Increased augmentation of central blood pressure is associated with increases in carotid intima-media thickness in type 2 diabetic patients

Elevated Brain Natriuretic Peptide and High Brachial Pulse Pressure in Patients With Diabetes

BACKGROUND

Heart failure (HF) is frequent in patients with diabetes mellitus (DM), and early detection improves prognosis. We investigated whether analysis of brachial blood pressure (BP) in daily practice can identify patients with DM and high risk for subsequent HF, as defined by brain natriuretic peptide (BNP) >50 pg/ml.

METHODS

3,367 outpatients with DM without a history of cardiovascular disease were enrolled in a prospective study.

RESULTS

Age (mean ± SD) was 56 ± 14 years, 57% were male, 78% had type 2 DM, and HbA1C was 7.4 ± 1.4%. A history of hypertension was recorded in 43% of patients and uncontrolled BP was observed in 13%. BNP concentration (mean ± SD) was 21 ± 21 ng/l and 9% of patients had high risk of incident HF. Brachial pulse pressure (PP) was the best BP parameter associated with high risk of incident HF compared with diastolic, systolic, or mean BP (area under the receiver operating characteristic curve: 0.70, 0.65, 0.57, and 0.57, respectively). A multivariate analysis demonstrated that elevated PP was independently associated with high risk of incident HF (odds ratio [95% confidence interval, CI]: 2.1 [1.5-2.8] for PP ≥65 mm Hg). Study of central aortic BP and pulse wave velocity on 117 patients demonstrated that high risk of incident HF was associated with increased arterial stiffness and subendocardial ischemia. After a mean follow-up of 811 days, elevated PP was associated with increased all-cause mortality (hazard ratio [95% CI]: 1.7 [1.1-2.8]).

CONCLUSIONS

Brachial PP is powerful and independent "easy to record" BP parameter associated with high risk of incident HF in diabetic patients.

Associations between measurements of central blood pressure and target organ damage in high-risk patients

Background

It is not well-known which components of central blood pressure (CBP) are more influential to target organ damage (TOD). This study aimed to determine the relationship between CBP measurements and various types of TOD in high-risk patients.

Methods

A total of 148 patients who had documented atherosclerotic cardiovascular disease or its multiple risk factors were prospectively enrolled. CBP was measured by using applanation tonometry of the radial artery. The following nine TOD parameters were evaluated: left ventricular mass index, relative wall thickness, septal e′ velocity, septal E/e′, brachial-ankle pulse wave velocity, ankle-brachial index, estimated glomerular filtration rate, urine protein and obstructive coronary artery disease.

Results

The mean age of the study population was 67.1 ± 9.0 years and 108 (73 %) were male. Among four CBP measurements (systolic, diastolic, mean, and pulse pressures), central pulse pressure (CPP) was associated with the largest number of TOD parameters. As CPP increased, the number of TOD increased (P = 0.010), but this association was not observed in other CBP measurements (P > 0.05 for each).

Conclusions

CPP had a stronger correlation with TOD than other CBP measurements. Non-invasive CPP could be a useful indicator for predicting TOD in patients at high coronary risk.

Relation of blood pressure and organ damage: comparison between feasible, noninvasive central hemodynamic measures and conventional brachial measures

OBJECTIVE

The present cross-sectional study investigated whether central SBP and pulse pressure (PP) measured noninvasively with a novel cuff-based stand-alone monitor are more strongly associated with hypertensive end-organ damage than corresponding brachial measures.

METHODS

We investigated the cross-sectional association of central versus brachial SBP and PP with echocardiographic left ventricular mass index (LVMI), LV hypertrophy (LVH), carotid intima-media thickness (IMT), and increased IMT (IMT ≥ 75th percentile) among 246 participants drawn from the general population (mean age 57.2 years, 55.3% women).

RESULTS

All blood pressure (BP) measures were positively correlated with LVMI and IMT (P < 0.001 for all). Brachial and central SBP correlated equally strongly with LVMI (r = 0.42 versus 0.40, P for difference 0.19) and IMT (r = 0.32 versus 0.33, P = 0.60). However, brachial PP correlated more strongly than central PP with LVMI (r = 0.34 versus 0.27, P = 0.03) and IMT (r = 0.40 versus 0.35, P = 0.04). In multivariable-adjusted logistic models, all four BP measures were significantly associated with LVH and increased IMT (P ≤ 0.03 for all). However, the diagnostic accuracy of logistic regression models that included brachial or central hemodynamic parameters was similar for LVH [area under curve (AUC) for SBP: 0.74 versus 0.76, P = 0.16; AUC for PP: 0.75 versus 0.73, P = 0.35] and IMT (AUC for SBP: 0.61 versus 0.61, P = 0.67; AUC for PP: 0.63 versus 0.61, P = 0.29).

