Retinal vascular caliber and metabolic syndrome in a Chinese population

Higher prevalence of diabetic retinopathy among female Chinese diabetic patients with metabolic syndrome

PURPOSE

To investigate the association between metabolic syndrome (MetS) and diabetic retinopathy (DR), as well as the association between MetS and retinal vessel caliber, among Chinese patients with type 2 diabetes mellitus in north-eastern China.

STUDY DESIGN

Cross-sectional study.

PATIENTS AND METHODS

The patients were recruited from a community-based study, the Fushun Diabetic Retinopathy Cohort Study (FS-DIRECT). The presence of DR was determined using a modified version of the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. The central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE) were identified by use of Integrative Vessel Analysis software. The presence of MetS was defined according to the Joint Interim Statement proposed in 2009.

RESULTS

The prevalence of DR was significantly higher among female patients with MetS than among those without it (47.2% vs 30.9%, P = 0.002), and it increased as the number of MetS components increased (P = 0.003). Furthermore, the presence of MetS (odds ratio 2.43, 95% CI 1.39-4.26) as well as higher numbers of MetS components were significantly associated with DR in female patients, after adjustment for potential risk factors. Patients with MetS (multivariate β coefficient, 95% CI - 6.9, - 10.0, to - 3.8) or a higher number of Mets components tended to have significantly smaller CRAE.

CONCLUSION

In this study cohort, female patients with MetS had a higher prevalence of DR. Patients tended to have thinner central retinal arterioles as the number of MetS components increased.

Measurement of Retinal Vessels as a Biomarker of Cerebrovascular Aging in Older HIV-Positive Men Compared With Controls

BACKGROUND

To compare retinal vascular measurements, biomarkers of cerebral small vessel disease, in HIV-positive men aged 50 years and older with similarly aged HIV-negative men and younger HIV-positive men.

METHODS

We recruited white, nondiabetic men into a cross-sectional substudy of a larger cohort including 3 demographically matched groups. Optic disc-centered 45-degree color fundus photographs were used to calculate central retinal arterial and venous caliber and the arterial-venous ratio (AVR). We used univariate and multivariable linear regression to compare retinal vessel measurements in the 3 groups and to identify factors associated with AVR.

RESULTS

All HIV-positive men were virologically suppressed. In a multivariable model, study group was not associated with AVR [adjusted β 0.010 for HIV-positive men <50 (n = 39) compared with HIV-positive men aged ≥50 years (n = 120), 95% confidence interval [CI] -0.018 to 0.038, P = 0.47; adjusted β 0.00002 for HIV-negative men ≥50 years (n = 52), 95% CI -0.022 to 0.022, P = 0.99]. Factors associated with lower AVR were systolic blood pressure (adjusted β -0.009 per +10 mm Hg, 95% CI -0.015 to -0.003, P = 0.002), history of stroke or transient ischemic attack (adjusted β -0.070, 95% CI -0.12 to -0.015, P = 0.01), and recent recreational drug use (adjusted β -0.037, 95% CI -0.057 to -0.018, P = 0.0002).

CONCLUSIONS

There were no differences in retinal vascular indices between HIV-positive men aged ≥50 years and HIV-negative men aged ≥50 years or HIV-positive men aged <50 years, suggesting that HIV is not associated with an increased burden of cerebral small vessel disease.

The effect of obesity and insulin resistance on macular choroidal thickness in a pediatric population as assessed by enhanced depth imaging optical coherence tomography

BACKGROUND

The purpose of this study was to evaluate the macular choroidal thickness in obese children with and without insulin resistance (IR).

METHODS

Thirty-six patients with obesity and 26 healthy volunteers were included in this cross-sectional study. The choroidal thickness was measured with enhanced depth imaging optical coherence tomography (EDI-OCT) at the fovea and at positions 500 μm, 1000 μm, 1500 μm nasal and temporal to the fovea. The choroidal thickness measurements of the groups were compared and the correlation between the homeostasis model assessment of insulin resistance (HOMA-IR) and choroidal thickness values was evaluated.

