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Arterial tonometry is a novel technique for measuring ambulatory blood pressure (AMBP). The watch-like device BPro(®) (HealthSTATS International, Singapore) captures radial pulsewave reflection and calculates brachial blood pressure (BP). In this study we investigate if arterial tonometry is applicable and reliable in patients with diabetes. We compared tonometric (BPro) to cuff-based oscillometric and auscultatoric BPs (Takeda model TM2421, A&D Medical, Tokyo, Japan) in 25 Caucasian patients with type 1 or type 2 diabetes. Patients were seen twice within 2 weeks. At visit 1, a 15-min rest was followed by the recording of three cuff-based BPs and 2-min continuous tonometric BPs. At both visits 24-h AMBP measurements were recorded with the BPro device. At Visit 1, auscultatoric BP (mean±SD) was 136±19/72±8 mm Hg versus 138±19/78±8 mm Hg with the tonometric device. Visit 1 AMBP was 131±20/76±9 mm Hg versus 131±12/75±9 mm Hg at Visit 2. Mean 24-h AMBP, daytime BP, nighttime BP, and dipping at the two visits were similar (P>0.40). Linear and intraclass correlations coefficients between auscultatoric and tonometric systolic and diastolic BP were r=0.86 and 0.65, respectively (P<0.001 for both), and r=0.83 and 0.77, respectively (P<0.001 for both). The mean differences between devices were 1.9±10 and 5.5±6.6 mm Hg for systolic and diastolic BP, respectively. In patients with diabetes tonometric and cuff-based BPs are comparable, and tonometric AMBPs are reproducible and feasible.
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Ambulatory Tonometric Blood Pressure Measurements
in Patients with Diabetes
Simone Theilade, M.D., Christel Joergensen, M.D., Frederik Persson, M.D., Maria Lajer, Ph.D.,
and Peter Rossing, DmSc
Background: Arterial tonometry is a novel technique for measuring ambulatory blood pressure (AMBP). The watch-like
device BPro
(HealthSTATS International, Singapore) captures radial pulsewave reflection and calculates brachial blood
pressure (BP). In this study we investigate if arterial tonometry is applicable and reliable in patients with diabetes.
Subjects and Methods: We compared tonometric (BPro) to cuff-based oscillometric and auscultatoric BPs (Takeda model
TM2421, A&D Medical, Tokyo, Japan) in 25 Caucasian patients with type 1 or type 2 diabetes. Patients were seen twice within
2 weeks. At visit 1, a 15-min rest was followed by the recording of three cuff-based BPs and 2-min continuous tonometric BPs.
At both visits 24-h AMBP measurements were recorded with the BPro device.
Results: At Visit 1, auscultatoric BP (mean SD) was 136 19/72 8 mm Hg versus 138 19/78 8 mm Hg with the tono-
metric device. Visit 1 AMBP was 131 20/76 9 mm Hg versus 131 12/75 9 mm Hg at Visit 2. Mean 24-h AMBP, daytime
BP, nighttime BP, and dipping at the two visits were similar (P>0.40). Linear and intraclass correlations coefficients between
auscultatoric and tonometric systolic and diastolic BP were r=0.86 and 0.65, respectively (P<0.001 for both), and r=0.83 and
0.77, respectively (P<0.001 for both). The mean differences between devices were 1.9 10 and 5.5 6.6 mm Hg for systolic and
diastolic BP, respectively.
Conclusions: In patients with diabetes tonometric and cuff-based BPs are comparable, and tonometric AMBPs are repro-
ducible and feasible.
Blood pressure (BP) control is paramount in preven-
tion of complications to diabetes, and hypertension
significantly increases macro- and microvascular compli-
ABPof 130 mm Hg defines hypertension in
Conventionally, BP has been measured with sphygmo-
manometry, using a device consisting of an inflatable cuff for
occlusion of blood flow and a manometer for measuring
In recent years arterial tonometry has emerged as
an alternative way of indirect BP measuring. A tonometric
device captures pulsewaves from arterial surfaces (e.g.,
the radial artery) and translate wave characteristics to BPs.
Oscillometric devices are less accurate in measuring BP in
persons with increased arterial stiffness.
It is possible that
increased arterial stiffness also impair the accuracy of tono-
metric BP measurements. Patients with diabetes have in-
creased arterial stiffness,
and with this study we aimed to
investigate if tonometry is applicable and reliable in BP
measuring in patients with diabetes.
Some of these data have been previously published in ab-
stract form.
Subjects and Methods
The study design is cross-sectional, including 25 patients: 17
with type 1 and eight with type 2 diabetes. All were Caucasian.
Patients were 59.6 7.8 years old, with a duration of diabetes
of 24.5 14.3 years, and 18 (72%) men. Nine patients had
normoalbuminuria, defined as persistent normoalbuminuria
with a urinary albumin excretion rate of <30 mg/24-h period.
Two and 14 patients had micro- and macroalbuminuria,
respectively, defined as a urinary albumin excretion rate be-
tween 30 and 300 mg/24-h period and >300 mg/24-h period
in two out of three consecutive measurements. Glomerular
Steno Diabetes Center, Gentofte, Denmark.
Data were previously presented in abstract form at the 2011 meeting of the European Association for the Study of Diabetes and the 2011
meeting of the Danish Society of Hypertension.