CONCLUSION

Our findings suggest that central SBP and PP measured with a stand-alone noninvasive BP monitor do not improve diagnostic accuracy for end-organ damage over corresponding brachial measures.

Screening Validity of Arterial Pressure-Volume Index and Arterial Velocity-Pulse Index for Preclinical Atherosclerosis in Japanese Community-Dwelling Adults: the Nagasaki Islands Study

AIM

The arterial pressure-volume index (API) and arterial velocity-pulse index (AVI) are novel measurement indices of arterial stiffness. This study was performed to examine the screening validity of the API and AVI for preclinical atherosclerosis in Japanese community-dwelling adults.

METHODS

We conducted a cross-sectional study of 2,809 participants aged ≥40 years who underwent Japanese national medical check-ups from 2014 to 2016. Preclinical atherosclerosis was defined as a mean carotid intima-media thickness (CIMT) of ≥1.0 mm. Multivariable linear regression analysis was performed to investigate the association of CIMT with API and AVI, adjusting for body mass index, sex, and the Framingham-D'Agostino score. We also examined receiver operating characteristic curves, sensitivity, and specificity to predict preclinical atherosclerosis defined by the CIMT. The cardio-ankle vascular index was also measured for comparison with the API and AVI.

RESULTS

Of 2,809 participants, 68 (2.4%) had preclinical atherosclerosis. In the multivariable linear regression analysis, the API and AVI maintained a positive association with the mean CIMT (B=2.6, P=0.009 and B=3.7, P=0.001, respectively). The cut-offs of the API and AVI that demonstrated better sensitivity and specificity for detection of subclinical atherosclerosis were 31 [area under the curve (AUC), 0.64] and 29 (AUC, 0.60).

CONCLUSIONS

The API and AVI were positively associated with preclinical carotid atherosclerosis independent of the participants' cardiovascular risk. The ability of these scores to predict carotid atherosclerosis could make them a useful screening tool for atherosclerosis.

Arterial indices and serum cystatin C level in individuals with occupational wide band noise exposure

BACKGROUND

Chronic exposure to noise is known to cause a wide range of health problems including extracellular matrix (ECM) proliferation and involvement of cardiovascular system. There are a few studies to investigate noise-induced vascular changes using noninvasive methods. In this study we used carotid artery intima-media thickness (CIMT) and aortic augmentation as indices of arterial properties and cystatin C as a serum biomarker relating to ECM metabolism.

MATERIALS AND METHODS

Ninety-three male participants were included in this study from aeronautic technicians: 39 with and 54 without a history of wide band noise (WBN) exposure. For better discrimination, the participants were divided into the two age groups: <40 and >40 years old. Adjusted aortic augmentation index (AI) for a heart rate equal to 75 beats per minute (AIx@HR75) were calculated using pulse wave analysis (PWA). CIMT was measured in 54 participants who accepted to undergo Doppler ultrasonography. Serum cystatin C was also measured.

RESULTS

Among younger individuals the mean CIMT was 0.85 ± 0.09 mm and 0.75 ± 0.22 mm in the in the exposed and the control groups respectively. Among older individuals CIMT had a mean of 1.04 ± 0.22 mm vs. 1.00 ± 0.25 mm for the exposed vs. the control group. However, in both age groups the difference was not significant at the 0.05 level. A comparison of AIx@HR75 between exposure group and control group both in younger age group (5.46 ± 11.22 vs. 8.56 ± 8.66) and older age group (17.55 ± 10.07 vs. 16.61 ± 5.77) revealed no significant difference. We did not find any significant correlation between CIMT and AIx@HR75 in exposed group (r = 0.314, P value = 0.145) but the correlation was significant in control group (r = 0.455, P value = 0.019). Serum cystatin C level was significantly lower in individuals with WBN exposure compared to controls (441.10 ± 104.70 ng/L vs. 616.89 ± 136.14, P value < 0.001) both in younger and older groups.

CONCLUSION

We could not find any evidence for the association of WBN exposure with arterial properties, but cystatin C was significantly lower in the exposed group.

Which Measurement of Blood Pressure Is More Associated With Albuminuria in Patients With Type 2 Diabetes: Central Blood Pressure or Peripheral Blood Pressure?

The aim of this study was to investigate whether central systolic blood pressure (SBP) was associated with albuminuria, defined as urinary albumin excretion (UAE) ≥30 mg/g creatinine, and, if so, whether the relationship of central SBP with albuminuria was stronger than that of peripheral SBP in patients with type 2 diabetes. The authors performed a cross-sectional study in 294 outpatients with type 2 diabetes. The relationship between peripheral SBP or central SBP and UAE using regression analysis was evaluated, and the odds ratios of peripheral SBP or central SBP were calculated to identify albuminuria using logistic regression model. Moreover, the area under the receiver operating characteristic curve (AUC) of central SBP was compared with that of peripheral SBP to identify albuminuria. Multiple regression analysis demonstrated that peripheral SBP (β=0.255, P<.0001) or central SBP (r=0.227, P<.0001) was associated with UAE. Multiple logistic regression analysis demonstrated that peripheral SBP (odds ratio, 1.029; 95% confidence interval, 1.016-1.043) or central SBP (odds ratio, 1.022; 95% confidence interval, 1.011-1.034) was associated with an increased odds of albuminuria. In addition, AUC of peripheral SBP was significantly greater than that of central SBP to identify albuminuria (P=0.035). Peripheral SBP is superior to central SBP in identifying albuminuria, although both peripheral and central SBP are associated with UAE in patients with type 2 diabetes.

