Arterial stiffness is associated with diabetic retinopathy in type 2 diabetes

AST/ALT ratio is an independent risk factor for diabetic retinopathy: A cross-sectional study

The aspartate to alanine transaminase (AST/ALT) ratio indicates oxidative stress and inflammatory reactions related to the occurrence of diabetic retinopathy (DR). Currently, there are no reports on the correlation between AST/ALT ratio and DR. Hence, this study aimed to explore the relationship between AST/ALT ratio and DR. This cross-sectional study utilized data from the Metabolic Management Center of the First People's Hospital in City. In total, 1365 patients with type 2 diabetes mellitus (T2DM) participated in the study, including 244 patients with DR and 1121 patients without DR. We collected the results of fundus photography, liver function, and other research data and grouped them according to tertiles of AST/ALT ratios. DR prevalence was the highest in the group with the highest AST/ALT ratio (22.12%, P = .004). Both univariate (OR = 2.25, 95% CI: 1.51-3.34, P < .001) and multivariable logistic regression analyses (adjusted for confounding factors) showed that the risk of DR increased by 36% when the AST/ALT ratio increased by 1 standard deviation (SD) (OR = 1.36, 95% CI: 1.16-1.59, P < .001), and 29.3% was mediated by the duration of diabetes. A sensitivity analysis confirmed the stability of the results. This study showed that an increase in AST/ALT ratio is an independent risk factor for DR.

A retinal imaging system for combined measurement of optic nerve head vascular pulsation and stimulated vasodilation in humans

Vascular pulsation at the optic nerve head (ONH) reflects vessel properties. Reduction in the stimulated retinal vasodilatory capacity has been reported in diabetes, but its relation with vascular pulsation is unknown. Here we report a new retinal imaging system for correlative assessment of ONH vascular pulsation and stimulated retinal vasodilation. Retinal reflectance images were acquired before and during light flicker stimulation to quantify arterial and venous vasodilation (DAR, DVR) in subjects with and without diabetic retinopathy (N = 25). ONH vascular pulsation amplitude and frequency (PA, PF), were quantified by curve fitting of periodic intensity waveforms acquired in retinal vasculature (RV) and ONH tissue (ONHT) regions. The relationships between pulsation metrics, heart rate (HR), intraocular pressure (IOP), and vasodilatory responses were evaluated. Pulsation metrics were not significantly different between regions (p ≥ 0.70). In RV, inter-image variabilities of PA and PF were 10% and 6%, whereas inter-observer variabilities were 7% and 2% respectively. In both regions, PF was correlated with HR (p ≤ 0.001). PA was associated with DAR in both regions (p ≤ 0.03), but only with DVR in RV (p ≤ 0.05). Overall, ONH vascular pulsation was associated with stimulated retinal vasodilation, suggesting diabetes may have concomitant effects on retinal vasculature compliance and neurovascular coupling.

Increased Arterial Stiffness as a Predictor for Onset and Progression of Diabetic Retinopathy in Type 2 Diabetes Mellitus

INTRODUCTION

Brachial-ankle pulse wave velocity (baPWV), an indicator of arterial stiffness, has been demonstrated to be associated with type 2 diabetes mellitus (T2DM) and its vascular complications. This study was aimed at investigating the correlations of baPWV with both the presence and severity of diabetic retinopathy (DR) at baseline and at exploring the predictive role of baPWV in the new onset/progression of DR in the follow-up analysis.

METHODS

The prospective cohort study recruited 2,473 Chinese patients with T2DM, of whom 663 participants were finally included in the follow-up analysis. The presence and grading of DR were performed by the modified Early Treatment Diabetic Retinopathy Study. Uni- or multivariate linear and logistic regression models and Cox proportional-hazards regression analysis were conducted.

RESULTS

Of 2,473 patients with T2DM at baseline, 734 individuals were assessed to have DR and further categorized into 630 with non-sight-threatening DR (NSTDR) and 104 with STDR. In addition to the positive relationship between increased baPWV and the presence of DR, multinominal logistic regression analysis revealed that higher tertiles of baPWV were significantly related to the NSTDR (T2: OR = 1.62 (1.22, 2.15), p < 0.001, and T3: OR = 2.58 (1.86, 3.58), p < 0.001) and STDR group (T3: OR = 3.87 (1.87, 8.02), p < 0.001). During a follow-up (mean period of 16.4 months), 111 participants had new onset/progression of DR. The cox regressions showed that high baseline baPWV was correlated with increased risk of development/progression of DR (HR = 2.24, 95% CI (1.24, 4.03), p = 0.007, for T2 baPWV and HR = 2.90, 95% CI (1.49, 5.64), p = 0.002, for T3 baPWV) after adjustments for multiple factors.

CONCLUSIONS

Our results demonstrated that baseline baPWV might be an independent predictor in new onset/worsening of DR, suggesting that increased arterial stiffness might be involved in the development of DR. Follow-up studies with a longer duration are needed.

National trends in the prevalence of diabetic retinopathy among Thai patients with type 2 diabetes and its associated factors from 2014 to 2018

Introduction

Diabetic retinopathy (DR) is one of the most common and serious ocular complications in both developed and developing countries. To date, epidemiological data of DR and their associated factors in Southeast Asian countries especially in Thailand are scarce. We aimed to use the information from the Thailand Diabetes Mellitus/Hypertension (DM/HT) study to determine trends in DR prevalence and also risk factors among Thai patients with type 2 diabetes (T2D).

