Correlates of reactive hyperemic index in men and postmenopausal women

Peripheral arterial endothelial dysfunction predicts future cardiovascular events in diabetic patients with albuminuria: a prospective cohort study

Background

Reactive hyperemia-peripheral arterial tonometry (RH-PAT) is a noninvasive and simple test for evaluating the endothelial function. There has been sparse evidence on the usefulness of the RH-PAT index (RHI) in predicting future cardiovascular diseases among diabetic patients.

Methods

Asymptomatic diabetic patients with albuminuria were selected; their medical history and laboratory findings were evaluated every 3 to 4 months, respectively. The primary outcome was a composite of three-point major adverse cardiovascular events (3-point MACE): death from cardiovascular causes, acute coronary events, or nonfatal stroke. On the contrary, secondary outcomes included a composite of 3-point MACE, hospitalization for heart failure, or chronic kidney disease (CKD) progression. RHI was measured using the Endo-PAT2000 at the baseline. RHI < 1.67 was considered to indicate peripheral endothelial dysfunction (PED).

Results

In total, 149 subjects were included (mean age, 61.8 ± 9.2 years; duration of diabetes was 12 years). During the follow-up period (median, 49.7 months), of the 149 subjects, primary outcomes were detected in 12 (1 [2.3%] and 11 [10.5%] of those without and with PED, respectively). The presence of PED in baseline measurements significantly increased both primary and secondary outcomes, following adjustment for age, sex, hypertension, glycated hemoglobin, low-density lipoprotein cholesterol, triglyceride, systolic blood pressure, baseline estimated glomerular filtration rate, overt proteinuria, duration of diabetes, premedical history of ischemic events, anti-platelet agents, and smoking history (hazard ratio [HR]: 10.95; 95% confidence interval CI 1.00–119.91 for the primary outcome; HR, 4.12; 95% CI 1.37–12.41 for secondary outcome). In addition, PED could predict secondary outcomes independent of the risk score according to the American College of Cardiology/American Heart Association (HR: 3.24; 95% CI 1.14–9.17).

Conclusions

PED can independently predict future cardiovascular events among diabetic patients with albuminuria.

Clinical Phenotype and Microvascular Dynamics of Subjects with Endothelial Dysfunction as Assessed by Peripheral Tonometry

OBJECTIVE

To evaluate the characteristics and the determinants of ED, as measured by PAT.

METHODS

We measured basal and post-ischemic digital pulse amplitude (EndoPAT(®)) in a mixed outpatient population of 206 diabetic and 101 non-diabetic subjects, of whom 50% with clinically manifest CVD, undergoing to an extensive clinical, biochemical, and vascular phenotype characterization.

RESULTS

The major characteristics of ED (tertile 1 vs 3), in addition to lower post-ischemic vasodilatory reserve (34 vs 203%), were a 3-fold higher baseline pulse amplitude and a delayed (60 second) peak response. The main determinant of this response was the baseline pulse amplitude (Stβ = -0.59), which in turn was influenced by age (Stβ = 0.13), central obesity (Stβ = 0.27) and inversely by HDL cholesterol (Stβ = -0.17), and systolic blood pressure (Stβ = -0.19). No association was observed with cardiovascular risk factors, previous cardiovascular event or extent of atherosclerosis (ABI and IMT, PWV). Most of the variability in baseline pulse amplitude remained unexplained (r(2) = 0.14).

CONCLUSIONS

ED, as detected by PAT in a population enriched with subjects at risk for CVD neither reflects the burden of classical risk factors (under treatment) nor the severity of atherosclerosis. Aside from central obesity and HDL cholesterol, most of the factors responsible for this ED remain unknown.

