Type 2 diabetes mellitus worsens arterial stiffness in hypertensive patients through endothelial dysfunction

Assessment of arterial stiffness in patients with diabetic retinopathy: A systematic review and meta-analysis

BACKGROUND

Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus (DM). A number of studies have investigated if patients with diabetic retinopathy present altered arterial stiffness compared to diabetic individuals without retinopathy.

OBJECTIVES

To compare arterial stiffness parameters in participants with diabetic retinopathy (DR) compared to participants with diabetes without retinopathy.

METHODS

Medline and Scopus were searched for published articles comparing indices of arterial stiffness in participants with DR and in diabetic participants without retinopathy. Standardized Mean Difference (SMD) with 95% confidence interval (CI) was calculated for the comparisons. The study protocol was registered with PROSPERO with registration ID: CRD42023482577.

RESULTS

The meta-analysis analyzed 3 arterial stiffness parameters brachial ankle PWV, carotid-femoral PWV and augmentation index (AI). 8 studies were included in the analysis of brachial ankle PWV, 4 in the analysis of carotid-femoral PWV and 4 in the analysis of the augmentation index. Brachial ankle PWV, carotid-femoral PWV and augmentation index were found to be increased in participants with DR compared to diabetic participants without DR (SMD = 0.59, 95 %CI = 0.40-0.79, P < 0.00001, I2 = 89 %, SMD = 0.86, 95 %CI = 0.55-1.18P < 0.00001, I2 = 91 % and SMD = 0.23, 95 %CI = 0.13-0.32, P < 0.00001, I2 = 0 %, respectively).

CONCLUSION

Diabetic participants with DR exhibit increased arterial stiffness compared to diabetic participants without DR.

Impacts of hypertension and diabetes on the incidence of cardiovascular diseases and all-cause mortality: findings from the China Health and Retirement Longitudinal Study cohort

OBJECTIVE

The study aimed to examine the individual and joint effects of hypertension and diabetes on cardiovascular diseases and all-cause mortality among the middle-aged and older Chinese population.

METHODS

A total of 9681 individuals without preexisting CVD from the China Health and Retirement Longitudinal Study (CHARLS) were included. Participants were classified into four different groups: hypertension alone, diabetes alone, both conditions, neither condition. Multivariate Cox proportional hazards models were performed to estimate the risks of all-cause mortality and CVD.

RESULTS

During the 7-year follow-up, 967 deaths and 1535 CVD events were documented. Compared to individuals without hypertension and diabetes, hypertension alone [adjusted hazard ratio (aHR) 1.571, 95% confidence interval (CI) 1.316-1.875, P  < 0.001], diabetes alone (aHR 1.618, 95% CI 1.187-2.205, P  < 0.01) and comorbid hypertension and diabetes (aHR 2.041, 95% CI 1.557-2.677, P  < 0.001) increased risks of all-cause mortality. The aHRs for CVD events in individuals with both conditions, hypertension alone and diabetes only were 2.011 (95% CI 1.651-2.449, P  < 0.001), 1.408 (95% CI 1.233-1.608, P  < 0.001) and 1.036 (95% CI 0.808-1.327, P  > 0.05), respectively. The risk of CVD among those with comorbid hypertension and diabetes exceeded the sum of the risks due to hypertension and diabetes alone (relative excess risk ratio = 0.567, 95% CI 0.136-0.999).

CONCLUSION

Individuals with comorbid hypertension and diabetes had greater risks of CVD and all-cause mortality, beyond those associated with either condition alone. The synergistic interaction between hypertension and diabetes aggravated the risk of CVD.

Aortic Stiffness Measured by Carotid Femoral-Pulse Wave Velocity at Different Stages of Normal Glucose, Prediabetes, and Diabetes Mellitus: A Systematic Review and Meta-Analysis

Background

To explore aortic stiffness measured by carotid femoral-pulse wave velocity (cf-PWV) at different stages of normal glucose, prediabetes, and diabetes mellitus (DM).

Methods

The literature comparing aortic stiffness (AS) with cf-PWV between DM and non-DM samples was systematically retrieved from Pubmed, Ovid Medline, Web of Science, Embase, Scopus, CNKI, and Wanfang databases. The Newcastle-Ottawa Scale was used to assess the quality of the literature. The primary endpoint was the mean difference (MD) of cf-PWV between the normal glucose and DM samples and normal glucose and prediabetes samples. The secondary endpoints were the MD of carotid intima-media thickness (cIMT) and carotid-radial pulse wave velocity (cr-PWV). Aggregated MD and 95% confidence intervals were calculated. When the I2 value was >50% or p < 0.01, the heterogeneity was considered large, and the random-effect model was used; otherwise, the fixed-effect model was used. A sensitivity analysis was conducted to identify the source of heterogeneity, and a funnel plot and the regression Egger test was utilized to assess the publication bias.

Results

A total of 37 studies were finally enrolled. Samples with DM had a higher cf-PWV value and cIMT value than those without DM, and the differences were statistically significant. The cr-PWV measurements tended to be higher in the DM group than in the non-DM group, but the difference was not significant. Samples with prediabetes also had a significantly higher cf-PWV value than samples with normal glucose.

Conclusions

Samples with DM and prediabetes were associated with a higher cf-PWV value, indicating that DM patients had a higher central AS. Central AS progresses at the prediabetes stage. These data provide insight into understanding the mechanism of adverse effects of DM and prediabetes on artery stiffness.

Independent association of estimated pulse-wave velocity with all-cause mortality in individuals with type 2 diabetes

BACKGROUND

Estimated pulse-wave velocity (ePWV), a surrogate measure of arterial stiffness, was shown to independently predict morbidity and mortality from cardiovascular disease and other causes in both the general population and high-risk individuals. However, in people with type 2 diabetes, it is unknown whether ePWV adds prognostic information beyond the parameters used for calculating it.

AIMS

To assess the independent association of ePWV with all-cause mortality in individuals with type 2 diabetes.

DESIGN

Prospective cohort study that enrolled 15 773 patients in 19 Italian centres in 2006-08.

METHODS

ePWV was calculated from a regression equation using age and mean blood pressure (BP). All-cause mortality was retrieved for 15 656 patients in 2015.

RESULTS

Percentage and rate of deaths, Kaplan-Meier estimates and unadjusted hazard ratios increased from Quartile I to Quartile IV of ePWV. After adjustment for age, sex, BP levels and anti-hypertensive treatment, the strength of association decreased but mortality risk remained significantly higher for Quartiles II (+34%), III (+82%) and IV (+181%) vs. Quartile I and was virtually unchanged when further adjusting for other cardiovascular risk factors and complications/comorbidities. Each m·s- 1 increase in ePWV was associated with an increased adjusted risk of death in the whole cohort (+53%) and in participants with (+52%) and without (+65%) cardiorenal complications. Moreover, ePWV significantly improved prediction of mortality risk over cardiovascular risk factors and complications/comorbidities, though the net increase was modest.

CONCLUSIONS

These findings suggest that ePWV may represent a simple and inexpensive tool for providing prognostic information beyond traditional cardiovascular risk factors.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00715481, https://clinicaltrials.gov/ct2/show/NCT00715481.

Arterial Stiffness: From Basic Primers to Integrative Physiology

The elastic properties of conductance arteries are one of the most important hemodynamic functions in the body, and data continue to emerge regarding the importance of their dysfunction in vascular aging and a range of cardiovascular diseases. Here, we provide new insight into the integrative physiology of arterial stiffening and its clinical consequence. We also comprehensively review progress made on pathways/molecules that appear today as important basic determinants of arterial stiffness, particularly those mediating the vascular smooth muscle cell (VSMC) contractility, plasticity and stiffness. We focus on membrane and nuclear mechanotransduction, clearance function of the vascular wall, phenotypic switching of VSMCs, immunoinflammatory stimuli and epigenetic mechanisms. Finally, we discuss the most important advances of the latest clinical studies that revisit the classical therapeutic concepts of arterial stiffness and lead to a patient-by-patient strategy according to cardiovascular risk exposure and underlying disease.

Lack of Association between Serum Chitotriosidase Activity and Arterial Stiffness in Type 2 Diabetes without Cardiovascular Complications

Chitotriosidase (CHIT), a mammalian chitinase secreted by neutrophils and activated macrophages, is increased in both cardiovascular disease (CVD) and type 2 diabetes (T2D). Arterial stiffness rises early in T2D and increases the risk of CVD. The aim of this study is to evaluate CHIT activity as an early biomarker of arterial stiffness in people with T2D free from overt vascular complications. In this cross-sectional study, arterial stiffness as measured using standard pulse wave velocity (PWV) was evaluated in 174 people with T2D without overt vascular disease. Then, we measured CHIT serum activity with an electrochemiluminescence assay in two subgroups of participants: 35 with the highest (high-PWV) and 40 with the lowest (low-PWV) PWV values. CHIT activity was no different between the low-PVW and high-PWV groups (12.7 [9.6-17.9] vs. 11.4 [8.8-15.0] nmol/mL/h, respectively). Compared with the low-PWV group, the high-PWV participants were older (p < 0.001); had a longer duration of diabetes (p = 0.03); higher ankle-brachial index ABI (p = 0.04), systolic blood pressure (p = 0.002), diastolic blood pressure (p = 0.005), fasting blood glucose (p = 0.008), and HbA1c (p = 0.005); and lower eGFR (p = 0.03) and body mass index (BMI) (p = 0.01). No association was present with sex, duration of diabetes, age, BMI, peripheral blood pressure, laboratory parameters, and glucose-lowering medications or ongoing antihypertensive therapy. Although no association was found, this study provides novel data about the association of CHIT activity with CVD, focusing on a specific outcome (arterial stiffness) in a well-defined population of subjects with T2D without established CVD.