Volume 14, Number 6, 2012
ªMary Ann Liebert, Inc.
DOI: 10.1089/dia.2012.0006
filtration rate (GFR) in patients with macroalbuminuria was
73.6 34.2 mL/min/1.73 m
All patients were followed up at Steno Diabetes Center,
Gentofte, Denmark. They were randomly selected from the
outpatient clinic without regard for sex, age, type of diabetes,
or kidney function. The number of participants included in
the study was based on power calculations. One patient was
excluded from the validation analysis because of missing
sphygmomanometric measurements. Another patient only
had one valid 24-h ambulatory BP (AMBP) measurement and
was not included in the reproducibility analysis.
Sphygmomanometric BPs were recorded with a Takeda
device (TM2421, version 7, A&D Medical, Tokyo, Japan) and
tonometric measurements with the BPro
International, Singapore) device (Fig. 1). Both Takeda and
BPro measurements were recorded on the left arm on all pa-
tients. The Takeda device is currently used for AMBP mea-
surements at Steno Diabetes Center and was therefore chosen
for comparison with the BPro device. Measurements of both
cuff-based and tonometric BPs were performed by trained
laboratory technicians.
The cuff-based Takeda device obtains auscultatoric and
oscillometric BP measurements simultaneously. Auscultatoric
systolic BP (SBP) and diastolic BP (DBP) measurements are
recorded at the appearance of the first and by the disap-
pearance of the last Korotkoff sound, when entering the fifth
Korotkoff’s phase, respectively. The transducer records os-
cillations equivalent to mean arterial pressure (MAP) and
calculates oscillometric BPs based on accepted algorithms.
Auscultatoric SBPs are typically lower, whereas DBPs are
higher, than oscillometric measurements.
The BPro is a watch-like device that captures radial pulse-
wave reflection and calculates brachial AMBP. A brachial
AMBP can be recorded for every 10 s of pulsewave mea-
surements. The BPro has previously been validated and meets
European Society of Hypertension and Association for the
Advancement of Medical Instrumentation standards.
In this
study, the BPro device was calibrated with an oscillometric
device (model UA 787, A&D Medical) prior to BP measuring,
and every other year the device is serviced by the manufac-
turer (HealthSTATS).
At Visit 1, patients were placed supine in a resting position
for 15 min. A cuff of appropriate size was placed on the right
arm. The stethoscope for auscultatoric and the transducer
for oscillometric measurements were both placed above the
brachial artery. Three separate Takeda measurements were
obtained, and subsequently 2-min continuous BPro mea-
surements were recorded.
At both visits AMBP was recorded with BPro. AMBP re-
cordings were performed every 15 min during daytime and
nighttime. Daytime AMBP was from 7 a.m. to 11 p.m.,
whereas nighttime AMBP was 11 p.m. to 7 a.m. The BPro
device also calculated dipping, which refers to the percentage
decline in BP from daytime to nighttime. Mean AMBP was
calculated as the average of all measurements obtained
during the 24-h period.
Statistical analysis is performed using SPSS version 15.0 for
Windows (SPSS Inc., Chicago, IL). Variables are given as
mean SD values. Correlations between devices are calcu-
lated by linear regression equations and intraclass correlation.
Mean differences between devices are calculated and visual-
ized in a Bland–Altman plot, and 95% limits of agreement
are calculated. Paired Student’s ttests compare AMBPs, and
independent-samples ttest compares groups. A two-tailed
Pvalue of <0.05 is considered statistically significant.
The study conformed to the Declaration of Helsinki, and all
patients gave informed consent.
Auscultatoric, oscillometric, and tonometric BPs (mean
SD) were 136 19/72 8, 137 16/77 9, and 138 19/78
8 mm Hg, respectively.
Respective linear correlation coefficients between auscul-
tatoric and tonometric SBP and DBP were r=0.86 and 0.65
(P<0.001 for both) (Fig. 2a), with intraclass correlations co-
efficients of r=0.83 and 0.77 (P<0.001 for both). Respective
linear correlation coefficients between oscillometric and to-
nometric SBP and DBP were r=0.89 and 0.82 (P<0.001 for
both), with intraclass correlation coefficients of r=0.94 and
0.90 (P<0.001 for both). Respective linear correlation coeffi-
cients between auscultatoric and oscillometric SBP and DBP
were r=0.91 and 0.77 (P<0.001 for both), with intraclass
correlation coefficients of r=0.86 and 0.87 (P<0.001 for both).
Mean differences between tonometric and auscultatoric
SBP and DBP were 1.9 10 and 5.5 6.6 mm Hg, respectively,
with 95% limits of agreement of -17.7 to 21.5 and -7.4 to
18.4 mm Hg, respectively (Fig. 2b). Mean differences between
tonometric and oscillometric SBP and DBP were 1.9 8.6 and
0.0 5.1 mm Hg, respectively, with 95% limits of agreement of
-15.0 to 18.8 and -10 to 10 mm Hg, respectively. Mean dif-
ferences between auscultatoric and oscillometric SBP and
DBP were 0.2 8.0 and 5.6 5.8 mm Hg, respectively, with
95% limits of agreement of -15.5 to 15.9 and -5.8 to 17.0 mm
Hg, respectively.
FIG. 1. Photograph of the BPro.