Prediction and prevention of Gestational Diabetes: an update of recent literature

A diagnosis of Gestational Diabetes (GDM) confers adverse risk to the health of the mother and fetus both in pregnancy and later life. The background rate in pregnancy varies between 2 and 14% with incidences reported to be as high as 40% in obese populations. GDM diagnoses are escalating because of rising numbers of overweight and obesity in the reproductive age group but also because of different screening and diagnostic criteria. Lifestyle modification in those diagnosed with GDM has been proven to be an effective treatment in attenuating the metabolic dysregulation associated with this and potentially avoiding the need for medical therapy with either metformin or insulin. Emerging evidence in previous years suggests lifestyle interventions (dietary±physical activity and behavior modification) either pre-pregnancy or antenatally may reduce the incidence of GDM. The first trimester is also becoming an important interrogation period for the prediction of many adverse obstetric outcomes including abnormal glucose metabolism. This review outlines the most contemporary evidence on the prediction and non-pharmacological antenatal prevention strategies used for Gestational Diabetes.

Intrafamilial Aggregation and Heritability of Aortic Reflected (Backward) Waves Derived From Wave Separation Analysis

BACKGROUND

Although aortic wave reflection may be inherited, the extent to which indexes of wave reflection derived from wave separation analysis (reflected (backward) wave index (RI) and pressure (Pb)) show intrafamilial aggregation and heritability is uncertain. We therefore aimed to determine the intrafamilial aggregation and heritability of RI and Pb and compare these with indexes of pressure augmentation.

METHODS

Aortic Pb, RI, augmented pressure (Pa), and augmentation index (AIx) were determined using radial applanation tonometry and SphygmoCor software in 1,152 participants of 315 families (111 father-mother, 705 parent-child, and 301 sibling-sibling pairs) from an urban developing community of black Africans. Heritability estimates were determined from Statistical Analysis for Genetic Epidemiology software.

RESULTS

With appropriate adjustments, significant correlations were noted between parent-child pairs for Pb and Pa (P < 0.05 for all), but not for RI (P = 0.50) or AIx (P = 0.90) and between sib-sib pairs for Pb and Pa (P < 0.05), but not for RI (P = 0.54) or AIx (P = 0.14). No correlations for indexes of wave reflection were noted between fathers and mothers (P > 0.57). After adjustments, Pb (h2 = 0.24±0.07) and Pa (h2 = 0.23±0.07) (P < 0.001 for both) but not RI (h2 = 0.04±0.06, P = 0.27) or AIx (h2 = 0.10±0.07, P = 0.07) showed significant heritability.

CONCLUSIONS

Aortic reflected (backward) waves derived from either wave separation (Pb) or pulse wave analysis (Pa) show a similar degree of intrafamilial aggregation and heritability, but the use of RI or AIx may underestimate reflected wave effects.

Association of Central Versus Brachial Blood Pressure With Target-Organ Damage: Systematic Review and Meta-Analysis

Accumulating evidence suggests that central blood pressure (BP) may reflect the hemodynamic stress on target organs more accurately than brachial BP. A systematic review assessing the relationship of central versus brachial BP with preclinical target-organ damage was performed. Meta-analysis of cross-sectional data showed that central compared with brachial systolic BP was more closely associated with (1) left ventricular mass index (12 studies, n=6431; weighted age [SD], 49.9 [13.1] years; 51% hypertensives): pooled correlation coefficients r=0.30; 95% confidence interval (CI), 0.23-0.37 versus r=0.26; 95% CI, 0.19-0.33, respectively; P<0.01 for difference; (2) carotid intima-media thickness (7 studies, n=6136; weighted age, 55.6 [13.2] years; 48% hypertensives): r=0.27; 95% CI, 0.19-0.34 versus r=0.23; 95% CI, 0.16-0.30, respectively; P<0.01 for difference; (3) pulse-wave velocity (14 studies, n=3699; weighted age, 53.9 [13.3] years; 53% hypertensives): r=0.42; 95% CI, 0.37-0.47 versus r=0.39; 95% CI, 0.33-0.45, respectively; P<0.01 for difference. Four studies assessing urine albumin excretion (n=3718; weighted age, 56.4 [5] years; 69% hypertensives) reported similar correlations (P=not significant) with central (r=0.22; 95% CI, 0.14-0.29) and brachial systolic BP (r=0.22; 95% CI, 0.12-0.32). Similar findings were observed for central compared with brachial pulse pressure in terms of relationship with target-organ damage. Metaregression analyses did not reveal any significant effect of age. In conclusion, central compared with brachial BP seems to be more strongly associated with most of the investigated indices of preclinical organ damage.

