Combined effect of glycemic and blood pressure control on diabetic retinopathy among Chinese with type-2 diabetes mellitus

The causal effect of hypertension, intraocular pressure, and diabetic retinopathy: a Mendelian randomization study

Background

Previous research has indicated a vital association between hypertension, intraocular pressure (IOP), and diabetic retinopathy (DR); however, the relationship has not been elucidated. In this study, we aim to investigate the causal association of hypertension, IOP, and DR.

Methods

The genome-wide association study (GWAS) IDs for DR, hypertension, and IOP were identified from the Integrative Epidemiology Unit (IEU) Open GWAS database. There were 33,519,037 single-nucleotide polymorphisms (SNPs) and a sample size of 1,030,836 for DR. There were 16,380,466 SNPs and 218,754 participants in the hypertension experiment. There were 9,851,867 SNPs and a sample size of 97,465 for IOP. Univariable, multivariable, and bidirectional Mendelian randomization (MR) studies were conducted to estimate the risk of hypertension and IOP in DR. Moreover, causality was examined using the inverse variance weighted method, and MR results were verified by numerous sensitivity analyses.

Results

A total of 62 SNPs at the genome-wide significance level were selected as instrumental variables (IVs) for hypertension-DR. The results of univariable MR analysis suggested a causal relationship between hypertension and DR and regarded hypertension as a risk factor for DR [p = 0.006, odds ratio (OR) = 1.080]. A total of 95 SNPs at the genome-wide significance level were selected as IVs for IOP-DR. Similarly, IOP was causally associated with DR and was a risk factor for DR (p = 0.029, OR = 1.090). The results of reverse MR analysis showed that DR was a risk factor for hypertension (p = 1.27×10-10, OR = 1.119), but there was no causal relationship between DR and IOP (p > 0.05). The results of multivariate MR analysis revealed that hypertension and IOP were risk factors for DR, which exhibited higher risk scores (p = 0.001, OR = 1.121 and p = 0.030, OR = 1.124, respectively) than those in univariable MR analysis. Therefore, hypertension remained a risk factor for DR after excluding the interference of IOP, and IOP was still a risk factor for DR after excluding the interference of hypertension.

Conclusion

This study validated the potential causal relationship between hypertension, IOP, and DR using MR analysis, providing a reference for the targeted prevention of DR.

Development and evaluation of a risk prediction model for diabetes mellitus type 2 patients with vision-threatening diabetic retinopathy

Objective

This study aims to develop and evaluate a non-imaging clinical data-based nomogram for predicting the risk of vision-threatening diabetic retinopathy (VTDR) in diabetes mellitus type 2 (T2DM) patients.

Methods

Based on the baseline data of the Guangdong Shaoguan Diabetes Cohort Study conducted by the Zhongshan Ophthalmic Center (ZOC) in 2019, 2294 complete data of T2DM patients were randomly divided into a training set (n=1605) and a testing set (n=689). Independent risk factors were selected through univariate and multivariate logistic regression analysis on the training dataset, and a nomogram was constructed for predicting the risk of VTDR in T2DM patients. The model was evaluated using receiver operating characteristic (ROC) curves and area under the curve (AUC) in the training and testing datasets to assess discrimination, and Hosmer-Lemeshow test and calibration curves to assess calibration.

Results

The results of the multivariate logistic regression analysis showed that Age (OR = 0.954, 95% CI: 0.940-0.969, p = 0.000), BMI (OR = 0.942, 95% CI: 0.902-0.984, p = 0.007), systolic blood pressure (SBP) (OR =1.014, 95% CI: 1.007-1.022, p = 0.000), diabetes duration (10-15y: OR =3.126, 95% CI: 2.087-4.682, p = 0.000; >15y: OR =3.750, 95% CI: 2.362-5.954, p = 0.000), and glycated hemoglobin (HbA1C) (OR = 1.325, 95% CI: 1.221-1.438, p = 0.000) were independent risk factors for T2DM patients with VTDR. A nomogram was constructed using these variables. The model discrimination results showed an AUC of 0.7193 for the training set and 0.6897 for the testing set. The Hosmer-Lemeshow test results showed a high consistency between the predicted and observed probabilities for both the training set (Chi-square=2.2029, P=0.9742) and the testing set (Chi-square=7.6628, P=0.4671).

Conclusion

The introduction of Age, BMI, SBP, Duration, and HbA1C as variables helps to stratify the risk of T2DM patients with VTDR.

Systolic and Diastolic Blood Pressure Are Independent Risk Factors for Diabetic Retinopathy in Patients with Type 2 Diabetes

BACKGROUND AND AIMS

Diabetic retinopathy (DR) is a microvascular complication of diabetes and represents the leading cause of blindness in working-age adults. The aim of this study was to investigate the risk factors for DR in patients with type 2 diabetes (T2DM) with and without diabetic nephropathy (DN).

METHODS

A total of 160 patients with T2DM were included in the study. Photodocumented retinopathy status was determined according to the EURODIAB protocol. Renal function was determined using creatinine-based estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR). Binary univariate and multiple logistic regression analyses were performed to determine the main predictors of DR.