There were no significant differences in agreement between
devices when comparing normo- versus micro- and macro-
albuminuric patients, men versus women, or patients with
type 1 versus type 2 diabetes (P>0.05) (data not shown).
Evaluation of repeated measurements of AMBP
Mean BP values from the two visits were similar. Mean
AMBP was 131 20/76 9 mm Hg versus 132 12/75 9mm
Hg (P=0.917 and P=0.954, respectively), mean daytime BP
was 136 22/78 9 mm Hg versus 136 13/78 10 mm Hg
(P=0.385 and P=0.972, respectively), mean nighttime BP was
124 20/71 9 mm Hg versus 124 13/71 8mm Hg (P=
0.935 and P=0.984, respectively), and mean dipping was
9.3 5.7% versus 9.1 4.8% (P=0.871).
Patient satisfaction and AMBP completion
Only one patient (4%) declined to repeat the AMBP. For the
remaining patients the discomfort associated with the tono-
metric AMBP was acceptable, and AMBP measurements were
successful according to present guidelines.
In this study on patients with diabetes, we found tono-
metric and cuff-based BPs to be comparable and tonometric
AMBPs to be reproducible. The BPro values correlated better
with oscillometric than with auscultatoric values, which could
be explained by the BPro device being calibrated with an
oscillometric device.
We obtained lower SBP and DBP auscultatoric than oscil-
lometric values, despite oscillometric values typically over-
estimating SBP and underestimating DBP. This could be
caused by our cohort having increased arterial stiffness sec-
ondary to diabetes,
leading to overestimation of both SBP
and DBP oscillometric values and underestimation of aus-
cultatoric SBP.
We did not find any significant difference in agreement
between devices when subdividing patients according to al-
buminuria status, sex or type of diabetes. However, this
finding may be due to lack of power.
Aside from brachial arterial BP, the BPro device measures
various indices of arterial stiffness including augmentation
index, central BP, and MAP. Brachial arterial BP is an inferior
risk marker of cardiovascular outcome compared with mark-
ers of arterial stiffness.
As patients with diabetes have
increased arterial stiffness,
measuring indices of arterial
stiffness rather than peripheral BP may prove to be a better risk
marker as well as a better treatment target for management of
hypertension in patients with diabetes. Therefore the BPro
possess potentially advantageous qualities for the purpose of
measurements of both BP and arterial stiffness, although we
did not investigate arterial stiffness in the current study.
A great advantage of the BPro is the smaller size and more
accessible position of the device, causing less discomfort both
during and between BP measurements. The absence of an
inflatable cuff and the inaudibility of the device prevent an-
ticipation rise of BP and nighttime awakening in connection
with measurements. This allows for more frequent and un-
disturbed measuring and possibly a more accurate AMBP.
Our study has some limitations. The small number of
participants does not allow for scrutinizing patient data when
dividing patients according to kidney function, gender, or
type of diabetes. However, we did not see any association
between patient characteristics and reliability of tonometric
BPs. We only performed tonometric AMBPs. Concurrent
AMBP measurements with both cuff-based and tonometric
devices would have been interesting. However, as both de-
vices would have had to be strapped on to the same arm,
faulty measurements were likely to be obtained. Furthermore,
the application of two devices concurrently probably
would have been bothersome to patients, thereby affecting
FIG. 2. (a) Correlations plot and (b) Bland–Altman plot for systolic blood pressure (SBP) measured with sphygmoma-
nometry (auscultatoric) (Takeda) versus tonometry (BPro).
In conclusion, we find that the manufacturer-validated
BPro device recorded reliable and reproducible tonometric BP
measurements in patients with diabetes.
The BPro device offers frequent and undisturbed BP mea-
surements, along with additional information on arterial
state. Furthermore, tonometric measurements appear to be
feasible and possibly more convenient for the patients. We
therefore propose that in patients with diabetes tonometric
BPs may be preferable to sphygmomanometric measure-
However, larger studies with sufficient follow-up are
needed to establish the role of tonometric BP measurements in
diabetes, in particular for the purpose of evaluating the value
of parameters of arterial stiffness.
Author Disclosure Statement
No competing financial interests exist.
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Address correspondence to:
Simone Theilade, M.D.
Steno Diabetes Center
Niels Steensens Vej 2, NLC 2.07
DK-2820 Gentofte, Denmark
... Two previous studies, one study on a small diabetic population 15 and one study on 50 normo-and prehypertensive subjects 16 have examined the tonometric BPro device against an oscillometric device and concluded agreement between tonometric and oscillometric measurements. However, the study on diabetic patients only compared office tonometric and oscillometric measurements. ...
... As proposed by van Popele et al 10 in 2000, the overestimation of both systolic and diastolic BP using oscillometric devices may be related to arterial stiffness. If the tonometric device was more accurate in estimating BP, we would have expected lower tonometric SBP and DBP in the diabetic population from the previous study, 15 and similar tonometric and oscillometric measurements in the normo-and prehypertensive population. 16 In our study, increased arterial stiffness could explain why systolic BP was higher using oscillometric measurements. ...
