Association of Retinopathy and Insulin Resistance: NHANES 2005-2008

Sex-based differences in the associations between abdominal obesity and diabetic retinopathy in diabetic patients with normal weight

Purpose

To investigate sex-specific differences in associations of abdominal obesity indexes, systemic factors, and diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM) subjects with normal body mass index (BMI).

Methods

This cross-sectional study comprised 653 T2DM subjects (402 women and 251 men) with normal BMI (18.5 kg/m2

Results

In the multivariate logistic regressions, the presence of any DR was associated with a longer duration of T2DM (OR = 1.07, p = 0.007) and higher HbA1c (OR = 1.40, p = 0.001) in women, while any DR was associated with younger age at T2DM diagnosis (OR = 0.94, p = 0.020) and higher HbA1c (OR = 1.29, p = 0.011) in men. For women, we identified a positive association between WC (OR = 1.07, p = 0.011), WHR (OR = 1.67, p = 0.002), and WHtR (OR = 1.57, p = 0.004) with any DR after adjusting for confounders, and the third tertiles of WC (OR = 2.29, p = 0.028), WHR (OR = 3.03, p = 0.003), and WHtR (OR = 2.84, p = 0.007) were at high risk of any DR. For men, there were no associations between abdominal obesity indexes and any DR in either continuous variables or categorical variables (all p > 0.05).

Main conclusions

There were sex differences in the relationships between WC, WHR, WHtR, and DR in this T2DM population with normal BMI. Our findings provide new insight into a sex-specific mechanism of DR and management of the condition.

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Key Words

• Abdominal obesity
• Body mass index
• Diabetic retinopathy
• Sex differences

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Affiliation(s)

Yuan Liu State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Kaiqun Liu State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Liqiong Xie State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Chengguo Zuo State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Lanhua Wang State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Wenyong Huang State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China

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Metabolomics combined with intestinal microbiota reveals the mechanism of compound Qilian tablets against diabetic retinopathy

Background

Diabetic retinopathy (DR) is one of the common chronic complications of diabetes mellitus, which has developed into the leading cause of irreversible visual impairment in adults worldwide. Compound Qilian tablets (CQLT) is a traditional Chinese medicine (TCM) developed for treating DR, but its mechanism is still unclear. This study explored the mechanism of action of CQLT in treating DR through metabolomics and intestinal microbiota.

Methods

Histopathologic examination of the pancreas and retina of Zucker diabetic fatty (ZDF) rats and immunohistochemistry were used to determine the expression levels of retinal nerve damage indicators ionized calcium binding adaptor molecule-1 (Iba-1) and glial fibrillary acidic protein (GFAP). Rat fecal samples were tested by LC-MS metabolomics to search for potential biomarkers and metabolic pathways for CQLT treatment of DR. Characteristic nucleic acid sequences of rat intestinal microbiota from each group were revealed using 16S rDNA technology to explore key microbes and related pathways for CQLT treatment of DR. At the same time, we investigated the effect of CQLT on the gluconeogenic pathway.

Results

After CQLT intervention, islet cell status was improved, Iba-1 and GFAP expression were significantly decreased, and abnormal retinal microvascular proliferation and exudation were ameliorated. Metabolomics results showed that CQLT reversed 20 differential metabolites that were abnormally altered in DR rats. Intestinal microbiota analysis showed that treatment with CQLT improved the abundance and diversity of intestinal flora. Functional annotation of metabolites and intestinal flora revealed that glycolysis/gluconeogenesis, alanine, aspartate and glutamate metabolism, starch and sucrose metabolism were the main pathways for CQLT in treating DR. According to the results of correlation analysis, there were significant correlations between Iba-1, GFAP, and intestinal microbiota and metabolites affected by CQLT. In addition, we found that CQLT effectively inhibited the gluconeogenesis process in diabetic mice.

Conclusion

In conclusion, CQLT could potentially reshape intestinal microbiota composition and regulate metabolite profiles to protect retinal morphology and function, thereby ameliorating the progression of DR.

Association of systemic and demographic risk factors with prevalence of retinopathy in US adults with prediabetes

BACKGROUND/OBJECTIVES

To investigate the relative contribution of systemic risk factors to retinopathy in prediabetes using a nationally representative cohort in the US.

SUBJECTS/METHODS

A group of 2098 participants aged ≥40 years with available HbA1c and gradable retinal images from the National Health and Nutrition Examination Survey 2005-2008 were included in this retrospective cross-sectional analysis. Participants were stratified into control, prediabetes, and diabetes groups based on HbA1c and anti-hyperglycaemic medication use. Logistic regression was used to assess the contribution of potential systemic risk factors to retinopathy prevalence.