Role and mechanisms of SGLT-2 inhibitors in the treatment of diabetic kidney disease

Diabetic kidney disease (DKD) is a chronic inflammatory condition that affects approximately 20-40% of individuals with diabetes. Sodium-glucose co-transporter 2 (SGLT-2) inhibitors, emerging as novel hypoglycemic agents, have demonstrated significant cardiorenal protective effects in patients with DKD. Initially, it was believed that the efficacy of SGLT-2 inhibitors declined as the estimated glomerular filtration rate (eGFR) decreased, which led to their preferential use in DKD patients at G1-G3 stages. However, recent findings from the DAPA-CKD and EMPA-KIDNEY studies have revealed equally beneficial cardiorenal effects of SGLT-2 inhibitors in individuals at stage G4 DKD, although the underlying mechanism behind this phenomenon remains unclear. In this comprehensive analysis, we provide a systematic review of the mechanisms and functioning of SGLT-2 inhibitors, potential renal protection mechanisms, and the therapeutic efficacy and safety of SGLT-2 inhibitors in kidney diseases, with a particular focus on stage G4 DKD. Gaining a deeper understanding of the renal protective effect of SGLT-2 inhibitors and their underlying mechanisms is highly significance for the successful utilization of these inhibitors in the treatment of diverse kidney disorders.

Effects of concurrent aerobic and resistance training on vascular health in type 2 diabetes: a systematic review and meta-analysis

Objective

To determine the impacts of concurrent aerobic and resistance training on vascular structure (IMT) and function (PWV, FMD, NMD) in type 2 diabetes (T2D).

Methods

The electronic databases PubMed, Web of Science Core Collection, Cochrane Library, Embase, Scopus, CINAHL, and SPORTDiscus were systematically searched for articles on "type 2 diabetes" and "concurrent training" published from inception to August 2, 2022. We included randomized controlled trials that examined the effects of concurrent training versus passive controls on IMT, PWV, FMD and NMD in T2D.

Results

Ten studies were eligible, including a total of 361 participants. For IMT, concurrent training showed a slight decrease by 0.05 mm (95% CI -0.11 to 0.01, p > 0.05). concurrent training induced an overall significant improvement in FMD by 1.47% (95% CI 0.15 to 2.79, p < 0.05) and PWV by 0.66 m/s (95% CI -0.89 to -0.43, p < 0.01) in type 2 diabetics. However, concurrent training seemed to exaggerate the impaired NMD (WMD = -2.30%, 95% CI -4.02 to -0.58, p < 0.05).

Conclusions

Concurrent training is an effective method to improve endothelial function and artery stiffness in T2D. However, within 24 weeks concurrent training exacerbates vascular smooth muscle dysfunction. More research is needed to explore whether longer and/or higher-intensity concurrent training interventions could enhance the vascular structure and smooth muscle function in this population.

Systematic review registration

www.crd.york.ac.uk/PROSPERO/, identifier CRD42022350604.

A six-month low-carbohydrate diet high in fat does not adversely affect endothelial function or markers of low-grade inflammation in patients with type 2 diabetes: an open-label randomized controlled trial

BACKGROUND

While a low-carbohydrate diet (LCD) reduces HbA1c in patients with type 2 diabetes (T2D), the associated high intake of fat may adversely affect cardiovascular risk factors. To address this, we examined the effect of a non-calorie-restricted LCD high in fat on endothelial function and markers of low-grade inflammation in T2D over 6 months.

METHODS

In an open-label randomized controlled trial, 71 patients with T2D were randomized 2:1 to either a LCD (< 20 E% carbohydrates, 50-60 E% fat) or a control diet (50-60 E% carbohydrates, 20-30 E% fat) for six months. Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) were assessed by ultrasound in the brachial artery together with plasma interleukin-6 (IL-6) and serum high-sensitivity C-reactive protein (hsCRP) in the participants at baseline (n = 70) and after six months (n = 64).

RESULTS

The FMD and NID were unaltered in both groups after six months, and there were no between-group differences in change of either FMD (p = 0.34) or NID (p = 0.53) in response to the interventions. The circulating hsCRP and IL-6 levels decreased only in response to LCD (both p < 0.05). However, comparing changes over time with the control diet, the LCD did not reduce either IL-6 (p = 0.25) or hsCRP (p = 0.07) levels. The lack of changes in FMD and NID in response to LCD persisted after adjustment for cardiovascular risk factors.

CONCLUSION

A LCD high in fat for six months does not adversely affect endothelial function or selected markers of low-grade inflammation, which suggests that this nutritional approach does not increase the risk of cardiovascular disease. Trial registration ClinicalTrials.gov (NCT03068078).

High-plasma soluble prorenin receptor is associated with vascular damage in male, but not female, mice fed a high-fat diet

Plasma soluble prorenin receptor (sPRR) displays sexual dimorphism and is higher in women with type 2 diabetes mellitus (T2DM). However, the contribution of plasma sPRR to the development of vascular complications in T2DM remains unclear. We investigated if plasma sPRR contributes to sex differences in the activation of the systemic renin-angiotensin-aldosterone system (RAAS) and vascular damage in a model of high-fat diet (HFD)-induced T2DM. Male and female C57BL/6J mice were fed either a normal fat diet (NFD) or an HFD for 28 wk to assess changes in blood pressure, cardiometabolic phenotype, plasma prorenin/renin, sPRR, and ANG II. After completing dietary protocols, tissues were collected from males to assess vascular reactivity and aortic reactive oxygen species (ROS). A cohort of male mice was used to determine the direct contribution of increased systemic sPRR by infusion. To investigate the role of ovarian hormones, ovariectomy (OVX) was performed at 32 wk in females fed either an NFD or HFD. Significant sex differences were found after 28 wk of HFD, where only males developed T2DM and increased plasma prorenin/renin, sPRR, and ANG II. T2DM in males was accompanied by nondipping hypertension, carotid artery stiffening, and aortic ROS. sPRR infusion in males induced vascular thickening instead of material stiffening caused by HFD-induced T2DM. While intact females were less prone to T2DM, OVX increased plasma prorenin/renin, sPRR, and systolic blood pressure. These data suggest that sPRR is a novel indicator of systemic RAAS activation and reflects the onset of vascular complications during T2DM regulated by sex.NEW & NOTEWORTHY High-fat diet (HFD) for 28 wk leads to type 2 diabetes mellitus (T2DM) phenotype, concomitant with increased plasma soluble prorenin receptor (sPRR), nondipping blood pressure, and vascular stiffness in male mice. HFD-fed female mice exhibiting a preserved cardiometabolic phenotype until ovariectomy revealed increased plasma sPRR and blood pressure. Plasma sPRR may indicate the status of systemic renin-angiotensin-aldosterone system (RAAS) activation and the onset of vascular complications during T2DM in a sex-dependent manner.

Clinical Applications Measuring Arterial Stiffness: An Expert Consensus for the Application of Cardio-Ankle Vascular Index

BACKGROUND

The purpose of this document is to provide clinicians with guidance, using expert consensus, to help summarize evidence and offer practical recommendations.

METHODS

Expert Consensus Documents are intended to provide guidance for clinicians in areas in which there are no clinical practice guidelines, especially for new and evolving tests such as arterial stiffness measurements, until any formal guidelines are released.

RESULTS

This expert consensus document is intended as a source of information for decision-making and to guide clinician-patient discussions in various clinical scenarios.

CONCLUSIONS

The goal is to help clinicians and patients make a more informed decision together.

SGLT2 inhibition attenuates arterial dysfunction and decreases vascular F-actin content and expression of proteins associated with oxidative stress in aged mice

Aging of the vasculature is characterized by endothelial dysfunction and arterial stiffening, two key events in the pathogenesis of cardiovascular disease (CVD). Treatment with sodium glucose transporter 2 (SGLT2) inhibitors is now known to decrease cardiovascular morbidity and mortality in type 2 diabetes. However, whether SGLT2 inhibition attenuates vascular aging is unknown. We first confirmed in a cohort of adult subjects that aging is associated with impaired endothelial function and increased arterial stiffness and that these two variables are inversely correlated. Next, we investigated whether SGLT2 inhibition with empagliflozin (Empa) ameliorates endothelial dysfunction and reduces arterial stiffness in aged mice with confirmed vascular dysfunction. Specifically, we assessed mesenteric artery endothelial function and stiffness (via flow-mediated dilation and pressure myography mechanical responses, respectively) and aortic stiffness (in vivo via pulse wave velocity and ex vivo via atomic force microscopy) in Empa-treated (14 mg/kg/day for 6 weeks) and control 80-week-old C57BL/6 J male mice. We report that Empa-treated mice exhibited improved mesenteric endothelial function compared with control, in parallel with reduced mesenteric artery and aortic stiffness. Additionally, Empa-treated mice had greater vascular endothelial nitric oxide synthase activation, lower phosphorylated cofilin, and filamentous actin content, with downregulation of pathways involved in production of reactive oxygen species. Our findings demonstrate that Empa improves endothelial function and reduces arterial stiffness in a preclinical model of aging, making SGLT2 inhibition a potential therapeutic alternative to reduce the progression of CVD in older individuals.