Methods

A series of cross-sectional surveys of clinical outcomes was conducted annually in 2014, 2015 and 2018 among patients with T2D aged >18 years receiving medical care for at least 12 months. A stratified single stage cluster sampling method that was proportional to the size sampling technique was used to select a nationally and provincially representative sample of patients with T2D in Thailand. A standardized case report form was used to obtain the required information from medical records.

Results

A total of 104,472 Thai patients with T2D were included in the study from 2014 to 2018. The dominant proportion of participants, 70,756 (67.7%), were females. The overall prevalence of DR declined from 6.9% in 2014 to 6.3% in 2015 and 5.0% in 2018 (p for trend <0.001). The independent associated factors with DR included survey year, greater duration of DM, geographic region, hospital level, social security scheme, dyslipidemia, insulin therapy, high HbA1c level and elevated pulse pressure.

Conclusion

We reported a decreasing in trend in the prevalence of DR among Thai patients with T2D over one half decade. Patients with T2D should be encouraged to control their underlying diseases and engage in other effective interventions. When these modifiable risk factors can be inhibited, DR and other cardiovascular complications will be alleviated.

Pulse Pressure is a Stronger Predictor Than Systolic Blood Pressure for Severe Eye Diseases in Diabetes Mellitus

Background

Evidence of the role of systolic blood pressure (SBP) in development of severe diabetic retinopathy is not strong, although the adverse effect of low diastolic blood pressure has been a partial explanation. We assessed the predictive ability of incident severe diabetic retinopathy between pulse pressure (PP) which considers both SBP and diastolic blood pressure, compared with SBP.

Methods and Results

Eligible patients (12 242, 83% men) aged 19 to 72 years from a nationwide claims database were analyzed for a median observational 4.8‐year period. Severe diabetic retinopathy was defined as vision‐threatening treatment‐required diabetic eye diseases. Multivariate Cox regression analysis revealed that hazard ratios (95% CI) of treatment‐required diabetic eye diseases for 1 increment of standard deviation and the top tertile compared with the bottom tertile were 1.39 (1.21–1.60) and 1.72 (1.17–2.51), respectively, for PP and 1.22 (1.05–1.41) and 1.43 (0.97–2.11), respectively, for SBP adjusted for age, sex, body mass index, hemoglobin A1c, fasting plasma glucose, lipids, and smoking status. In a model with SBP and PP simultaneously as covariates, the hazard ratios of only PP (hazard ratios [95% CI], 1.57 [1.26–1.96]) but not SBP (0.85 [0.68–1.07]) were statistically significant. Delong test revealed a significant difference in the area under the receiver operating characteristic curve between PP and SBP (area under the receiver operating characteristic curve [95% CI], 0.58 [0.54–0.63] versus 0.54 [0.50–0.59]; P=0.03). The strongest predictor remained as hemoglobin A1c (area under the receiver operating characteristic curve [95% CI], 0.80 [0.77–0.84]).

Conclusions

After excluding the significant impact of glycemic control, PP in comparison with SBP is a better predictor of severe diabetic retinopathy, suggesting a role of diastolic blood pressure and arterial stiffness in pathology.

See Editorial Dart

High pulse wave velocity is associated with the severity of diabetic retinopathy in patients with type 2 diabetes

Pulse wave velocity (PWV) is a non-invasive test for assessing arterial stiffness, and brachial-ankle PWV has been used as an index of peripheral arterial stiffness. This study aimed to investigate the association between the PWV value and severity of diabetic retinopathy (DR). 846 patients with type 2 diabetes (T2DM) consecutively underwent brachial-ankle PWV, and the degree of PWV was defined by tertile. The severity of DR was categorized as no diabetic retinopathy (NDR), non-proliferative diabetic retinopathy (NPDR) or proliferative diabetic retinopathy (PDR) based on the Early Treatment Diabetic Retinopathy Study Scale. Multinomial logistic regression analyses were utilized not only to explore the association between the degree of PWV and severity of DR but also to examine the association of a high-tertile PWV with PDR. PWV levels, diabetes duration and blood pressure were all significantly higher in subjects with NPDR or PDR as compared with individuals with NDR. In the univariate analysis, the highest tertile of PWV (>19.6 m/s) was significantly associated with both NPDR (p<0.001) and PDR (p<0.001) as compared with NDR. After adjusting for confounding factors, the highest tertile of PWV remained significantly associated with PDR (p=0.005), but not with NPDR (p=0.107). Furthermore, the highest tertile of PWV was more significantly associated with PDR (OR=6.15, 95%CI 1.38 to 27.38) as compared with the lowest tertile. In our study, an increasing degree of PWV was positively associated with the severity of DR. High PWV was strongly associated with the risk of severe DR, especially PDR.

Association Between Atherosclerosis and Diabetic Retinopathy in Chinese Patients with Type 2 Diabetes Mellitus

AIM

To explore the association between the atherosclerosis and diabetic retinopathy (DR) in Chinese patients with type 2 diabetes mellitus (T2DM).