RESULTS

The prevalence of retinopathy in the prediabetes group was 7.69%. Multivariable logistic regression revealed an inverse association of female sex (OR, 0.25; 95% CI, 0.08-0.74; p = 0.02), eGFR (OR, 0.98; 95% CI, 0.96-1.00; p = 0.04), and fasting glucose levels (OR, 0.92; 95% CI 0.87-0.98; p = 0.02) with retinopathy in individuals with prediabetes and a positive association with a Race/Ethnicity classification of "Other" (OR, 6.05; 95% CI, 1.65-22.1; p = 0.01). Comparison of ORs between groups indicated differential associations of "Other" race, fasting glucose, and C-reactive protein (CRP) with retinopathy in prediabetes compared with diabetes.

CONCLUSIONS

The prevalence of retinopathy among individuals with prediabetes in the NHANES database is similar to other studies. Our findings suggest that nonglycemic metabolic risk factors may be especially relevant to the risk of retinopathy in prediabetes and extend the previously suggested protective effect of female sex on retinopathy in diabetes to prediabetes. The increased odds of retinopathy in underrepresented racial/ethnic groups in the setting of prediabetes also have implications for risk assessment in this population.

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.

Insulin resistance in the retina: possible implications for certain ocular diseases

Insulin resistance (IR) is becoming a worldwide medical and public health challenge as an increasing prevalence of obesity and metabolic disorders. Accumulated evidence has demonstrated a strong relationship between IR and a higher incidence of several dramatically vision-threatening retinal diseases, including diabetic retinopathy, age-related macular degeneration, and glaucoma. In this review, we provide a schematic overview of the associations between IR and certain ocular diseases and further explore the possible mechanisms. Although the exact causes explaining these associations have not been fully elucidated, underlying mechanisms of oxidative stress, chronic low-grade inflammation, endothelial dysfunction and vasoconstriction, and neurodegenerative impairments may be involved. Given that IR is a modifiable risk factor, it may be important to identify patients at a high IR level with prompt treatment, which may decrease the risk of developing certain ocular diseases. Additionally, improving IR through the activation of insulin signaling pathways could become a potential therapeutic target.

Magnesium Depletion Score Predicts Diabetic Retinopathy Risk among Diabetes: Findings from NHANES 2005-2018

Magnesium is essential for material and energy metabolism. The magnesium depletion score (MDS) is recognized as a more valuable and reliable predictor of body magnesium status than any other clinical used markers such as serum and urine magnesium. However, research on the relationship between MDS and diabetic retinopathy (DR) is limited. As a result, the current study sought to assess this issue in diabetic samples from a large population-based database in the United States. Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. MDS was calculated, and multivariate logistic regression analysis was applied to evaluate the presence of association between variables and DR risk. A total of 4308 participants was comprised in this study. Samples with DR consumed less magnesium (259.1 ± 113.6 vs 269.8 ± 113.2 mg, P < 0.001), and their MDS levels differed significantly from non-DR participants (P < 0.001). Increased dietary magnesium was linked to a lower incidence of DR (all P for trend < 0.05), and patients with a high level of MDS were more prone to DR (P = 0.001). Furthermore, subgroup analysis revealed that high (Q3) amount magnesium supplements was associated with lower DR risk when MDS was none to low or middle level (both P = 0.02). Our results indicated that MDS levels are associated with DR risk and that magnesium supplementation is benefit to DR prevention.

Ocular manifestations of central insulin resistance

Central insulin resistance, the diminished cellular sensitivity to insulin in the brain, has been implicated in diabetes mellitus, Alzheimer's disease and other neurological disorders. However, whether and how central insulin resistance plays a role in the eye remains unclear. Here, we performed intracerebroventricular injection of S961, a potent and specific blocker of insulin receptor in adult Wistar rats to test if central insulin resistance leads to pathological changes in ocular structures. 80 mg of S961 was stereotaxically injected into the lateral ventricle of the experimental group twice at 7 days apart, whereas buffer solution was injected to the sham control group. Blood samples, intraocular pressure, trabecular meshwork morphology, ciliary body markers, retinal and optic nerve integrity, and whole genome expression patterns were then evaluated. While neither blood glucose nor serum insulin level was significantly altered in the experimental or control group, we found that injection of S961 but not buffer solution significantly increased intraocular pressure at 14 and 24 days after first injection, along with reduced porosity and aquaporin 4 expression in the trabecular meshwork, and increased tumor necrosis factor α and aquaporin 4 expression in the ciliary body. In the retina, cell density and insulin receptor expression decreased in the retinal ganglion cell layer upon S961 injection. Fundus photography revealed peripapillary atrophy with vascular dysregulation in the experimental group. These retinal changes were accompanied by upregulation of pro-inflammatory and pro-apoptotic genes, downregulation of anti-inflammatory, anti-apoptotic, and neurotrophic genes, as well as dysregulation of genes involved in insulin signaling. Optic nerve histology indicated microglial activation and changes in the expression of glial fibrillary acidic protein, tumor necrosis factor α, and aquaporin 4. Molecular pathway architecture of the retina revealed the three most significant pathways involved being inflammation/cell stress, insulin signaling, and extracellular matrix regulation relevant to neurodegeneration. There was also a multimodal crosstalk between insulin signaling derangement and inflammation-related genes. Taken together, our results indicate that blocking insulin receptor signaling in the central nervous system can lead to trabecular meshwork and ciliary body dysfunction, intraocular pressure elevation, as well as inflammation, glial activation, and apoptosis in the retina and optic nerve. Given that central insulin resistance may lead to neurodegenerative phenotype in the visual system, targeting insulin signaling may hold promise for vision disorders involving the retina and optic nerve.

