Effect of Arterial Lumen Enlargement on Carotid Arterial Compliance in Normotensive Postmenopausal Women

Increased indexed proximal aortic diameter is a predictor of poor prognosis in maintenance hemodialysis patients

Background: Recent studies have shown that the baseline values of absolute aortic root diameter (ARD) and indexed diameter are associated with all-cause mortality and cardiovascular events in the general population, even in the absence of aneurysmal aortic disease. However, there is limited available data on the association between ARD and prognosis in end-stage renal disease (ESRD) patients receiving maintenance hemodialysis (MHD). Accordingly, the purpose of this study is to investigate the predictive value of ARD for all-cause mortality and cardiovascular events in this specific population.Methods: ARD was measured by echocardiography at the level of the sinuses of Valsalva at end diastole and indexed to body surface area (BSA). The primary endpoint was all-cause mortality. The secondary endpoint was major adverse cardiovascular events (MACE), including cardiovascular mortality, myocardial infarction and stroke. Cox proportional hazards models were conducted to evaluate the association between baseline ARD/BSA and clinical outcomes.Results: A total of 391 patients were included in this study. The primary endpoint occurred in 95 (24.3%) patients while the secondary endpoint occurred in 71 (18.2%) patients. Multivariate Cox regression analysis showed that ARD/BSA was an independent prognostic factor for all-cause mortality (HR, per 1-SD increase, 1.403; 95% CI, 1.118-1.761; p = 0.003) as well as MACE (HR, per 1-SD increase, 1.356; 95% CI, 1.037-1.772; p = 0.026).Conclusions: Our results show that ARD/BSA is predictive of all-cause mortality and MACE in MHD patients with ESRD and support the view that assessment of ARD/BSA may refine risk stratification and preventive strategies in this population.

The Implications of Aging on Vascular Health

Vascular aging encompasses structural and functional changes in the vasculature, significantly contributing to cardiovascular diseases, which are the leading cause of death globally. The incidence and prevalence of these diseases increase with age, with most morbidity and mortality attributed to myocardial infarction and stroke. Diagnosing and intervening in vascular aging while understanding the mechanisms behind age-induced vascular phenotypic and pathophysiological alterations offers the potential for delaying and preventing cardiovascular mortality in an aging population. This review delves into various aspects of vascular aging by examining age-related changes in arterial health at the cellular level, including endothelial dysfunction, cellular senescence, and vascular smooth muscle cell transdifferentiation, as well as at the structural level, including arterial stiffness and changes in wall thickness and diameter. We also explore aging-related changes in perivascular adipose tissue deposition, arterial collateralization, and calcification, providing insights into the physiological and pathological implications. Overall, aging induces phenotypic changes that augment the vascular system's susceptibility to disease, even in the absence of traditional risk factors, such as hypertension, diabetes, obesity, and smoking. Overall, age-related modifications in cellular phenotype and molecular homeostasis increase the vulnerability of the arterial vasculature to structural and functional alterations, thereby accelerating cardiovascular risk. Increasing our understanding of these modifications is crucial for success in delaying or preventing cardiovascular diseases. Non-invasive techniques, such as measuring carotid intima-media thickness, pulse wave velocity, and flow-mediated dilation, as well as detecting vascular calcifications, can be used for the early detection of vascular aging. Targeting specific pathological mechanisms, such as cellular senescence and enhancing angiogenesis, holds promise for innovative therapeutic approaches.

The effect of different estradiol levels on carotid artery distensibility during a long agonist IVF protocol

BACKGROUND

This study was made to figure out, does low and high estradiol levels during in vitro fertilization (IVF) cycles have a different effect on carotid artery distensibility (Cdis), carotid artery diameter (Cdia), blood pressure and metabolic factors? Can the stimulation protocol be considered safe to women's vasculature?

METHODS

We studied 28 women having a long agonist protocol IVF-treatment in Kuopio University Hospital during the years 2011-2016. Patients were examined at three time points: in the beginning of their own period (low estradiol), during the gonadotrophin releasing hormone (GnRH) analogue downregulation (low estradiol) and during the follicle stimulating hormone (FSH) stimulation (high estradiol). Women served as their own controls and their menstrual phase (2- to 5-day period after the beginning of menstruation with low estrogen) was used as the reference. Cdis and Cdia were assessed using ultrasound. Blood pressure, weight, estradiol levels and lipids were monitored.

