Journal Logo

Clinical Methods and Pathophysiology

Interrupted sleep by ambulatory blood pressure monitoring does not affect blood pressure

Geng, Xuea; Li, Fengb; Mao, Zhuofengc; Hu, Haijuana; Cui, Weia

Author Information
doi: 10.1097/MBP.0000000000000585
  • Open

Abstract

Background

For the past 20 years, many hypertension guidelines have strongly recommended the practical use of ambulatory blood pressure monitoring (ABPM) to the diagnosis and management of hypertension [1–3]. 2007 European Society of Hypertension-European Society of Cardiology guidelines for the management of arterial hypertension [2] recommended the use of ABPM to evaluate hypertension treatment and the assessment of patients with suspected hypertension. National Institute for Health and Clinical Excellence hypertension guideline 2011 [3] proposed a landmark suggestion that all people should be diagnosed with hypertension by ABPM. In 2014, the Japanese Society of Hypertension Committee [4] recommended home blood pressure monitoring (HBPM) and ABPM for the diagnosis of white coat and masked hypertension and to evaluate the effect of persistent hypertension treatment. The 2015 Canadian Hypertension Education Program [5] recommended the use of ABPM to diagnose patients with suspected hypertension. The 2017 ACC/AHA American College of Cardiology/American Heart Association guidelines [6] suggested that ABPM is preferred for diagnostic and therapeutic titration for people with blood pressure (BP) close to the hypertension threshold.

However, it has been found in clinical practice that the frequent measurements during ABPM affect the sleep of some people. The link between poor sleep or insomnia and BP measurements is controversial [7]. Whether different sleep conditions during ABPM will affect BP fluctuations and lead to inaccurate measurement results is a concern of clinicians.

The purpose of this study was to assess whether differences in sleep conditions during ABPM may affect the stability of ABPM results.

Methods

Study design

This is a prospective cohort study in the real-world setting. The participants were recruited between June 2018 and June 2019 in Hebei Province, China. The study was approved by the research ethics committee of the Second Hospital of Hebei Medical University. The Second Hospital of Hebei Medical University was the center of the study. All participants provided written informed consent. The study was registered.

Participants

The inclusion criteria were: (1) age ≥16 years; (2) the patient has no cognitive impairment and can cooperate with the examination and complete the questionnaire and (3) all those who meet the inclusion criteria in the family cooperate with the inspection.

The exclusion criteria were: (1) age <16 years; (2) participants with skin infectious diseases and (3) people cannot cooperate with the inspection.

Data collection

General information and related medical history were inquired by a professional physician in cardiology. ABPM is performed by professional medical staff.

Instrument and measurement

Instrument: Contec Dynamic Blood Pressure Monitor, Model: ABPM50, is used. Measurement method: BP is measured every half hour during the day and every hour during the night.

The daytime and night in ABPM were individually set according to the participant’s usual sleep time at night and wake time in the morning.

Related definitions

Sleep was undisturbed during ABPM, which was defined as sleep during ABPM is the same as when no ABPM was performed. Disturbed sleep is defined as nocturnal arousal caused by BP measurement at least once. Severely disturbed sleep is defined as continuous sleep for no more than 1 h due to BP measurements.

Insomnia is a clinical diagnosis made by a neurologist according to the symptoms of participants.

Statistical analysis

The continuous data conforming to the normal distribution were described as mean and SD and the comparison among multiple groups uses a one-way analysis of variance. The continuous data that do not meet the normal distribution are expressed as median (interquartile range), and comparisons between groups are tested by Kruskal–Wallis H test. The categorical data were presented as frequencies and analyzed using Pearson’s chi-square test. We conducted analyses by using SPSS, version 25.0.

Results

Characteristics of the participants

A total of 1415 people were tested for ABPM. Those with an inspection time of ≤20 h, those with a measurement count ≤20 and those who did not record sleep during the monitoring period were excluded. The final number of participants was 1154. Among those aged between 18 and 88 years, 51.5% were males, and 67.8% had hypertension. There were 197 cases of insomnia and 958 people were non-insomnia. The basic situation of the population is shown in Table 1.

