Elsevier

Computers in Biology and Medicine

Volume 92, 1 January 2018, Pages 73-77
Computers in Biology and Medicine

Relationship between carotid artery sclerosis and blood pressure variability in essential hypertension patients

https://doi.org/10.1016/j.compbiomed.2017.03.012Get rights and content

Highlights

  • Relationship between the CAS and BPV in hypertension patients was studied.

  • SSD and the difference between daytime and nighttime SBP were BPV risk factors.

  • Age, smoking and fasting blood glucose were identified as clinical risk factors.

Abstract

Objectives

This study aimed to investigate the relationship between the presence of carotid arteriosclerosis (CAS) and blood pressure variability (BPV) in patients with essential hypertension.

Methods

One hundred and forty four essential hypertension patients underwent ambulatory BP monitoring for 24 h after hospitalization. Common BPV metrics were calculated. General clinical parameters, including age, gender, height, weight, history of coronary heart disease, stroke, diabetes, hypertension, smoking and drink, were recorded. Biochemical indices were obtained from a blood test. Carotid intima-media thickness (IMT) and carotid plaques were assessed to separate patients into a non-CAS group (IMT≤0.9 mm; n=82) and a CAS group (IMT>0.9 mm; n=62). BPV metrics and clinical parameters were analyzed and compared between the two groups. Multivariate logistic regression analysis was performed to determine the associated risk factors of CAS.

Results

Multivariate logistic regression analysis revealed that two BPV metrics, the standard deviation of daytime systolic blood pressure (SSD) (OR: 1.587, 95%CI: 1.242–2.028), the difference between average daytime SBP and nighttime SBP (OR: 0.914, 95%CI: 0.855–0.977), as well as three clinical parameters (age, OR: 1.098, 95%CI: 1.034–1.167; smoking, OR: 4.072, 95%CI: 1.466–11.310, and fasting blood glucose, OR: 2.029, 95%CI: 1.407–2.928), were significant factors of CAS in essential hypertension patients.

Conclusion

SSD, in combination with the ageing, smoking and FBG, has been identified as risk factors for CAS in patients with essential hypertension.

Introduction

Carotid atherosclerosis (CAS) is the pathological basis of cardiovascular and cerebrovascular diseases. Many clinical and physiological factors are significantly associated with CAS, including ageing, smoking, hypertension, diabetes. Among them, hypertension is one of the most closely related to CAS [1], [2]. Published studies have confirmed that most patients with hypertension have different degrees of CAS [3], [4].

Patients with CAS normally have reduced blood pressure (BP) regulation because carotid sinus and aortic arch baroreflex play important roles in the regulation of cardiovascular reflex. The main clinical symptoms include either too high or too low BPs with large BP fluctuation, namely increased BPV. In general, patients with CAS have the carotid intima-media thickness (IMT) more than 0.9 [5], [6], [7]. Recent study has reported that daytime and all-day (24 h) systolic blood pressure variability (SBPV) in hypertensive patients are closely related to IMT [8], and SBPV is a good predictor of IMT progression. The clinical significance of BPV has become more attractive to researchers [9], [10], [11]. However, the relationship between different BPV metrics and CAS has not been fully agreed [8], [12], which requires further and comprehensive investigation.

Many studies have reported that BPV is a risk predictor for organ damage, and considered that BPV is more valuable than increased blood pressure (BP), leading to the suggestion that reducing BPV is more important than lowering BP [9], [10], [11], [13], [14], [15]. Recent research has also suggested that BPV is higher in hypertensive patients than in the healthy subjects [9], [10], [11]. Thus, controlling BPV has become a critical approach for BP management in hypertensive patients and patients with atherosclerotic diseases.

BPV has been defined in different ways depending on the time duration, including: very short-term (beat-to-beat), short-term (minute-to-minute or reading-to-reading within a 24-h period), middle-term (day-to-day), long-term (visit-to-visit and seasonal) [9], [10], [11], from which different BPV metrics have been derived, including the standard deviations (SD) of systolic BP (SBP), diastolic BP(DBP) and pulse pressure (PP), as well as the variability uncorrelated with mean BP [9], [10], [11]. In addition, most studies mainly focused on the increased BPV while ignoring the clinical significance of decreased BPV. Most of current BPV metrics are consistent, and have positive correlation with target organ damage. However, some studies suggested that low-reactive BPV (such as blunted surge, nocturnal hypertension, orthostatic hypotension) is also a risk factor of cardiovascular disease, which is also associated with target organ lesions of hypertensive patients. Therefore, it is necessary to study hyporeactive BPV indices and explore its relationship with hypertensive atherosclerosis [16], [17].