RESULTS

Cdis, Cdia, systolic and diastolic blood pressures peaked during the GnRH-analogue treatment with the lowest estradiol levels. Cdis, Cdia and systolic blood pressures declined by 11% (P = 0.002), 3,8% (P < 0.001) and 2,5% (P = 0.026) during the FSH-stimulation when the estradiol levels were high. Cdis correlated significantly (P < 0.05) with systolic blood pressure, diastolic blood pressure and triglycerides in high estrogenic environment and with diastolic blood pressure (P < 0.05) when estrogen profiles were low.

CONCLUSIONS

Carotid artery stiffens during the high estradiol levels compared to low levels and this was not explained by the higher diameter of the carotid artery, hyperlipidemia or blood pressure profiles. All the changes in Cdis and Cdia are variations of normal, and if there is no history of cardiovascular problems, it can be considered, that the stimulation protocol is not hazardous to vasculature.

The effects of the elastin polymorphisms on carotid intima-media thickness in women aged 30 - 70

[Purpose]

Elastin is one of the major determinants of arterial distensibility of large blood vessels that forms the principal component of elastic fibers from the media of arteries. However, the association between elastin(ELN) genotype and vascular function is still unclear.

[Methods]

120women were recruited from the Saha-gu (Busan, Korea) Community Center. Measurements of body composition and vascular function included carotid intima-media thickness (CIMT), carotid artery luminal diameter (CLD), minimum (diastolic) artery luminal diameter (CLD_min) and maximum (systolic) artery luminal diameter (CLD_max). Genotyping for the ELN (rs 2071307) polymorphism was performed using the TaqMan approach. ELN gene distribution of subjects were in the Hardy-Weinberg equilibrium (p=0.402).

[Results]

The relative CIMT differed significantly among the ELN genotypes. And not significant differences in CLD and CIMT/CLD ratio, but AA genotype was tended higher than other genotypes (AG and GG). The relative CIMT and CLD min differed significantly between the ELN alleles. And not significant differences in CLD max and CIMT/CLD ratio, but A allele was tended higher than G allele.

[Conclusion]

These results suggest that ELN gene polymorphism might be used a one of the genetic determinants of vascular disease in both pre- and postmenopausal women.

Effect of Exercise on Arterial Stiffness: Is There a Ceiling Effect?

BACKGROUND

Whether arterial stiffness (AS) can be improved by regular exercise in healthy individuals remains equivocal according to cross-sectional and longitudinal studies assessing arterial properties at discrete time points. The purpose of the present study was to pinpoint the time course of training-induced adaptations in central AS.

METHODS

Aorta characteristic impedance (Zc) and carotid distensibility (CD) were determined with ultrasonography prior to (week 0) and across 8 weeks (weeks 2, 4, and 8) of supervised endurance training (ET) (3 × 60 minutes cycle ergometry sessions per week), in 9 previously untrained healthy normotensive adults (27 ± 4 years) with no history of cardiovascular disease. Exercise capacity was assessed by maximal oxygen consumption (VO2max) elicited by incremental ergometry.

RESULTS

VO2max increased throughout the ET intervention (+12% from week 0 to week 8, P < 0.001, P for linear trend <0.001). Systolic blood pressure rose with ET (+7% from week 0 to week 8, P = 0.019, P for linear trend <0.001). Aorta Zc augmented from week 0 to week 8 of ET in all individuals (+38%, P = 0.003, P for linear trend = 0.002). CD did not significantly differ among time points (P = 0.196) although a linear decreasing trend was detected (P = 0.016).

CONCLUSIONS

Central AS augments during a conventional ET intervention that effectively enhances aerobic exercise capacity in young individuals. This suggests that normal, healthy elastic arteries are not amendable to improvement unless impairment is present.