Relationship between Indices of Vascular Function and Presence of Overt Cardiovascular Disease among Persons with Poorly Controlled Type 2 Diabetes

The aim of this study was to assess the factors associated with impaired vascular function in patients with poorly controlled type 2 diabetes (DM2) with and without overt cardiovascular disease (CVD). Ninety-five patients with DM2 and poor glycemic control were recruited and divided into two groups: Group 1, with known CVD (n = 38), and Group 2, without CVD (n = 57). Patients in Group 2 were further subdivided into those with short (<5 years, group 2b) and long (>5 years, group 2a) diabetes duration. Subclinical markers of atherosclerosis were assessed. Glycemic control was similar in the two groups (HbA1c: 9.2% (1.5) vs. 9.4% (1.8), p = 0.44). In Group 1, lower FMD (3.13 (2.16)% vs. 4.7 (3.4)%, p < 0.05) and higher cIMT (1.09 (0.3) mm vs. 0.96 (0.2) mm, p < 0.05) was seen compared with Group 2, whereas PWV was similar (12.1 (3.4) vs. 11.3 (3.0) m/s, p = 0.10). Patients in Group 2b had significantly lower PWV and cIMT and higher FMD compared to Group 1 (p < 0.05). Among patients with poorly controlled T2D, more pronounced vascular dysfunction was present in those with overt macrovascular disease. In patients with T2D without known CVD, vascular dysfunction was associated with disease duration. The use of vascular indices for cardiovascular risk stratification in patients with T2D requires further study.

Exercise blood pressure and cardiovascular disease risk: a systematic review and meta-analysis of cross-sectional studies

BACKGROUND

A hypertensive response to exercise (HRE) is associated with cardiovascular disease and high blood pressure (BP). A poor cardiovascular risk factor profile may underlie these associations, although this has not been systematically elucidated. Via systematic review and meta-analysis, we aimed to assess the relationship between exercise BP and cardiovascular risk factors, and determine if cardiovascular risk is higher in those with an HRE vs. no-HRE across different study populations (including those with/without high BP at rest).

METHODS

Three online databases were searched for cross-sectional studies reporting data on exercise BP, an HRE and cardiovascular risk factors (including arterial structure, lipid, metabolic, inflammatory and kidney function markers). Random-effects meta-analyses and meta-regression were used to calculate pooled correlations between exercise BP and each risk factor and pooled mean differences between those with/without an HRE.

RESULTS

Thirty-eight studies (38 295 participants, aged 50 ± 3years; 78% male) were included. Exercise SBP was associated with arterial, lipid and kidney function risk markers (P < 0.05). Those with an HRE had greater aortic stiffness (+0.80 ± 0.35 m/s), total (+0.14 ± 0.03 mmol/l) and low-density lipoprotein (+0.12 ± 0.03 mmol/l) cholesterol, triglycerides (+0.24 ± 0.04 mmol/l), glucose (+0.15 ± 0.05 mmol/l), white blood cell count (+0.49 ± 0.16 mmol/l) and albumin-to-creatinine ratio (standardized mean difference: +0.97 ± 0.34), and lower flow-mediated dilation (-4.13 ± 1.02%) and high-density lipoprotein cholesterol (-0.04 ± 0.01 mmol/l) vs. those with no-HRE (P < 0.05 all). Results were broadly similar across study populations.

CONCLUSION

Exercise SBP is associated with multiple cardiovascular risk factors, which appear worse in those with an HRE vs. no-HRE. As results were similar across population groups, an HRE should be considered an important indicator of cardiovascular risk.

Elevation Mechanisms and Diagnostic Consideration of Cardiac Troponins under Conditions Not Associated with Myocardial Infarction. Part 2

This article proceeds with a discussion of the causes and mechanisms of an elevation in cardiac troponins in pathological conditions not associated with acute myocardial infarction. The second part of the article discusses the causes and mechanisms of cardiac troponins elevation in diabetes mellitus, arterial hypertension, hereditary cardiomyopathies, cardiac arrhythmias (atrial fibrillation, supraventricular tachycardia), acute aortic dissection, and diseases of the central nervous system (strokes, subarachnoidal hemorrhage). The final chapter of this article discusses in detail the false-positive causes and mechanisms of elevated cardiac troponins.

Effects of Greater Central Arterial Stiffness on Cardiovagal Baroreflex Sensitivity in Resistance-Trained Men

Background

Compared with age-matched untrained men, resistance-trained men who have undergone long duration training (> 2 years) at a high frequency (> 5 days/week) may be lower cardiovagal baroreflex sensitivity (BRS) because of central arterial stiffening. Therefore, the purpose of this study was to examine the effect of greater central arterial stiffness in resistance-trained men on cardiovagal BRS in a cross-sectional study to compare resistance-trained men with age-matched untrained men.

Methods

This cross-sectional study included resistance-trained men (n = 20; age: 22 ± 3; body mass index: 26.7 ± 2.2) and age-matched untrained men (control group: n = 20; age: 25 ± 2; body mass index: 23.7 ± 2.4). The β-stiffness index and arterial compliance were assessed at the right carotid artery using a combination of a brightness mode ultrasonography system for the carotid artery diameter and applanation tonometry for the carotid blood pressure. And, the cardiovagal BRS was estimated by the slope of the R–R interval and systolic blood pressure during Phase II and IV of Valsalva maneuver (VM). The participants maintained an expiratory mouth pressure of 40 mmHg for 15 s in the supine position.

Results

The β-Stiffness index was significantly higher in the resistance-trained group than in the control group (5.9 ± 1.4 vs. 4.4 ± 1.0 a.u., P < 0.01). In contrast, the resistance-trained group had significantly lower arterial compliance (0.15 ± 0.05 vs. 0.20 ± 0.04 mm²/mmHg, P < 0.01) and cardiovagal BRS during Phase IV of VM (9.0 ± 2.5 vs. 12.9 ± 5.4 ms/mmHg, P < 0.01) than the control group and. Moreover, cardiovagal BRS during Phase IV of VM was inversely and positively correlated with the β-stiffness index (r = − 0.59, P < 0.01) and arterial compliance (r = 0.64, P < 0.01), respectively.

Conclusion

Resistance-trained group had greater central arterial stiffness and lower cardiovagal BRS Phase IV compared with control group. Moreover, the central arterial stiffening was related to cardiovagal BRS Phase IV. These results suggest that greater central arterial stiffness in resistance-trained men may be associated with lower cardiovagal BRS.

Trial Registration University hospital Medical Information Network (UMIN) in Japan, UMIN000038116. Registered on September 27, 2019.

Determination of risk factors associated with inflammation in hypertensive patients with type-2 diabetes mellitus in a Palestinian Diabetes Study

OBJECTIVE

To determine the risk factors associated with inflammation in hypertensive patients with type-2 diabetes mellitus.

METHODS

A total of 164 hypertensive patients with type 2 diabetes patients aged 38-60 years were selected from 7 primary healthcare centers in Gaza city, Palestine. Interview questionnaire were employed to collect data related to age, gender, smoking habits, and physical activity pattern. Laboratory biochemical tests included fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), interleukin 6 (IL-6), high sensitive C reactive protein (hs-CRP), and adiponectin were estimated in all patients.

RESULTS

The study involved 118 (72%) women and 46 (28%) men; the mean of age was 53.7 ± 0.46 years. A tertile of inflammation feature with hs-CRP was developed. The highest tertile of hs-CRP was significantly associated with women, higher obesity indices, metabolic dysregulation involving lipid profile markers, FBG and blood pressure, IL-6, and lower adiponectin. After adjusting for age, gender, smoking habits, and physical activity; the risk factor of high level of hs-CRP were the increased body mass index [OR: 1.17, p = .018], IL-6 [OR: 2.22, p = .025] and FBG [OR: 1.01, p = .007], as well as reduced adiponectin [OR: 0.81, p = .002].

CONCLUSION

The inflammation state was affected by obesity and had been related to altered adipokines levels of IL-6 and adiponectin, as well as affected by the glycemic control, as evidenced by higher serum level of FBG.

Mutation of the 5'-untranslated region stem-loop mRNA structure reduces type I collagen deposition and arterial stiffness in male obese mice

Arterial stiffening, a characteristic feature of obesity and type 2 diabetes, contributes to the development and progression of cardiovascular diseases (CVD). Currently, no effective prophylaxis or therapeutics is available to prevent or treat arterial stiffening. A better understanding of the molecular mechanisms underlying arterial stiffening is vital to identify newer targets and strategies to reduce CVD burden. A major contributor to arterial stiffening is increased collagen deposition. In the 5'-untranslated regions of mRNAs encoding for type I collagen, an evolutionally conserved stem-loop (SL) structure plays an essential role in its stability and post-transcriptional regulation. Here, we show that feeding a high-fat/high-sucrose (HFHS) diet for 28 wk increases adiposity, insulin resistance, and blood pressure in male wild-type littermates. Moreover, arterial stiffness, assessed in vivo via aortic pulse wave velocity, and ex vivo using atomic force microscopy in aortic explants or pressure myography in isolated femoral and mesenteric arteries, was also increased in those mice. Notably, all these indices of arterial stiffness, along with collagen type I levels in the vasculature, were reduced in HFHS-fed mice harboring a mutation in the 5'SL structure, relative to wild-type littermates. This protective vascular phenotype in 5'SL-mutant mice did not associate with a reduction in insulin resistance or blood pressure. These findings implicate the 5'SL structure as a putative therapeutic target to prevent or reverse arterial stiffening and CVD associated with obesity and type 2 diabetes.NEW & NOTEWORTHY In the 5'-untranslated (UTR) regions of mRNAs encoding for type I collagen, an evolutionally conserved SL structure plays an essential role in its stability and posttranscriptional regulation. We demonstrate that a mutation of the SL mRNA structure in the 5'-UTR decreases collagen type I deposition and arterial stiffness in obese mice. Targeting this evolutionarily conserved SL structure may hold promise in the management of arterial stiffening and CVD associated with obesity and type 2 diabetes.