RESULTS

The average choroidal thickness in the obese group was significantly lower than that of controls at locations 1000 μm (303.31±58.52 vs. 340.58±69.47, p=0.026) and 1500 μm (284.14±65.06 vs. 336.85±71.37, p=0.004) temporal to the fovea. A subgroup analysis depending on the presence of IR revealed that the choroidal thickness measurements at all positions were thinner in obese children without IR compared to children with IR and healthy controls. This thinning reached a statistical significance at locations 500 μm temporal, 1000 μm temporal and 1500 μm temporal to the fovea (p=0.03, p=0.009 and p=0.006; respectively). There was a moderate correlation between the choroidal thickness measurements and HOMA-IR values (r-values between 0.37 and 0.48; p<0.05).

CONCLUSIONS

Our results suggest that obesity and IR may have an influence on the choroidal thickness in children. Longitudinal studies will clarify whether these choroidal changes are progressive and are a sign of microvascular dysfunction in childhood obesity.

Validity and reproducibility of retinal arteriole and venule diameter measurements: ELSA-Brasil study. A cross-sectional study

BACKGROUND

Investigation of alterations to retinal microvasculature may contribute towards understanding the role of such changes in the pathophysiology of several chronic non-communicable diseases. The objective here was to evaluate the validity and reproducibility of retinal arteriole and venule diameter measurements made by Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) graders.

DESIGN AND SETTING

Cross-sectional study at six teaching and research institutions.

METHODS

To evaluate validity, each of 25 retinal images from the University of Wisconsin (gold standard) was measured by five ELSA-Brasil graders. To evaluate reproducibility, 105 images across the spectrum of vessel diameters were selected from 12,257 retinal images that had been obtained between 2010 and 2012, and each image was reexamined by the same grader and by an independent grader. All measurements were made using the Interactive Vessel Analysis (IVAN) software. Bland-Altman plots, paired t tests and intraclass correlation coefficients (ICCs) were analyzed.

RESULTS

Mean differences between ELSA-Brasil and gold-standard readings were 0.16 µm (95% CI -0.17-0.50; P = 0.31) for central retinal artery equivalent (CRAE), -0.21 µm (95% CI -0.56-0.14; P = 0.22) for central retinal vein equivalent (CRVE) and 0.0005 (95% CI -0.008-0.009; P = 0.55) for arteriole/venule ratio (AVR). Intragrader ICCs were 0.77 (95% CI 0.67-0.86) for CRAE, 0.90 (95% CI 0.780.96) for CRVE and 0.70 (0.55-0.83) for AVR. Intergrader ICCs were 0.75 (95% CI 0.64-0.85) for CRAE, 0.90 (95% CI 0.79-0.96) for CRVE and 0.68 (95% CI 0.55-0.82) for AVR.

CONCLUSIONS

Retinal microvascular diameter measurements are valid and present moderate to high intra and intergrader reproducibility in ELSA-Brasil.

Retinal vasculature and 5-year metabolic syndrome among women with gestational diabetes mellitus

BACKGROUND

Women with gestational diabetes mellitus (GDM) are at greater risk of metabolic syndrome (MetS). We studied the association between second-trimester retinal microvasculature and 5-year MetS incidence in women with GDM.

METHODS

A total of 142 mothers with GDM were recruited and followed up 5years after delivery. Retinal photography was performed at 26-28weeks gestation and metabolic outcomes were assessed at the 5-year postpartum follow-up visit. GDM and MetS were defined based on World Health Organization (WHO) guidelines and Adults Treatment Panel (ATP) III guidelines, respectively. Modified-Poisson regression was applied to study the association between second-trimester retinal microvasculature and incident 5-year maternal MetS, after adjusting for major confounders. Area under the curve (AUC) was calculated based on the final model.