Increased Proximal Aortic Diameter is Associated With Risk of Cardiovascular Events and All-Cause Mortality in Blacks The Jackson Heart Study

BACKGROUND

Enlargement of the proximal aorta is associated with aortic wall tissue remodeling, including fragmentation of the elastin fibers, increased synthesis of collagen, and calcification, all of which are associated with aortic wall stiffening. We hypothesized that the proximal aortic diameter (AoD) is associated with cardiovascular events in a community-based cohort of blacks.

METHODS AND RESULTS

We investigated the associations between AoD and cardiovascular events among 3018 black participants (mean age, 55.9 years; 69% women) without past history of cardiovascular disease in the Jackson Heart Study. AoD was measured using echocardiography at the level of the sinuses of Valsalva at end diastole. Cardiovascular event was defined as incident myocardial infarction, fatal coronary artery disease, stroke, or heart failure hospitalization. Cox proportional hazards regression models were used to evaluate the association between baseline AoD and cardiovascular events. Over a median follow-up of 8.3 years, there were 258 cardiovascular events (incident rate, 10.5 per 1000 person-years). After adjustment for traditional risk factors, increased AoD was significantly associated with cardiovascular events (hazard ratio per 1-cm increase, 1.72; 95% CI, 1.10-2.69; P<0.05). Participants in the top AoD quintile had a higher incidence of cardiovascular events compared to those not in the top quintile (hazard ratio, 1.47; 95% CI, 1.11-1.94; P<0.005) after adjustment for risk factors.

CONCLUSIONS

Greater AoD was associated with an increased risk of cardiovascular events in a community-based cohort of blacks. AoD may be useful as a predictor of incident cardiovascular events and further investigation is warranted.

Small proximal aortic diameter is associated with higher central pulse pressure and poor outcome in patients with congestive heart failure

BACKGROUND

A small proximal aortic diameter (AoD) is thought to be associated with a higher characteristic impedance of the proximal aorta. However, there has been no evidence of a relationship between directly evaluated AoD and directly measured central aortic pressure or the outcome of patients with cardiovascular diseases.

METHODS AND RESULTS

(a) In 135 patients without heart failure (HF), who underwent coronary catheterization, we retrospectively examined the relationship between the AoD and the central aortic pressure or aortic elastance. The AoD adjusted with covariates was inversely correlated with the central pulse pressure (cPP; coefficient=-0.75; P=0.04; model R(2)=0.575) and the effective arterial elastance index (coefficient=-0.12; P=0.001; model R(2)=0.366). (b) In 197 patients who were hospitalized due to HF, we examined the relationship between the AoD (evaluated using echocardiography) and the outcome using a Cox proportional hazard model. Fifty-three patients died from various causes during the follow-up period (2.2±1.1 years). Multivariable analysis revealed that the AoD remained an independent risk factor for all-cause death (hazard ratio for 1 s.d. increase of the AoD: 0.68, 95% confidence interval: 0.50-0.92, P=0.013) and cardiovascular death (hazard ratio for 1 s.d. increase of the AoD: 0.63, 95% confidence interval: 0.43-0.93, P=0.019).

CONCLUSIONS

A small AoD was associated with a higher cPP and aortic stiffening in the patients without HF, as well as with a poor outcome for HF patients. Although it is easy to evaluate the AoD, it may offer important information regarding the pulsatile load and may be useful for risk stratification of HF patients.

The correlation of common carotid arterial diameter with atherosclerosis and diabetic retinopathy in patients with type 2 diabetes mellitus

The clinical significance of the diameter of the common carotid artery (CCA) measured ultrasonographically in diabetic practice has not been sufficiently established. The objective of this study was to investigate the relationship of the ultrasonic CCA diameter with atherosclerotic measures and diabetic retinopathy as a microvascular complication in patients with type 2 diabetes mellitus (T2DM). This hospital-based cross-sectional study included 102 patients with T2DM (men: 65%, mean age: 57 years) who had no apparent carotid arterial stenosis and no history of cardiovascular or severe renal disease. The current smoking status, body mass index, blood pressure, hemoglobin A1c, serum low-density lipoprotein cholesterol, and ultrasonic measures of carotid arteries (CCA diameter, intima-media thickness (IMT), plaque score) were measured. The cardio-ankle vascular index (CAVI) and the presence of diabetic retinopathy were also assessed. The CCA diameter showed a significant positive correlation with the mean IMT or plaque score. The CAVI had a significant positive correlation with the mean IMT, plaque score, and CCA diameter, while diabetic retinopathy had a significant positive correlation with the CCA diameter, but not the mean IMT or plaque score. These results were unaltered after adjusting for multiple confounders. The CCA diameter may serve as a useful marker for atherosclerosis and diabetic retinopathy, and in particular, may be a marker associated with diabetic retinopathy more clearly than the carotid IMT and plaque score, in patients with T2DM.