METHODS

This hospital-based cross-sectional study included 949 patients (700 males and 249 females) with T2DM. The atherosclerotic parameters were assessed using the cardio-ankle vascular index (CAVI), ankle-brachial index (ABI), and carotid plaque. DR was assessed and graded using digital retinal photography and fundus fluorescein angiography as either nonproliferative DR (NPDR) or proliferative DR (PDR). Multiple logistic regression analysis was performed to identify the associations between the atherosclerotic parameters and DR status.

RESULTS

The prevalence of DR was 23.6% in total patients, including 167 (17.6%) patients with NPDR and 57 (6.0%) patients with PDR. Patients with NPDR and PDR were more likely to have higher prevalence of increased CAVI, increased ABI, and carotid plaque than those without DR. In multivariable adjusted logistic regression analysis, patients with NPDR showed an odds ratio (OR) of 2.59 [95% confidence interval (CI), 1.61-4.19] for increased CAVI, 1.99 (0.62-6.34) for increased ABI, and 1.75 (1.13-2.71) for carotid plaque. Patients with PDR showed an OR of 7.83 (3.52-17.41) for increased CAVI, 10.65 (3.33-34.04) for increased ABI, and 11.40 (2.67-48.63) for carotid plaque.

CONCLUSION

Both NPDR and PDR were independently associated with increased CAVI and presence of carotid plaque in Chinese patients with T2DM.

Association of central arterial stiffness with the presence and severity of diabetic retinopathy in Asians with type 2 diabetes

OBJECTIVE

Arterial stiffness has been associated with diabetic retinopathy; however, the information is limited in Asians. We aim to examine the association of central arterial stiffness with the presence and severity of diabetic retinopathy in type 2 diabetes mellitus patients in Singapore.

METHODS

Arterial stiffness was estimated by carotid-femoral pulse wave velocity and augmentation index using applanation tonometry method. Digital colour fundus photographs from 1,203 patients were assessed for diabetic retinopathy. Diabetic retinopathy severity was categorized into non-proliferative diabetic retinopathy and proliferative diabetic retinopathy. Logistic regression model was used to evaluate the associations of diabetic retinopathy with pulse wave velocity and augmentation index.

RESULTS

Diabetic retinopathy was diagnosed in 391 (32.5%) patients, including 271 non-proliferative diabetic retinopathy and 108 proliferative diabetic retinopathy. Diabetic retinopathy have higher pulse wave velocity (11.2 ± 3.3 vs 9.5 ± 2.6 m/s, p < 0.001) and augmentation index (28.4 ± 9.4 vs 26.1 ± 10.6%, p < 0.001) than non-diabetic retinopathy. After multivariable adjustment, pulse wave velocity [odds ratio = 1.11 (95% confidence interval = 1.05-1.17), p < 0.001] and augmentation index [odds ratio = 1.03 (95% confidence interval = 1.01-1.04), p = 0.009] was associated with diabetic retinopathy. In severity analyses, pulse wave velocity was associated with non-proliferative diabetic retinopathy [odds ratio = 1.10 (95% confidence interval = 1.03-1.17), p = 0.002] and proliferative diabetic retinopathy [odds ratio = 1.15 (95% confidence interval = 1.06-1.25), p = 0.001] (p-trend < 0.001). Augmentation index showed significant associations with non-proliferative diabetic retinopathy [odds ratio = 1.02 (95% confidence interval = 1.01-1.04), p = 0.008], but not with proliferative diabetic retinopathy [odds ratio = 1.01 (95% confidence interval = 0.98-1.04), p = 0.36] (p-trend = 0.03).

CONCLUSION

Central arterial stiffness was associated with the presence and severity of diabetic retinopathy in type 2 diabetes mellitus patients, suggesting its etiologic implication in diabetic retinopathy.

Retinal vessel reactivity is not attenuated in patients with type 2 diabetes compared with matched controls and is associated with peripheral endothelial function in controls

BACKGROUND AND AIMS

Attenuated retinal vasoreactivity in patients with type 2 diabetes preceding diabetic retinopathy development has been proposed to reflect local endothelial dysfunction. Whether retinal vessel reactivity is associated with peripheral endothelial dysfunction and large artery stiffness in patients with type 2 diabetes remains to be elucidated.

METHODS

Twenty patients with type 2 diabetes without retinopathy and 20 sex- and age matched controls (diabetes duration: 9.9 years (range 6.0;12.4), 40% male, age: 66.5 ± 7.3 (diabetes) and 65.2 ± 7.6 years (controls)) were included. Endothelial function was assessed using EndoPAT. Arterial stiffness was assessed by carotid-femoral pulse wave velocity using the SphygmoCor. Retinal blood supply regulation was examined by retinal arteriolar diameter change during 1) isometric exercise (hand-weight lifting), 2) exposure to flickering lights, and 3) a combined stimulus of 1) + 2) using the Dynamic Vessel Analyzer.

RESULTS

No significant differences were observed in retinal vessel reactivity in T2DM patients compared to controls. Endothelial function was associated with mean arteriolar diameter change during only the combination intervention, (Beta = 0.033 [0.0013;0.064], p = 0.042) in the overall population of patients and controls. When groups were analyzed separately, the associations was statistically significant only in controls. However, formal test for interaction was not statistically significant, p = 0.40. No association was observed between pulse wave velocity and retinal arteriolar %-diameter change in patients or controls.