Associations of serum uric acid level with diabetic retinopathy and albuminuria in patients with type 2 diabetes mellitus

Objectives

To analyze the associations of serum uric acid (SUA) level with diabetic microvascular complications, including diabetic retinopathy (DR) and diabetic nephropathy (DN), in patients with type 2 diabetes mellitus (DM).

Methods

Three hundred eighty-nine inpatients with type 2 DM were included in this retrospective analysis. Nonmydriatic fundus cameras were used to identify DR. Urinary albumin creatinine ratio was used to identify DN. Patients were divided into four groups according to SUA quartiles.

Results

The prevalences of DR and albuminuria increased with increasing SUA level. Multivariate logistic regression analysis showed that, following adjustment for other risk factors, higher levels of SUA (Q3 and Q4) were associated with greater risk for DR, compared with the lower level (Q1) (odds ratio [OR]: 3.056, 95% confidence interval [CI]: 1.506–6.198; OR: 3.417, 95% CI: 1.635–7.139, respectively). Moreover, higher levels of SUA (Q2, Q3, and Q4) were associated with greater risk for albuminuria (OR: 2.418, 95% CI: 1.059–5.522; OR: 7.233, 95% CI: 3.145–16.635; and OR: 8.911, 95% CI: 3.755–21.147, respectively).

Conclusions

SUA level was independently associated with DR and albuminuria in patients with type 2 DM. Elevated SUA level might be predictive for the occurrence of DR and DN.

Impact of glycemic control on the association of endothelial dysfunction and coronary artery disease in patients with type 2 diabetes mellitus

Background

We investigated whether glycemic control affects the relation between endothelial dysfunction and coronary artery disease in patients with type 2 diabetes mellitus (T2DM).

Methods

In 102 type 2 diabetic patients with stable angina, endothelial function was evaluated using brachial artery flow-mediated dilation (FMD) with high-resolution ultrasound, and significant stenosis of major epicardial coronary arteries (≥ 50% diameter narrowing) and degree of coronary atherosclerosis (Gensini score and SYNTAX score) were determined. The status of glycemic control was assessed by blood concentration of glycated hemoglobin (HbA1c).

Results

The prevalence of significant coronary artery stenosis (67.9% vs. 37.0%, P = 0.002) and degree of coronary atherosclerosis (Gensini score: 48.99 ± 48.88 vs. 15.07 ± 21.03, P < 0.001; SYNTAX score: 15.88 ± 16.36 vs. 7.28 ± 10.54, P = 0.003) were higher and FMD was lower (6.03 ± 2.08% vs. 6.94 ± 2.20%, P = 0.036) in diabetic patients with poor glycemic control (HbA1c ≥ 7.0%; n = 56) compared to those with good glycemic control (HbA1c < 7.0%; n = 46). Multivariate regression analysis revealed that tertile of FMD was an independent determinant of presence of significant coronary artery stenosis (OR = 0.227 95% CI 0.056–0.915, P = 0.037), Gensini score (β =  − 0.470, P < 0.001) and SYNTAX score (β =  − 0.349, P = 0.004) in diabetic patients with poor glycemic control but not for those with good glycemic control (P > 0.05).

Conclusion

Poor glycemic control negatively influences the association of endothelial dysfunction and coronary artery disease in T2DM patients.

Exercise blood pressure and cardiac structure: A systematic review and meta-analysis of cross-sectional studies

OBJECTIVES

A hypertensive response to exercise (HRE) is associated with cardiovascular disease and high blood pressure (BP). Sub-clinical changes to cardiac structure may underlie these associations, although this has not been systematically determined. Via systematic review and meta-analysis, we aimed to (1) assess the relationship between exercise BP and cardiac structure, and (2) determine if cardiac structure is altered in those with an HRE, across various study populations (including those with/without high BP at rest).

DESIGN AND METHODS

Three online databases were searched for cross-sectional studies reporting exercise BP, HRE and cardiac structural variables. Random-effects meta-analyses and meta-regressions were used to calculate pooled correlations between exercise BP and cardiac structure, and pooled mean differences and relative risk between those with/without an HRE.

RESULTS

Forty-nine studies, (n=23,707 total; aged 44±4 years; 63% male) were included. Exercise systolic BP was associated with increased left ventricular (LV) mass, LV mass index, relative wall thickness, posterior wall thickness and interventricular septal thickness (p<0.05 all). Those with an HRE had higher risk of LV hypertrophy (relative risk: 2.6 [1.85-3.70]), increased LV mass (47±7g), LV mass index (7±2g/m²), relative wall thickness (0.02±0.005), posterior wall thickness (0.78±0.20mm), interventricular septal thickness (0.78±0.17mm) and left atrial diameter (2±0.52mm) vs. those without an HRE (p<0.05 all). Results were broadly similar between studies with different population characteristics.

CONCLUSIONS

Exercise systolic BP is associated with cardiac structure, and those with an HRE show evidence towards adverse remodelling. Results were similar across different study populations, highlighting the hypertension-related cardiovascular risk associated with an HRE.

Dapagliflozin decreases ambulatory central blood pressure and pulse wave velocity in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled clinical trial

OBJECTIVES

Sodium-glucose co-transporter 2 (SGLT-2) inhibitors reduce the incidence of heart failure and death in patients with type-2 diabetes mellitus. Arterial stiffness is a prominent risk factor for heart failure and overall mortality. The aim of this study was to evaluate the effects of dapagliflozin on ambulatory brachial and central blood pressure (BP) levels and arterial stiffness parameters in patients with type-2 diabetes mellitus.

METHODS

This is a double-blind, randomized, placebo-controlled clinical trial including 85 adult patients with type-2 diabetes mellitus on monotherapy or combination therapy with two of: metformin, sulphonylurea, DPP-4 inhibitor, or insulin. Patients were randomized in a 1 : 1 ratio to oral dapagliflozin 10 mg per day or placebo for 12 weeks. Study participants underwent 24-h ambulatory BP monitoring with the Mobil-O-Graph NG monitor at baseline and study-end.

RESULTS

Baseline demographic, clinical and laboratory parameters were similar in the two groups. During follow-up, 24-h brachial SBP/DBP (129.0 ± 12.6/77.3 ± 7.3 vs. 123.2 ± 12.4/75.1 ± 6.4 mmHg; P < 0.001/P = 0.008) and central SBP/DBP (117.4 ± 10.5/78.9 ± 7.3 vs. 113.3 ± 8.8/77.3 ± 6.5 mmHg; P = 0.002/P = 0.047) significantly decreased in dapagliflozin but not in the placebo group. Corresponding reductions of 24-h brachial SBP (-5.8 ± 9.5 vs. -0.1 ± 8.7, P = 0.005) and central SBP (-4.1 ± 8.0 vs. -0.7 ± 7.8; P = 0.046) were greater with dapagliflozin than placebo. Twenty-four-hour heart-rate adjusted augmentation index significantly decreased with dapagliflozin and insignificantly with placebo. Importantly, there was a significant difference in change of estimated 24-h PWV (-0.16 ± 0.32 vs. 0.02 ± 0.27; P = 0.007) favoring dapagliflozin. In generalized linear mixed models including 24-h brachial SBP as a random covariate, the adjusted marginal means of delta 24-h central SBP and delta 24-h PWV were not significantly different between-groups.

CONCLUSION

Treatment with dapagliflozin significantly reduces ambulatory brachial and central BP levels and PWV in patients with type-2 diabetes mellitus. Improvement in these parameters may substantially contribute to the cardiovascular benefits of SGLT-2 inhibitors.

QardioArm Blood Pressure Monitoring in a Population With Type 2 Diabetes: Validation Study

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.

Diabetes knowledge among non-diabetic hypertensive patients in Calabar, Nigeria

INTRODUCTION

among hypertensive patients, the comorbidity of diabetes is not uncommon. Yet, little is known about diabetes prevention among non-diabetic hypertensive patients. This study sought to assess such patients' knowledge about diabetes and its risk factors.

METHODS

a cross-sectional descriptive study design and random sampling were used to recruit non-diabetic hypertensive patients from University of Calabar Teaching Hospital. A pretested 33-item questionnaire was used to assess various aspects of diabetes knowledge. Participants' alcohol consumption, smoking habits, physical activity, and fresh fruit consumption were also assessed. The p-value was set to 0.05.

RESULTS

of 212 respondents with a mean age of 45.5 ± 10.8 years, approximately half (49.1%) had inadequate knowledge of diabetes. Most participants demonstrated poor knowledge of diabetes' clinical features (81.1%) and complications (59.4%), while fewer participants showed poor knowledge of causes and risk factors (24.5%) and diabetes management (40.6%). Older subjects, those in the wards, non-drinkers, physically active people, and those who frequently consumed fresh fruit had a significantly greater understanding of diabetes symptoms and complications (p<0.05).

CONCLUSION

hypertensive patients' diabetes knowledge is generally suboptimal, with greater knowledge deficiencies being apparent in specific areas. More strategic health education initiatives are required, about minimizing the risk of developing diabetes comorbidities.

Antihypertensive and antidiabetic activities of Erythrina senegalensis DC (Fabaceae) stem bark aqueous extract on diabetic hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Erythrina senegalensis is traditionally used in Cameroon for its relaxing and hypoglycemic properties in the treatment of cardiovascular diseases and diabetes.