Indexes of aortic pressure augmentation markedly underestimate the contribution of reflected waves toward variations in aortic pressure and left ventricular mass

Although indexes of wave reflection enhance risk prediction, the extent to which measures of aortic systolic pressure augmentation (augmented pressures [Pa] or augmentation index) underestimate the effects of reflected waves on cardiovascular risk is uncertain. In participants from a community sample (age >16), we compared the relative contribution of reflected (backward wave pressures and the reflected wave index [RI]) versus augmented (Pa and augmentation index) pressure wave indexes to variations in central aortic pulse pressure (PPc; n=1185), and left ventricular mass index (LVMI; n=793). Aortic hemodynamics and LVMI were determined using radial applanation tonometry (SphygmoCor) and echocardiography. Independent of confounders, RI and backward wave pressures contributed more than forward wave pressures, whereas Pa and augmentation index contributed less than incident wave pressure to variations in PPc (P<0.0001 for comparison of partial r values). In those <50 years of age, while backward wave pressures (partial r=0.28, P<0.0001) contributed more than forward wave pressures (partial r=0.15, P<0.001; P<0.05 for comparison of r values), Pa (partial r=0.13, P<0.005) contributed to a similar extent as incident wave pressure (partial r=0.22, P<0.0001) to variations in LVMI. Furthermore, in those ≥50 years of age, backward wave pressures (partial r=0.21, P<0.0001), but not forward wave pressures (P=0.98), while incident wave pressure (partial r=0.23, P<0.0001), but not Pa (P=0.80) were associated with LVMI. Pa and augmentation index underestimated the effect of wave reflection on PPc and LVMI in both men and women. Thus, as compared with relations between indexes of aortic pressure augmentation and PPc or LVMI, strikingly better relations are noted between aortic wave reflection and PPc or LVMI.

Brachial vs. central systolic pressure and pulse wave transmission indicators: a critical analysis

This critique is intended to provide background for the reader to evaluate the relative clinical utilities of brachial cuff systolic blood pressure (SBP) and its derivatives, including pulse pressure, central systolic pressure, central augmentation index (AI), and pulse pressure amplification (PPA). The critical question is whether the newer indicators add sufficient information to justify replacing or augmenting brachial cuff blood pressure (BP) data in research and patient care. Historical context, pathophysiology of variations in pulse wave transmission and reflection, issues related to measurement and model errors, statistical limitations, and clinical correlations are presented, along with new comparative data. Based on this overview, there is no compelling scientific or practical reason to replace cuff SBP with any of the newer indicators in the vast majority of clinical situations. Supplemental value for central SBP may exist in defining patients with exaggerated PPA ("spurious systolic hypertension"), managing cardiac and aortic diseases, and in studies of cardiovascular drugs, but there are no current standards for these possibilities.

[Assessment of central hemodynamic properties of the arterial wall in women with previous preeclampsia]

BACKGROUND

We investigated viscoelastic properties of the arterial wall in women with previous preeclampsia (PE) compared to those with normal pregnancy (NP).

METHODS

In a cross-sectional study 45 women with previous PE and 55 with NP were included, matched for age (PE 38±6 vs. NP 38±5 years, NS) and body mass index: (PE 25±4 vs. NP 26±4 kg/m(2), NS) studied, respectively, 76±34 and 86±48 months after delivery. We assessed arterial distensibility - pulse wave velocity (PWV, Complior) and reflected waves (augmentation pressure [AP], mmHg) and augmentation index (AIx) - in the central pressure wave and blood pressure (BP) on 24-h ambulatory BP monitoring (ABPM).

RESULTS

PE showed higher (p<0.01) peripheral systolic blood pressure (SBP): PE 131±18 vs. NP 121±19, and central SBP: PE 122±18 vs. NP 110±19 mmHg, with less amplification of central-peripheral pressure: PE 10±4 vs. NP 12±5, p=0.041, and higher (p<0.05) AP: PE 10±3 vs. NP 8±2, and AIx: PE 26±5 vs. NP 20±5 mmHg, but PE and NP did not differ in pulse wave velocity. On ABPM, PE (n=39) vs. NP (n=33) had higher nighttime SBP: PE 121±10 vs. NP 108±10 mmHg and lower percentage nocturnal SBP fall: PE 11±6 vs. NP 18±11%, both p<0.02. During follow-up, the need for antihypertensive medication was seven times higher in PE than in NP.