CONCLUSION

Peripheral endothelial function was associated with retinal arteriolar diameter change in the combined sample. The association seemed to be driven primarily by the controls. Our findings indicate that peripheral endothelial function is reflective of endothelial function in the retina mainly in subjects without T2DM, whereas an association in T2DM without retinopathy was not observed. Further studies are needed in T2DM patients with more advanced retinopathy.

Retinopathy and RAAS Activation: Results From the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

The importance of renin-angiotensin-aldosterone system (RAAS) activation in retinopathy for long-standing diabetes is not well understood. We determined retinopathy stage and evaluated associations with other vascular complications before and after physiological RAAS activation in adults with long-standing (≥50 years duration) type 1 diabetes.

RESEARCH DESIGN AND METHODS

Participants underwent retinal examination by digital funduscopic photography and optical coherence tomography and were classified as having nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), or no diabetic retinopathy (NDR) with or without diabetic macular edema (DME). Neuropathy was measured by clinical neuropathy examination scores, electrophysiologically, and by corneal confocal microscopy. Renal function was measured by inulin and para-aminohippurate clearance methods. Arterial stiffness was measured by applanation tonometry. Renal function, blood pressure, and arterial stiffness were measured before and after RAAS activation with angiotensin II (ANGII). Associations were determined using linear regression.

RESULTS

Twelve (16%) of the 75 participants had NDR, 24 (32%) had NPDR, and 39 (52%) had PDR. A low overall prevalence of DME (4%) was observed. Those with PDR had worse nerve function and reduced corneal nerve density, were more likely to have macrovascular disease, and had increased arterial stiffness in response to ANGII compared with those with NPDR or NDR. Prevalence of kidney disease or renal hemodynamic function did not differ by retinopathy status.

CONCLUSIONS

PDR was associated with neuropathy severity and cardiovascular and peripheral vascular disease. In those with PDR, RAAS activation may be linked to vascular stiffening, an effect that persists in long-standing type 1 diabetes.

Cardio-Ankle Vascular Index as a Surrogate Marker of Early Atherosclerotic Cardiovascular Disease in Koreans with Type 2 Diabetes Mellitus

BACKGROUND

Carotid artery intima medial thickness (IMT), brachial-ankle pulse wave velocity (baPWV), and ankle-brachial index (ABI) are commonly used surrogate markers of subclinical atherosclerosis in patients with type 2 diabetes mellitus (T2DM). The cardio-ankle vascular index (CAVI) is a complement to the baPWV, which is affected by blood pressure. However, it is unclear which marker is the most sensitive predictor of atherosclerotic cardiovascular disease (ASCVD).

METHODS

This was a retrospective non-interventional study that enrolled 219 patients with T2DM. The correlations among IMT, ABI, and CAVI as well as the relationship of these tests to the 10-year ASCVD risk were also analyzed.

RESULTS

Among the 219 patients, 39 (17.8%) had ASCVD. In the non-ASCVD group, CAVI correlated significantly with IMT after adjusting for confounding variables, but ABI was not associated with CAVI or IMT. The analyses after dividing the non-ASCVD group into three subgroups according to the CAVI score (<8, ≥8 and <9, and ≥9) demonstrated the significant increase in the mean IMT, 10-year ASCVD risk and number of metabolic syndrome risk factors, and decrease in the mean ABI in the high-CAVI group. A high CAVI was an independent risk factor in the non-ASCVD group for both a high 10-year ASCVD risk (≥7.5%; odds ratio [OR], 2.42; P<0.001) and atherosclerosis (mean IMT ≥1 mm; OR, 1.53; P=0.007).

CONCLUSION

In Korean patients with T2DM without ASCVD, CAVI was the most sensitive of several surrogate markers for the detection of subclinical atherosclerosis.

A randomised study of the impact of the SGLT2 inhibitor dapagliflozin on microvascular and macrovascular circulation

Background

The sodium–glucose cotransporter 2 inhibitor, dapagliflozin, has been shown to improve diabetic control and reduce blood pressure in patients with type 2 diabetes mellitus. Its effects on micro- and macrovascular structure and function have not yet been reported.

Methods

This was a prospective, single-centre, placebo-controlled, double-blind, randomised crossover phase IIIb study conducted between March 2014 and February 2015. After a 4-week run-in/washout phase, patients (N = 59) received 6 weeks of either dapagliflozin 10 mg or placebo once daily. They then underwent a 1-week washout before crossing over to the other treatment. Changes in retinal capillary flow (RCF) and arteriole remodelling were evaluated using scanning laser Doppler flowmetry, while micro- and macrovascular parameters in the systemic circulation were assessed using pulse wave analysis.

Results

Six weeks of dapagliflozin treatment resulted in improvements in diabetes control, including blood glucose and insulin resistance, and reduced office and 24-h ambulatory blood pressure values. RCF decreased from 324 AU at baseline to 308 AU after treatment with dapagliflozin (p = 0.028), while there was little difference after the placebo (318 AU; p = 0.334). Furthermore, the arteriole remodelling that was seen after the placebo phase was not evident after the dapagliflozin phase. Central systolic and diastolic blood pressure values were significantly lower after 6 weeks of dapagliflozin, by 3.0 and 2.2 mmHg, respectively (p = 0.035 and 0.020, respectively vs. baseline).