Preserved structural and functional characteristics of common carotid artery in properly treated normoglycemic women with gestational diabetes mellitus

Women with gestational diabetes mellitus (GDM) are at high risk of subsequently developing type 2 diabetes mellitus which is an important cardiovascular risk factor. We have evaluated whether preclinical morphological and functional arterial changes are present in GDM. Diameter, intima-media thickness (IMT), intima-media cross-section area (IMCSA) and elasticity features (compliance, distensibility coefficient, circumferential strain, stiffness index (SI) α and β, incremental elastic modulus) of the common carotid arteries (CCA) were studied in the 3rd trimester in 25 women with GDM, and 17 normal pregnant women matched for age and body mass index using an ultrasonographic vessel wall-movement tracking system and applanation tonometry. Mean IMT, IMCSA and SI α tended to be larger, whereas compliance was smaller in women with GDM but none of these differences were significant. Serum glucose (4.99 ± 0.51 vs. 4.79 ± 0.61 mmol/L, p=0.37) and HbA1c (5.33 ± 0.27 vs. 5.36 ± 0.47 mmol/L, p=0.85) proved normoglycemia in both groups. In conclusion, by the combination of methods we applied in this case control study, neither morphological nor functional characteristics of large elastic arteries differ significantly between well-treated normoglycemic women with GDM and non-diabetic pregnant women in the 3rd trimester.

Evolution and predictors of morphological and functional arterial changes in the course of type 1 diabetes mellitus

BACKGROUND

Diabetes mellitus results in accelerated atherosclerosis. We evaluated preclinical, morphological and functional vascular changes in type 1 diabetes mellitus.

METHODS

Diameter, intima-media thickness, intima-media cross-section area, and elasticity features (compliance, distensibility coefficient, circumferential strain, stiffness index, incremental elastic modulus) of the common carotid arteries and carotid-femoral pulse wave velocity were studied in 42 patients with type 1 diabetes mellitus without macroangiopathy, and 41 control subjects matched for sex, age and body mass index using an ultrasonographic vessel wall-movement tracking system and applanation tonometry.

RESULTS

Significantly larger intima-media thickness (523 ± 55 versus 567 ± 89 µm, p < 0.01), intima-media cross-section area (11.60 ± 1.81 versus 13.08 ± 3.02 mm(2) , p < 0.01), SI (5.58 ± 1.24 versus 7.08 ± 2.69, p < 0.01) and pulse wave velocity (6.00 ± 0.82 versus 6.61 ± 1.56 m/s, p < 0.05) were found in type 1 diabetes mellitus patients compared to controls. When type 1 diabetes mellitus patients with short and long disease duration (≤ or > 10 years) were compared, diameter (6450 ± 433 versus 6847 ± 750 µm, p < 0.05), intima-media cross-section area (11.97 ± 1.98 versus 14.01 ± 3.43 mm, p < 0.05) and pulse wave velocity (5.90 ± 0.92 versus 7.20 ± 1.74 m/s, p < 0.01) differed significantly. When multivariate analyses were restricted to type 1 diabetes mellitus patients, age was an independent predictor of stiffness index and pulse wave velocity, the duration of diabetes mellitus of intima-media cross-section area and pulse wave velocity, systolic blood pressure of diameter and pulse wave velocity, and low-density lipoprotein-cholesterol of intima-media thickness, intima-media cross-section area and stiffness index.

CONCLUSIONS

There are differences in the time course of evolution and in predictors of morphological and functional changes in arteries in type 1 diabetes mellitus.