Table 1 - Characteristics of the patients
Characteristics Total Insomnia Noninsomnia P value
Number 1155 197 958
Age (year) 53 (45, 62) 56 (48, 64) 53 (45, 61) 0.001
Men (%) 595 (51.5) 73 (37.1) 522 (54.5) <0.001
BMI 25.06 (23.18, 27.43) 24.77 (22.72, 27.28) 25.15 (23.31, 27.44) 0.220
Hypertension (%) 784 (67.8) 135 (68.5) 649 (67.7) 0.867
Stroke (%) 44 (3.8) 14 (7.1) 30 (3.1) 0.159
Heart failure (%) 4 (0.3) 1 (0.5) 3 (0.3) 0.527
Hyperlipidemia (%) 161 (13.9) 42 (26.1) 119 (12.4) 0.002
DM (%) 103 (8.9) 20 (10.2) 83 (8.7) 0.494
COPD (%) 14 (1.2) 7 (3.6) 7 (0.7) 0.004
CKD (%) 33 (2.9) 6 (3.0) 27 (2.8) 0.816
CHD (%) 92 (8.0) 14 (7.1) 78 (8.1) 0.772
Smoke (%) 313 (27.1) 45 (22.8) 268 (28.0) 0.159
Drink (%) 477 (41.3) 70 (35.5) 407 (42.5) 0.080
SBP (mmHg) 120.80 (113.00, 130.00) 120.00 (113.00, 128.30) 121.00 (113.00, 130.00) 0.640
DBP (mmHg) 75.50 (69.90, 81.80) 74.90 (68.30, 80.00) 75.70 (70.00, 82.00) 0.059
Daytime SBP (mmHg) 122.55 (114.80, 131.50) 121.20 (114.40, 129.80) 122.70 (114.80, 131.50) 0.526
Daytime SBP (mmHg) 77.00 (71.00, 83.20) 77.00 (69.00, 81.70) 77.00 (71.00, 83.70) 0.050
Nocturnal SBP (mmHg) 113.25 (103.30, 124.00) 114.00 (104.00, 122.90) 113.00 (103.10, 124.00) 0.724
Nocturnal DBP (mmHg) 70.00 (63.00, 76.90) 69.40 (62.00, 76.50) 70.00 (63.10, 76.90) 0.507
CHD, coronary heart disease; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; DM, diabetes mellitus.

Blood pressure and sleep during ambulatory blood pressure monitoring and ambulatory blood pressure monitoring results for the general population

During ABPM, sleep was not disturbed in 866 of 1155 people, sleep was disturbed in 247 people and sleep was seriously disturbed in 42 people. There was no significant difference in BP and circadian rhythm of BP among the three groups. There are statistically significant differences among the three groups in the variation coefficient of 24-h BP, variation coefficient of day BP and variation coefficient of nocturnal SBP. There was no statistical difference between the severely disturbed sleep group and the disturbed sleep group by pairwise comparison. The variation coefficient of 24-h BP, daytime BP and nocturnal SBP were higher in the disturbed sleep group including severely disturbed sleep group than in the undisturbed sleep group. The detailed results are shown in Table 2.