Conclusions

Six weeks of dapagliflozin treatment resulted in numerous beneficial effects. In addition to achieving superior diabetes control and blood pressure, parameters associated with the early stages of vascular remodelling were also improved.

Trial registrationhttp://www.clinicaltrials.gov (NCT02383238)

Arterial stiffness in diabetes mellitus

Arterial stiffness is an age-related process that is a shared consequence of numerous diseases including diabetes mellitus (DM), and is an independent predictor of mortality both in this population and in the general population. While much has been published about arterial stiffness in patients with DM, a thorough review of the current literature is lacking. Using a systematic literature search strategy, we aimed to summarize our current understanding related to arterial stiffness in DM. We review key studies demonstrating that, among patients with established DM, arterial stiffness is closely related to the progression of complications of DM, including nephropathy, retinopathy, and neuropathy. It is also becoming clear that arterial stiffness can be increased even in pre-diabetic populations with impaired glucose tolerance, and in those with the metabolic syndrome (METS), well before the onset of overt DM. Some data suggests that arterial stiffness can predict the onset of DM. However, future work is needed to further clarify whether large artery stiffness and the pulsatile hemodynamic changes that accompany it are involved in the pathogenesis of DM, and whether interventions targeting arterial stiffness are associated with improved clinical outcomes in DM. We also review of the potential mechanisms of arterial stiffness in DM, with particular emphasis on the role of advanced glycation endproducts (AGEs) and nitric oxide dysregulation, and address potential future directions for research.

Brachial-ankle pulse wave velocity predicts all-cause mortality and cardiovascular events in patients with diabetes: the Kyushu Prevention Study of Atherosclerosis

OBJECTIVE

Whether brachial-ankle pulse wave velocity (baPWV), a noninvasive marker for arterial stiffness, is a useful predictive maker for cardiovascular events in subjects with diabetes is not established. In the present cohort study, we evaluated the benefit of baPWV for the prediction of cardiovascular morbidity and mortality in subjects with diabetes.

RESEARCH DESIGN AND METHODS

A total of 4,272 outpatients with diabetes were enrolled in the Kyushu Prevention Study of Atherosclerosis. Of these, 3,628 subjects, excluding those with an ankle-brachial index of <0.9, were prospectively followed for 3.2 ± 2.2 years. The baPWV at baseline was classified by recursive partitioning (RP) for each end point. We plotted the Kaplan-Meier curves for high- and low-baPWV groups, which were designated based on the cutoff points, and calculated Cox proportional hazards models.

RESULTS

The elevation of baPWV quartiles was significantly correlated to the incidence of coronary artery events, cerebrovascular events, and all-cause mortality. RP revealed baPWVs of 14 and 24 m/s as statistically adequate cutoff points for cardiovascular events and mortality, respectively. High-baPWV classes showed significantly low event-free ratios in Kaplan-Meier curves for all end points and remained independent risks for all-cause mortality and cerebrovascular events, but not for coronary artery events after adjustments for age, sex, BMI, hypertension, hyperlipidemia, smoking, and hemoglobin A1c by Cox proportional hazards models.

CONCLUSIONS

This large-scale cohort study provided evidence that high baPWV is a useful independent predictor of mortality and cardiovascular morbidity in subjects with diabetes.

Relationship between Stage of Diabetic Retinopathy and Pulse Wave Velocity in Japanese Patients with Type 2 Diabetes

Objectives. We investigated the relationship between the stage of diabetic retinopathy and pulse wave velocity (PWV). Methods. This was a cross-sectional study of 689 patients (406 men and 283 women) with type 2 diabetes who were admitted to our hospital from 2004 to 2007. Brachial-ankle pulse wave velocity (baPWV) was measured by an arterial pressure measurement device as PWV/ABI. Diagnosis of diabetic retinopathy was made by ophthalmologists based on the Davis classification: no diabetic retinopathy (NDR), simple retinopathy (SDR), pre-proliferative retinopathy (pre-PDR), and proliferative retinopathy (PDR). Results. There was a significant difference in PWV between patients without diabetic retinopathy (1657.0 ± 417.9 m/s (mean ± SD)) and with diabetic retinopathy (1847.1 ± 423.9 m/s) (P < 0.001). In addition, the stage of diabetic retinopathy was associated with aortic PWV (1657.0 ± 417.9 m/s in NDR (n = 420), 1819.4 ± 430.3 m/s in SDR (n = 152), 1862.1 ± 394.0 m/s in pre-PDR (n = 54), and 1901.1 ± 433.5 m/s in PDR (n = 63) (P < 0.001)). Conclusions. In patients with diabetic retinopathy, even in those with SDR, PWV was higher than that in patients without diabetic retinopathy. Physicians should therefore pay attention to the value of PWV and macroangiopathy regardless of the stage of diabetic retinopathy.

The association between regional arterial stiffness and diabetic retinopathy in type 2 diabetes

OBJECTIVES

Although several studies have reported that PWV is associated with diabetic retinopathy, it remains controversial as to which segment provides the PWV that might best reflect the presence of retinopathy. The aim of this study was to determine the pulse wave velocity (PWV) of arterial segments that is most closely associated with diabetic retinopathy in subjects without a history of macrovascular complications.

