Body mass index and retinopathy in Asian populations with diabetes mellitus

Prevalence of diabetic retinopathy and its risk factors in rural patients with type 2 diabetes referring to Beijing Huairou Hospital, China

BACKGROUND

China has the largest population of diabetic patients worldwide. A diverse population and regional discrepancy in access to health care and diabetes management may lead to unique risk factors for diabetic retinopathy (DR) in different regions of China. This study aimed to evaluate the prevalence and risk factors of DR in rural patients with type 2 diabetes.

METHODS

This hospital-based cross-sectional study recruited a sample of 704 type 2 diabetic patients from rural areas referred to Beijing Huairou Hospital, China, from June 1, 2022, to June 1, 2023. The medical history, demographic information, and results of laboratory examinations of patients were collected and analyzed. The diagnosis of DR were performed by experienced ophthalmologists using mydriatic fundus photography.

RESULTS

Out of all patients, 53.8% were male and 46.2% were female. The mean age of patients and duration of diabetes were 54.9 ± 13.0 and 6.2 ± 4.5 years, respectively. The DR prevalence was 16.8%. The independent risk factors for DR in multivariate analysis were diabetes duration > 10 years (OR = 9.16, 95%CI = 5.49-15.30), fasting plasma glucose ≥ 7.2 mmol/L (OR = 3.25, 95%CI = 1.42-7.42), glycosylated hemoglobin ≥ 7% (OR = 6.49, 95%CI = 2.59-16.23), hypertension (OR = 1.59, 95%CI = 1.05-2.40), hyperlipidemia (OR = 2.16, 95%CI = 1.30-3.59), diabetic nephropathy (OR = 1.95, 95%CI = 1.17-3.23), high uric acid level (OR = 3.57, 95%CI = 1.56-8.15), high albumin to creatinine ratio (OR = 2.48, 95%CI = 1.06-5.82), and insulin treatment (OR = 1.79, 95%CI = 1.12-2.88).

CONCLUSIONS

This study evaluated the DR prevalence and its associated risk factors among type 2 diabetic patients from rural areas in Beijing's Huairou District, China. Paying attention to these risk factors may be useful in screening high-risk diabetic patients for DR and adopting early preventive and therapeutic interventions.

Association of urinary creatinine excretion and body mass index with diabetic retinopathy in patients with type 2 diabetes

This study aimed to determine whether urinary creatinine excretion rate (CER), a marker of muscle mass, is associated with diabetic retinopathy in individuals with type 2 diabetes and to ascertain whether this putative association depends on body mass index (BMI). This cross sectional study evaluated 2035 individuals with type 2 diabetes. Twenty-four-hour urine was collected. Individuals with diabetic retinopathy had lower CER and BMI values than those without. Patients in higher CER quartiles had higher BMI values and a lower prevalence of diabetic retinopathy. A significant relationship between CER and diabetic retinopathy persisted, even after adjusting for traditional risk factors, including glycated hemoglobin, diabetes duration, and hypertension, in multivariable analysis. Further adjustment for BMI did not significantly alter the association between CER and diabetic retinopathy. This study suggests that CER is inversely associated with diabetic retinopathy in individuals with type 2 diabetes, and this association is independent of BMI.

Major adverse events in youth-onset type 1 and type 2 diabetes: The SEARCH and TODAY studies

AIMS

To determine contemporary incidence rates and risk factors for major adverse events in youth-onset T1D and T2D.

METHODS

Participant interviews were conducted once during in-person visits from 2018 to 2019 in SEARCH (T1D: N = 564; T2D: N = 149) and semi-annually from 2014 to 2020 in TODAY (T2D: N = 495). Outcomes were adjudicated using harmonized, predetermined, standardized criteria.

RESULTS

Incidence rates (events per 10,000 person-years) among T1D participants were: 10.9 ophthalmologic; 0 kidney; 11.1 nerve, 3.1 cardiac; 3.1 peripheral vascular; 1.6 cerebrovascular; and 15.6 gastrointestinal events. Among T2D participants, rates were: 40.0 ophthalmologic; 6.2 kidney; 21.2 nerve; 21.2 cardiac; 10.0 peripheral vascular; 5.0 cerebrovascular and 42.8 gastrointestinal events. Despite similar mean diabetes duration, complications were higher in youth with T2D than T1D: 2.5-fold higher for microvascular, 4.0-fold higher for macrovascular, and 2.7-fold higher for gastrointestinal disease. Univariate logistic regression analyses in T1D associated age at diagnosis, female sex, HbA1c and mean arterial pressure (MAP) with microvascular events. In youth-onset T2D, composite microvascular events associated positively with MAP and negatively with BMI, however composite macrovascular events associated solely with MAP.