CONCLUSION

Women with previous PE have a greater risk of hypertension, higher nighttime BP values, blunted nocturnal BP fall and changes in central pressure suggestive of increased reflected waves and peripheral vascular resistance. These factors may contribute to their higher cardiovascular risk after pregnancy.

Effect of age and Blood Pressure on Surrogate Markers of Atherosclerosis in Patients with Type 2 Diabetes Mellitus

BACKGROUND

Increased arterial stiffness may be an important path- way linking diabetes mellitus to increased cardiovascular risk.

AIM

The study was conducted to assess the surrogate markers of arterial stiffness in patients with Type 2 diabetes mellitus (T2DM), and compare with age-matched hypertensive and healthy controls. Also the effect of age and blood pressure on these markers was evaluated.

SETTINGS AND DESIGN

This cross-sectional study was carried out at a tertiary care hospital in West India.

METHODS

After a detailed medical history and anthropometric evaluation, all the participants were subjected to measurements of Arterial Stiffness Index (ASI), Pulse Wave Velocity (PWV), and Augmentation Index (AIx) using a non-invasive oscillometric method. The four study groups consisted of patients with T2DM (>5 years) along with hypertension, newly diagnosed patients with T2DM (<2years) without hypertension, hypertensive controls, and healthy controls.

RESULTS

PWV, ASI, AIx were elevated in patients with T2DM compared to healthy controls (p<0.05). Patients with T2DM above 60 years had higher carotid-femoral PWV, ASI and AIx than those below 60 years (p<0.05). ASI and AIx were significantly increased in patients with T2DM with hypertension having systolic BP > 140 mmHg compared to those with systolic BP < 140 mmHg. A very strong correlation between PWV and AIx in patients with T2DM and hypertensive controls was observed.

CONCLUSION

This study reveals that markers of arterial stiffness (PWV, ASI, AIx) were increased significantly in patients with T2DM compared to healthy controls. Age and systolic blood pressure had significant influence on these markers. Thus, oscillometric markers have potential utility in identifying subclinical atherosclerosis in patients with T2DM.

Differential associations of central and brachial blood pressure with carotid atherosclerosis and microvascular complications in patients with type 2 diabetes

Background

We examined the relationship between central blood pressure (BP), brachial BP with carotid atherosclerosis and microvascular complications in type 2 diabetes mellitus (T2DM).

Methods

We recruited 201 patients who were evaluated for central BP, brachial BP, carotid ultrasonography, brachial-ankle pulse wave velocity (baPWV), ankle-brachial index (ABI) and microvascular complications. Central BP were calculated using a radial automated tonometric system.

Results

Agreement between central BP and brachial BP was very strong (concordance correlation coefficient between central and brachial SBP = 0.889, between central and brachial PP = 0.816). Central pulse pressure (PP) was correlated with mean carotid intima-media thickness (CIMT), baPWV and ABI, whereas brachial PP was borderline significantly correlated with CIMT. The prevalence of nephropathy(DN) and retinopathy(DR) according to the brachial PP tertiles increased, the prevalences of microvascular complications were not different across central PP tertiles. In multivariate analysis, the relative risks (RRs) for the presence of DR were 1.2 and 4.6 for the brachial PP tertiles 2 and 3 when compared with the first tertile. Also, the RRs for the presence of DN were 1.02 and 3 for the brachial PP tertiles 2 and 3 when compared with the first tertile.

Conclusions

Agreement of central BP and brachial BP was very strong. Nonetheless, this study showed that higher brachial PP levels are associated with increased probability for the presence of microvascular complications such as DR/DN. However, there are no associations with central SBP and central PP with microvascular complications. Central BP levels than brachial BP are correlated with surrogate marker of macrovascular complications.

Arterial insulin resistance in Yucatan micropigs with diet-induced obesity and metabolic syndrome

AIM

Metabolic syndrome affects a large proportion of the population and increases cardiovascular disease risk. Because metabolic syndrome often co-exists clinically with atherosclerosis, it is difficult to distinguish the respective contributions of the components to vascular abnormalities. Accordingly, we utilized a porcine dietary model of metabolic syndrome without atherosclerosis to investigate early abnormalities of vascular function and signaling.

METHODS

Thirty-two Yucatan micropigs were fed either a high-fat, high-simple-sugar, high-calorie (HFHS) or standard chow diet (STD) for 6 months. Neither diet contained added cholesterol. Blood pressure and flow-mediated vasodilatation were assessed at baseline and 6 months. Aortas were harvested at 6 months to assess histology, insulin signaling, and endothelial nitric oxide (eNOS) phosphorylation.