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Aim: Correct measurement of blood pressure (BP) is important for optimal diagnosis and treatment of patients with hypertension. The aim of this study was to compare a wrist-worn device using tonometric measurements of BP to a conventional device using oscillometric measurements of 24 h BP, diagnosing of hypertension, and non-dipping. Methods: One-hundred patients in the Renal Outpatient Clinic had 24 h ambulatory BP monitoring performed with a tonometric device, BPro, and an oscillometric device, A&D, simultaneously. Results: Twenty-four-hour and daytime systolic BP was significantly lower using tonometric monitoring compared to oscillometric (7 and 6 mmHg, respectively, p< 0.001). In the population of patients diagnosed with hypertension, the tonometric device diagnosed 90% of patients with uncontrolled hypertension correctly (positive predictive value), whereas 49% of patients classified as normotensive were uncontrolled hypertensive (negative predictive value). The mean difference between relative nocturnal BP decrease between tonometric and oscillometric was 2±8% (p< 0.01), and 33% of patients classified as dippers were non-dippers (negative predictive value). Conclusion: Using the BPro device for tonometric monitoring of BP and classification of hypertension and non-dipping in patients diagnosed with hypertension leads to misclassification of patients. Therefore, the BPro device is not suitable for clinical practice in hypertensive patients from a Renal Outpatient Clinic.
... Clinic blood pressure was measured after a 10-minute rest, using an appropriately sized cuff, and the mean of three measurements was calculated. 7 We also obtained a standard 12-lead resting electrocardiogram (ECG). ...
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Background Cardiac Rubidium‐82 (⁸²Rb) positron emission tomography/computed tomography (PET/CT) provides a measure of the myocardial blood flow and the myocardial flow reserve, which reflects the function of both large epicardial arteries and the myocardial microcirculation. Knowledge on changes in the myocardial microvascular function over time is lacking. Methods In this cohort study, we recruited 60 persons with type 2 diabetes (T2D) and 30 non‐diabetic controls, in 2013; all free of overt cardiovascular disease. All underwent a cardiac ⁸²Rb PET/CT scan. In 2019, all survivors (n=82) were invited for a repeated cardiac ⁸²Rb PET/CT scan using the same protocol, and 29 with T2D and 19 controls participated. Results Median duration between visits was 6.2 years [IQR 6.1–6.3]. In the total cohort, the mean age was 66.4 years (SD 9.3) and 33% were females. The myocardial flow reserve was lower in persons with T2D compared to controls (p=0.002) but there was no temporal change in the myocardial flow reserve in participants with T2D: mean change: ‐0.22 (95% CI: ‐0.47 to 0.02) nor in controls: ‐0.12 (‐0.49 to 0.25) or when comparing T2D to controls: mean difference: ‐0.10 (95% CI: ‐0.52 to 0.31). The temporal reduction in stress‐induced myocardial blood flow did not differ within the groups but was more pronounced in T2D compared to controls: mean difference: ‐0.30 (95%CI ‐0.55 to ‐0.04). Conclusion The myocardial microvascular function was impaired in persons with T2D compared to controls but did not change significantly in either of the groups when evaluated over 6 years.
... Nevertheless, we found very few studies analyzing the validity of automatic blood pressure monitors in a population with noninsulin-dependent type 2 diabetes, [37,[45][46][47][48], and furthermore, most of these validations did not follow specific protocols such as ESH-IP2 [9][10][11]. ...
Background Home blood pressure monitoring has many benefits, even more so, in populations prone to high blood pressure, such as persons with diabetes. Objective The purpose of this research was to validate the QardioArm mobile device in a sample of individuals with noninsulin-dependent type 2 diabetes in accordance with the guidelines of the second International Protocol of the European Society of Hypertension. Methods The sample consisted of 33 patients with type 2 diabetes. To evaluate the validity of QardioArm by comparing its data with that obtained with a digital sphygmomanometer (Omron M3 Intellisense), two nurses collected diastolic blood pressure, systolic blood pressure, and heart rate with both devices. Results The analysis indicated that the test device QardioArm met all the validation requirements using a sample population with type 2 diabetes. Conclusions This paper reports the first validation of QardioArm in a population of individuals with noninsulin-dependent type 2 diabetes. QardioArm for home monitoring of blood pressure and heart rate met the requirements of the second International Protocol of the European Society of Hypertension.
... For the control subjects, all clinical measurements were assessed and defined as described above with the exceptions that (i) urinary albumin excretion rate (UAER) was measured in two 24-h urine collections by an enzyme immunoassay; and (ii) 24-h blood pressure was recorded using BPro (HealthStats, Singapore), a tonometric wrist-device that records brachial blood pressure derived from radial pulse waves. 10 The device captured the blood pressure every 15 min for 24 h. ...