METHODS

After excluding subjects with a history of ischemic heart disease, peripheral artery disease, ischemic stroke, renal insufficiency, overt proteinuria, and other nondiabetic ophthalmic lesions or insufficient retinal examinations, a total of 494 subjects were analyzed by cross-sectional study. The central PWVs, including the heart-femoral (hf), heart-carotid (hc), heart-ankle (ha), and carotid-brachial (cb) segments, and the peripheral PWVs, including brachial-ankle (ba) and femoral-ankle (fa), were measured for each subject.

RESULTS

The group with diabetic retinopathy exhibited significantly higher hfPWV, hcPWV, haPWV and baPWV, but notcbPWV, faPWV or augmentation index (AI). Age, duration of diabetes, systolic and diastolic BP and pulse pressure were all positively associated with hfPWV, hcPWV, haPWV and baPWV. Quartiles of hfPWV were significantly associated with diabetic retinopathy after adjustment for covariates and known risk factors of diabetic retinopathy (P for trend = 0.023). Conversely, all quartiles of haPWV, hcPWV and baPWV lost significance after adjustment.

CONCLUSIONS

We found that diabetic retinopathy was most closely associated with hfPWV, suggesting the most reliable index of regional arterial stiffness index in retinopathy.

Arterial stiffness is associated with diabetic retinopathy in Korean type 2 diabetic patients

Objectives

We evaluated the association between common carotid artery intima-media thickness (CCA-IMT), brachial-ankle pulse wave velocity (baPWV), carotid plaque, and peripheral arterial disease (PAD) as indicators of macroangiopathy and diabetic retinopathy as an indicator of microangiopathy in type 2 diabetic patients.

Methods

We analyzed 605 type 2 diabetic patients registered at a public health center in Korea. Following overnight fasting, venous blood and urine samples were collected and analyzed. The CCA-IMT, levels of carotid plaque, baPWV, and ankle-brachial index (ABI) of the subjects were assessed. We used non-mydriatic fundus photography to diagnose diabetic retinopathy. Multiple logistic regression analyses were used to evaluate the association between macroangiopathy and diabetic retinopathy. CCA-IMT and baPWV were divided into tertiles: CCA-IMT, 0.39 to 0.65 mm, 0.66 to 0.78 mm, and 0.79 to 1.30 mm; baPWV, 9.9 to 15.8 m/s, 15.9 to 18.9 m/s, and 19.0 to 38.0 m/s.

Results

The association between baPWV and diabetic retinopathy remained significant after adjustment, with an increasing odds ratio (OR) in the second tertile (OR, 2.41; 95% confidence interval [CI], 1.27 to 4.55) and the third tertile (OR, 4.63; 95% CI, 2.33 to 9.21). No significant differences were observed in carotid plaque, PAD, and each tertile of CCA-IMT.

Conclusions

BaPWV was associated with diabetic retinopathy, while CCA-IMT, carotid plaque, and PAD were not. This study suggests that the association between macroangiopathy and microangiopathy may be attributable to functional processes rather than structural processes within the vascular system.

Values of cardio-ankle vascular index (CAVI) between Amami islands and Kagoshima mainland among health checkup examinees

AIM

To investigate the prevalence and geographical variation of high arterial stiffness in groups from the Amami islands (Amami) and Kagoshima mainland (mainland), Japan, using the cardio-ankle vascular index (CAVI) as a surrogate marker of arterial stiffness.

METHODS

We recruited 4,523 health checkup examinees from Amami and 440 examinees from the mainland, with an age range of 40-69 years. The frequency of high arterial stiffness (CAVI≥9.0) was geographically compared between the regions, and both mean CAVI values were compared with those of the healthy Japanese population with less risk factors for coronary artery disease. Clinical, lifestyle, and regional factors for increased CAVI values were estimated by the multiple linear regression model.

RESULTS

The frequency of high arterial stiffness on Amami was significantly lower than on the mainland. Mean CAVI values on Amami were similar in males and lower in females than in the healthy Japanese population, but those on the mainland were higher for both sexes. Age, systolic blood pressure, triglycerides, fasting blood glucose, and a history of hypertension and diabetes mellitus were positively related to increased CAVI values on Amami. The regional factor of Amami, compared with the mainland, was negatively related to increased CAVI values in both sexes after adjusting for traditional cardiovascular risk factors.

CONCLUSION

CAVI values in Amami residents were significantly lower than in mainland residents, suggesting that environmental or genetic factors might have improved arterial stiffness in the Amami population.

Association between Diabetic Polyneuropathy and Cardiovascular Complications in Type 2 Diabetic Patients

BACKGROUND

Diabetes mellitus is a major independent risk factor for cardiovascular disease (CVD), but high cardiovascular risk in diabetes mellitus patients is not completely explained by clustering traditional risk factors. Recently, associations between diabetic polyneuropathy (DPN) and macrovasculopathy have been suggested. We aimed to assess associations between DPN and cardiovascular complications in type 2 diabetic patients.

METHODS

Microvascular and cardiovascular complications were evaluated in 1,041 type 2 diabetic patients.