CONCLUSIONS

In youth-onset diabetes, end-organ events were infrequent but did occur before 15 years diabetes duration. Rates were higher and had different risk factors in T2D versus T1D.

Mendelian randomization analysis reveals a causal effect of Streptococcus salivarius on diabetic retinopathy through regulating host fasting glucose

Diabetic retinopathy (DR) is one of leading causes of vision loss in adults with increasing prevalence worldwide. Increasing evidence has emphasized the importance of gut microbiome in the aetiology and development of DR. However, the causal relationship between gut microbes and DR remains largely unknown. To investigate the causal associations of DR with gut microbes and DR risk factors, we employed two-sample Mendelian Randomization (MR) analyses to estimate the causal effects of 207 gut microbes on DR outcomes. Inputs for MR included Genome-wide Association Study (GWAS) summary statistics of 207 taxa of gut microbes (the Dutch Microbiome Project) and 21 risk factors for DR. The GWAS summary statistics data of DR was from the FinnGen Research Project. Data analysis was performed in May 2023. We identified eight bacterial taxa that exhibited significant causal associations with DR (FDR < 0.05). Among them, genus Collinsella and species Collinsella aerofaciens were associated with increased risk of DR, while the species Bacteroides faecis, Burkholderiales bacterium_1_1_47, Ruminococcus torques, Streptococcus salivarius, genus Burkholderiales_noname and family Burkholderiales_noname showed protective effects against DR. Notably, we found that the causal effect of species Streptococcus salivarius on DR was mediated through the level of host fasting glucose, a well-established risk factor for DR. Our results reveal that specific gut microbes may be causally linked to DR via mediating host metabolic risk factors, highlighting potential novel therapeutic or preventive targets for DR.

Excessive generalized and visceral adiposity is associated with a higher prevalence of diabetic retinopathy in Caucasian patients with type 2 diabetes

BACKGROUND AND AIMS

Type 2 Diabetes Mellitus (T2D) has heterogeneous clinical phenotypes related to different risk of developing diabetes complications. We investigated the correlation between generalized and abdominal adiposity and the prevalence of both micro- and macrovascular complications in Caucasian patients with T2D.

METHODS AND RESULTS

We evaluated 769 individuals with T2D consecutively referred to our diabetes center. Body mass index (BMI), waist circumference (WC), waist to hip (W/H) ratio, glycated hemoglobin (HbA1c), systolic and diastolic blood pressure, lipid profile, smoking habit, diabetes therapy, and micro- and macrovascular complications were recorded. Patients were divided into three groups based on BMI and WC: non-obese with normal WC (nWC, n = 220), non-obese with excess of abdominal fat (AF, n = 260) and obese (Ob, n = 289). We found that nWC, compared with AF and Ob individuals, were predominantly males (p<0.01), had lower HbA1c (p<0.01), diastolic blood pressure (p<0.01), triglycerides (p<0.01), and showed a significantly lower prevalence of diabetic retinopathy (DR) (p = 0.01). The rate of proliferative DR was significantly higher in Ob (13.2 %) compared to the other groups (p = 0.03). Multivariate analyses showed a significantly decreased prevalence of DR in nWC compared to both AF (OR 0.58, 95 CI 0.34-0.96; p = 0.03) and Ob (OR 0.57, 95 CI 0.33-0.98; p = 0.04) individuals. Conversely, DR was associated, mainly in women, to higher WC and W/H ratio. The prevalence of the other diabetes-related complications was similar among the studied groups.

CONCLUSIONS

In our population, nWC subjects showed a lower prevalence of DR. An increased generalized and abdominal adiposity was associated to a higher prevalence of DR, especially among females.

Association of anthropometric parameters as a risk factor for development of diabetic retinopathy in patients with diabetes mellitus

OBJECTIVE

To study the relationship of body fat distribution in patients with diabetes mellitus (DM), and its long-term complications like diabetic retinopathy (DR), in Indian population.

METHODS

This was a prospective, cross-sectional observational study involving 1773 subjects diagnosed with DM and 1778 age and gender-matched individuals. The patients with DM were assessed for the presence and severity of DR. Severe non-proliferative DR and proliferative DR were categorised as sight threatening DR (STDR). Anthropometric parameters, i.e., neck circumference (NC); mid-upper arm circumference (MAC); waist circumference (WC); hip circumference (HC); mid-thigh circumference (MTC) and body mass index (BMI) were measured using standardised technique.