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Aims: To evaluate myocardial flow reserve (MFR) and coronary artery calcium (CAC) in persons with Type 1 diabetes with or without albuminuria and in non-diabetic controls. MFR reflects the function of large epicardial arteries and myocardial microcirculation. CAC represents structural aspects of atherosclerosis. In addition, we evaluated the association of MFR and CAC with retinopathy, another microvascular complication. Methods and results: Cross-sectional study in Type 1 diabetes, stratified by normoalbuminuria (NORMO; n = 30) and macroalbuminuria (MACRO; n = 30), and in non-diabetic controls (n = 30). MFR (pharmacological stress flow/rest flow) was evaluated by cardiac 82Rb positron emission tomography/computed tomography. MFR was similar in patients with NORMO and controls (3.1 ± 0.79 vs. 3.0 ± 0.79; P = 0.74). Patients with MACRO had lower (impaired) MFR when compared with NORMO (2.1 ± 0.92 vs. 3.1 ± 0.79; P < 0.0001). The CAC score [median (interquartile range)] was higher in NORMO when compared with controls [72 (22-247) vs. 0 (0-81), P = 0.03], and comparable between MACRO and NORMO. MFR was comparable in patients with diabetes and simplex or no retinopathy (n = 24 and n = 12, 2.8 ± 0.84 vs. 3.3 ± 0.77, P = 0.11), but lower in proliferative (n = 24) compared with simplex retinopathy (2.1 ± 0.97 vs. 2.8 ± 0.84, P = 0.02). The CAC score was comparable between groups of retinopathy. Conclusion: Myocardial microvascular function was comparable in non-diabetic controls and patients with Type 1 diabetes and NORMO; but impaired in the presence of microvascular complications (MACRO and proliferative retinopathy). Coronary calcification was elevated in diabetes, however, not explained by albuminuria.
... 15 Knowing that arterial stiffness is more critical in type II diabetic patients with hypertension than those without hypertension, 16 and that increase in arterial stiffness may affect the accuracy of automatic BP measurements, 17,18 accurate BP measurements in such populations is therefore crucial for the diagnosis and management. However, only a limited number of studies have tested the accuracy of automated BP monitors in the type II diabetic population, [19][20][21][22] and the majority of these validations did not adhere to existing validation standards according to specific protocols cited above. [3][4][5] Therefore, the issue of BP measurements accuracy remains controversial. ...
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Background: Following the European Society of Hypertension International Protocol (ESH-IP) Revision 2010, QardioArm® and Omron M6 Comfort IT® oscillometric devices were evaluated in the general population and in patients with type II diabetes, respectively, for self-blood pressure (BP) measurement. Methods: Both devices, QardioArm® and Omron M6 Comfort®, measure BP at the brachial level. The ESH-IP Revision 2010 includes a total number of 33 subjects. For each measure, the difference between observer and device BP values was calculated. In all, 99 pairs of BP differences are classified into three categories (≤5, ≤10, and ≤15 mmHg). The protocol procedures were followed precisely. Results: QardioArm® and Omron M6 Comfort® fulfilled the requirements of the ESH-IP and passed the validation process successfully. For QardioArm®, a total of 69 out of 99 comparisons for systolic blood pressure (SBP) showed an absolute difference within 5 mmHg and 82 out of 99 for diastolic blood pressure (DBP). As for Omron M6 Comfort®, a total of 83 out of 99 comparisons for SBP showed an absolute difference within 5 mmHg and 77 out of 99 for DBP. The mean differences between the device and mercury readings were 0.7±5.9 mmHg for SBP and 0.3±4.1 mmHg for DBP for QardioArm® and -1.4±4.7 mmHg for SBP and -2.1±4.3 mmHg for DBP for Omron M6 Comfort®. With regard to part 2 of ESH-IP 2010, 27 out of 33 subjects had a minimum of two out of three measurements within 5 mmHg difference for SBP and 31 out of 33 subjects for DBP for the QardioArm®, and 29 out of 33 patients had a minimum of two out of three measurements within 5 mmHg difference for SBP and 26 out of 33 patients for DBP for Omron M6 Comfort®. Conclusion: QardioArm® and Omron M6 Comfort® readings differing from the mercury standard by <5, 10, and 15 mmHg fulfill the ESH-IP Revision 2010 requirements. Consequently, these two devices are suitable for use in the general population and non-insulin-dependent type II diabetic patients, respectively.
... A validated tonometric watch-like device (BPro, HealthStats, Singapore) was used to record these 24-h ABPM. This device captured radial pulse wave reflections and calculated ABPM [27,28]. The device was calibrated to brachial blood pressure and calculated central blood pressure. ...
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Background: Altered regulation of extracellular matrix (ECM) composition by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) may contribute to arterial stiffening. We investigated associations between circulating MMP-1, -2, -3, -9, -10 and TIMP-1, and carotid-femoral pulse wave velocity (cfPWV) and pulse pressure (PP), as markers of arterial stiffness in type 1 diabetic patients. Methods: Individuals with type 1 diabetes from three different cohorts were included in this study: EURODIAB Prospective Complications study (n = 509), LEACE (n = 370) and PROFIL (n = 638). Linear regression analyses were used to investigate cross-sectional associations between circulating levels of MMP-1, -2, -3, -9, -10, and TIMP-1 and cfPWV (n = 614) as well as office PP (n = 1517). Data on 24-h brachial and 24-h central PP were available in 638 individuals from PROFIL. Analyses were adjusted for age, sex, duration of diabetes, HbA1c, mean arterial pressure (MAP), and eGFR, and additionally for other cardiovascular risk factors and presence of vascular complications. Results: After adjustment for potential confounders and presence of vascular complications, circulating MMP-3 was associated with cfPWV [β per 1 SD higher lnMMP3 0.29 m/s (0.02; 0.55)]. In addition, brachial and central 24-h PP measurements in PROFIL were significantly associated with MMP-2 [(1.40 (0.47:2.33) and 1.43 (0.63:2.23)]. Pooled data analysis showed significant associations of circulating levels of MMP-1 and MMP-2 with office PP [β per 1 SD higher lnMMP-1 and lnMMP-2 = - 0.83 mmHg (95% CI - 1.50; - 0.16) and = 1.33 mmHg (0.55; 2.10), respectively]. Conclusions: MMPs-1, -2, and -3 are independently associated with markers of arterial stiffening in patients with type 1 diabetes and may become therapeutic targets.