RESULTS

In patients with DPN, the age, prevalence of hypertension, diabetes duration, systolic blood pressure, pulse pressure, and hemoglobin glycation (HbA1c) levels were significantly higher, while the high density lipoprotein cholesterol (HDL-C) levels were lower than in those without DPN. The prevalence of CVD was higher in patients with DPN. In multivariate analysis, DPN was independently associated with CVD (odds ratio, 1.801; 95% confidence interval, 1.009 to 3.214).

CONCLUSION

Our results showed that DPN was associated with a high prevalence of cardiovascular disease in type 2 diabetic patients, but further studies are needed to investigate the causative nature of associations between DPN and CVD.

Diabetic peripheral neuropathy is associated with increased arterial stiffness without changes in carotid intima-media thickness in type 2 diabetes

OBJECTIVE

This study was conducted to investigate the association of diabetic peripheral neuropathy (DPN) with both arterial stiffness and intima-media thickness (IMT).

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional analysis of 731 subjects with type 2 diabetes. DPN was diagnosed on the basis of neuropathic symptoms, insensitivity to a 10-g monofilament, abnormal pin-prick sensation, and abnormal current perception threshold. Arterial stiffness was assessed by cardio-ankle vascular index (CAVI), and IMT was assessed by B-mode ultrasonography.

RESULTS

Patients with DPN had higher CAVI than those without DPN in multivariate-adjusted models, whereas no differences in IMT were observed between patients with and without DPN after adjustment for age and sex. In the multivariate analysis, CAVI was a significant determinant of DPN (odds ratio 1.36 [95% CI 1.13-1.65], P = 0.001).

CONCLUSIONS

DPN is significantly associated with arterial stiffness without carotid intimal changes in patients with type 2 diabetes.

Adverse association between diabetic retinopathy and cardiac structure and function

BACKGROUND

Recent work has demonstrated a link between retinopathy, a marker of microvascular disease, and the development of heart failure, a finding particularly relevant in individuals with diabetes. Our objective was to assess the relationship between retinopathy and cardiac structure and function in a cohort of individuals with type 2 diabetes mellitus.

METHODS

Stereoscopic fundus photography of 7 standard fields was obtained in 531 Mexican American adults with type 2 diabetes mellitus recruited as sibships from Starr County, Texas. Retinopathy was centrally scored and classified as no retinopathy, early nonproliferative diabetic retinopathy, moderate to severe nonproliferative diabetic retinopathy, or proliferative diabetic retinopathy. Echocardiography was used to assess cardiac structure and function. Multilevel mixed models were used to assess associations of clinical and echocardiographic variables with retinopathy while accounting for correlations among siblings.

RESULTS

More severe diabetic retinopathy was associated with the presence of hypertension, previous cardiovascular disease, longer duration of diabetes, elevated glycosylated hemoglobin, and greater albuminuria. With worsening severity of diabetic retinopathy, left ventricular (LV) mass and left atrial dimension increased, and LV ejection fraction and LV fractional shortening decreased, independent of potential confounding variables.

CONCLUSIONS

More severe diabetic retinopathy was associated with worse cardiac structure and function by echocardiography independent of potential confounding variables. These data suggest a possible microvascular contribution to the development of diabetes-associated cardiac enlargement and dysfunction. Alternatively, common pathways may be leading to both disorders.

Microvascular degenerative complications are associated with increased aortic stiffness in type 2 diabetic patients

OBJECTIVE

Diabetes is a risk factor for increased arterial stiffness; however, few studies had investigated its associated factors. The aim was to evaluate the correlates of increased arterial stiffness in type 2 diabetes, particularly the relationships with microvascular complications.

METHODS

482 type 2 diabetic patients without peripheral arterial disease were evaluated in a cross-sectional study. Clinical (including tests of cardiovascular dysautonomy), laboratory, ECG, echocardiographic and 24h ambulatory blood pressure monitoring data were obtained. Arterial stiffness was assessed by carotid-femoral (aortic) and carotid-radial (peripheral) pulse wave velocity (PWV) measurements. Statistics included multivariate linear and logistic regressions to investigate the independent correlates of increased arterial stiffness.

RESULTS

No diabetes-related variable was associated with peripheral arterial stiffness. 148 patients (31%) had increased aortic PWV (>12m/s). On multiple linear regression, retinopathy and nephropathy, besides age, heart rate, 24h pulse pressure, diabetes duration, dyslipidemia and number of antihypertensive drugs in use, were independently associated with aortic PWV. On multivariate logistic regression increased aortic stiffness was associated with retinopathy (odds ratio: 3.83, 95% confidence interval [CI]: 2.24-6.56, p<0.001) and peripheral neuropathy (odds ratio: 1.79, 95%CI: 1.06-3.02, p=0.03) after adjusting for possible confounding variables. Other variables associated with increased aortic stiffness were older age, heart rate, diabetes duration, 24h pulse pressure, dyslipidemia and physical inactivity.

CONCLUSIONS

In type 2 diabetic patients, increased central arterial stiffness is associated with the presence of microvascular complications independent of other established determinants of aortic stiffness.