Association of mid-life cerebral small vessel disease with diabetic retinopathy in type 2 diabetes in an Indian population

PURPOSE

Prevalence of cerebral small vessel disease (SVD) in elderly patients with diabetic retinopathy (DR) is higher than in those without DR. We determined the prevalence and severity of SVD in middle-aged patients with DR and compared it with those without DR (NODR) in a subset of the Indian population. We feel this information is critical with evolving trends of an increasing incidence of stroke at younger ages.

METHOD

Institution-based analytical cross-sectional study with 88 middle-aged type 2 diabetes patients; 44 in each group with <10 years diabetes duration, <8% HbA1C value, and with no history of cardiovascular disease. The presence and severity of SVD were determined by magnetic resonance imaging (MRI).

RESULT

Prevalence of SVD was 59.1% among study participants; 70.5% in DR and 47.7% in NODR (p = .03). Significantly increased SVD score (p = .008), high SVD score (p = .030), and white matter hyperintensity (WMH) load (p = .017) were observed in DR compared to NODR. There was no difference in the load of lacune and microbleed. SVD score did not differ according to the severity of DR (p = .395). The location-wise study of MRI revealed a significantly higher SVD load at the centrum semiovale in DR than in NODR (p = .014). We observed a 2.6 times greater chance of SVD (Odds ratio: 2.6, 95% CI 1.1-6.3) and a 9.6 times greater chance of high SVD score (Odds ratio: 9.6, 95% CI 1.1-80.0) in DR compared to NODR.

CONCLUSION

Significantly higher burden of SVD in DR was observed, particularly affecting the centrum semiovale suggesting an association of mid-life SVD with DR in this population.

High remnant cholesterol level is relevant to diabetic retinopathy in type 2 diabetes mellitus

Background

Diabetic retinopathy (DR) is the primary oculopathy causing blindness in diabetic patients. Currently, there is increasing interest in the role of lipids in the development of diabetic retinopathy, but it remains controversial. Remnant cholesterol (RC) is an inexpensive and easily measurable lipid parameter; however, the relationship between RC and DR in type 2 diabetes mellitus (T2DM) has not been elucidated. This research investigates the relevance between RC levels and DR severity while building a risk prediction model about DR.

Methods

In this single-centre retrospective cross-sectional study. Each hospitalised T2DM patient had no oral lipid-lowering drugs in the past three months, and coronary angiography showed epicardial coronary artery stenosis of less than 50% and completed seven-field stereo photographs, fluorescein fundus angiography, and optical coherence tomography detection. The RC value is calculated according to the internationally recognised formula. Binary logistic regression was used to correct confounding factors, and the receiver operating characteristic (ROC) analysis was used to identify risk factors and assess the nomogram’s diagnostic efficiency.

Results

A total of 456 T2DM patients were included in the study. The RC levels in the DR team was higher [0.74 (0.60–1.12) mmo/l vs 0.54 (0.31–0.83) mmol/l P < 0.001] in the non-DR team. After adjusting for confounding elements, RC levels are still associated with DR risk (OR = 5.623 95%CI: 2.996–10.556 P < 0.001). The ratio of DR in every stage (except mild non-proliferative diabetic retinopathy) and DME in the high RC level team were further increased compared to the low-level team (all P < 0.001). After ROC analysis, the overall risk of DR was predicted by a nomogram constructed for RC, diabetes duration, and the neutrophil-lymphocyte ratio as 0.758 (95%CI 0.714–0.802 P < 0.001).

Conclusions

High RC levels may be a potential risk factor for diabetic retinopathy, and the nomogram does better predict DR. Despite these essential findings, the limitation of this study is that it is single-centred and small sample size analysis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01621-7.