Table 2 - Blood pressure and sleep during ambulatory blood pressure monitoring (ABPM) and ABPM results for the general population
Outcome Undisturbed
n = 866
Disturbed
n = 247
Severely disturbed
n = 42
P value
SBP (mmHg) 120.90 (113.00, 130.00) 120.00 (112.90, 129.70) 121.10 (112.50, 127.00) 0.760
DBP (mmHg) 75.60 (70.00, 82.00) 75.00 (68.55, 81.30) 76.00 (72.40, 80.10) 0.516
Daytime SBP (mmHg) 122.85 (114.90, 132.00) 121.40 (114.30, 131.15) 122.10 (115.00, 128.40) 0.614
Daytime DBP (mmHg) 77.10 (71.00, 83.70) 76.20 (69.90, 82.55) 75.80 (72.30, 80.50) 0.423
Nocturnal SBP (mmHg) 113.00 (103.00, 124.00) 114.00 (104.45, 123.25) 115.25 (100.50, 124.90) 0.932
Nocturnal DBP (mmHg) 70.00 (63.20, 76.50) 69.80 (62.95, 77.00) 72.40 (64.00, 78.10) 0.750
SBP rhythm (%) 7.50 (2.90, 11.90) 7.00 (2.40, 11.20) 6.50 (2.10, 13.20) 0.348
DBP rhythm (%) 9.10 (3.60, 14.80) 8.80 (2.05, 14.55) 5.25 (1.70, 14.40) 0.363
SBP variation coefficient (%) 10.90 (7.20, 14.20) 12.20 (9.25, 16.20) 11.00 (8.90, 14.20) <0.001
DBP variation coefficient (%) 14.00 (9.00, 20.00) 16.40 (11.50, 24.25) 14.65 (11.40, 19.50) <0.001
Daytime SBP variation coefficient (%) 10.30 (6.70, 14.10) 12.00 (8.90, 16.65) 11.30 (8.60, 14.80) <0.001
Daytime DBP variation coefficient (%) 13.40 (8.20, 20.10) 16.30 (11.10, 24.10) 14.65 (9.90, 19.50) <0.001
Nocturnal SBP variation coefficient (%) 6.70 (2.60, 9.10) 6.70 (5.00, 9.05) 8.10 (5.00, 10.70) 0.018
Nocturnal DBP variation coefficient (%) 9.10 (3.20, 12.60) 9.10 (6.65, 12.35) 9.05 (6.30, 13.50) 0.064

Blood pressure and sleep during ambulatory blood pressure monitoring and ambulatory blood pressure monitoring results for the insomnia people

There were 197 cases of insomnia. During ABPM, sleep was not disturbed in 95 people, sleep was disturbed in 82 people and sleep was seriously disturbed in 20 people. There was no significant difference in mean BP, circadian rhythm of BP and variation coefficient of BP among the three groups. The detailed results are shown in Table 3.

Table 3 - Blood pressure and sleep during ambulatory blood pressure monitoring (ABPM) and ABPM results for the insomnia people
Outcome Undisturbed
n = 95
Disturbed
n = 82
Severely disturbed
n = 20
P value
SBP (mmHg) 119.00 (112.85, 126.85) 122.20 (115.10, 130.10) 118.55 (112.45, 127.30) 0.204
DBP (mmHg) 74.90 (68.30, 79.35) 74.40 (66.00, 80.50) 76.10 (72.60, 79.05) 0.731
Daytime SBP (mmHg) 120.40 (114.00, 128.60) 124.00 (116.00, 133.00) 120.00 (114.65, 127.55) 0.295
Daytime SBP (mmHg) 77.00 (69.30, 80.60) 76.35 (67.60, 82.40) 76.75 (73.65, 80.05) 0.809
Nocturnal SBP (mmHg) 112.00 (103.00, 119.85) 115.05 (109.00, 125.70) 113.65 (99.50, 128.60) 0.077
Nocturnal DBP (mmHg) 68.00 (61.95, 76.15) 69.55 (63.50, 77.00) 73.00 (62.85, 79.00) 0.573
SBP rhythm (%) 7.30 (2.60, 11.50) 5.30 (2.00, 9.80) 7.75 (1.60, 12.85) 0.315
DBP rhythm (%) 8.20 (4.45, 14.40) 7.30 (1.40, 13.50) 4.95 (0.90, 17.70) 0.487
SBP variation coefficient (%) 11.70 (6.50, 16.30) 9.85 (7.30, 13.80) 10.15 (8.50, 14.90) 0.432
DBP variation coefficient (%) 15.10 (9.65, 23.05) 13.50 (8.80, 18.60) 14.45 (10.90, 19.60) 0.543
Daytime SBP variation coefficient (%) 11.20 (5.25, 16.10) 9.65 (6.70, 13.90) 9.15 (8.20, 14.70) 0.446
Daytime DBP variation coefficient (%) 14.70 (7.85, 23.80) 13.00 (8.00, 19.10) 14.25 (10.85, 19.05) 0.479
Nocturnal SBP variation coefficient (%) 6.00 (2.85, 8.10) 6.05 (3.60, 9.00) 7.70 (4.90, 10.45) 0.282
Nocturnal DBP variation coefficient (%) 8.90 (4.35, 11.75) 8.80 (4.40, 12.10) 10.40 (6.35, 13.20) 0.474