RESULTS

HFHS pigs developed characteristics of metabolic syndrome including obesity, dyslipidemia, and insulin resistance, but without histologic evidence of atherosclerosis. Although arterial intima-media thickness did not differ between groups, vascular dysfunction in HFHS was manifest by increased blood pressure and impaired flow-mediated vasodilation of the femoral artery. Compared with STD, aortas from HFHS exhibited increased p85α expression and Ser307 IRS-1 phosphorylation, and blunted insulin-stimulated IRS-1-associated phosphatidylinositol (PI) 3-kinase activity. In the absence of insulin stimulation, aortic Akt Ser473-phosphorylation was greater in HFHS than in STD. With insulin stimulation, Akt phosphorylation increased in STD, but not HFHS. Insulin-induced Ser1177-phosphorylation of eNOS was decreased in HFHS, compared with STD.

CONCLUSIONS

Pigs with metabolic syndrome develop early vascular dysfunction and aortic insulin signaling abnormalities, and could be a useful model for early human vascular abnormalities in this condition.

Brachial artery tonometry and the Popeye phenomenon: explanation of anomalies in generating central from upper limb pressure waveforms

BACKGROUND

Noninvasive applanation tonometry studies of the brachial and radial artery pressure waves show that the arterial pulse is substantially amplified between the brachial and radial sites. Brachial tonometry waveforms have also been used to calibrate carotid tonometry waves as a measure of central pressure in major clinical trials. These trials assume identity of mean and of DBP in calculation of central (carotid) SBP. None of these trials showed superiority of central over brachial pressure in predicting outcome, but all showed equivalence of SBP and pulse pressure at brachial and carotid sites!

METHOD

We tested this method by measuring pressure waves at brachial, radial and carotid sites by applanation tonometry in 100 patients, with attention to any subtle difference between brachial and radial waveforms, and with both calibrated to cuff SBP and DBP.

RESULTS

The results confirmed no proximal and strong distal amplification in the arm. However, this was accompanied by blunting of the brachial compared with radial waveform with brachial pressure 2.7 mmHg higher during most of the cardiac cycle. Form factor of the ensemble-averaged brachial wave [39.1 standard deviation (SD) 4.9%] was similar to the carotid (40.2 SD 4.1%) but different to the radial wave (34.8 SD 3.7%; P < 0.01).

CONCLUSIONS

All findings were explained by inability to applanate the brachial artery, and resulting systematic error in generating brachial waveforms. In estimation of central pressure with applanation tonometry, the radial pressure wave, which can be accurately applanated, should be used, and calibrated to the brachial cuff.

The relationship between aortic stiffness and changes in retinal microvessels among Asian ischemic stroke patients

Large-artery stiffness is a risk factor for stroke, including cerebral small-vessel disease. Retinal microvascular changes are thought to mirror those in cerebral microvessels. We investigated the relationship between aortic stiffness and retinal microvascular changes in Asian ischemic stroke patients. We studied 145 acute ischemic stroke patients in Singapore who had aortic stiffness measurements using carotid-femoral pulse wave velocity (cPWV). Retinal photographs were assessed for retinal microvessel caliber and qualitative signs of focal arteriolar narrowing, arteriovenous nicking and enhanced arteriolar light reflex. Aortic stiffening was associated with retinal arteriolar changes. Retinal arteriolar caliber decreased with increasing cPWV (r=-0.207, P=0.014). After adjusting for age, gender, hypertension, diabetes, mean arterial pressure and small-vessel stroke subtype, patients within the highest cPWV quartile were more likely to have generalized retinal arteriolar narrowing defined as lowest caliber tertile (odds ratio (OR) 6.84, 95% confidence interval (CI) 1.45-32.30), focal arteriolar narrowing (OR 13.85, CI 1.82-105.67), arteriovenous nicking (OR 5.08, CI 1.12-23.00) and enhanced arteriolar light reflex (OR 3.83, CI 0.89-16.48), compared with those within the lowest quartile. In ischemic stroke patients, aortic stiffening is associated with retinal arteriolar luminal narrowing as well as features of retinal arteriolosclerosis.

Relationship between intima-media thickness of the common carotid artery and arterial stiffness in subjects with and without type 2 diabetes: a case-series report

BACKGROUND

We examined the relationship between the intima-media thickness of the common carotid artery (CCA-IMT) and arterial stiffness, assessed by pulse wave velocity (PWV), the ambulatory arterial stiffness index (AASI) and the augmentation index (AIx) in subjects with and without type 2 diabetes.

METHODS

A case-series study was made in 366 patients (105 diabetics and 261-non-diabetics). Ambulatory blood pressure monitoring was performed on a day of standard activity with the SpaceLabs 90207 system. AASI was calculated as "1-slope" from the within-person regression of diastolic-on-systolic ambulatory blood pressure readings. PWV and AIx were measured with the SphygmoCor system, and a Sonosite Micromax ultrasound unit was used for automatic measurements of CCA-IMT.