RESULTS

The prevalence of DR in this studied sample was 46.3%. No significant correlation was observed between DR and age, body mass index, serum lipids, and renal function. Binary logistic regression analysis (no DR/DR) showed that longer diabetes duration (p = 0.008), poor glycemic control (HbA1c) (p = 0.008), higher systolic blood pressure (p = 0.001), and diastolic blood pressure (p = 0.003) were the main predictors of DR in patients with T2DM. However, the influence of systolic blood pressure (AOR = 1.06, p = 0.004) and diastolic blood pressure (AOR = 1.12, p = 0.007) on DR development remained significant even after adjustment for diabetes duration and HbA1c.

CONCLUSIONS

Our results suggest that systolic and diastolic blood pressure are independent risk factors for DR in patients with T2DM.

Severity of diabetic retinopathy and its relationship with age at onset of diabetes mellitus in India: A multicentric study

Purpose:

To present clinical profile and risk factors of sight-threatening diabetic retinopathy (STDR) among people with age of onset of diabetes (AOD) <25 versus ≥25 years.

Methods:

A retrospective chart analysis of consecutive patients with diabetic retinopathy (DR) n = 654) treated at 14 eye care centers across India between 2018 and 2019 was performed. Patients were divided into two groups, Group 1: AOD <25 years and Group 2: AOD ≥25 years. DR and diabetic macular edema (DME) were classified using the International Clinical Classification of DR severity scale. STDR included severe nonproliferative DR (NPDR), proliferative DR (PDR), and moderate to severe DME. A multilevel mixed-effects model was used for comparison between two groups: 1) Patients with DR and AOD <25 years and 2) Patients with DR and AOD ≥25 years. Bivariate and multivariate regression analyses were used to evaluate risk factors between the two groups.

Results:

A total of 654 patients were included, 161 (307 eyes) in AOD <25 and 493 (927 eyes) in AOD >25 group. There was a higher prevalence of PDR with high-risk characteristics in AOD <25 group (24% vs. 12%) at baseline and 12-month follow-up (25% vs. 6%); P < 0.001. Systolic hypertension and poor glycemic control were risk factors in both groups, with no difference in these modifiable risk factors between groups.

Conclusion:

People with youth-onset DM are likely to present with severer form of STDR despite similar modifiable risk factors. Therefore, strict control of systolic blood pressure, glycemic status, and regular screening for DR are recommended to reduce the risk of STDR irrespective of the age of onset of diabetes.

Global and Regional Prevalence of Diabetic Retinopathy; A Comprehensive Systematic Review and Meta-analysis

PURPOSE

We conducted a systematic search to estimate DR prevalence in different age and gender groups, and to evaluate the determinants of heterogeneity in its prevalence.

METHODS

A systematic and comprehensive search from inception to August 10, 2020, was done in international databases, including Scopus, PubMed, Web of Science, Embase, and other data sources without any restriction to find cross-sectional studies related to the prevalence of DR.

RESULTS

Of 6399 studies, 90 articles with a sample size of 563460 individuals and 204189 diabetic patients were analyzed. The estimated pooled prevalence of DR in the diabetic population in general; in female and in male was 28.41% (95% CI: 25.98 to 30.84); 25.93% (95% CI: 23.54 to 28.31) and 28.95% (95% CI: 26.57 to 31.32); respectively and the prevalence of DR showed no inter-gender difference. The heterogeneity of the pooled prevalence according to I² was 99% (p < .001). According to the meta-regression results, the variables of WHO region (Coefficient of AMRO vs SEARO: 15.56; p: 0.002), age (Coefficient of above 60 years vs below 40 year: 18.67; p: 0.001), type of DR (Coefficient: 19.01; p < .001), and publication year (Coefficient: -0.60; p: 0.001) had a significant correlation with heterogeneity.

CONCLUSION

One third of diabetic patients suffered from DR, mostly NPDR. DR increased markedly after the age of 60 years, which could be due to the longer duration of diabetes. Age, WHO region, type of DR, and publication year affected the heterogeneity in the prevalence of DR.

Cardiorenal protection with SGLT2: Lessons from the cardiovascular outcome trials

Sodium glucose cotransporter 2 (SGLT2) inhibitors are a class of drugs that were primarily developed for the treatment of type 2 diabetes mellitus. However, these agents have shown to provide additional beneficial effects. We will discuss three main topics regarding the use of SGLT2 inhibitors: noncardiovascular effects, cardiovascular benefits, and novel clinical indications. Multiple clinical trials and preliminary studies across varying disciplines have shown that these agents exhibit cardiorenal-protective benefits, retinoprotective benefits, and may aid in weight loss without causing marked hypoglycemia. Therefore, these agents represent an avenue in clinical practice to manage comorbid conditions in the hyperglycemic patient. Because of their multifaceted effects and robust action, SGLT2 inhibitors represent therapy options for providers that not only provide beneficial clinical results but also reduce total patient drug burden.