RESULTS

The mean age was 59.33 ± 9.32 for DM group, and 66.03 ± 11.04 for non-DM group. DM group showed significantly greater NC, WC, and MTC and significantly reduced MAC and weight. HC and BMI were comparable between the groups. There was a significant positive correlation of MAC and WC (with any level of DR) and MAC, WC, and weight (for STDR); and a significant negative correlation of HC and MTC (with any level of DR) and NC, HC, MTC, and BMI (for STDR). Multiple logistic regression analysis confirmed that WC was the single most important predictor for any level of DR and STDR.

CONCLUSIONS

Association of body fat distribution with DM and DR appears multifactorial. However, central obesity signified by waist circumference appears to be the significant risk related to the development of DR and STDR in Indian population.

Association between abdominal obesity and diabetic retinopathy in patients with diabetes mellitus: A systematic review and meta-analysis

OBJECTIVE

Previous studies have reported different opinions regarding the association between abdominal obesity and diabetic retinopathy (DR) in patients with diabetes mellitus (DM). In this study, we aimed to investigate this problem through a systematic review and meta-analysis to provide a basis for clinical interventions.

METHODS

A comprehensive search was conducted in the PubMed, Embase, and Web of Science databases up to May 1, 2022, for all eligible observational studies. Standardized mean differences (SMD) and 95% confidence intervals (CI) were evaluated using a random-effects model in the Stata software. We then conducted, publication bias assessment, heterogeneity, subgroup and sensitivity analyses.

RESULTS

A total of 5596 DR patients and 17907 non-DR patients were included from 24 studies. The results of the meta-analysis of abdominal obesity parameters showed statistically significant differences between DR and non-DR patients in both type 1 and type 2 diabetes. Waist circumference (WC) was higher in patients with DR than in the non-DR patients. In the waist-hip ratio (WHR) subgroup, the level of WHR was higher in patients with DR than that in non-DR patients. The association between abdominal obesity and mild to moderate nonproliferative DR or vision-threatening DR groups did not show any statistical difference. Subgroup analysis according to ethnicity showed that Caucasians had higher levels of combined abdominal obesity parameters than Asians.

CONCLUSION

We found that abdominal obesity measured by WC and WHR is associated with DR in patients with type 1 and type 2 diabetes. This association is stronger in Caucasians than in Asians, where isolated abdominal obesity might be more related to DR. However, no correlation was found between abdominal obesity and varying degrees of diabetic retinopathy. Further prospective cohort studies with larger sample sizes are yet to be conducted to clarify our findings.

Geriatric nutritional risk index is associated with retinopathy in patients with type 2 diabetes

The geriatric nutritional risk index (GNRI) is a nutrition-related risk assessment tool and has been used in various clinical settings. The relationship between body mass index (BMI) and the associated risk of diabetic retinopathy (DR) remains inconclusive. We aimed to evaluate the association between GNRI and DR in patients with type 2 diabetes. We included a total of 1359 patients with type 2 diabetes who followed up in our diabetes clinic and underwent fundus photographic examinations from August 2006 to February 2014. DR was assessed by retinal ophthalmologists using comprehensive ophthalmologic examinations. Patients were divided into tertiles according to their GNRI category. Patients in a lower GNRI tertile tended to have a higher proportion of nonproliferative DR (NPDR) and proliferative DR (PDR) compared with those in the other tertiles. The risk of PDR was higher in patients included in GNRI tertile 1 (Odds ratio (OR) 2.252, 95% Confidence Interval (CI) 1.080–4.823, P = 0.033) and GNRI tertile 2 (OR 2.602, 95% CI 1.323–5.336, P = 0.007) compared with those in GNRI tertile 3. In patients with lower GNRIs, the prevalence of DR was higher than in those with higher GNRIs. When GNRI was compared with BMI using the area under the curve, overall accuracy was high in GNRI. The risk of PDR was high in patients with low GNRI and there is an inverse association between GNRI scores and prevalence of DR. GNRI might be a useful tool to predict DR in patients with type 2 diabetes.

Obesity and Diabetic Complications: A Study from the Nationwide Diabetes Report of the National Program for Prevention and Control of Diabetes (NPPCD-2021) Implications for Action on Multiple Scales

BACKGROUND

Obesity plays a major role in the pathogenesis and development of macro- and microvascular complications of type 2 diabetes (T2D) and type 1 diabetes (T1D). We aimed to assess the association between obesity and macrovascular and microvascular complications of diabetes.