Common pathways in dementia and diabetic retinopathy: understanding the mechanisms of diabetes-related cognitive decline

Type 2 diabetes (T2D) is associated with multiple comorbidities, including diabetic retinopathy (DR) and cognitive decline, and T2D patients have a significantly higher risk of developing Alzheimer's disease (AD). Both DR and AD are characterized by a number of pathological mechanisms that coalesce around the neurovascular unit, including neuroinflammation and degeneration, vascular degeneration, and glial activation. Chronic hyperglycemia and insulin resistance also play a significant role, leading to activation of pathological mechanisms such as increased oxidative stress and the accumulation of advanced glycation end-products (AGEs). Understanding these common pathways and the degree to which they occur simultaneously in the brain and retina during diabetes will provide avenues to identify T2D patients at risk of cognitive decline.

Retinal Neurodegeneration in Diabetes: an Emerging Concept in Diabetic Retinopathy

PURPOSE OF REVIEW

Diabetic retinopathy (DR), the leading cause of blindness in working-aged adults, remains clinically defined and staged by its vascular manifestations. However, early retinal neurodegeneration may precede vascular pathology, suggesting that this neuronal damage may contribute to disease pathogenesis and represent an independent target for intervention. This review will discuss the evidence and implications for diabetic retinal neurodegeneration.

RECENT FINDINGS

A growing body of literature has identified progressive retinal thinning and visual dysfunction in patients with diabetes even prior to the onset of DR, though advances in retinal vascular imaging suggest that vascular remodeling and choroidal changes occur during these early stages as well. Animal models of diabetes and in vitro studies have also suggested that diabetes may directly affect the retinal neural and glial tissue, providing support to the concept that diabetic retinal neurodegeneration occurs early in the disease and suggesting potentially relevant molecular pathways. Diabetic retinal neurodegeneration may represent a "preclinical" manifestation of diabetic retinal disease and remains an active area of investigation. As the natural history and molecular mechanisms become increasingly understood, it may lead to upcoming developments in not only the treatment options but also the clinical definition of DR.

Emerging Roles of Dyslipidemia and Hyperglycemia in Diabetic Retinopathy: Molecular Mechanisms and Clinical Perspectives

Diabetic retinopathy (DR) is a significant cause of vision loss and a research subject that is constantly being explored for new mechanisms of damage and potential therapeutic options. There are many mechanisms and pathways that provide numerous options for therapeutic interventions to halt disease progression. The purpose of the present literature review is to explore both basic science research and clinical research for proposed mechanisms of damage in diabetic retinopathy to understand the role of triglyceride and cholesterol dysmetabolism in DR progression. This review delineates mechanisms of damage secondary to triglyceride and cholesterol dysmetabolism vs. mechanisms secondary to diabetes to add clarity to the pathogenesis behind each proposed mechanism. We then analyze mechanisms utilized by both triglyceride and cholesterol dysmetabolism and diabetes to elucidate the synergistic, additive, and common mechanisms of damage in diabetic retinopathy. Gathering this research adds clarity to the role dyslipidemia has in DR and an evaluation of the current peer-reviewed basic science and clinical evidence provides a basis to discern new potential therapeutic targets.

Awareness of diabetic retinopathy among Saudis with diabetes type 2 in Riyadh city

Objective:

To assess awareness of diabetic retinopathy (DR) for Saudis with diabetes mellitus (DM) type 2 in Riyadh City.

Methods:

A cross-sectional study that used self-administered questionnaires conducted in primary healthcare centers in Riyadh City between October and December 2019.

Results:

There were 267 Saudi participants with diabetes mellitus type 2 visiting primary healthcare clinics. (52.4%) were aged 40 years or above at time of diagnosis with diabetes. (73%) had diabetes for at least 5 years. Most of the participants have a good blood glucose control and they do home measurements. In regard to DR, (64.4%) of participants had no subjective or objective indicators of retinopathy, and (70%) had visited ophthalmology clinics. Majority of the participants were advised about DR or referred to an ophthalmologist by their primary physician, with the percentages being (64.8%) and (59.6%), respectively. Regarding other risk factors of DR, (19.5%) had a family history of DR, (23.2%) of participant are smokers and (41.6%) were hypertensives. Majority of the participants were aware about all the aspects of DR, its consequences, and appropriate management except the laser therapy. In terms of area of living and education respondents, who lived in the center of Riyadh City and the secondary level or less educated participants had the lowest level of education.

Conclusions:

Awareness of DR is acceptable but should not lead this information to reduced awareness and educational programs. Outreach researchers' efforts should cover other directions instead awareness of DR.