Multiple regression analysis revealed the following independent direct relationships between: (i) office SBP and PWV in nondippers (β = 0.35, p = 0.01) and extreme dippers (β = 0.49, p < 0.001), (ii) office SBP and E/Ea in extreme dippers (β = 0.39, p = 0.007), (iii) 24-h diurnal and nocturnal SBP and E/Ea in dippers (β = 0.40, p = 0.004, β = 0.39, p = 0.005, and β = 0.40, p = 0.004, respectively), and (iv) 24-h and nocturnal SBP and LVMI in nondippers (β = 0.29, p = 0.04 and β = 0.36, p = 0.009, respectively). In the early phases of untreated-arterial hypertension disease, extreme dipping phenotype in middle-aged hypertensives does not imply an adverse or favorable prognosis regarding the incidence of HMOD either as continuous variables or as abnormal HMOD compared to other dipping phenotypes.

Associations of the nocturnal blood pressure fall and morning surge with cardiovascular events and mortality in individuals with resistant hypertension

OBJECTIVE

The prognostic importance of the nocturnal blood pressure (BP) fall and early-morning surge were scarcely investigated in patients with resistant hypertension (RHT). We investigated them in a prospective cohort of 1726 RHT individuals.

METHODS

The nocturnal fall and morning surge were calculated from the baseline ambulatory BP monitoring (ABPM) and also as mean cumulative values using all ABPMs performed during follow-up. Dipping patterns (normal, extreme, reduced, and reverse) were defined by classic cut-off values of the night-to-day ratio, while MS (difference between early-morning and night-time BP) was categorized into quartiles and at the extremes of its distribution (5th, 10th, 90th, and 95th percentiles). The primary outcomes were total cardiovascular events (CVEs), major adverse cardiovascular events (MACEs), all-cause and cardiovascular mortalities. Multivariate Cox analyses examined the associations between nocturnal BP fall and morning surge and outcomes.

RESULTS

Over a median follow-up of 8.3 years, 417 CVEs occurred (358 MACEs), and 391 individuals died (233 cardiovascular deaths). Reduced and reverse dipping patterns were significant predictors of CVEs and MACEs, with hazard ratios between 1.6 and 2.5, whereas extreme dipping was a protective factor in younger individuals (hazard ratios 0.3--0.4) but a hazardous factor in elderly (hazard ratios 3.7--5.0) and in individuals with previous cardiovascular diseases (hazard ratios 2.6--4.4). No morning surge parameter was predictive of any outcome in fully adjusted analyses.

CONCLUSION

Abnormal dipping patterns but not the early-morning BP surge, were important prognostic markers for future cardiovascular morbidity in RHT patients. The prognosis of extreme dippers depended on age and the presence of cardiovascular diseases.

[Antihypertensives always evenings-absolutely not or sensible?]

The Spanish Hygia study has led to considerable irritation due to the general recommendation to prescribe antihypertensives preferably to be taken in the evening, especially since the lay press as well as medical media made enthusiastic comments. The discussion about the optimal time to take antihypertensive drugs shows once again how dangerous the uncritical handling of study data can be. No possible risks were pointed out. The Hygia study compared 19,084 patients with morning and evening intake of antihypertensive drugs under the control of a 48‑h blood pressure measurement (!). There was a significantly better reduction in blood pressure and the rate of cardiovascular and cerebrovascular events with evening intake. The data are scientifically valuable; however, the conclusions are incomprehensible based on the data, contradict many other studies and are dangerous for certain patient groups. There are also methodological shortcomings. Therefore, a general evening intake is not justified and nonsensical due to the diverse, individually very different pathophysiological findings of the nocturnal blood pressure behavior. Basically, the outpatient 24‑h blood pressure measurement (ABPM) enables a better assessment of the individual cardiovascular and cerebrovascular risks and prevents an incorrect assessment of the blood pressure and thus unnecessary or sufficient treatment. Instead of a general recommendation, the ABPM offers the option of an individually tailored treatment. Taking antihypertensive drugs in the evening should always be preceded by an ABDM in the case of prognostically unfavorable nocturnal hypertension in order to avoid the risk of nocturnal ischemic risks due to excessive drops in blood pressure.