Aims People with type 1 diabetes have increased risk of cardiovascular (CV) and kidney disease. A 24-hour ambulatory blood pressure (BP) measurement (ABPM) examines diurnal variations in BP. We aimed to determine the prognostic significance of blunted decrease in nocturnal systolic BP of <10 % (non-dipping of nocturnal BP) for CV- and kidney disease and all-cause mortality in type 1 diabetes. Methods From 2009 to 2011, at Steno Diabetes Center Copenhagen, 654 participants with type 1 diabetes had 24-hour ABPM obtained with a tonometric wrist-watch device (BPro, HealthStats, Singapore). In 2017, outcomes (composite CV endpoint; all-cause mortality; decline in estimated glomerular filtration rate (eGFR) ≥30 %; end-stage kidney disease (ESKD); and a composite kidney endpoint including decline in eGFR ≥30 %, ESKD and all-cause mortality) were registered. Hazard Ratios (HR) were calculated using Cox regressions. Results Participants were mean ± SD 55 ± 13 years old and had median (IQR) 35 (24–44) years diabetes duration. Mean daytime and nocturnal systolic BP were 133 ± 16 and 121 ± 16 mm Hg while 337 (52 %) participants demonstrated non-dipping. After CV risk factor adjustments, non-dipping was associated with all-cause mortality (HR 2.12 (1.09–4.11), p = 0.03) and the composite kidney endpoint (HR 1.92 (1.23–3.00), p = 0.004). Conclusions Non-dipping entailed increased risk of all-cause mortality and kidney disease in type 1 diabetes.
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The healthcare-related functions of wearable devices are very useful for continuous monitoring of biological information. Wearable devices equipped with communication function can be used for additional healthcare services. Among the wearable devices, the wristband type is most suitable for acquiring biological signals, and the wear preference of the user is high, so it is highly likely to be used more in the future. In this paper, the health-related functions of wristband were investigated and the technical limitations and prospects were also reviewed. Most current wristband-type devices are equipped with the combination of accelerometer, optical sensor, and electrodes for their health functions, and continuously measured data are expanding the possibility of discovering new medical meanings. The blood pressure measurement function without using cuff is the most useful and expected function among the health-related functions expected to be mounted on the wrist wearable device, in spite of its technical limits and difficulties.
The link between cardiac autonomic neuropathy and risk of cardiovascular disease is highlighted as an area in which research is needed. This study was undertaken to evaluate the association between measures of cardiac autonomic function and cardiac vascular function in type 1 diabetes using new and sensitive methods. This was a cross-sectional study in patients with type 1 diabetes, stratified by normoalbuminuria (n = 30) and macroalbuminuria (n = 30), and in healthy control subjects (n = 30). Cardiac autonomic function was evaluated using heart rate variability (HRV) indices, cardiovascular autonomic reflex tests (CARTs), and cardiac 123I-metaiodobenzylguanidine (MIBG) imaging. Cardiac vascular function was assessed as myocardial flow reserve (MFR) measured by cardiac 82Rb-positron emission tomography/computed tomography. The measures of cardiac autonomic function (except low frequency-to-high frequency ratio and the Valsalva test ratio) were positively correlated to MFR in unadjusted analysis. All the HRV indices lost significance after adjustment for age and heart rate. After further adjustment for relevant cardiovascular risk factors, the late heart-to-mediastinum ratio directly measuring the function of adrenergic receptors and sympathetic integrity (from the MIBG scintigraphy) and the 30-to-15 ratio (a CART), remained positively associated with MFR (P ≤ 0.04). Cardiac autonomic dysfunction, including loss of cardiac sympathetic integrity in type 1 diabetes, is associated with and may contribute to impaired myocardial blood flow regulation.
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The accurate measurement of blood pressure (BP) is essential for the diagnosis and management of hypertension. Restricted use of mercury devices, increased use of oscillometric devices, discrepancies between clinic and out-of-clinic BP, and concerns about measurement error with manual BP measurement techniques have resulted in uncertainty for clinicians and researchers. The National Heart, Lung, and Blood Institute of the U.S. National Institutes of Health convened a working group of clinicians and researchers in October 2017 to review data on BP assessment among adults in clinical practice and clinic-based research. In this report, the authors review the topics discussed during a 2-day meeting including the current state of knowledge on BP assessment in clinical practice and clinic-based research, knowledge gaps pertaining to current BP assessment methods, research and clinical needs to improve BP assessment, and the strengths and limitations of using BP obtained in clinical practice for research and quality improvement activities.