Endothelial Dysfunction of Patients with Peripheral Arterial Disease Measured by Peripheral Arterial Tonometry

Objective. Endothelial dysfunction plays a key role in atherosclerotic disease. Several methods have been reported to be useful for evaluating the endothelial dysfunction, and we investigated the endothelial dysfunction in patients with peripheral arterial disease (PAD) using peripheral arterial tonometry (PAT) test in this study. Furthermore, we examined the factors significantly correlated with PAT test. Methods. We performed PAT tests in 67 patients with PAD. In addition, we recorded the patients' demographics, including comorbidities, and hemodynamical status, such as ankle brachial pressure index (ABI). Results. In a univariate analysis, the ABI value (r = 0.271, P = 0.029) and a history of cerebrovascular disease (r = 0.208, P = 0.143) were found to significantly correlate with PAT test, which calculated the reactive hyperemia index (RHI). In a multivariate analysis, only the ABI value significantly and independently correlated with RHI (β = 0.254, P = 0.041). Conclusion. This study showed a significant correlation between RHI and ABI. The PAT test is a useful tool for evaluating not only endothelial dysfunction but also the hemodynamical state in patients with PAD.

Beyond type 2 diabetes, obesity and hypertension: an axis including sleep apnea, left ventricular hypertrophy, endothelial dysfunction, and aortic stiffness among Mexican Americans in Starr County, Texas

BACKGROUND

There is an increasing appreciation for a series of less traditional risk factors that should not be ignored when considering type 2 diabetes, obesity, hypertension, and cardiovascular disease. These include aortic stiffness, cardiac structure, impaired endothelial function and obstructive sleep apnea. They are associated to varying degrees with each disease categorization and with each other. It is not clear whether they represent additional complications, concomitants or antecedents of disease. Starr County, Texas, with its predominantly Mexican American population has been shown previously to bear a disproportionate burden of the major disease categories, but little is known about the distribution of these less traditional factors.

METHODS

Type 2 diabetes, obesity and hypertension frequencies were determined through a systematic survey of Starr County conducted from 2002 to 2006. Individuals from this examination and an enriched set with type 2 diabetes were re-examined from 2010 to 2014 including assessment of cardiac structure, sleep apnea, endothelial function and aortic stiffness. Individual and combined frequencies of these inter-related (i.e., axis) conditions were estimated and associations evaluated.

RESULTS

Household screening of 5230 individuals aged 20 years and above followed by direct physical assessment of 1610 identified 23.7 % of men and 26.7 % of women with type 2 diabetes, 46.2 and 49.5 % of men and women, respectively with obesity and 32.1 and 32.4 % with hypertension. Evaluation of pulse wave velocity, left ventricular mass, endothelial function and sleep apnea identified 22.3, 12.7, 48.6 and 45.2 % of men as having "at risk" values for each condition, respectively. Corresponding numbers in women were 16.0, 17.9, 23.6 and 28.8 %. Cumulatively, 88 % of the population has one or more of these while 50 % have three or more.

CONCLUSIONS

The full axis of conditions is high among Mexican Americans in Starr County, Texas. Individual and joint patterns suggest a genesis well before overt disease. Whether they are all mediated by common underlying factors or whether there exist multiple mechanisms remains to be seen.

The impact of long-term changes in metabolic status on cardiovascular biomarkers and microvascular endothelial function in middle-aged men: a 25-year prospective study

BACKGROUND

The aim of this analysis was to examine long-term effects of changes in metabolic status on microvascular endothelial function and cardiovascular diseases (CVD) biomarkers among physically active middle-aged men.

METHODS

Metabolically healthy men (n = 101, mean age 59.7 years), free of symptoms and treatment, have been prospectively observed for their lifestyle and CVD risk factors (observation period 24.7 years). At the latest follow-up (2011/2012) a set of CVD biomarkers was measured using enzyme-linked immunosorbent assay. Microvascular endothelial function was evaluated by means of the reactive hyperemia index (RHI) using Endo-PAT2000 system. At follow-up the participants were divided into metabolically healthy (0-1 metabolic parameters) and metabolically unhealthy (≥2 metabolic parameters) groups. Metabolic syndrome was defined according to the NCEP ATP III definition.