Association between carotid diameter and the advanced glycation end product N-epsilon-carboxymethyllysine (CML)

Background

N^ε-Carboxymethyllysine (CML) is the major non-cross linking advanced glycation end product (AGE). CML is elevated in diabetic patients and apparent in atherosclerotic lesions. AGEs are associated with hypertension and arterial stiffness potentially by qualitative changes of elastic fibers. We investigated whether CML affects carotid and aortic properties in normoglycemic subjects.

Methods

Hundred-two subjects (age 48.2 ± 11.3 years) of the FLEMENGHO study were stratified according to the median of the plasma CML level (200.8 ng/ml; 25^th percentile: 181.6 ng/ml, 75^th percentile: 226.1 ng/ml) into "high CML" versus "low CML" as determined by ELISA. Local carotid artery properties, carotid intima media thickness (IMT), aortic pulse wave velocity (PWV), blood pressure and fetuin-A were analyzed. In 26 patients after carotidectomy, CML was visualized using immunohistochemistry.

Results

According to the CML median, groups were similar for anthropometric and biochemical data. Carotid diameter was enlarged in the "high" CML group (485.7 ± 122.2 versus 421.2 ± 133.2 μm; P < 0.05), in particular in participants with elevated blood pressure and with "high" CML ("low" CML: 377.9 ± 122.2 μm and "high" CML: 514.5 ± 151.6 μm; P < 0.001). CML was associated fetuin-A as marker of vascular inflammation in the whole cohort (r = 0.28; P < 0.01) and with carotid diameter in hypertensive subjects (r = 0.42; P < 0.01). CML level had no effect on aortic stiffness. CML was detected in the subendothelial space of human carotid arteries.

Conclusion

In normoglycemic subjects CML was associated with carotid diameter without adaptive changes of elastic properties and with fetuin-A as vascular inflammation marker, in particular in subjects with elevated blood pressure. This may suggest qualitative changes of elastic fibers resulting in a defective mechanotransduction, in particular as CML is present in human carotid arteries.

Effects of changes in the physical properties of the central elastic artery on haemodynamic characteristics during ageing

The change in blood pressure during the ageing process depends on the changes in the physical properties of the arterial system. The conventional method of studying ageing, i.e. observing a focus group of people, requires long periods of time and also makes it difficult to separate the ageing effect from the effects of complex geriatric diseases. Therefore, a computer simulation was used to analyse how physical property changes in the central elastic artery during the ageing process affect the blood pressure and input impedance of the blood vessels. An increase in the arterial stiffness and an increase in the wall thickness increased the systolic pressure and the pulse pressure. An increase in the lumen diameter decreased the mean pressure. The pulse wave velocity and shape were changed in the central elastic artery group but were not changed outside this group. Also, the input impedance at a low frequency was increased in the central elastic artery group but was not changed outside this group. In this study, the way in which changes in specific physical properties of the artery affect the haemodynamic characteristics during ageing was analysed.

Age-associated elongation of the ascending aorta in adults

OBJECTIVES

To determine whether human aorta lengthens with aging and to evaluate the impact of the hypothesized aortic elongation on pulse wave velocity (PWV) measurements.

BACKGROUND

Although it is generally thought that the aorta becomes tortuous with aging, there has been no systematic study to date in healthy adults to determine if this is so. Such age-related aortic elongation may be a confounding factor for the PWV measurement in elderly people.

METHODS

Arterial lengths were computed by the 3-dimensional transverse magnetic resonance image arterial tracing of the aorta and carotid and iliac arteries in 256 apparently healthy adults (age 19 to 79 years).

RESULTS

The ascending aorta was greater with advancing age (r = 0.72), whereas the lengths of the descending aorta and carotid and iliac arteries were not associated with age. The elongation of the ascending aorta was associated with the corresponding increases in aortic PWV (beta = 0.50) and brachial/aortic pulse pressure ratio (beta = 0.24), which is an index of pulse wave amplification. The straight distance between carotid and femoral sites (car-fem), the most popular arterial length measurement, overestimated the aortic length measured with the magnetic resonance image by approximately 25%. The most accurate arterial length estimation was the distance obtained by subtracting carotid length from the car-fem, with <5% difference from the magnetic resonance image-measured length. Because the ascending aorta was omitted or subtracted from the length estimation in PWV, the impact of age-related elongation of the aorta on PWV was small.

