Long sleep duration and cardiovascular disease: Associations with arterial stiffness and blood pressure variability

Although short and long sleep duration are both risk factors of cardiovascular disease (CVD), the recent meta‐analyses have been shown that long sleep duration was closely associated with CVD mortality. While the specific mechanism underlying the association between long sleep duration and CVD remains unclear, long sleep duration was shown to be associated with arterial stiffness and blood pressure variability (BPV) in many Asian populations. This review article will focus on the pathophysiology of long sleep duration, arterial stiffness, BPV and their effects on CVD. To set the stage for this review, we first summarize the current insights for the relationship between long sleep duration and CVD in relation to arterial stiffness and BPV.

Visit-to-visit blood pressure variability and dementia

Visit-to-visit blood pressure variability has been shown to be an independent risk factor for stroke and cognitive impairment. However, the underlying mechanisms are not fully understood. Artery remodeling and silent cerebral injury are suggested to be involved in the relationship between visit-to-visit blood pressure variability and cognitive impairment. The present review article summarizes the recent literature on these topics. Here we review visit-to-visit blood pressure variability, artery remodeling, silent cerebral injury and an issue regarding the impact of these components on dementia including Alzheimer's disease.

Impact of baseline systolic blood pressure on visit-to-visit blood pressure variability: the Kailuan study

Background

To investigate the relationship between baseline systolic blood pressure (SBP) and visit-to-visit blood pressure variability in a general population.

Methods

This is a prospective longitudinal cohort study on cardiovascular risk factors and cardiovascular or cerebrovascular events. Study participants attended a face-to-face interview every 2 years. Blood pressure variability was defined using the standard deviation and coefficient of variation of all SBP values at baseline and follow-up visits. The coefficient of variation is the ratio of the standard deviation to the mean SBP. We used multivariate linear regression models to test the relationships between SBP and standard deviation, and between SBP and coefficient of variation.

Results

Approximately 43,360 participants (mean age: 48.2±11.5 years) were selected. In multivariate analysis, after adjustment for potential confounders, baseline SBPs <120 mmHg were inversely related to standard deviation (P<0.001) and coefficient of variation (P<0.001). In contrast, baseline SBPs ≥140 mmHg were significantly positively associated with standard deviation (P<0.001) and coefficient of variation (P<0.001). Baseline SBPs of 120–140 mmHg were associated with the lowest standard deviation and coefficient of variation. The associations between baseline SBP and standard deviation, and between SBP and coefficient of variation during follow-ups showed a U curve.

Conclusion

Both lower and higher baseline SBPs were associated with increased blood pressure variability. To control blood pressure variability, a good target SBP range for a general population might be 120–139 mmHg.

Antihypertensive Drug Use, Blood Pressure Variability, and Incident Stroke Risk in Older Adults

Background and Purpose—

The aim was to determine the association between antihypertensive drug class and incident stroke controlling for long-term blood pressure (BP) variability (BPV) in people aged ≥65 years.

Methods—

The sample included 5951 participants (median age 74 years, 60% women) taking at least 1 drug for hypertension (3727/5951) or with systolic BP >140 mm Hg or diastolic BP >90 mm Hg. Participants were evaluated for incident fatal and nonfatal stroke to 12 years follow-up. BPV was calculated with the coefficient of variation method and regressed against 9 antihypertensive drug classes (BPV reg ). Hazard models were used to determine hazard ratios for incident stroke risk attributable to drug class, adjusted for BP, BPV reg , covariates, and delayed entry bias.

Results—

There were 273 incident strokes over a median of 9.1 years (interquartile range 6.4–10.4). Stroke risk was generally not reduced by BP-lowering drugs. Angiotensin receptor blockers (hazard ratio 1.56; 95% confidence interval 1.06–2.28; P =0.02) and β-blockers (hazard ratio 1.41; 95% confidence interval 1.03–1.92; P =0.03) were associated with an increased total stroke risk. Angiotensin receptor blockers and β-blockers were also associated with ischemic strokes after adjustment for systolic BPV. Diastolic BPV was associated with stroke risk in analyses stratified by systolic BP 140 to 160 mm Hg (per 0.10 increase in coefficient of variation, hazard ratio 1.59; 95% confidence interval 1.05–2.40; P =0.03).

Conclusions—

The angiotensin receptor blocker and β-blocker drug classes were associated with incident stroke and ischemic stroke in older adults. BPV was generally not associated with incident stroke.

Visit-to-visit blood pressure variability, silent cerebral injury, and risk of stroke

Apart from the well-known role of hypertension in cerebrovascular disease, visit-to-visit blood pressure (BP) variability is emerging as an independent risk factor for stroke. Although the underlying mechanism is not fully understood, artery remodeling is thought to be closely involved in the relationship between visit-to-visit BP variability and stroke. This review article summarizes the recent literature on these topics. Silent cerebral injury is considered to serve as a common pathophysiology in the relationship of visit-to-visit BP variability with cognitive impairment and stroke. Here we review visit-to-visit BP variability, some comparisons of the effects of antihypertensive agents on visit-to-visit BP variability, and an issue regarding the impact of these agents on stroke.

Blood pressure variability and outcomes in chronic kidney disease

BACKGROUND

We investigated the effects of visit-to-visit systolic blood pressure variability (SBPV) on both mortality and dialysis inception in a cohort of chronic kidney disease (CKD) patients not requiring dialysis therapy. Furthermore, we also explored the carry-over effect of visit-to-visit SBPV on mortality after dialysis initiation.

METHODS

We conducted a longitudinal retrospective, observational, multi-centre study in three tertiary care nephrology outpatient clinics. All the ambulatory CKD patients admitted to the outpatient clinics from 1 January 2004 to 31 December 2005 were screened for study eligibility. We selected all consecutive patients older than 18 years of age with a mean estimated glomerular filtration rate of <60 mL/min/m(2), free from cardiovascular disease. SBPV was defined as the ratio of the SD to the mean SBP of five values recorded during a run-in phase of 4-5 months. Data on dialysis inception and mortality were recorded through 31 December 2010.

RESULTS

Overall, we selected a cohort of 374 elderly (median age: 79 years) subjects. A total of 232 (62%) and 103 (29%) patients were male and had diabetes, respectively. A significant association between SBPV and the risk of death but not of CKD progression to dialysis was noted at univariate and after multivariable adjustments (hazard ratio for all-cause mortality per 1% increase in SBPV: 1.05; 95% confidence interval: 1.02-1.09; P = 0.001). Notably, no lethal event was recorded after dialysis initiation.

CONCLUSIONS

Current findings suggest that SBPV may be of use for risk stratification in CKD patients.