AIM OF THE STUDY

High blood pressure and diabetes mellitus are frequently linked. These pathologies represent major risk factors for cardiovascular and renal diseases. The present study was designed to evaluate the antidiabetic and antihypertensive activity of the stem bark of Erythrina senegalensis aqueous extract in male hypertensive diabetic rats (HDR).

MATERIALS AND METHODS

Hypertension and diabetes were induced by oral administration of sucrose (15%) and ethanol (40°) at doses of 1.5 g/kg and 5 g/kg respectively for 30 days, followed by an intravenous injection of streptozotocin (STZ; 40 mg/kg). A control group of 5 rats received distilled water (10 mL/kg) followed by intravenous injection of 0.9% NaCl (1 mL/100 g). HDR were divided into 4 groups of 5 rats each according to their blood glucose level and continued to receive ethanol in association with: distilled water (10 mL/kg); group I, metformin (200 mg/kg)+nifedipine (10 mg/kg); group II, plant extract (100 and 200 mg/kg) group IV and V, respectively for 28 days. At the end of the treatment, hemodynamic parameters were recorded by the direct method. Animals were sacrificed; blood and organs (aorta, heart, liver, and kidneys) were collected for biochemical and histological analysis. Phytochemistry and HPLC-DAD-HRESI-MS were used to determine the major compounds of the extract.

RESULTS

The administration of sucrose, alcohol, and STZ resulted in a significant increase in blood glucose, hemodynamic parameters, and body weight loss. A significant decrease in pancreatic islets size, nitrite, GSH, SOD and catalase activity was observed in HDR. There was also a significant increase in serum triglycerides, total cholesterol, creatinine, bilirubin, and transaminases activity in HDR. The aqueous extract of E. senegalensis, as well as the metformin + nifedipine combination, significantly improved all these parameters. HPLC coupled to both diode array and mass spectrometry detectors revealed the presence of 15 compounds and 11 of them were identified.

CONCLUSION

These results suggest that the aqueous extract of E. senegalensis possess antihypertensive, hypoglycemic, hypolipidemic, cardiomodulator and antioxidant properties involved in the improvement of the metabolic disorders found in HDR. This may be due at least in part to the presence of Erysenegalensein (D, O, N, E), Warangalone, senegalensin and 6,8-diprenylgenistein identified in the extract.

Matrix stiffening induces endothelial dysfunction via the TRPV4/microRNA-6740/endothelin-1 mechanotransduction pathway

Vascular stiffening is associated with the prognosis of cardiovascular disease (CVD). Endothelial dysfunction, as shown by reduced vasodilation and increased vasoconstriction, not only affects vascular tone, but also accelerates the progression of CVD. However, the precise effect of vascular stiffening on endothelial function and its mechanism is unclear and a possible underlying has not been determined. In this study, we found that increasing substrate stiffness promoted endothelin-1 (ET-1) expression and inhibited endothelial nitric oxide synthase expression in human umbilical vein endothelial cells. Additionally, miR-6740-5p was identified as a stiffness-sensitive microRNA, which was downregulated by a stiff substrate, resulting in increased ET-1 expression. Furthermore, we found that substrate stiffening reduced the expression and activity of the calcium channel TRPV4, which subsequently enhanced ET-1 expression by inhibiting miR-6740-5p. Finally, analysis of clinical plasma samples showed that plasma miR-6740-5p levels in patients with carotid atherosclerosis were significantly lower than those in healthy people. Taken together, our findings show a novel mechanically regulated TRPV4/miR-6740/ET-1 signaling axis by which substrate stiffness affects endothelial function. Our findings indicate that vascular stiffening induces endothelial dysfunction, thereby accelerating progression of CVD. Furthermore, this study indicates that endothelial dysfunction induced by improper biophysical cues from cardiovascular implants may be an important reason for complications arising from the use of cardiovascular implants. STATEMENT OF SIGNIFICANCE: Cardiovascular disease is the leading cause of morbidity and mortality worldwide. The incidence of cardiovascular disease is accompanied by increased vascular stiffness. Our work indicated that increased vascular stiffness accelerates the development of cardiovascular disease by inducing endothelial dysfunction, which is a key contributor to the pathogenesis of cardiovascular disease. In addition, we identified a novel underlying molecular pathophysiological mechanism by which increased stiffness induce endothelial dysfunction. Our work could help determine the pathogenesis of cardiovascular disease induced by biomechanical factors.

The renal resistive index as a new complementary tool to predict microvascular diabetic complications in children and adolescents: a groundbreaking finding

The increasing prevalence of type 1 diabetes mellitus (DM) has made it necessary to have new markers for early detection of diabetic nephropathy. Renal resistive index (RI) by using renal Doppler can be a helpful tool in detecting functional alterations in renal hemodynamics. This study was conducted on 100 children and adolescents with type 1 DM. They were further subdivided into two equal subgroups: group 1 with type 1 DM and normo-albuminuria [urinary albumin excretion (UAE) <30 mg/24 hours], and group 2 with type 1 DM and hyper-albuminuria (increased UAE >30 mg/24 hours). There were 37 males (37%) and 63 females (63%); their mean ages were 13.6±2.53 (range, 10-19) years and mean disease duration was 8.867±2.260 (range, 5-13) years. Progressive increase in RI was significantly associated with increased disease duration more than 10 years, elevated serum HbA1c more than 7.5% and early pubertal stages. While not significantly related to sex, weight, height, blood pressure or serum lipid profile, diabetic micro-vascular complications (nephropathy and sensory neuropathy) were more prevalent among patients with RI more than 0.58. Renal RI could be a useful complementary test for the evaluation of functional alterations in renal hemodynamics in the early stages of diabetic nephropathy.

Hemodynamic and autonomic effects of low-dose glyceryl trinitrate used to test endothelium-independent vasodilation of the brachial artery

Smooth muscle function is explored by sublingual glyceryl trinitrate (GTN) administration to compare with endothelium-dependent vasodilation of the brachial artery by flow-mediated-dilation (FMD). This study compared the hemodynamic and autonomic effects of the two most often used GTN dosages. In 80 essential hypertensive patients (HT) and 60 normotensive subjects (NT), FMD of the brachial artery and endothelium-independent response to sublingual GTN (25 μg and 400 μg) were evaluated by high-resolution ultrasound and automated image analysis. In 10 HT, muscle sympathetic nerve activity (MSNA) was also assessed by microneurography. HT showed significantly (p < .01) lower FMD (5.5 ± 3.3%) compared to NT (6.9 ± 2.2%). The response to GTN 25 μg tended to be lower (HT:7.2 ± 3.3%; NT:7.9 ± 2.9%; p = .06), whereas response to GTN 400 μg was similar (HT:14.3 ± 4.8%, NT:14.5 ± 4.7%, p = ns). Blood pressure (BP) reduction induced by GTN 400 μg (systolic-BP:-3.2 ± 7.7 mm Hg, diastolic-BP:-4.7 ± 5.0 mm Hg) was greater (p < .001) compared to GTN 25 μg (systolic-BP:-0.7 ± 5.8 mm Hg, diastolic-BP:-0.7 ± 4.4 mm Hg). Changes in heart rate were also greater (+5.6 ± 6.4 bpm versus -0.2 ± 5.4 bpm, p < .001). This behaviour was similar in either NT or HT. MSNA was significantly increased by GTN 400 μg (31 ± 7bursts/min to 41 ± 6bursts/min, p < .001) but not by 25 μg (33 ± 9bursts/min to 37 ± 11bursts/min, p = .19). In conclusion, the administration of low-dose GTN allows exploring endothelium-independent vasodilation in FMD protocols, inducing only modest hemodynamic and sympathetic responses.

The continuums of impairment in vascular reactivity across the spectrum of cardiometabolic health: A systematic review and network meta-analysis

This study aimed to assess, for the first time, the change in vascular reactivity across the full spectrum of cardiometabolic health. Systematic searches were conducted in MEDLINE and EMBASE databases from their inception to March 13, 2017, including studies that assessed basal vascular reactivity in two or more of the following health groups (aged ≥18 years old): healthy, overweight, obesity, impaired glucose tolerance, metabolic syndrome, or type 2 diabetes with or without complications. Direct and indirect comparisons of vascular reactivity were combined using a network meta-analysis. Comparing data from 193 articles (7226 healthy subjects and 19344 patients), the network meta-analyses revealed a progressive impairment in vascular reactivity (flow-mediated dilation data) from the clinical onset of an overweight status (-0.41%, 95% CI, -0.98 to 0.15) through to the development of vascular complications in those with type 2 diabetes (-4.26%, 95% CI, -4.97 to -3.54). Meta-regressions revealed that for every 1 mmol/l increase in fasting blood glucose concentration, flow-mediated dilation decreased by 0.52%. Acknowledging that the time course of disease may vary between patients, this study demonstrates multiple continuums of vascular dysfunction where the severity of impairment in vascular reactivity progressively increases throughout the pathogenesis of obesity and/or insulin resistance, providing information that is important to enhancing the timing and effectiveness of strategies that aim to improve cardiovascular outcomes.

Comparison between newly diagnosed hypertension in diabetes and newly diagnosed diabetes in hypertension

BACKGROUND

Hypertension and diabetes mellitus are often jointly present, especially in early onset cases of either disease. We investigated clinical characteristics of hypertensive patients with newly diagnosed diabetes and diabetic patients with newly diagnosed hypertension.

METHODS

Our study subjects were recruited in a China nationwide multicenter registry of hypertension and diabetes (n = 2510). We performed logistic regression to compare patients seen for hypertension in cardiology, with newly diagnosed diabetes (n = 137) and patients seen for diabetes mellitus in endocrinology, with newly diagnosed hypertension (n = 155). Albuminuria was defined as a urinary albumin-to-creatinine ratio of ≥ 30 mg/g, and left ventricular hypertrophy according to the Cornell product index.