Blood pressure and sleep during ambulatory blood pressure monitoring and ambulatory blood pressure monitoring results for the noninsomnia population

There were 958 cases of insomnia. During ABPM, sleep was not disturbed in 771 people, sleep was disturbed in 165 people and sleep was seriously disturbed in 22 people. There was no significant difference in mean BP and circadian rhythm of BP among the three groups. There are statistically significant differences among the three groups in the variation coefficient of BP. There was no statistical difference between the severely disturbed sleep group and the disturbed sleep group by pairwise comparison. The variation coefficient of 24-h BP, daytime BP and nocturnal SBP were higher in the disturbed sleep group including severely disturbed sleep group than in the undisturbed sleep group. The detailed results are shown in Table 4.

Table 4 - Blood pressure and sleep during ambulatory blood pressure monitoring (ABPM) and ABPM results for the noninsomnia population
Outcome Undisturbed
n = 771
Disturbed
n = 165
Severely disturbed
n = 22
P value
SBP (mmHg) 121.30 (113.30, 130.10) 119.00 (111.90, 128.80) 121.75 (115.10, 127.00) 0.279
DBP (mmHg) 75.90 (70.00, 82.30) 75.00 (69.00, 81.70) 75.10 (70.00, 81.40) 0.757
Daytime SBP (mmHg) 123.20 (115.00, 132.00) 120.80 (113.90, 129.70) 123.90 (115.00, 130.50) 0.269
Daytime SBP (mmHg) 77.10 (71.10, 84.00) 76.20 (70.70, 82.80) 75.65 (70.90, 81.80) 0.629
Nocturnal SBP (mmHg) 113.30 (103.05, 124.90) 111.00 (103.10, 122.7) 116.55 (100.50, 124.90) 0.618
Nocturnal DBP (mmHg) 70.00 (63.60, 76.60) 70.00 (62.10, 77.40) 71.65 (64.30, 78.10) 0.879
SBP rhythm (%) 7.60 (2.90, 11.90) 7.80 (2.60, 11.80) 6.00 (2.20, 13.30) 0.756
DBP rhythm (%) 9.30 (3.50, 14.90) 9.50 (2.60, 15.30) 5.25 (2.10, 14.10) 0.471
SBP variation coefficient (%) 10.90 (7.20, 16.60) 13.30 (10.00, 16.60) 11.80 (9.50, 14.20) <0.001
DBP variation coefficient (%) 13.90 (8.95, 19.70) 18.80 (13.20, 25.20) 16.00 (11.60, 19.00) <0.001
Daytime SBP variation coefficient (%) 10.20 (6.80, 13.90) 12.90 (9.90, 17.50) 12.10 (9.60, 14.80) <0.001
Daytime DBP variation coefficient (%) 13.30 (8.25, 19.80) 18.10 (12.70, 25.90) 14.65 (9.60, 20.40) <0.001
Nocturnal SBP variation coefficient (%) 6.70 (2.60, 9.20) 6.80 (5.40, 9.20) 8.35 (5.00, 12.60) 0.010
Nocturnal DBP variation coefficient (%) 9.10 (3.20, 12.70) 9.60 (7.20, 12.40) 8.85 (6.30, 13.50) 0.031

Discussion

Some studies show that hypertension is an important related factor for insomnia [8,9]. The incidence of hypertension in insomnia participants is much higher than that in noninsomnia participants [9]. An observational study [10] involving 45 000 people showed that people with insomnia had a higher risk of developing hypertension within 8 years compared with people who slept better (hazard ratio, 1.24; 95% confidence interval, 1.01–1.53). Specifically, insomnia syndrome, including its individual symptoms, is thought to play an important role in hypertension [7,11–14]. Some studies [15–17] show that insomnia is related to hypertension, insomnia and short sleep time increase the risk of hypertension and insomnia is a risk factor for future hypertension. This shows that there is a close relationship between sleep and BP.