METHODS

This study consisted of 111,830 patients (age range: 1-106) with diabetes including 10,641 T1D (3187 obese [38.2% men] and 7454 non-obese [45.5% men]) and 101,189 T2D (51,873 obese [27.5% men] and 49,316 non-obese [33.4% men]) from the National Program for Prevention and Control of Diabetes (NPPCD-2021) in Iran, who attended academic tertiary care outpatient clinics from February 2016 to April 2021. A pooled logistic regression model was used to examine the association between obesity and diabetic complications.

RESULTS

Among patients with T1D, a significant association was found between obesity and cardiovascular disease (CVD), neuropathy, nephropathy and retinopathy (OR= 1.75, 1.56, 1.80 and 1.92, P-value= 0.001, 0.004, 0.001 and <0.001, respectively). In T2D, a statistically significant association was found between obesity and CVD, neuropathy and nephropathy (OR= 1.63, 1.98, 1.21, respectively, P-values <0.001).

CONCLUSION

Obesity was independently associated with CVD, neuropathy and nephropathy in patients with T1D and T2D and with retinopathy only in T1D, to different degrees. The association between obesity and retinopathy and neuropathy was the strongest among T1D and T2D, respectively. Findings from this study suggest that obesity affects diabetic complications differently among the two types of diabetes, in terms of epidemiology and pathophysiology. This signifies the importance of different preventive and therapeutic approaches to obesity in T1D compared to T2D, on a national and global scale.

Long-term prediction models for vision-threatening diabetic retinopathy using medical features from data warehouse

We sought to evaluate the performance of machine learning prediction models for identifying vision-threatening diabetic retinopathy (VTDR) in patients with type 2 diabetes mellitus using only medical data from data warehouse. This is a multicenter electronic medical records review study. Patients with type 2 diabetes screened for diabetic retinopathy and followed-up for 10 years were included from six referral hospitals sharing same electronic medical record system (n = 9,102). Patient demographics, laboratory results, visual acuities (VAs), and occurrence of VTDR were collected. Prediction models for VTDR were developed using machine learning models. F1 score, accuracy, specificity, and area under the receiver operating characteristic curve (AUC) were analyzed. Machine learning models revealed F1 score, accuracy, specificity, and AUC values of up 0.89, 0.89.0.95, and 0.96 during training. The trained models predicted the occurrence of VTDR at 10-year with F1 score, accuracy, and specificity up to 0.81, 0.70, and 0.66, respectively, on test set. Important predictors included baseline VA, duration of diabetes treatment, serum level of glycated hemoglobin and creatinine, estimated glomerular filtration rate and blood pressure. The models could predict the long-term occurrence of VTDR with fair performance. Although there might be limitation due to lack of funduscopic findings, prediction models trained using medical data can facilitate proper referral of subjects at high risk for VTDR to an ophthalmologist from primary care.

The Prevalence and Risk Factors of Diabetic Retinopathy: Screening and Prophylaxis Project in 6 Provinces of China

PURPOSE

To investigate the prevalence and associated factors of diabetic retinopathy (DR) and advanced DR in Chinese adults with diabetes mellitus (DM).

PATIENTS AND METHODS

A cross-sectional study was performed on 4831 diabetic patients from 24 hospitals from April 2018 to July 2020. Non-mydriatic fundus of patients were interpreted by an artificial intelligence (AI) system. Fundus photos that were unsuitable for AI interpretation were interpreted by two ophthalmologists trained by one expert ophthalmologist at Beijing Tongren Hospital. Medical history, height, weight, body mass index (BMI), glycosylated hemoglobin (HbA1c), blood pressure, and laboratory examinations were recorded.

RESULTS

A total of 4831 DM patients were included in this study. The prevalence of DR and advanced DR in the diabetic population was 31.8% and 6.6%, respectively. In multiple logistic regression analysis, male (odds ratio [OR], 1.39), duration of diabetes (OR, 1.05), HbA1c (OR, 1.11), farmer (OR, 1.39), insulin treatment (OR, 1.61), region (northern, OR, 1.78; rural, OR, 6.96), and presence of other diabetic complications (OR: 2.03) were associated with increased odds of DR. The factors associated with increased odds of advanced DR included poor glycemic control (HbA1c >7.0%) (OR, 2.58), insulin treatment (OR, 1.73), longer duration of diabetes (OR, 3.66), rural region (OR, 4.84), and presence of other diabetic complications (OR, 2.36), but overweight (BMI > 25 kg/m²) (OR, 0.61) was associated with reduced odds of advanced DR.