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To determine the relation between systolic blood pressure over time and the risk of macrovascular or microvascular complications in patients with type 2 diabetes. Prospective observational study. Setting: 23 hospital based clinics in England, Scotland, and Northern Ireland. 4801 white, Asian Indian, and Afro-Caribbean UKPDS patients, whether randomised or not to treatment, were included in analyses of incidence; of these, 3642 were included in analyses of relative risk. Primary predefined aggregate clinical outcomes: any complications or deaths related to diabetes and all cause mortality. Secondary aggregate outcomes: myocardial infarction, stroke, lower extremity amputation (including death from peripheral vascular disease), and microvascular disease (predominantly retinal photocoagulation). Single end points: non-fatal heart failure and cataract extraction. Risk reduction associated with a 10 mm Hg decrease in updated mean systolic blood pressure adjusted for specific confounders. The incidence of clinical complications was significantly associated with systolic blood pressure, except for cataract extraction. Each 10 mm Hg decrease in updated mean systolic blood pressure was associated with reductions in risk of 12% for any complication related to diabetes (95% confidence interval 10% to 14%, P<0.0001), 15% for deaths related to diabetes (12% to 18%, P<0.0001), 11% for myocardial infarction (7% to 14%, P<0.0001), and 13% for microvascular complications (10% to 16%, P<0.0001). No threshold of risk was observed for any end point. In patients with type 2 diabetes the risk of diabetic complications was strongly associated with raised blood pressure. Any reduction in blood pressure is likely to reduce the risk of complications, with the lowest risk being in those with systolic blood pressure less than 120 mm Hg.
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Accurate measurement of blood pressure is essential to classify individuals, to ascertain blood pressure-related risk, and to guide management. The auscultatory technique with a trained observer and mercury sphygmomanometer continues to be the method of choice for measurement in the office, using the first and fifth phases of the Korotkoff sounds, including in pregnant women. The use of mercury is declining, and alternatives are needed. Aneroid devices are suitable, but they require frequent calibration. Hybrid devices that use electronic transducers instead of mercury have promise. The oscillometric method can be used for office measurement, but only devices independently validated according to standard protocols should be used, and individual calibration is recommended. They have the advantage of being able to take multiple measurements. Proper training of observers, positioning of the patient, and selection of cuff size are all essential. It is increasingly recognized that office measurements correlate poorly with blood pressure measured in other settings, and that they can be supplemented by self-measured readings taken with validated devices at home. There is increasing evidence that home readings predict cardiovascular events and are particularly useful for monitoring the effects of treatment. Twenty-four-hour ambulatory monitoring gives a better prediction of risk than office measurements and is useful for diagnosing white-coat hypertension. There is increasing evidence that a failure of blood pressure to fall during the night may be associated with increased risk. In obese patients and children, the use of an appropriate cuff size is of paramount importance.
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Although ambulatory blood pressure (BP) monitoring provides a better guide to the management of hypertension,(1-4) these devices are cumbersome and inconvenient, and therefore not widely used. HealthSTATS International (Singapore) developed a wrist-bound BP measurement device (BPro), which measures BP using arterial tonometry. 5 We aimed to validate the accuracy of this device in measuring BP according to the modified European Society of Hypertension (ESH) protocol(6) and Association for the Advancement of Medical Instrumentation (AAMI) standard.
We designed this study to explore to what extent the excess risk of cardiovascular events in diabetic individuals is attributable to hypertension. We retrospectively analyzed prospectively collected data from the Framingham original and offspring cohorts. Of the 1145 Framingham subjects newly diagnosed with diabetes mellitus who did not have a previous history of cardiovascular events, 663 (58%) had hypertension at the time that diabetes mellitus was diagnosed. During 4154 person-years of follow-up, 125 died, and 204 experienced a cardiovascular event. Framingham participants with hypertension at the time of diabetes mellitus diagnosis exhibited higher rates of all-cause mortality (32 versus 20 per 1000 person-years; P<0.001) and cardiovascular events (52 versus 31 per 1000 person-years; P<0.001) compared with normotensive subjects with diabetes mellitus. After adjustment for demographic and clinical covariates, hypertension was associated with a 72% increase in the risk of all-cause death and a 57% increase in the risk of any cardiovascular event in individuals with diabetes mellitus. The population-attributable risk from hypertension in individuals with diabetes mellitus was 30% for all-cause death and 25% for any cardiovascular event (increasing to 44% and 41%, respectively, if the 110 normotensive subjects who developed hypertension during follow-up were excluded from the analysis). In comparison, after adjustment for concurrent hypertension, the population-attributable risk from diabetes mellitus in Framingham subjects was 7% for all-cause mortality and 9% for any cardiovascular disease event. Although diabetes mellitus is associated with increased risks of death and cardiovascular events in Framingham subjects, much of this excess risk is attributable to coexistent hypertension.
While patients with type 1 diabetes (T1D) are known to suffer from early cardiovascular disease (CVD), we examined associations between arterial stiffness and diabetic complications in a large patient group with T1D. This study included 807 subjects (622 T1D and 185 healthy volunteers (age 40.6 ± 0.7 versus 41.6 ± 1.2 years; P = NS)). Arterial stiffness was measured by pulse wave analysis from each participant. Furthermore, information on diabetic retinopathy, nephropathy, and CVD was collected. The renal status was verified from at least two out of three urine collections. Patients with T1D without signs of diabetic nephropathy had stiffer arteries measured as the augmentation index (AIx) than age-matched control subjects (17.3% ± 0.6% versus 10.0% ± 1.2%; P < 0.001). Moreover, AIx (OR 1.08; 95% CI 1.03-1.13; P = 0.002) was associated with diabetic laser-treated retinopathy in patients with normoalbuminuria in a multivariate logistic regression analysis. The same was true for AIx and diabetic nephropathy (1.04 (1.01-1.08); P = 0.004) as well as AIx and CVD (1.06 (1.00-1.12); P = 0.01) in patients with T1D. Arterial stiffness was associated with microvascular and macrovascular complications in patients with T1D.