Insomnia is a clinical diagnosis made by the neurologist according to the symptoms of participants. There may be a certain misdiagnosis rate. The results showed regardless of the insomniac or noninsomniac population, sleep conditions during ABPM do not affect BP value and BP rhythm. This misdiagnosis did not affect the statistical results.

Sleep disturbance was actually self-reported and not evaluated by, for example, actigraphy or sleep clinical assessment. In actual clinical practice, it would be costly and impractical for physicians to give actigraphy or sleep clinical assessment to every patient undergoing ABPM at the same time. Therefore, the diagnosis method of sleep disturbance in this study is applicable to clinical practice.

Some studies [18] have suggested that there is a sleep peak in BP. BP reached a trough during sleep at night. It began to rise before waking in the morning, and peak BP appeared after waking. These two values are independent risk factors for mortality and cardiovascular events [19]. It can be inferred that deep sleep and wakefulness can cause BP fluctuations. Therefore, it is thought that the patients repeated awake during sleep due to BP measurement during sleep will cause BP fluctuations. However, observational studies have reported no significant correlation between high BP and occasional insomnia [20] and occasional poor sleep [21]. The results in this article confirm that sleep conditions during ABPM have no effect on the measured BP results, regardless of the insomniac or noninsomniac population.

The main advantages of ABPM are that it eliminates the white coat phenomenon and finds masked hypertension, and it can more accurately evaluate BP. Regardless of the general population, the insomnia group, and the noninsomnia group, the difference in sleep conditions during measurement does not affect the BP value. Therefore, the application of ABPM is not limited by the sleep conditions during monitoring.

Another advantage of ABPM is that it can assess BP rhythm. As early as the 1980s, it has been confirmed that abnormal BP rhythm is associated with advanced organ damage [22]. The circadian rhythm of BP is determined to some extent by the internal rhythm of the central nervous system and the peripheral circadian clock gene system that regulates neurohumoral factors and cardiovascular, in part by sleep-wake behavior patterns. It is also a concern of clinicians whether repeated awake due to BP measurement during ABPM will affect BP rhythm assessment. This article confirms that different sleep conditions during ABPM do not affect the assessment of circadian rhythms.

ABPM could more extensively assess the 24-h ambulatory BP profile including BP variability of individual participants. It was found that different sleep conditions in the whole population and noninsomniacs during monitoring may lead to different BP variation coefficients. Studies [23] have shown that the highest SBP is significantly related to the elevation of the left ventricular mass index and carotid intima-media thickness assessed by echocardiography, and also to microalbuminuria in participants with hypertension who have not been treated with drugs. When we find that the variation coefficient of BP is large and the maximum SBP is high, we need to consider whether there is corresponding target organ damage or the measurement error caused by the sleep situation during ABPM.

Conclusion

Regardless of the insomniac or noninsomniac population, sleep conditions during ABPM do not affect BP value and BP rhythm. For noninsomniac people, the sleep situation during ABPM may affect the BP variation coefficient.

Acknowledgements

All author takes responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation

Conflicts of interest

There are no conflicts of interest.