Association of Extreme Nocturnal Dipping With Cardiovascular Events Strongly Depends on Age

Whether extreme dipping is associated with cardiovascular events (CVE) is unclear. The present study was conducted to test the hypothesis that the prognostic role of extreme dipping varies as a function of age. The analysis was performed in 10 868 participants (53% men) aged 53±15 (mean±SD) years enrolled in 8 prospective studies. Using the ambulatory systolic blood pressure nocturnal decline, we identified 4 groups: dippers (>10%–20%), nondippers (>0%–10%), reverse dippers (≤0%), and extreme dippers (>20%). The association between dipping category and CVE was estimated as a function of age using Cox models adjusted for sex, average 24-hour systolic blood pressure, and traditional risk factors. During a median follow-up of 5.7 years, there were a total of 829 CVE (168 fatal). For extreme dippers, no increase in risk of CVE was observed among the participants <70 years (hazard ratio, 0.99 [95% CI, 0.73–1.34]; P =0.93) compared with dippers. In contrast, among the participants ≥70 years, there was a significant increase in risk (hazard ratio, 1.88 [95% CI, 1.14–3.11]; P =0.013). Among the octogenarians, the hazard ratio (95% CI) for CVE were 2.34 (1.12–4.93) for nondippers ( P =0.024), 3.91 (1.75–8.73) for reverse dippers ( P =0.001), and 4.12 (1.64–10.37) for extreme dippers ( P =0.003) compared with dippers. These data show that extreme dipping is not associated with poorer outcome in people younger than 70 years. A U-shaped relationship between nocturnal blood pressure dipping and adverse outcome is present in subjects older than 70 years. In the octogenarian extreme dippers, the risk of CVEs was 4× higher than in the dippers and similar to that in the reverse dippers.

The Prognostic Effect of Circadian Blood Pressure Pattern on Long-Term Cardiovascular Outcome is Independent of Left Ventricular Remodeling

We aimed to investigate the predictive value of 24 h blood pressure (BP) patterns on adverse cardiovascular (CV) outcome in the initially untreated hypertensive patients during long-term follow-up. This study included 533 initially untreated hypertensive patients who were involved in this study in the period between 2007 and 2012. All participants underwent laboratory analysis, 24 h BP monitoring, and echocardiographic examination at baseline. The patients were followed for a median period of nine years. The adverse outcome was defined as the hospitalization due to CV events (atrial fibrillation, myocardial infarction, myocardial revascularization, heart failure, stroke, or CV death). During the nine-year follow-up period, adverse CV events occurred in 85 hypertensive patients. Nighttime SBP, non-dipping BP pattern, LV hypertrophy (LVH), left atrial enlargement (LAE), and LV diastolic dysfunction (LV DD) were risk factors for occurrence of CV events. However, nighttime SBP, non-dipping BP pattern, LVH, and LV DD were the only independent predictors of CV events. When all four BP pattern were included in the model, non-dipping and reverse dipping BP patterns were associated with CV events, but only reverse-dipping BP pattern was independent predictor of CV events. The current study showed that reverse-dipping BP pattern was predictor of adverse CV events independently of nighttime SBP and LV remodeling during long-term follow-up. The assessment of BP patterns has very important role in the long-time prediction in hypertensive population.

Extreme dipping: More complex than it looks

Information on clinical and prognostic implications of the extreme dipping (ED) pattern is scanty and findings provided by studies are controversial. Increasing evidence suggests than mean night-time blood pressure (BP), a powerful predictor of cardiovascular outcomes, in ED can be markedly different between patients and distributed over a wide range of values ranging from hypotension to hypertension. On the whole, these findings emphasize the need to know that the ED pattern is a heterogeneous phenotype that deserve to be evaluated more in detail in future studies.