CONCLUSIONS

The aorta lengthens with age, even in healthy humans, due primarily to the elongation of the ascending aorta. Age-related aortic elongation has little impact on PWV measurements, as the ascending aorta, which undergoes lengthening with age, is not included in the arterial length measurements.

Pulse wave velocity as a marker of arteriosclerosis and its comorbidities in Chinese patients

To obtain reliable data on the epidemiology of arteriosclerosis and the comorbidities in patients with hypertension (HP), coronary heart disease (CHD), type 2 diabetes mellitus (T2DM) and stroke, we evaluated the clinical significance of pulse wave velocity (PWV) as an indicator of arteriosclerosis and its comorbidities in Chinese patients. A total of 910 subjects, including 748 Chinese patients with one or more cardiovascular risk factors (80.2% male, mean age 73.69+/-5.03 years) and 162 healthy volunteers (78.4% male, mean age 73.60+/-5.32 years) were recruited into the study. PWV was measured in 910 subjects, and large artery arteriosclerosis was defined as PWV >or=12 m/s. Multivariable logistic regression analyses were performed to identify risk factors associated with arteriosclerosis. The prevalence of large artery arteriosclerosis in the patients overall was 67.4%, and the prevalence was higher in patients with than in those without HP (63.3% vs. 34.0%; odds ratio [OR]: 3.451), T2DM (24.8% vs. 11.1%; OR: 2.854), CHD (56.1% vs. 45.1%; OR: 1.246) and stroke (26.6% vs. 19.2%; OR: 1.236), but the OR values of CHD and stroke did not differ significantly (p>0.05). After multiple logistic regression analysis, female sex, older age, HP and T2DM were risk factors for large artery arteriosclerosis. In conclusion, PWV can be used as a routine measurement to scan arteriosclerosis in patients with HP or T2DM.

Effect of systemic nitric oxide synthase inhibition on arterial stiffness in humans

Stiffening of large elastic arteries impairs the buffering function of the arterial system and contributes to cardiovascular disease. The aim of this study was to determine whether endothelium-derived nitric oxide (NO) modulates the stiffness of large elastic arteries in humans. Seven apparently healthy adults (60+/-3 years, 2 males and 5 females) underwent systemic alpha-adrenergic blockade (phentolamine) and systemic NO synthase inhibition using NG-monomethyl-L-arginine (L-NMMA) in sequence. Phentolamine was given first to isolate contribution of NO to arterial stiffness by preventing reflex changes in sympathetic tone that result from systemic NO synthase inhibition, and also to compare arterial stiffness at a similar mean arterial pressure. Mean arterial blood pressure decreased (p<0.05) after phentolamine infusion but returned to baseline levels after L-NMMA infusion. The carotid beta-stiffness index (via simultaneous ultrasound and applanation tonometry on the common carotid artery) did not change after the restraint of systemic alpha-adrenergic nerve activity (9.8+/-1.2 vs. 9.1+/-1.1 U) but increased (p<0.05) after NO synthase inhibition (12.6+/-2.0 U). These results suggest that NO appears to modulate central arterial stiffness in humans.

Lower blood flow velocity, higher resistance index, and larger diameter of extracranial carotid arteries are associated with ischemic stroke independently of carotid atherosclerosis and cardiovascular risk factors

PURPOSE

To investigate the association between diameter and flow velocity of the carotid arteries and ischemic stroke.

METHODS

Peak systolic velocity, end diastolic velocity, Pourcelot resistance index, blood flow volume, luminal diameter, and carotid plaque burden were measured and compared in 240 ischemic stroke (IS) patients without history of stroke, 163 chronic stable IS patients, and 236 nonstroke controls (age, >or=40 years). Data were also compared between stroke subtypes (large artery atherosclerosis, lacunar, cardioembolic, or undetermined origin).