CONCLUSION

This study shows that the prevalence of DR is very high in Chinese adults with DM, highlighting the necessity of early diabetic retinal screening.

Association between Systolic Blood Pressure and Diabetic Retinopathy in Both Hypertensive and Normotensive Patients with Type 2 Diabetes: Risk Factors and Healthcare Implications

A common diabetes-related microvascular complication is diabetic retinopathy (DR), yet associations between blood pressure (BP) and risks for DR in diabetic patients with normal BP received inadequate attention. This may lead to 'clinical inertia' in early DR prevention. We aimed to assess whether the extent to which systolic BP levels were associated with DR in patients with type 2 diabetes (T2DM) and normal BP were similar to that in those with concurrent hypertension. Data were collected from patients with T2DM attending ophthalmic check-up with primary care referral (n = 2510). BP measurements, clinical laboratory tests, and dilated fundus examination were conducted according to gold standard of diagnosis and routine clinical procedure. Of all subjects, over 40% were normotensive and one fifth were clinically diagnosed with DR. Systolic BP levels increased across DR categories of escalated severity irrespective of the coexistence of hypertension. Ordinal logistic regression analysis showed that an increased systolic BP was independently and significantly associated with DR (adjusted odds ratio [aOR] = 1.020, p < 0.001 for hypertensives; aOR = 1.019, p = 0.018 for normotensives), after adjusting for diabetes duration, sex, lifestyles, and haemoglobin A1c levels. Regular monitoring of systolic BP should not be neglected in routine diabetes management even when BP falls within the normal range. (200 words).

Higher Serum Uric Acid Levels Are Associated With an Increased Risk of Vision-Threatening Diabetic Retinopathy in Type 2 Diabetes Patients

Purpose

To investigate the association between serum uric acid (SUA) levels and vision-threatening diabetic retinopathy (VTDR) in patients with type 2 diabetes.

Methods

This cross-sectional study evaluated 3481 patients with type 2 diabetes from four communities in China between 2016 and 2019. VTDR was defined as severe nonproliferative, proliferative diabetic retinopathy, or clinically significant macular edema evaluated by fundus photography and optical coherence tomography. Potential association between SUA and VTDR was examined using multivariable logistic regression. Sub-group analyses based on sex were constructed.

Results

A total of 305 participants had VTDR. Both higher SUA (odds ratio [OR], 1.22 per 100 µmol/L; 95% confidence interval [CI], 1.04–1.44; P = 0.013) and hyperuricemia (OR, 1.47; 95% CI, 1.07–2.04; P = 0.019) were positively associated with VTDR after adjustment for relevant covariates. Compared with those in the lowest SUA quartile, participants in the third (OR, 1.60; 95% CI, 1.07–2.39; P = 0.022) and fourth (OR, 2.05; 95% CI, 1.37–3.08; P = 0.001) sex-specific SUA quartiles showed a significantly increased risk of VTDR after adjustment. No sex-related difference was observed.

Conclusions

Higher SUA levels were associated with an increased risk of VTDR in patients with type 2 diabetes in both sexes, although females seemed to be more sensitive to high SUA than males. Prospective cohort studies are needed to verify SUA as a biomarker for predicting the risk of VTDR. Whether decreased SUA levels could decrease the risk of VTDR also requires further investigation.

Association between body mass index and diabetic retinopathy in Asians: the Asian Eye Epidemiology Consortium (AEEC) study

BACKGROUND/AIMS

Obesity is a well-known risk factor for diabetes, but its association with diabetic retinopathy (DR) is inconclusive, in particular in Asians. We aimed to assess whether body mass index (BMI) is associated with the presence and severity of DR in Asian populations with diabetes.

METHODS

Pooled analysis of individual-level cross-sectional data from 10 010 adults with diabetes who participated in 12 population-based studies conducted in China, India, Japan, Russia (Asian), Singapore and South Korea that were part of the Asian Eye Epidemiology Consortium (AEEC). BMI was calculated as weight in kilograms divided by height in square metres and categorised into normal (<25 kg/m², reference), overweight (25-29.9 kg/m²) and obese (≥30 kg/m²). Any-DR (n=1669) and vision-threatening DR (VTDR, n=489) were assessed from digital retinal photographs and graded according to standard protocols. Each study was analysed separately using multivariable logistic regression models adjusted for age, sex, haemoglobin A1c%, systolic blood pressure and diabetes duration, and the estimated odds ratios (ORs) and 95% confidence interval (CIs) from all studies were then combined using random-effects models.