Various factors, including neuroendocrine factors, vascular wall elasticity, environmental factors, emotional turmoil and sudden movements, affect BPV values [9], [10], [11]. Although many studies have provided evidence that CAS is closely associated with BPV [13], [14], [15], [18], the relationship between CAS and BPV has not been quantified. In addition, different studies have used different BPV indices. This study aimed to explore the relationship between BPV metrics and the degree of CAS in patients with essential hypertension.

Section snippets

Patients

The study recruited 144 essential hypertension patients who were hospitalized in the Department of Neurology and Department of Cardiology, Weihai Central Hospital Affiliated to Qingdao University Medical College. There were 80 male and 64 female. Their age range was 45–89 year (66±9 year). This study was approved by the College Ethics Committee of Weihai Central Hospital Affiliated to Qingdao University Medical College.

The diagnosis of essential hypertension was based on the criteria reported

Results

As shown in Table 1, there was no significant difference between the non-CAS and CAS groups in gender; history of drinking, hypertension and coronary heart disease; BMI values; levels of TC, HDL-C, LDL-C, uric acid; GFR and fibrinogen (all P>0.05). However, there was a significant difference between the two groups in age, history of smoking, history of stroke, history of diabetes and the levels of TG, FBG, hs-CRP, HCY and urine protein (P<0.01 or 0.05).

Table 2 shows the 24 h ambulatory BPV

Discussion

BPV has recently attracted great attention in basic and clinical research. An increasing number of studies have concluded that increased BPV, independent of the average BP values, is a risk factor for cardiovascular and cerebrovascular diseases, which is more valuable than average BP to predict target organ lesions in hypertensive patients [9], [10]. However, other studies reported that BPV was not relevant to target organ damage in hypertensive patients [18], [19]. Therefore, further

Conflict of interest statement

The authors declare no conflict of interest.

Acknowledgments

This research was sponsored by the National Natural Science Foundation of China (Grant 61671275).

References (33)

  • S. Ebrahim et al.

    Carotid plaque, intima media thickness, cardiovascular risk factors, and prevalent cardiovascular disease in men and women: the British Regional Heart Study

    Stroke

    (1999)
  • G. Parati et al.

    Assessment and management of blood-pressure variability

    Nat. Rev. Cardiol.

    (2013)
  • X.L. Chi et al.

    Doubts and difficulties in studying blood pressure variability

    Eur. Rev. Med. Pharmacol. Sci.

    (2016)
  • H. Xiong et al.

    The relationship between the 24  h blood pressure variability and carotid intima-media thickness: a compared study

    Comput. Math. Methods Med.

    (2014)
  • A. Tatasciore et al.

    Awake systolic blood pressure variability correlates with target-organ damage in hypertensive subjects

    Hypertension

    (2007)
  • G. Leoncini et al.

    Blood pressure variability and multiple organ damage in primary hypertension

    J. Hum. Hypertens.

    (2013)
  • Cited by (11)

    • Subject-wise model generalization through pooling and patching for regression: Application on non-invasive systolic blood pressure estimation

      2022, Computers in Biology and Medicine
      Citation Excerpt :

      Both abnormalities are dangerous to health; however, hypertension is much more common and severe, with an estimate of 1.13 billion patients in 2015 [50]. Hypertension is highly associated with life-degrading and life-threatening diseases such as atherosclerosis [51], hypertensive retinopathy [52], dementia [53], kidney failure [54], aneurysms [55], and heart failure [56]. In fact, according to the world health organization (WHO), hypertension is associated with the top two causes of death worldwide [57].

    • Relationships between blood pressure variability and silent cerebral infarction in patients with primary hypertension

      2018, Artery Research
      Citation Excerpt :

      In other words, these patients had different levels of increased blood pressure and most of them had intake history of antihypertensive drugs; 2) they met the diagnostic criteria for hypertension; and 3) currently, it is estimated that almost 50% of stroke cases may be attributable to hypertension.21 However, if we consider the relationships between BPV and cardiovascular/cerebrovascular diseases, more than 90% of strokes may be related to hypertension.11 Assuming that BPV is risk factor affecting SCI independent of blood pressure, then we have reason to find BPV indicators that are independently related to SCI, which is the purpose of this study.

    View all citing articles on Scopus
    View full text