RESULTS

These two groups of patients with both hypertension and diabetes mellitus were similar in most of the characteristics (P ≥ 0.06). However, hypertensive patients with newly diagnosed diabetes, compared to diabetic patients with newly diagnosed hypertension, had a significantly greater body mass index (26.3 vs. 25.4 kg/m², P = 0.03) and slower heart rate (73.7 vs. 78.1 beats/min, P = 0.01). In logistic regression analyses adjusted for sex (48.3% women) and age (mean 60.0 ± 11.5 years), the odds ratio for newly diagnosed diabetes mellitus versus newly diagnosed hypertension was 1.27 (95% CI 1.03-1.56) and 0.80 (95% CI 0.66-0.96) for body mass index (+ 3 kg/m²) and heart rate (+ 10 beat/min), respectively. Hypertensive patients with newly diagnosed diabetes also had a lower prevalence of albuminuria (16.0% vs. 30.1%, P = 0.02) and slightly and non-significantly higher prevalence of left ventricular hypertrophy (5.1% vs. 1.9%, P = 0.14) than diabetic patients with newly diagnosed hypertension.

CONCLUSIONS

Earlier or later onset of hypertension than diabetes mellitus may have different risk factors and organ damage.

[Current aspects of performing treadmill test in patients with peripheral artery disease]

The protocols of performing treadmill tests (TMT) in patients presenting with peripheral artery disease have over the last decades undergone significant changes, with the alterations concerning not only the speed and time values of the load, but also the parameters measured. Currently, there is no unified generally accepted method of TMT, hence the need for an optimal protocol for carrying out this type of examination, which would help obtain reliable results in assessment of everyday life functional activity of patients and efficacy of various methods of treatment for peripheral atherosclerosis. The choice of an optimal methodology of performing a TMT in patients with intermittent claudication is extremely important because studying the haemodynamic parameters alone not always clearly reflect functional peculiarities of the course of the disease, since they depend not only on the presence of arterial stenoses or occlusions, but also on the activity of oxidative enzymes, endothelial and mitochondrial dysfunction, taking therapeutic agents, concomitant pathology and a series of other factors. The article is a review of the related literature contained in such databases as the Medline, PubMed, Russian Science Citation Index (RSCI) and Scopus and concerning TMT in patients with peripheral artery disease. The authors summarized the information from a total of 63 literature sources over the period from the 1970s to 2018.

Resistance Training Augments Cerebral Blood Flow Pulsatility: Cross-Sectional Study

BACKGROUND

Increased central arterial stiffness and/or decreased compliance reduces buffer function and increases cerebral blood flow (CBF) pulsatility, which leads to increased cerebral microvascular damage, resulting in the augmentation of the risk of cerebrovascular diseases. Resistance-trained men showed higher central arterial stiffness and lower arterial compliance than age-matched, sedentary men. This study examined the effect of increased central arterial stiffness and/or decreased arterial compliance on CBF pulsatility.

METHODS

The study participants included 31 young healthy men (15 resistance-trained men, aged 21 ± 1 years; and 16 controls, aged 23 ± 1 years). β-Stiffness index and arterial compliance were measured in the right carotid artery as index of central arterial stiffness and compliance, respectively. The pulsatility index (PI) was measured in the middle cerebral artery as index of CBF pulsatility.

RESULTS

β-Stiffness index and PI were significantly higher in the resistance-trained group than in the control group (β-stiffness index: 5.3 ± 0.3 vs. 3.5 ± 0.3 a.u., P < 0.05, PI: 0.80 ± 0.02 vs. 0.70 ± 0.02, P < 0.05). The resistance-trained group showed significantly lower arterial compliance than the control group (0.16 ± 0.01 vs. 0.23 ± 0.01 mm2/mm Hg, P < 0.05). Positive and negative correlations were observed between β-stiffness index and PI (r = 0.39, P < 0.05), and between arterial compliance and PI (r = -0.59, P < 0.05), respectively.

CONCLUSIONS

The resistance-trained group showed higher central arterial stiffness and PI and lower arterial compliance. Central arterial stiffness and arterial compliance were associated with PI. Increased arterial stiffness and decreased arterial compliance with resistance training impair buffer function, resulting in increased CBF pulsatility.

CLINICAL TRIAL REGISTRATION

Trial Number UMIN000023816 URL: http://www.umin.ac.jp/icdr/index.html Official scientific title of the study: effect of increase arterial stiffness by resistance training on cerebral hemodynamic.

Validation of BP devices QardioArm® in the general population and Omron M6 Comfort® in type II diabetic patients according to the European Society of Hypertension International Protocol (ESH-IP)

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.

Dapagliflozin acutely improves endothelial dysfunction, reduces aortic stiffness and renal resistive index in type 2 diabetic patients: a pilot study

Background

Sodium-glucose cotransporter-2 inhibitors reduce blood pressure (BP) and renal and cardiovascular events in patients with type 2 diabetes through not fully elucidated mechanisms. Aim of this study was to investigate whether dapagliflozin is able to acutely modify systemic and renal vascular function, as well as putative mechanisms.

Methods

Neuro-hormonal and vascular variables, together with 24 h diuresis, urinary sodium, glucose, isoprostanes and free-water clearance were assessed before and after a 2-day treatment with dapagliflozin 10 mg QD in sixteen type 2 diabetic patients; data were compared with those obtained in ten patients treated with hydrochlorothiazide 12.5 mg QD. Brachial artery endothelium-dependent and independent vasodilation (by flow-mediated dilation) and pulse wave velocity were assessed. Renal resistive index was obtained at rest and after glyceryl trinitrate administration. Differences were analysed by repeated measures ANOVA, considering treatment as between factor and time as within factor; Bonferroni post hoc comparison test was also used.

Results

Dapagliflozin decreased systolic BP and induced an increase in 24 h diuresis to a similar extent of hydrochlorothiazide; 24 h urinary glucose and serum magnesium were also increased. 24 h urinary sodium and fasting blood glucose were unchanged. Oxidative stress was reduced, as by a decline in urinary isoprostanes. Flow-mediated dilation was significantly increased (2.8 ± 2.2 to 4.0 ± 2.1%, p < 0.05), and pulse-wave-velocity was reduced (10.1 ± 1.6 to 8.9 ± 1.6 m/s, p < 0.05), even after correction for mean BP. Renal resistive index was reduced (0.62 ± 0.04 to 0.59 ± 0.05, p < 0.05). These vascular modifications were not observed in hydrochlorothiazide-treated individuals.

Conclusions

An acute treatment with dapagliflozin significantly improves systemic endothelial function, arterial stiffness and renal resistive index; this effect is independent of changes in BP and occurs in the presence of stable natriuresis, suggesting a fast, direct beneficial effect on the vasculature, possibly mediated by oxidative stress reduction.

Carotid and aortic stiffness in essential hypertension and their relation with target organ damage: the CATOD study

OBJECTIVE

The objective of the study is to investigate in the hypertensive population the possible differential association between increased aortic and/or carotid stiffness and organ damage in multiple districts, such as the kidney, the vessels, and the heart.

METHODS

In 314 essential hypertensive patients, carotid-femoral pulse wave velocity (cfPWV, by applanation tonometry) and carotid stiffness (from ultrasound images analysis), together with left ventricular hypertrophy, carotid intima-media thickness, urinary albumin-creatinin ratio, and glomerular filtration rate were measured. Increased cfPWV and carotid stiffness were defined according to either international reference values or the 90th percentile of a local control group (110 age and sex-matched healthy individuals).

RESULTS

When considering the 90th percentile of a local control group, increased cfPWV was associated with reduced glomerular filtration rate, either when carotid stiffness was increased [odds ratio (OR) 13.27 (confidence limits (CL) 95% 3.86-45.58)] or not [OR 7.39 (CL95% 2.25-24.28)], whereas increased carotid stiffness was associated with left ventricular hypertrophy, either when cfPWV was increased [OR 2.86 (CL95% 1.15-7.09)] or not [OR 2.81 (CL95% 1.13-6.97)]. No association between increased cfPWV or carotid stiffness and target organ damage was found when cutoffs obtained by international reference values were used. The concomitance of both increased cfPWV and carotid stiffness did not have an additive effect on organ damage.

CONCLUSION

Aortic and carotid stiffness are differentially associated with target organ damage in hypertensive patients. Regional arterial stiffness as assessed by cfPWV is associated with renal organ damage and local carotid stiffness with cardiac organ damage.

Relationship Between Occupational Physical Activity and Subclinical Vascular Damage in Moderate-Altitude Dwellers

Ujka, Kristian, Rosa Maria Bruno, Luca Bastiani, Eva Bernardi, Paolo Sdringola, Nenad Dikic, Bikash Basyal, Sanjeeb Sundarshan Bhandari, Buddha Basnyat, Annalisa Cogo, and Lorenza Pratali. Relationship between occupational physical activity and subclinical vascular damage in moderate-altitude dwellers. High Alt Med Biol. 18:249-257, 2017.

BACKGROUND

Occupational physical activity (OPA) has been associated with increased cardiovascular (CV) events. The aim of this study was to investigate the association between OPA and markers of subclinical vascular damage among a moderate-altitude population living in the rural village of Chaurikharka (Nepal; 2600 m sea level).

METHODS

Seventy-two individuals (age 42 ± 15 years, ranges 15-85 years, 23 men) were enrolled. Physical activity (PA) was evaluated using the International Physical Activity Questionnaire (IPAQ). Carotid-femoral pulse wave velocity (PWV), carotid ultrasound assessment, and flow-mediated dilation (FMD) were performed.