RESULTS

In multivariable models, obesity showed a significant inverse association with any-DR (pooled OR (95% CI) =0.74 (0.59 to 0.91)) and VTDR (0.75 (0.60 to 0.93)). Similarly, in continuous analysis, BMI showed a significant inverse association with both any-DR (0.93 (0.87 to 0.99)) and VTDR (0.79 (0.68 to 0.92) per SD increase). Overweight did not show a significant association with any-DR.

CONCLUSIONS

Among Asian adults with diabetes, both BMI and obesity showed an inverse association with DR. These findings warrant confirmation in further longitudinal studies.

Differential associations between body mass index with diabetes and vision-threatening diabetic retinopathy in an adult Chinese population

PURPOSE

To investigate the associations between body mass index (BMI) with diabetes mellitus (DM) and vision-threatening diabetic retinopathy (VTDR).

METHODS

This was a longitudinal study which included DM-free participants aged ≥40 years from the Lingtou Eye Cohort Study at baseline (2008-2010). Physical and ocular examinations were performed at baseline and annual follow-ups under standardised protocol. Two 45° non-mydriatic colour digital retinal photographs were obtained for each eye at all study visits, and presence of VTDR at the 2016 follow-up was graded by a deep-learning algorithm (LableMe) with proved high accuracy for detection of VTDR.

RESULTS

A total of 2934 participants were included with a mean (SD) age of 59.5 (7.3) years (58.3% men). Participants with incident DM (441/2934, 15%) were significantly older (p<0.001), had higher obesity levels (p<0.001), higher systolic blood pressure (SBP) (p<0.001), diastolic blood pressure (p<0.001), fasting plasma glucose (FPG) (p<0.001), triglycerides (p=0.002) and high-density lipoprotein cholesterol (p<0.001), as compared with those without. Participants with incident VTDR (48/2934, 1.63%) were also older (p<0.001), had higher SBP (p=0.013) and FPG (p<0.001), but did not differ in baseline BMI, comparing with those without. Regression analysis showed that higher baseline BMI was significantly related to incident DM (p<0.005), but not incident VTDR, during the follow-up. Subgroup analysis among participants with incident DM also revealed no association between BMI and VTDR.

CONCLUSIONS

Higher baseline BMI increased the risk of incident DM, but was not related to the risk of VTDR in this adult Chinese population.

Analysis of factors related to diabetic retinopathy in patients with newly diagnosed type 2 diabetes: a cross-sectional study

AIM

To investigate the related factors of diabetic retinopathy (DR) and explore the correlation between smoking and DR in patients with newly diagnosed type 2 diabetes mellitus (T2DM).

DESIGN

A single-centre cross-sectional study.

SETTING

Tianjin 4th Central Hospital.

PARTICIPANTS

Patients with newly diagnosed T2DM who visited the outpatient department of the hospital from December 2018 to April 2019.

METHODS

A total of 947 patients were enrolled in the study. They were divided into two groups according to whether they were diagnosed with DR (diabetic retinopathy group, DR group; non-diabetic retinopathy group, NDR group). The smoking index (SI) was calculated to assess smoking status. Factors such as sex, age, hypertension, T2DM diagnosed age, family history of diabetes, drinking history, haemoglobin A1c (HbA1c), body mass index (BMI) and smoking status were compared between the two groups. Logistic regression was used to analyse the relationship between DR and the above factors.

RESULTS

There was no statistically significant difference between the two groups in sex, age, hypertension, DM diagnosed age, family history of diabetes, drinking history and HbA1c. BMI was significantly higher in DR patients (27.7±4.2 vs 26.7±4.4, p=0.004). Smoking status was also different between the two groups (χ²=6.350, p=0.042). BMI was shown to be a related factor for DR in patients with newly diagnosed diabetes (OR=0.592, p=0.004). When BMI was ≥28 kg/m², heavy smoking was significantly associated with DR (OR=2.219, p=0.049), and there was a negative correlation between DR and the age of diagnosis of diabetes ≥60 years (OR=0.289, p=0.009).

CONCLUSIONS

Heavy smoking was an important related factor for DR in patients with newly diagnosed diabetes mellitus when BMI was ≥28 kg/m². Delaying the age of diabetes might prevent the occurrence of DR. To elucidate the correlation, long-term cohort studies with large samples are needed.