RESULTS

Acute as well as chronic stable IS patients had significantly lower flow velocities and flow volume, higher resistance index than nonstroke controls in the common carotid artery (CCA), internal carotid artery and external carotid artery, and larger common carotid artery diameter. The differences were found across all IS subtypes and in stroke patients with as well as without carotid plaque. Comparisons between these subgroups showed significant differences in end diastolic velocity, resistance index, flow velocity, and diameter that were more prominent in the CCA. After adjusting for carotid plaque and cardiovascular risk factors, the associations between the above-mentioned parameter and stroke remained significant.

CONCLUSIONS

Stroke patients in acute as well as chronic stable phase appeared to have larger CCA diameters, lower carotid flow velocities and volume, and higher resistance index than nonstroke patients independently of extracranial carotid atherosclerosis. These findings need to be confirmed by a prospective study.

Age-related reduction of systemic arterial compliance relates to decreased aerobic capacity during sub-maximal exercise

A decrease in systemic arterial compliance (SAC) increases left ventricular load along with the demand for excessive myocardial oxygen consumption when the age-related reduction of SAC reaches a marked level, and consequently may depress left ventricular pump function. Reduced left ventricular pump function decreases aerobic capacity, and some study groups have shown that SAC and/or central arterial distensibility is correlated with maximal aerobic capacity in humans. We thus hypothesize that, once the age-related reduction of SAC reaches a marked level, the participation of SAC in aerobic capacity will be significant even during sub-maximal exercise. Thirty young humans and 46 elderly humans participated in this study. SAC, oxygen uptake at the ventilatory threshold (VO2VT), and the ratio of increase in oxygen uptake, in cardiac output, and in effective arterial elastance to increase in work rate (deltaVO2/deltaWR, deltaCO/deltaWR and deltaEa/deltaWR) were measured. SAC was significantly higher in young subjects compared with elderly subjects, and was significantly related to VO2VT in elderly subjects. SAC also significantly correlated with deltaVO2/deltaWR, deltaCO/deltaWR and deltaEa/deltaWR in elderly subjects. When total subjects were divided by the value of SAC into 6 groups, the VO2VT values in the 3 groups with lower SAC were significantly lower than those in the 3 groups with higher SAC, and gradually decreased with the reduction of SAC. There were no changes in VO2VT among the 3 groups with higher SAC. These results suggest that the participation of SAC in aerobic capacity is significant even during sub-maximal exercise in individuals who show a pronounced age-related reduction of SAC.

Correlation between brachial-ankle pulse wave velocity and arterial compliance and cardiovascular risk factors in elderly patients with arteriosclerosis

The objective of this study was to investigate an association between major cardiovascular risk factors and each of brachial-ankle pulse wave velocity (baPWV), ankle-brachial index (ABI), capacitive arterial compliance (C1), and oscillatory arterial compliance (C2) in elderly patients with arteriosclerosis. We analyzed 160 elderly patients with arteriosclerosis. Vessel wall properties were assessed by baPWV and ABI using a VP-1000 Automatic Arteriosclerosis Measurement System, and C1 and C2 were measured using a DO-2020 Cardiovascular Profiling Instrument. In multiple regression analysis, baPWV was significantly correlated with systolic blood pressure (SBP), mean artery pressure, pulse pressure, diastolic blood pressure (DBP), age, and heart rate (r = 0.670, 0.627, 0.580, 0.523, 0.490, 0.200; p < 0.05), ABI was significantly correlated with pulse pressure, SBP and age (r = -0.250, -0.206, -0.168; p < 0.05), C1 was significantly correlated with pulse pressure, SBP, mean artery pressure, age, DBP and heart rate (r = -0.481, -0.469, -0.363, -0.356, -0.239, -0.188; p < 0.05), and C2 was significantly correlated with age, SBP, pulse pressure, DBP, fasting blood glucose, mean artery pressure and heart rate (r = -0.411, -0.395, -0.383, -0.277, -0.213, -0.183, -0.173; p < 0.05). There were no close correlations between baPWV, ABI, or C1 and fasting blood glucose, total cholesterol, triglycerides, or body mass index. Moreover, there were significant correlations between baPWV and C1 (r = -0.444, p < 0.001), and between baPWV and C2 (r = -0.257, p < 0.01). In conclusion, these findings underscore the efficacy of baPWV and ABI in identifying the vascular damage of the aged.