RESULTS

OPA was 9860 ± 5385 Metabolic Equivalent of Task (MET)-minutes/week, representing 77% of total energy expenditure, with 97% of the population performing high-intensity PA. In the univariate analysis, OPA was significantly associated with PWV (β = 0.474, p = 0.001) and carotid stiffness (CS) (β = 0.29, p = 0.019). In the multivariate analysis, including age, sex, oxygen saturation, mean blood pressure, low-density lipoprotein (LDL), and OPA, OPA remained an independent predictor of PWV (β = 0.403, p = 0.001) but not of CS (β = 0.028, p = 0.8). OPA remained an independent predictor of PWV independently from the Framingham risk score (FRS).

CONCLUSION

High-intensity OPA shows a positive, independent association with aortic stiffness in Himalayan moderate-altitude dwellers. This study suggests how vigorous OPA performed in moderate altitude may be a CV risk factor.

The role of increased glucose on neurovascular dysfunction in patients with the metabolic syndrome

Metabolic syndrome (MetS) causes autonomic alteration and vascular dysfunction. The authors investigated whether impaired fasting glucose (IFG) is the main cause of vascular dysfunction via elevated sympathetic tone in nondiabetic patients with MetS. Pulse wave velocity, muscle sympathetic nerve activity (MSNA), and forearm vascular resistance was measured in patients with MetS divided according to fasting glucose levels: (1) MetS+IFG (blood glucose ≥100 mg/dL) and (2) MetS-IFG (<100 mg/dL) compared with healthy controls. Patients with MetS+IFG had higher pulse wave velocity than patients with MetS-IFG and controls (median 8.0 [interquartile range, 7.2-8.6], 7.3 [interquartile range, 6.9-7.9], and 6.9 [interquartile range, 6.6-7.2] m/s, P=.001). Patients with MetS+IFG had higher MSNA than patients with MetS-IFG and controls, and patients with MetS-IFG had higher MSNA than controls (31±1, 26±1, and 19±1 bursts per minute; P<.001). Patients with MetS+IFG were similar to patients with MetS-IFG but had higher forearm vascular resistance than controls (P=.008). IFG was the only predictor variable of MSNA. MSNA was associated with pulse wave velocity (R=.39, P=.002) and forearm vascular resistance (R=.30, P=.034). In patients with MetS, increased plasma glucose levels leads to an adrenergic burden that can explain vascular dysfunction.

Cholecalciferol treatment downregulates renin-angiotensin system and improves endothelial function in essential hypertensive patients with hypovitaminosid D

BACKGROUND

Vitamin D deficiency is related to an increased prevalence of cardiovascular disease. Renin-angiotensin-aldosterone system suppression and vascular dysfunction are considered among the main mechanisms implicated in this association. However, interventional studies demonstrating that vitamin D replacement reduces circulating renin-angiotensin-aldosterone components and improves vascular function in humans are still lacking.

METHODS

Thirty-three consecutive patients with essential hypertension and hypovitaminosis D underwent therapy with cholecalciferol 50 000 IU/week orally for 8 weeks. Thirty-three hypertensive patients with normal vitamin D levels and 20 normotensive individuals were also enrolled as control groups. At baseline and at the end of the study, we evaluated plasma renin activity, circulating renin, angiotensin II, aldosterone and plasma vitamin D levels. Endothelial function [flow-mediated dilation (FMD)], carotid-femoral pulse wave velocity and augmentation index, peripheral and central blood pressure were also acquired.

RESULTS

After 8-week cholecalciferol administration, all treated patients normalized plasma 25(OH)D values. Furthermore, a reduction in plasma levels of plasma renin activity (1.17 ± 0.3 vs 1.51 ± 0.4 ng/ml per h, P = 0.02), renin (13.4 ± 1.7 vs 19.2 ± 2.9 pg/ml, P < 0.001), angiotensin II (11.6 ± 1.6 vs 15.8 ± 2.7 pg/ml, P = 0.02) was observed at the end of the study. FMD was significantly increased after cholecalciferol treatment (4.4 ± 2.6 vs 3.3 ± 2.1%, P < 0.05), in the absence of changes of brachial artery diameter and endothelium-independent vasodilation. Carotid-femoral pulse wave velocity and augmentation index were not modified, as well peripheral and central blood pressure.

CONCLUSION

The restoration of normal vitamin D levels after 8-week cholecalciferol treatment is able to inhibit peripheral renin-angiotensin system and improve FMD in essential hypertensive patients with hypovitaminosis D.

Association between long-term blood pressure control and ten-year progression in carotid arterial stiffness among hypertensive individuals: the multiethnic study of atherosclerosis

BACKGROUND

Arterial stiffness was shown to be higher among hypertensive patients with diabetes than those without diabetes and among older than younger hypertensive patients. We examined whether the association between long-term blood pressure (BP) control and 10-year progression in carotid arterial stiffness varies by diabetes status and age.

METHODS

Participants were 906 individuals with hypertension at baseline and three follow-up visits in the Multi-Ethnic Study of Atherosclerosis (mean age 63.7 years, 44% males). Participants with SBP of less than 140 mmHg and DBP of less than 90 mmHg were considered to have a controlled BP. Arterial stiffness was measured using distensibility coefficient × 10/mmHg and Young's elastic modulus (YEM × 10 mmHg) at baseline and after a mean of 9.5 years (visit 5). Multiple linear regression model was used for the analysis.

RESULTS

Having controlled BP at three visits (distensibility coefficient: β = 3.6, P = 0.004; YEM: β = -6.8, P = 0.07) or four visits (distensibility coefficient: β = 2.4, P = 0.04; YEM: β = -6.8, P = 0.05), when compared with having uncontrolled BP at all four visit, was associated with lesser progression in arterial stiffness. In a stratified analysis, arterial stiffness progression was slower only among nondiabetics with controlled BP at three visits (distensibility coefficient: β = 4.3, P = 0.002; YEM: β = -8.8, P = 0.04) or four visits (β = 3.7, P = 0.01; YEM: β = -10.4, P = 0.01) and among those less than 70 years with controlled BP at three visits (distensibility coefficient: β = 4.9, P = 0.004; YEM: β = -10.6, P = 0.01) or four visits (distensibility coefficient: β = 2.9, P = 0.07; YEM: β = -7.6, P = 0.03).

CONCLUSION

These findings suggest that controlling BP alone may not be sufficient to slow progression of arterial stiffness among hypertensive patients with concurrent diabetes and elderly hypertensive patients.

Impact of seasonality and air pollutants on carotid-femoral pulse wave velocity and wave reflection in hypertensive patients

Objective

The effects of seasonality on blood pressure (BP) and cardiovascular (CV) events are well established, while the influence of seasonality and other environmental factors on arterial stiffness and wave reflection has never been analyzed. This study evaluated whether seasonality (daily number of hours of light) and acute variations in outdoor temperature and air pollutants may affect carotid-femoral pulse wave velocity (PWV) and pressure augmentation.

Design and method

731 hypertensive patients (30–88 years, 417 treated) were enrolled in a cross-sectional study during a 5-year period. PWV, central BP, Augmentation Index (AIx) and Augmentation Pressure (AP) were measured in a temperature-controlled (22–24°C) room. Data of the local office of the National Climatic Data Observatory were used to estimate meteorological conditions and air pollutants (PM₁₀, O₃, CO, N₂O) exposure on the same day.

Results

PWV (mean value 8.5±1.8 m/s) was related to age (r = 0.467, p<0.001), body mass index (r = 0.132, p<0.001), central systolic (r = 0.414, p<0.001) and diastolic BP (r = 0.093, p = 0.013), daylight hours (r = -0.176, p<0.001), mean outdoor temperature (r = -0.082, p = 0.027), O₃ (r = -0.135, p<0.001), CO (r = 0.096, p = 0.012), N₂O (r = 0.087, p = 0.022). In multiple linear regression analysis, adjusted for confounders, PWV remained independently associated only with daylight hours (β = -0.170; 95% CI: -0.273 to -0.067, p = 0.001). No significant correlation was found between pressure augmentation and daylight hours, mean temperature or air pollutants. The relationship was stronger in untreated patients and women. Furthermore, a positive, independent association between O₃ levels and PWV emerged in untreated patients (β: 0.018; p = 0.029; CI: 0.002 to 0.034) and in women (β: 0.027; p = 0.004; CI: 0.009 to 0.045).

Conclusions

PWV showed a marked seasonality in hypertensive patients. Environmental O₃ levels may acutely reduce arterial stiffness in hypertensive women and in untreated patients.

Advances in the non-invasive assessment of vascular dysfunction in metabolic syndrome and diabetes: Focus on endothelium, carotid mechanics and renal vessels

AIM

The present paper is a selective review on the methodology and clinical significance of techniques to assess specifically endothelial function, carotid mechanics and renal vascular function, particularly in the light of vascular dysfunction in metabolic syndrome and type 2 diabetes.

DATA SYNTHESIS

Endothelial dysfunction appears to be earlier detectable in the microcirculation of patients with altered glucose metabolism, while it attains significance in the macrocirculation at more advanced disease stages. Smooth muscle cell dysfunction is now increasingly recognized to play a role both in the development of endothelial dysfunction and abnormal arterial distensibility. Furthermore, impaired glucose metabolism affects carotid mechanics through medial calcification, structural changes in extracellular matrix due to advanced glycation and modification of the collagen/elastin material stiffness. The assessment of renal vascular function by dynamic ultrasound or magnetic resonance imaging has recently emerged as an appealing target for identifying subtle vascular alterations responsible for the development of diabetic nephropathy.