Nomogram for the Risk of Diabetic Nephropathy or Diabetic Retinopathy Among Patients with Type 2 Diabetes Mellitus Based on Questionnaire and Biochemical Indicators: A Cross-Sectional Study

PURPOSE

This study aimed to develop a diabetic nephropathy (DN) or diabetic retinopathy (DR) incidence risk nomogram in China's population with type 2 diabetes mellitus (T2DM) based on a community-based sample.

METHODS

We carried out questionnaire evaluations, physical examinations and biochemical tests among 4219 T2DM patients in Shanghai. According to the incidence of DN and DR, 4219 patients in our study were divided into groups of T2DM patients with DN or DR, patients with both, and patients without any complications. We successively used least absolute shrinkage and selection operator regression analysis and logistic regression analysis to optimize the feature selection for DN and DR. To ensure the accuracy of the results, we carried out multivariable logistic regression analysis of the above significant risk factors on the sample data for both DN and DR. The selected features were included to establish a prediction model. The C-index, calibration plot, curve analysis and internal validation were used to validate the distinction, calibration, and clinical practicality of the model.

RESULTS

The predictors in the prediction model included disease course, body mass index (BMI), total triglycerides (TGs), systolic blood pressure (SBP), postprandial blood glucose (PBG), haemoglobin A1C (HbA1c) and blood urea nitrogen (BUN). The model displayed moderate predictive power with a C-index of 0.807 and an area under the receiver operating characteristic curve of 0.807. In internal verification, the C-index reached 0.804. The risk threshold was 16-75% according to the analysis of the decision curve, and the nomogram could be applied in clinical practice.

CONCLUSION

This DN or DR incidence risk nomogram incorporating disease course, BMI, TGs, SBP, PBG, HbA1c and BUN can be used to predict DN or DR incidence risk in T2DM patients. The research team has developed an online app based on a clinical prediction model incorporating risk factors for rapid and simple prediction.

Prevalence of diabetic retinopathy, proliferative diabetic retinopathy and non-proliferative diabetic retinopathy in Asian T2DM patients: a systematic review and Meta-analysis

AIM

To investigate the pooled prevalence of diabetic retinopathy (DR), proliferative DR (PDR) and nonproliferative DR (NPDR) in Asian type 2 diabetes mellitus (T2DM) patients.

METHODS

We performed a systematic search online search using PubMed, EMBASE, Web of Science, the Cochrane Library, and China WeiPu Library to identify eligible studies that reported the prevalence of DR, PDR and NPDR in Asian T2DM patients. Effect size (ES) with 95% confidence interval (CI) was used to evaluate the prevalence of DR, PDR and NPDR in Asian T2DM patients, respectively.

RESULTS

There were 41 references and 48 995 T2DM patients involved in this study. The prevalence of DR, PDR, and NPDR was 28%, 6%, and 27% in T2DM patients, respectively; while the prevalence of PDR and NPDR in DR patients was 17% and 83%, respectively. Subgroup analysis showed that prevalence of DR in T2DM patients from Singaporean, Indian, South Korean, Malaysian, Asian, and Chinese was 33%, 42%, 16%, 35%, 21% and 25%, respectively. In T2DM patients with NPDR from Indian, South Korean, Malaysian, Asian, Chinese, higher prevalence was found than that in PDR patients (45% vs 17%, 13% vs 3%, 30% vs 5%, 23% vs 2% and 22% vs 3%), as well as in DR patients (74% vs 26%, 81% vs 19%, 86% vs 14%, 92% vs 8% and 85% vs 15%). The prevalence of PDR in T2DM from India was higher than patients from other locations of Asia, and the same results were also observed in NPDR patients.

CONCLUSION

In either T2DM Asian patients or DR patients, NPDR is more common than PDR. Based on our results, we should pay more attention to NPDR screening and management in T2DM patients, and we also recommend suitable interventions to prevent its progression.

Relationship between body fat and diabetic retinopathy in patients with type 2 diabetes: a nationwide survey in Korea

PURPOSE

To evaluate the association of body mass index (BMI), waist circumference, and body fat with diabetic retinopathy (DR) in Korean patients with type 2 diabetes.

METHODS

Among the 1130 participants 19 years of age or older with type 2 diabetes enrolled in the nationwide survey, a total of 887 participants were included in the analyses after excluding patients with ungradable fundus images. The presence and severity of DR were graded with seven-field fundus photographs. The associations between DR and anthropometric parameters and total body fat, which was assessed by dual-energy X-ray absorptiometry, were analysed using multivariate logistic regression models.