Coronary artery calcification, arterial stiffness and renal insufficiency associate with serum levels of tumor necrosis factor-alpha in Japanese type 2 diabetic patients

Although the kidneys are the major source of proinflammatory cytokines, association of tumor necrosis factor-alpha (TNF-alpha) with severity of atherosclerosis or kidney function in diabetic patients is unclear. Two hundred type 2 diabetic patients and 30 age-matched nondiabetic subjects consecutively admitted to our hospital were enrolled. The Agatston coronary artery calcium score (CACS), a quantitative marker of coronary atherosclerosis, was obtained using multidetector-row computed tomography. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV). Diabetic patients had higher log(CACS+1) (p=0.0089), baPWV (p=0.0293), frequency of elevated urinary albumin excretion (UAE) (p<0.0001) and TNF-alpha (p=0.0029) and similar estimated glomerular filtration rate (eGFR) compared to nondiabetic subjects. When diabetic patients were grouped into four subgroups with or without elevated UAE and renal insufficiency (UAE of >/=30 or <30mg/24h and eGFR of <60 or >/=60ml/min per 1.73m(2)), patients with micro- and macroalbuminuric renal insufficiency showed the highest log(CACS+1) (p<0.0001), baPWV (p=0.0068) and TNF-alpha (p<0.0001) of these groups. Log(CACS+1) (p=0.0008) and baPWV (p=0.0006) positively and eGFR (p<0.0001) negatively correlated with TNF-alpha in diabetic patients. We find that coronary artery calcification, arterial stiffness, and renal insufficiency associate with circulating levels of TNF-alpha in type 2 diabetic patients.

Diabetic retinopathy is associated with pulse wave velocity, not with the augmentation index of pulse waveform

Background

To investigate the clinical differences between pulse wave velocity and augmentation index in diabetic retinopathy.

Methods

The subjects were 201 patients with type 2 diabetes. These subjects were measured for both augmentation index (AI) and brachial-ankle pulse wave velocity (baPWV) by a pulse wave analyzer. The relationships between AI, baPWV, and diabetic retinopathy were examined.

Results

BaPWV was significantly higher in patients with diabetic retinopathy than in individuals without the disease. (20.13 ± 3.66 vs.17.14 ± 3.60 m/s p < 0.001) AI was higher in patients with diabetic retinopathy, but not significantly. (19.5 ± 15.2 vs. 14.8 ± 20.5% p = 0.14) The association between baPWV and diabetic retinopathy remained statistically significant after adjustment. (Odds ratio: 1.21 Per m/s, 95% confidence interval: 1.07–1.37) On the other hand, the association between AI and diabetic retinopathy was not statistically significant. (Odds ratio: 1.01 Per %, 95% confidence interval: 0.98–1.03)

Conclusion

BaPWV is associated with diabetic retinopathy, but AI is not. The clinical significance appears to be different between PWV and AI in patients with diabetes.

Retinal hemodynamics in early diabetic macular edema

The objective of this study was to establish the baseline retinal hemodynamic characteristics of stratified groups of diabetic patients at increasing risk for the development of diabetic macular edema (DME). Group 1 had 50 control subjects, group 2 had 56 diabetic patients without clinically visible retinopathy, group 3 had 54 diabetic patients with microaneurysms and/or hard exudates within two disc diameters of the fovea in the absence of clinically manifest DME, and group 4 had 40 patients with clinically manifest DME. Retinal hemodynamics (diameter, velocity, maximum-to-minimum velocity ratio, and flow) were assessed. Intraocular pressure, blood pressure, and relevant systemic markers of diabetes control and complications were also undertaken. The maximum-to-minimum velocity ratio was elevated with increasing risk of clinically significant DME (P < 0.0001). No significant differences were found between the groups with respect to diameter, velocity, or flow. The maximum-to-minimum velocity ratio was correlated to age, duration of diabetes, blood pressure, pulse rate, intraocular pressure, and serum potassium levels. In conclusion, the maximum-to-minimum velocity ratio was significantly increased with increasing risk of development of DME. Retinal arteriolar hemodynamics were positively correlated to age, duration of diabetes, and blood pressure. These findings suggest a reduction in the compliance (i.e., an increase of vascular rigidity) of the arteriolar circulation with increasing risk of DME.

Impact of Type A Behavior on Brachial-Ankle Pulse Wave Velocity in Japanese

Pulse wave velocity (PWV) is the velocity of a pulse wave traveling a given distance between 2 sites in the arterial system, and is a well-known indicator of arteriosclerosis. Brachial-ankle PWV (baPWV) is a parameter more simple to obtain, compared with the conventional PWV, and is an easy and effective means of evaluating arteriosclerosis. BaPWV can be obtained by only wrapping the four extremities with blood pressure cuffs, and it can be easily used to screen a large number of subjects. Type A behavior has been confirmed as an independent risk factor for the development of coronary heart disease. To examine the relationship between Type A behavior and arteriosclerosis, 307 normal Japanese subjects were classified into either a Type A group (n = 90) or a non-Type A group (n = 217) by using Maeda's Type A Scale. BaPWV was evaluated using a PWV diagnosis device. The baPWV in the Type A group was significantly higher than that obtained in the non-Type A group. The baPWV showed a positive correlation with age both in the Type A group and in the non-Type A group; however, the straight-line regression slope of baPWV versus age in the Type A group was significantly larger than that in the non-Type A group. Therefore, our results suggest that arteriosclerosis might be promoted earlier in subjects expressing the Type A behavior pattern. Type A behavior pattern is confirmed as a risk factor for arteriosclerosis, and may increase the risk of the cardiovascular disease related to arteriosclerosis.