References

1. Williams B, Mancia G, Spiering W, Agabiti Rosei E, Azizi M, Burnier M, et al.; ESC Scientific Document Group. 2018 ESC/ESH Guidelines for the management of arterial hypertension. Eur Heart J. 2018; 39:3021–3104.
2. Mansia G, De Backer G, Dominiczak A, Cifkova R, Fagard R, Germano G, et al.; European Society of Hypertension; European Society of Cardiology. 2007 ESH-ESC Guidelines for the management of arterial hypertension: the task force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). Blood Press. 2007; 16:135–232.
3. McManus RJ, Caulfield M, Williams B; National Institute for Health and Clinical Excellence. NICE hypertension guideline 2011: evidence based evolution. BMJ. 2012; 344:e181.
4. Shimamoto K, Ando K, Fujita T, Hasebe N, Higaki J, Horiuchi M, et al.; Japanese Society of Hypertension Committee for Guidelines for the Management of Hypertension. The Japanese Society of Hypertension guidelines for the management of hypertension (JSH 2014). Hypertens Res. 2014; 37:253–390.
5. Houle SK, Padwal R, Poirier L, Tsuyuki RT. The 2015 Canadian Hypertension Education Program (CHEP) guidelines for pharmacists: An update. Can Pharm J (Ott). 2015; 148:180–186.
6. Whelton PK, Carey RM, Aronow WS, Casey DE Jr, Collins KJ, Dennison Himmelfarb C, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2018; 138:e426–e483.
7. Palagini L, Bruno RM, Gemignani A, Baglioni C, Ghiadoni L, Riemann D. Sleep loss and hypertension: a systematic review. Curr Pharm Des. 2013; 19:2409–2419.
8. Jarrin DC, Alvaro PK, Bouchard MA, Jarrin SD, Drake CL, Morin CM. Insomnia and hypertension: a systematic review. Sleep Med Rev. 2018; 41:3–38.
9. Shivashankar R, Kondal D, Ali MK, Gupta R, Pradeepa R, Mohan V, et al. Associations of sleep duration and disturbances with hypertension in metropolitan cities of Delhi, Chennai, and Karachi in South Asia: cross-sectional analysis of the CARRS study. Sleep. 2017; 40:zsx119.
10. Lin CL, Liu TC, Lin FH, Chung CH, Chien WC. Association between sleep disorders and hypertension in Taiwan: a nationwide population-based retrospective cohort study. J Hum Hypertens. 2017; 31:220–224.
11. Meng L, Zheng Y, Hui R. The relationship of sleep duration and insomnia to risk of hypertension incidence: a meta-analysis of prospective cohort studies. Hypertens Res. 2013; 36:985–995.
12. Thomas SJ, Calhoun D. Sleep, insomnia, and hypertension: current findings and future directions. J Am Soc Hypertens. 2017; 11:122–129.
13. Javaheri S, Redline S. Sleep, slow-wave sleep, and blood pressure. Curr Hypertens Rep. 2012; 14:442–448.
14. Javaheri S, Redline S. Insomnia and Risk of Cardiovascular Disease. Chest. 2017; 152:435–444.
15. Phillips B, Bůzková P, Enright P; Cardiovascular Health Study Research Group. Insomnia did not predict incident hypertension in older adults in the cardiovascular health study. Sleep. 2009; 32:65–72.
16. Fernandez-Mendoza J, Vgontzas AN, Liao D, Shaffer ML, Vela-Bueno A, Basta M, Bixler EO. Insomnia with objective short sleep duration and incident hypertension: the Penn State Cohort. Hypertension. 2012; 60:929–935.
17. Bathgate CJ, Edinger JD, Wyatt JK, Krystal AD. Objective but not subjective short sleep duration associated with increased risk for hypertension in individuals with insomnia. Sleep. 2016; 39:1037–1045.
18. Kario K, Pickering TG, Umeda Y, Hoshide S, Hoshide Y, Morinari M, et al. Morning surge in blood pressure as a predictor of silent and clinical cerebrovascular disease in elderly hypertensives: a prospective study. Circulation. 2003; 107:1401–1406.
19. Li Y, Thijs L, Hansen TW, Kikuya M, Boggia J, Richart T, et al.; International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes Investigators. Prognostic value of the morning blood pressure surge in 5645 subjects from 8 populations. Hypertension. 2010; 55:1040–1048.
20. Singareddy R, Vgontzas AN, Fernandez-Mendoza J, Liao D, Calhoun S, Shaffer ML, Bixler EO. Risk factors for incident chronic insomnia: a general population prospective study. Sleep Med. 2012; 13:346–353.
21. Fernandez-Mendoza J, Vgontzas AN, Bixler EO, Singareddy R, Shaffer ML, Calhoun SL, et al. Clinical and polysomnographic predictors of the natural history of poor sleep in the general population. Sleep. 2012; 35:689–697.
22. O’Brien E, Sheridan J, O’Malley K. Dippers and non-dippers. Lancet. 1988; 2:397.
23. Matsui Y, Ishikawa J, Eguchi K, Shibasaki S, Shimada K, Kario K. Maximum value of home blood pressure: a novel indicator of target organ damage in hypertension. Hypertension. 2011; 57:1087–1093.
Keywords:

ambulatory blood pressure monitoring; blood pressure; hypertension; insomnia; sleep

Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.