RESULTS

Traditional metabolic risk factors were significantly associated with hsCRP, ox-LDL, Il-6, leptin and adiponectin/leptin ratio. Reactive hyperemia index was negatively related to body mass (p < 0.01), waist circumference (p < 0.05), triglycerides (p < 0.01), TG/HDL ratio (p < 0.01), uric acid (p < 0.05), sICAM-1 (p < 0.05) and Il-6 (p < 0.05), and positively to HDL-C (p < 0.01) and leisure-time physical activity (p < 0.01). Men who maintained metabolically healthy status (n = 47) through the observation had significantly lower hsCRP and uric acid (p < 0.05), higher adiponectin/leptin ratio (p < 0.05), higher mean RHI and lower prevalence of endothelial dysfunction (p < 0.05) as compared to the metabolically unhealthy group (n = 54). Regular physical activity level was significantly higher among metabolically healthy individuals during the whole observation.

CONCLUSIONS

Even subtle changes in metabolic profile influence inflammatory biomarkers and microvascular endothelial function. Leptin, adiponectin/leptin ratio and hsCRP are significant predictors of metabolic profile. Interleukine-6 and sICAM-1 may be used as indicators of early endothelial dysfunction in asymptomatic men. High leisure-time physical activity level is an important contributor of metabolically healthy profile through middle adulthood.

Reproducibility of peripheral arterial tonometry measurements in male cardiovascular patients

BACKGROUND

Assessment of endothelial function of the microvasculature by peripheral arterial tonometry (EndoPAT(®)) has gained increasing popularity in patients with cardiovascular risk factors. Only limited knowledge about its reproducibility in patients with coronary artery disease (CAD) is available. We therefore aimed to quantify reproducibility of EndoPAT(®) parameters in patients with stable CAD.

DESIGN

EndoPAT(®) measurements were performed repeatedly in 78 male patients (age 66 ± 8 years) with CAD on stable medication. We calculated overall mean, standard deviation (SD), coefficient of variation (CV) and intraclass correlation coefficient (ICC) of the following parameters: reactive hyperemic index (RHI), PAT ratio of the postocclusion period 90-150 s as used for calculation of the RHI (PAT ratio90-150 s) and 90-120 s (PAT ratio90-120 s) as used for the often employed Framingham RHI (F-RHI), as well as PAT ratio of the peak hyperemic response (PAT ratiopeak response). Additionally, least significant changes (LSC) for individual subjects and minimum sample sizes for parallel and cross-over design studies were calculated.

RESULTS

Mean RHI was 1·84 (SD 0·36). For RHI, PAT ratio90-150 s , PAT ratio90-120 s , and PAT ratiopeak response the CVs were 17·0%, 25·4%, 26·1%, and 25·0%, respectively. The ICCs were 0·45, 0·49, 0·48 and 0·51, respectively, and LSC for RHI was 47·2%.

CONCLUSIONS

CV of RHI in our population was moderate; however, we consider this precision insufficient to monitor changes in individual patients, as they would need to exceed 47% to show a significant change. Further, the poor ICCs reflect the difficulty of detecting treatment effects in homogenous populations, such as patients with stable CAD.

Hemodynamic Aging as the Consequence of Structural Changes Associated with Early Vascular Aging (EVA)

An increase in peripheral vascular resistance at rest is not routinely observed in healthy older persons, but often associated with increased stiffness of central elastic arteries, as hallmarks of aging effects on the vasculature, referred to as early vascular aging (EVA). In clinical practice, the increased arterial stiffness translates into increased brachial and central systolic blood pressure and corresponding pulse pressure in subjects above 50 years of age, as well as increased carotid-femoral pulse wave velocity (c-f PWV), a marker of arterial stiffness. A c-f PWV value ≥ 10 m/s is currently defined as a threshold for increased cardiovascular risk, based on consensus statement from 2012. Prevention and treatment strategies include a healthy lifestyle and the control of risk factors via appropriate drug therapy to achieve vascular protection related to EVA. New drugs are under development for vascular protection, for example the selective Angiotensin II (AT2) receptor agonist called compound 21. One target group for early intervention could be members of risk families including subjects with early onset cardiovascular disease.