RESULTS

PWV, AASI and CCA-IMT were found to be greater in diabetic patients, while no differences in AIx were observed between the two groups. CCA-IMT was independently correlated to the three measures of arterial stiffness in both groups. We found an increase in CCA-IMT of 0.40, 0.24 and 0.36 mm in diabetics, and of 0.48, 0.17 and 0.55 mm in non-diabetics for each unit increase in AASI, AIx and PWV. The variability of CCA-IMT was explained mainly by AASI, AIx and gender in diabetic patients, and by age, gender, AASI and PWV in non-diabetic patients.

CONCLUSIONS

CCA-IMT showed a positive correlation to PWV, AASI and AIx in subjects with and without type 2 diabetes. However, when adjusting for age, gender and heart rate, the association to PWV was lost in diabetic patients, in the same way as the association to Alx in non-diabetic patients. The present study demonstrates that the three measures taken to assess arterial stiffness in clinical practice are not interchangeable, nor do they behave equally in all subjects.

Height constitutes an important predictor of mortality in end-stage renal disease

Aim. Height is an important determinant of augmentation index (AI) that anticipates cardiovascular prognosis. There is a scanty of the data whether short height predicts survival in patients with end-stage renal diseases, a high risk population. Methods. Fifty two hypertensive patients with type 2 diabetic nephropathy receiving hemodialysis and 52 patients with nondiabetic nephropathy were enrolled. In addition to AI estimated with radial artery tonometry, classical cardiovascular risk factors were considered. Patients were followed for 2 years to assess cardiovascular prognosis. Results. Cox hazards regression revealed that both smoking and shortness in height independently contributed to total mortality and indicated that smoking as well as the presence of left ventricular hypertrophy predicted cardiovascular mortality. Our findings implicated that high AI, the presence of diabetes, and low high-density lipoprotein cholesterol were significant contributors to cardiovascular events. Conclusions. Our findings provide new evidence that shortness in height independently contributes to total mortality in hemodialysis patients.

Lower blood pressure goals in high-risk cardiovascular patients: are they defensible?

This review highlights the paucity of data that support actively decreasing blood pressures (BP) to a level of less than 130/80 mm Hg. Although the data support a lower cardiovascular (CV) event rate with this lower level of pressure in high-risk CV people, early aggressive intervention to prevent levels from going above this mark prevent development of worsening atherosclerosis. Although no trial will ever prove this concept of prevention, common sense and multiple animal experiments support it. Most patients should have their systolic BP reduced to levels well below 140 mm Hg approaching 130 mm Hg, not 140 mm Hg.

Maternal arterial stiffness in pregnancies complicated by gestational and type 2 diabetes mellitus

OBJECTIVE

We sought to investigate whether maternal arterial stiffness is altered in pregnant women with gestational diabetes mellitus (GDM) and type 2 diabetes compared to normoglycemic women.

STUDY DESIGN

We conducted a cross-sectional study involving 34 women with GDM and their controls (n = 34), and 34 women with type 2 diabetes and their controls (n = 34). Maternal arterial stiffness was assessed using applanation tonometry.

RESULTS

In patients with GDM, compared to their controls, augmentation index (a measure of arterial wave reflection) was higher (13.1 +/- 8.9% vs 0.7 +/- 11.4%; P < .001) and pulse wave velocity (PWV) (arterial stiffness of the carotid-femoral) was marginally increased (6 +/- 1.5 vs 5.4 +/- 0.6 m/s; P = .07). In type 2 diabetics, compared to their controls, both augmentation index and PWV were increased (11.5 +/- 11.4% vs 3.3 +/- 12.5%; P = .006, and 6.8 +/- 1.2 vs 5.6 +/- 1 m/s; P < .001). When all groups were considered together, there was a significant trend of increasing augmentation index (P = .001) and PWV (P < .001) from controls to those with GDM to type 2 diabetes.

CONCLUSION

Pregnancies complicated by GDM and type 2 diabetes are associated with increased maternal arterial stiffness.

Noninvasive measurement of central vascular pressures with arterial tonometry: clinical revival of the pulse pressure waveform?

The arterial pulse has historically been an essential source of information in the clinical assessment of health. With current sphygmomanometric and oscillometric devices, only the peak and trough of the peripheral arterial pulse waveform are clinically used. Several limitations exist with peripheral blood pressure. First, central aortic pressure is a better predictor of cardiovascular outcome than peripheral pressure. Second, peripherally obtained blood pressure does not accurately reflect central pressure because of pressure amplification. Lastly, antihypertensive medications have differing effects on central pressures despite similar reductions in brachial blood pressure. Applanation tonometry can overcome the limitations of peripheral pressure by determining the shape of the aortic waveform from the radial artery. Waveform analysis not only indicates central systolic and diastolic pressure but also determines the influence of pulse wave reflection on the central pressure waveform. It can serve as a useful adjunct to brachial blood pressure measurements in initiating and monitoring hypertensive treatment, in observing the hemodynamic effects of atherosclerotic risk factors, and in predicting cardiovascular outcomes and events. Radial artery applanation tonometry is a noninvasive, reproducible, and affordable technology that can be used in conjunction with peripherally obtained blood pressure to guide patient management. Keywords for the PubMed search were applanation tonometry, radial artery, central pressure, cardiovascular risk, blood pressure, and arterial pulse. Articles published from January 1, 1995, to July 1, 2009, were included in the review if they measured central pressure using radial artery applanation tonometry.