RESULTS

Our prospective cohort reported a 9.2% incidence rate of 5-year MetS among women with GDM. After adjusting for maternal age, ethnicity, college degree, pre-pregnancy BMI and fasting glucose at 26-28week gestation, each 10μm widening in retinal venular caliber was associated with an increased relative risk of 1.6 (95% confidence interval [CI]: 1.0, 2.8) in incident MetS. In addition to traditional risks of pre-pregnancy BMI and fasting glucose level at 26-28week gestation, retinal venular caliber mildly increased the prediction of 5-year maternal MetS by 1.8%.

CONCLUSIONS

Second-trimester retinal venular widening was associated with incident 5-year maternal MetS in women with GDM. Our study suggests that mother with GDM at risk of future MetS development may have already presented retinal microvascular abnormalities during pregnancy.

The relationship of retinal vessel diameters and fractal dimensions with blood pressure and cardiovascular risk factors

BACKGROUND

This study aimed to investigate the correlation between quantitative retinal vascular parameters such as central retinal arteriolar equivalent (CRAE) and retinal vascular fractal dimension (D(f)), and cardiovascular risk factors in the Chinese Han population residing in the in islands of southeast China.

METHODOLOGY/PRINCIPLE FINDINGS

In this cross-sectional study, fundus photographs were collected and semi-automated analysis software was used to analyze retinal vessel diameters and fractal dimensions. Cardiovascular risk factors such as relevant medical history, blood pressure (BP), lipids, and blood glucose data were collected. Subjects had a mean age of 51.9 ± 12.0 years and included 812 (37.4%) males and 1,357 (62.6%) females. Of the subjects, 726 (33.5%) were overweight, 226 (10.4%) were obese, 272 (12.5%) had diabetes, 738 (34.0%) had hypertension, and 1,156 (53.3%) had metabolic syndrome. After controlling for the effects of potential confounders, multivariate analyses found that age (β = 0.06, P = 0.008), sex (β = 1.33, P = 0.015), mean arterial blood pressure (β = -0.12, P<0.001), high-sensitivity C-reactive protein (β = -0.22, P = 0.008), and CRVE (β = 0.23, P<0.001) were significantly associated with CRAE. Age (β = -0.0012, P < 0.001), BP classification (prehypertension: β = -0.0075, P = 0.014; hypertension: β = -0.0131, P = 0.002), and hypertension history (β = -0.0007, P = 0.009) were significantly associated with D(f).

CONCLUSIONS/SIGNIFICANCE

D(f) exhibits a stronger association with BP than CRAE. Thus, D(f) may become a useful indicator of cardiovascular risk.

Associations between metabolic syndrome and syndrome components and retinal microvascular signs in a rural Chinese population: the Handan Eye Study

BACKGROUND

Our purpose was to determine the relationship of metabolic syndrome (MetS) and its components with retinal microvascular abnormalities in a rural Chinese population.

METHODS

The Handan Eye Study, a population-based survey, recruited 6,830 (90.4 % of eligible) rural Chinese ≥30 years of age. A diagnosis of metabolic syndrome was based on the International Diabetes Federation definition. Retinal microvascular signs and arteriolar and venular diameters were assessed from fundus photographs by graders who were trained at the Retinal Vascular Imaging Centre, University of Melbourne.

RESULTS

After adjusting for age, gender, and smoking status, 5,519 participants with MetS, or with the specific components of large waist circumference, elevated blood pressure (BP), or elevated fasting blood glucose (FG), were more likely to have retinopathy, arteriovenous nicking, focal arteriolar narrowing, enhanced arteriolar wall reflex, and generalized retinal arteriolar narrowing than those without MetS or the corresponding component. Individuals with elevated triglycerides were significantly more likely to have arteriovenous nicking and retinopathy.

CONCLUSION

These results show that individual components of MetS are associated with different retinal microvascular signs and with changes in retinal arteriolar and venular diameters.