CONCLUSIONS

Vascular dysfunction represents a major mechanism for the development of cardiovascular disease in patients with abnormal glucose metabolism. Hence, the currently available non-invasive techniques to assess early structural and vascular abnormalities merit recommendation in this population, although their predictive value and sensitivity to monitor treatment-induced changes have not yet been established and are still under investigation.

Arterial stiffness and its association with clustering of metabolic syndrome risk factors

BACKGROUND

Metabolic syndrome (MetS) is associated with structural and functional vascular abnormalities, which may lead to increased arterial stiffness, more frequent cardiovascular events and higher mortality. However, the role played by clustering of risk factors and the combining pattern of MetS risk factors and their association with the arterial stiffness have yet to be fully understood. Age, hypertension and diabetes mellitus seem to be strongly associated with increased pulse wave velocity (PWV). This study aimed at determining the clustering and combining pattern of MetS risk factors and their association with the arterial stiffness in non-diabetic and non-hypertensive patients.

METHODS

Recently diagnosed and untreated patients with MetS (n = 64, 49 ± 8 year, 32 ± 4 kg/m²) were selected, according to ATP III criteria and compared to a control group (Control, n = 17, 49 ± 6 year, 27 ± 2 kg/m²). Arterial stiffness was evaluated by PWV in the carotid-femoral segment. Patients were categorized and analyzed according MetS risk factors clustering (3, 4 and 5 factors) and its combinations.

RESULTS

Patients with MetS had increased PWV when compared to Control (7.8 ± 1.1 vs. 7.0 ± 0.5 m/s, p < 0.001). In multivariate analysis, the variables that remained as predictors of PWV were age (β = 0.450, p < 0.001), systolic blood pressure (β = 0.211, p = 0.023) and triglycerides (β = 0.212, p = 0.037). The increased number of risk factors reflected in a progressive increase in PWV. When adjusted to systolic blood pressure, PWV was greater in the group with 5 risk factors when compared to the group with 3 risk factors and Control (8.5 ± 0.4 vs. 7.5 ± 0.2, p = 0.011 and 7.2 ± 0.3 m/s, p = 0.012). Similarly, the 4 risk factors group had higher PWV than the Control (7.9 ± 0.2 vs. 7.2 ± 0.3, p = 0.047).

CONCLUSIONS

The number of risk factors seems to increase arterial stiffness. Notably, besides age and increased systolic blood pressure, alterations in the triglycerides worsened the stiffness of large vessels, emphasizing the importance in addressing this risk factor in MetS patients.

Metabolic and Hormonal Determinants of Glomerular Filtration Rate and Renal Hemodynamics in Severely Obese Individuals

OBJECTIVE

Renal function is often compromised in severe obesity. A true measurement of glomerular filtration rate (GFR) is unusual, and how estimation formulae (EstForm) perform in such individuals is unclear. We characterized renal function and hemodynamics in severely obese individuals, assessing the reliability of EstForm.

METHODS

We measured GFR (mGFR) by iohexol plasma clearance, renal plasma flow (RPF) by 123I-ortho-iodo-hippurate, basal and stimulated vascular renal indices, endothelium-dependent and -independent vasodilation using flow-mediated dilation (FMD) as well as metabolic and hormonal profile in morbid, otherwise healthy, obese subjects.

RESULTS

Compared with mGFR, the better performing EstForm was CKD-EPI (5.3 ml/min/1.73 m2 bias by Bland-Altman analysis). mGFR was directly related with RPF, total and incremental glucose AUC, and inversely with PTH and h8 cortisol. Patients with mGFR below the median shown significantly higher PTH and lower vitamin D3. Basal or dynamic renal resistive index, FMD, pulse wave velocity were not related with mGFR. In an adjusted regression model, renal diameter and plasma flow remained related with mGFR (R2 = 0.67), accounting for 15% and 21% of mGFR variance, respectively.

CONCLUSIONS

CKD-EPI formula should be preferred in morbid obesity; glucose increments during oral glucose tolerance test correlate with hyperfiltration; RPF and diameter are independent determinants of mGFR; slightly high PTH values, frequent in obesity, might influence mGFR.

Low Physical Activity Is Associated With Increased Arterial Stiffness in Patients Recently Diagnosed With Type 2 Diabetes

AIMS

Several studies have indicated that low physical activity is associated with increased risk of cardiovascular disease (CVD) and all-cause mortality among patients with diabetes. The association between physical activity and subclinical cardiovascular changes preceding clinical events remains to be elucidated. We investigated the relationship between physical activity and arterial stiffness, an independent predictor of CVD, in patients with type 2 diabetes and controls.

METHODS

We included 100 patients with type 2 diabetes and 100 sex- and age-matched controls in a cross-sectional study. Arterial stiffness (carotid-femoral pulse wave velocity, cfPWV) was measured using the SphygmoCor device (AtCor Medical, Sydney, Australia). Physical activity was assessed by an accelerometer (counts per minute (cpm), Actiheart (CamNtech, Cambridge, UK)) worn by the participants for up to 6 days. High vs. low levels of physical activity was defined according to the median level of activity (cpm = 31).

RESULTS

Sixty-five patients and 65 controls were included in the final analysis (median age 59 years, 55% men, median diabetes duration 1.9 years). Participants with low physical activity had higher cfPWV compared to participants with high physical activity: (i) Patients and controls combined: 9.3±1.7 m/s vs. 7.8±1.5 m/s, P < 0.001; (ii) Patients with diabetes: 9.5±1.8 m/s vs. 8.3±1.6 m/s, P = 0.02 and C) Controls: 9.0±1.4 m/s vs. 7.7±1.4 m/s, P < 0.01). The difference remained significant after adjustment for other determinants of cfPWV including whole body fat percentage (P < 0.01). No significant interaction between diabetes and the effect of low activity was seen.

CONCLUSIONS

Low physical activity is associated with increased arterial stiffness in patients recently diagnosed with type 2 diabetes and in healthy controls.

CLINICAL TRIALS REGISTRATION

Trial Number NCT00674271.

Effects of the small molecule SIRT1 activator, SRT2104 on arterial stiffness in otherwise healthy cigarette smokers and subjects with type 2 diabetes mellitus

Objective

Arterial stiffness increases with age, and is associated with adverse cardiovascular outcome including increased mortality. The effect of the oral small molecule SIRT1 activator, SRT2104, on arterial stiffness was examined in otherwise healthy cigarette smokers and participants with type 2 diabetes mellitus.

Methods

24 otherwise healthy cigarette smokers and 15 people with stable type 2 diabetes were randomised in a double-blind placebo-controlled crossover trial and received 28 days of oral SRT2104 (2.0 g/day) or matched placebo. Blood pressure was measured using non-invasive oscillatory sphygmomanometry. Pulse wave analysis and velocity were measured using applanation tonometry at baseline and the end of each treatment period. Owing to the small sample size and similar trends for both groups, data for the two groups were pooled (post hoc analysis).

Results

Compared to placebo, treatment with SRT2104 was associated with a significant reduction in augmentation pressure (p=0.0273) and a trend towards improvement in the augmentation index and corrected augmentation index (p>0.05 for both). However, no changes were observed in pulse wave velocity and time to wave reflection (p>0.05). Systolic and diastolic blood pressures remained unchanged throughout the study. Treatment by cohort interaction was not significant for any of the pulse wave parameters, suggesting that the response to SRT2104 in otherwise healthy smokers and people with diabetes was consistent.

Conclusions

SRT2104 may improve measures of arterial stiffness in otherwise healthy cigarette smokers and in participants with type 2 diabetes. Definitive conclusions are not possible given the small sample size and exploratory nature of this analysis.

Trial registration number

NCT01031108.

Influence of Postprandial Hyperglycemic Conditions on Arterial Stiffness in Patients With Type 2 Diabetes

CONTEXT

Patients with type 2 diabetes (T2D) are at an increased risk of cardiovascular disease.

OBJECTIVE

The objective of the study was to determine whether postprandial hyperglycemia affects arterial function in T2D.

DESIGN

A single-center, open-label study of three groups of men were studied: 1) T2D patients with albuminuria (n = 22), 2) T2D patients without albuminuria (n = 24), and 3) nondiabetic controls (n = 25). Patients were randomized to a two-period crossover study schedule, ingesting breakfast, with or without insulin lispro (to induce low or high postprandial glycemia).

MAIN OUTCOME MEASURES

Arterial stiffness was assessed by calculating pulse wave velocity (PWV) and augmentation index using applanation tonometry, and endothelial dysfunction was assessed using peripheral arterial tonometry, 30 minutes before breakfast and up to 240 minutes after breakfast.

RESULTS

At baseline, arterial stiffness was increased in patients. When adjusted for age and body mass index, in a combined group of patients with and without albuminuria, brachial PWV was higher during low (P = .032) and high (P = .038) postprandial glycemia vs controls. These differences were driven by the albuminuria group vs controls during low (P = .014) and high (P = .018) postprandial glycemia. No differences were observed in aortic PWV, augmentation index, or peripheral arterial tonometry ratio between patients and controls. Endothelin-1 and IL-6 were higher, and superoxide dismutase was lower, during postprandial hyperglycemia in T2D patients vs controls.

CONCLUSIONS

In patients with T2D and albuminuria, brachial PWV was higher under postprandial hyperglycemic conditions, relative to controls. These data suggest that hyperglycemia induces an increase in stiffness of intermediate-sized arteries. We found no changes in other parts of the arterial bed.