Aortic pulse pressure is associated with carotid IMT in chronic kidney disease: report from Chronic Renal Insufficiency Cohort

BACKGROUND

Patients with chronic kidney disease (CKD) have a disproportionate risk of cardiovascular disease. This study was designed to assess the association between two noninvasive measures of cardiovascular risk, pulse wave analysis (PWA), and carotid intima-media thickness (IMT), in a cohort of CKD patients enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study.

METHODS

Three hundred and sixty-seven subjects with CKD enrolled in the CRIC study at the University of Pennsylvania site (mean age 59.9 years, blood pressure 129/74 mm Hg, estimated glomerular filtration rate 48 ml/min/1.73 m2, IMT 0.8 mm) had both carotid IMT and PWA measurements. Carotid ultrasound was also used to determine the presence of plaque. PWA was used to determine augmentation index (AI), amplification ratio (AMPR), aortic pulse pressure (C_PP), and central aortic systolic pressure (C_SP).

RESULTS

IMT was significantly associated with all PWA-derived measures. However, on multivariable linear regression analysis, only AMPR (regression coefficient -0.072, P = 0.006), C_PP (regression coefficient 0.0025, P < 0.001), and C_SP (regression coefficient 0.0017, P < 0.001) remained significantly associated with IMT. The prevalence of carotid plaque in the cohort was 59%. Of the PWA-derived measures, only C_PP was significantly associated with the presence of carotid plaque (P < 0.001).

CONCLUSIONS

PWA-derived measures are associated with carotid IMT and plaque in the CKD. Of these measures, C_PP was most associated with carotid IMT and plaque.

Prospective assessment of lower-extremity peripheral arterial disease in diabetic patients using a novel automated optical device

A new optical device based on the photoplethysmograph (PPG) method and an innovative algorithm for the assessment of lower-extremity peripheral arterial disease was investigated prospectively in patients with type II diabetes. This new functional PPG (fPPG) technique uses a cuffless functional test to assess diabetic peripheral arterial disease without operator dependency and the incompressible arteries, issues associated with ankle brachial pressure index (ABPI) measurement. Diabetic patients (n = 24; 47 legs; age, 70 +/- 3 years) were recruited from the vascular clinic, and controls (n = 15; 30 legs; age, 66 +/- 5 years) were recruited from the orthopedic outpatient clinic. All underwent resting ABPI, fPPG, and duplex angiography (DA) as "gold standard." fPPG requires the placement of an optical probe on the toe for acquisition of pulsatile arterial perfusion for a period of 30 seconds with the leg in supine and raised at 45 degrees positions. The data were analyzed, and indices were generated by an automated computer system. In those with diabetes, fPPG correlated significantly with DA (r = -.68, P < .01) and ABPI (r = -.65, P < .01). We also found a significant correlation between ABPI and DA (r = .81, P < .01). The analysis of the receiver operator curve showed that optimum sensitivity and specificity for ABPI and fPPG were 80% and 93% and 83% and 71%, respectively, against DA. This method uses changes in pulsatile arterial blood volume using a simple cuffless functional test. The fPPG investigation period was much shorter (5 minutes) with independence of operator skills, whereas ABPI took longer (10-15 minutes) and required operator experience. Although the fPPG results are promising, further improvement (eg, by incorporation of functional skin color and temperature changes) is required to improve the sensitivity and specificity of the system.

Alterações das propriedades funcionais e estruturais de grandes artérias no diabetes mellitus

Alterações funcionais e estruturais das grandes artérias exercem um importante papel na patogênese das doenças cardiovasculares. O diabetes mellitus, ao lado da hipertensão arterial e do envelhecimento, pode induzir essas alterações em diferentes territórios arteriais, e assim levar ao desenvolvimento de aterosclerose e suas conseqüências cardiovasculares. A principal alteração da função das grandes artérias é o aumento da rigidez, enquanto que a principal alteração estrutural é o maior espessamento da camada intima-media da artéria carótida, encontradas em ambos os tipos 1 e 2 de diabetes. Os mecanismos destas alterações estruturais e funcionais arteriais no diabetes incluem a resistência à insulina, o acúmulo de colágeno devido à glicação enzimática inadequada, disfunção endotelial e do sistema nervoso autônomo. O aumento de rigidez arterial é um marcador de risco cardiovascular em pacientes diabéticos, e o tratamento tanto do diabetes per se quanto de dislipidemia e hipertensão arterial associadas pode modificar beneficamente essas alterações arteriais.