Central aortic pressures and waveform convey important information about cardiovascular status, but direct measurements are invasive. Peripheral pressures can be measured noninvasively, and although they often differ substantially from central pressures, they may be mathematically transformed to approximate the latter. We tested this approach, examining intersubject and intrasubject variability and the validity of using a single averaged transformation, which would enhance its applicability. Invasive central aortic pressure by micromanometer and radial pressure by automated tonometry were measured in 20 patients at steady state and during hemodynamic transients (Valsalva maneuver, abdominal compression, nitroglycerin, or vena caval obstruction). For each patient, transfer functions (TFs) between aortic and radial pressures were calculated by parametric model and results averaged to yield individual TFs. A generalized TF was the average of individual functions. TFs varied among patients, with coefficients of variation for peak amplitude and frequency at peak amplitude of 24.9% and 16.9%, respectively. Intrapatient TF variance with altered loading (> 20% variation in peak amplitude) was observed in 28.5% of patients. Despite this, the generalized TF estimated central arterial pressures to < or = 0.2 +/- 3.8 mm Hg error, arterial compliance to 6 +/- 7% accuracy, and augmentation index to within -7% points (30 +/- 45% accuracy). Individual TFs were only marginally superior to the generalized TF for reconstructing central pressures. Central aortic pressures can be accurately estimated from radial tonometry with the use of a generalized TF. The reconstructed waveform can provide arterial compliance estimates but may underestimate the augmentation index because the latter requires greater fidelity reproduction of the wave contour.
Oscillometric blood pressure devices tend to overestimate systolic blood pressure and underestimate diastolic blood pressure compared with sphygmomanometers. Recent studies indicate that discrepancies in performance between these devices may differ between healthy and diabetic subjects. Arterial stiffness in diabetics could be the underlying factor explaining these differences. We studied differences between a Dinamap oscillometric blood pressure monitor and a random-zero sphygmomanometer in relation to arterial stiffness in 1808 healthy elderly subjects. The study was conducted within the Rotterdam Study, a population-based cohort study of subjects aged 55 years and older. Systolic and diastolic blood pressure differences between a Dinamap and a random-zero sphygmomanometer were related to arterial stiffness, as measured by carotid-femoral pulse wave velocity. Increased arterial stiffness was associated with higher systolic and diastolic blood pressure readings by the Dinamap compared with the random-zero sphygmomanometer, independent of age, gender, and average mean blood pressure level of both devices. The beta-coefficient (95% CI) was 0.25 (0.00 to 0.50) mm Hg/(m/s) for the systolic blood pressure difference and 0.35 (0.20 to 0.50) mm Hg/(m/s) for the diastolic blood pressure difference. The results indicate that a Dinamap oscillometric blood pressure device, in comparison to a random-zero sphygmomanometer, overestimates systolic and diastolic blood pressure readings in subjects with stiff arteries.
Arterial stiffness may predict coronary heart disease beyond classic risk factors. In a longitudinal study, we assessed the predictive value of arterial stiffness on coronary heart disease in patients with essential hypertension and without known clinical cardiovascular disease. Aortic stiffness was determined from carotid-femoral pulse wave velocity at baseline in 1045 hypertensives. The risk assessment of coronary heart disease was made by calculating the Framingham risk score according to the categories of gender, age, blood pressure, cholesterol, diabetes, and smoking. Mean age at entry was 51 years, and mean follow-up was 5.7 years. Coronary events (fatal and nonfatal myocardial infarction, coronary revascularization, and angina pectoris) and all cardiovascular events served as outcome variables in Cox proportional-hazard regression models. Fifty-three coronary events and 97 total cardiovascular events occurred. In univariate analysis, the relative risk of follow-up coronary event or any cardiovascular event increased with increasing level of pulse wave velocity; for 1 SD, ie, 3.5 m/s, relatives risks were 1.42 (95% confidence interval [CI], 1.10 to 1.82; P<0.01) and 1.41 (95% CI, 1.17 to 1.70; P<0.001), respectively. Framingham score significantly predicted the occurrence of coronary and all cardiovascular events in this population (P<0.01 and P<0.0001, respectively). In multivariate analysis, pulse wave velocity remained significantly associated with the occurrence of coronary event after adjustment either of Framingham score (for 3.5 m/s: relative risk, 1.34; 95% CI, 1.01 to 1.79; P=0.039) or classic risk factors (for 3.5 m/s: relative risk, 1.39; 95% CI, 1.08 to 1.79; P=0.01). Parallel results were observed for all cardiovascular events. This study provides the first direct evidence in a longitudinal study that aortic stiffness is an independent predictor of primary coronary events in patients with essential hypertension.
954, respectively), mean daytime BP was 136 – 22/78 – 9 mm Hg versus 136 – 13/78 – 10 mm Hg
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Hg (P = 0.917 and P = 0.954, respectively), mean daytime BP was 136 – 22/78 – 9 mm Hg versus 136 – 13/78 – 10 mm Hg (P = 0.385 and P = 0.972, respectively), mean nighttime BP was 124 – 20/71 – 9 mm Hg versus 124 – 13/71 – 8 mm Hg (P = 0.935 and P = 0.984, respectively), and mean dipping was