RESULTS

Patients were divided into three groups according to severity of DR: no DR (n = 702, 79.1%), mild/moderate DR (n = 130, 14.7%), and vision-threatening DR (n = 55, 6.2%). In multivariate-adjusted analyses, higher BMI (adjusted odds ratio [aOR], 0.80; 95% confidence interval [CI], 0.70-0.92; P = 0.001), larger waist circumference (aOR, 0.96; 95% CI, 0.91-1.00; P = 0.047), and higher total body fat (aOR, 0.86; 95% CI, 0.79-0.92; P < 0.001) were significantly associated with a lower risk of vision-threatening DR. In sex-stratified analyses, however, only total body fat in women showed a significant inverse association with the presence of DR (aOR, 0.93; 95% CI, 0.88-0.98; P < 0.001) and independently with the severity of DR (P for trend = 0.004).

CONCLUSION

In Korean patients with type 2 diabetes, obese patients might be less likely to have vision-threatening DR. Total body fat in women appears to be inversely and independently associated with DR prevalence and progression.

Profile of a population-based diabetic macular oedema study: the Liverpool Eye and Diabetes Study (Sydney)

PURPOSE

The population prevalence of diabetic macular oedema (DME) is unclear. Previous estimates have depended on photographic grading of clinically significant macular oedema, which is subjective and has resulted in widely varying estimates. With the advent of optical coherence tomography (OCT), the presence and severity of DME can now be assessed objectively and accurately.

METHODS

The Liverpool Eye and Diabetes Study (LEADS) is a cross-sectional population-based study of patients with type 1 and type 2 diabetes in a multi-ethnic region of Sydney, Australia, to determine the population prevalence of OCT-defined DME, how this varies by ethnicity and association with systemic factors. This report describes the rationale, methodology and study aims.

RESULTS

To date 646 patients out of an expected sample size of 2000 have been recruited. Baseline data are presented for patients with type 1 (n=75, 11.8%) and type 2 (n=562, 88.2%) diabetes recruited to date. Patients with type 1 diabetes were younger (39.5vs60.7 years), with longer duration of diabetes (18.1vs11.7 years), slightly worse glycaemic control (HbA1c 9.0vs8.3), and less likely to have hypertension (30.7vs71.4%), hypercholesterolaemia (33.3vs74.6%) and obesity (31.1vs51.5%, respectively, all p<0.05).

CONCLUSIONS

The LEADS will provide objective estimates of the population prevalence of DME, how this varies with ethnicity and associations with systemic disease.

Is there a relationship between body mass index and diabetic retinopathy in type II diabetic patients? A cross sectional study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is one of the most important leading causes of disability, premature mortality and Diabetic Retinopathy (DR) that is one of the diabetes-related complications in diabetic patients and the most common cause of vision loss in diabetic patients. The aim of the study was to evaluate the association between DR and body mass index (BMI) in those patients with T2DM.

METHODS

This was a central-based, cross-sectional study on 518 diabetic patients. Their medical history and the laboratory data were collected. All the patients received examination of diabetic retinopathy by professional ophthalmologist. Based on their optic fundi findings, they were classified into five groups: No retinopathy, Mild Non-proliferative Diabetic Retinopathy (NPDR), Moderate NPDR, Severe NPDR, Proliferative diabetic retinopathy (PDR). To analysis data SPSS v18 software used. Frequency, percent, mean and standard deviation were used for population description. t test, spearman correlation, partial correlation, analysis of variance (ANOVA) and Chi-square test (χ2) were used for analytic analysis. Multivariate logistic regression was used to estimate the odds ratio.

RESULTS

518 patients with T2DM 198 male (38%), 320 female (62%) included in this study. The mean age of patients was 61.02 ± 10.18 years. The mean age at onset was 49.06 + 10.52 years and the mean duration of diabetes was 12.09 ± 7.81 years. There was a strong relationship between duration of diabetes and DR (P = 0.001). There were strong significant association between the development of DR and Insulin therapy (OR = 5.975). Correlation analysis between Retinopathy and BMI showed that BMI had inverse relationship with DR when BMI considered as a continuous variable (p-value = 0.009 and correlation coefficient = -0.467).

CONCLUSION

BMI in diabetic patient is one of the most important clinical parameter for their health and disease progression. We conclude that BMI had inverse relationship with DR when BMI considered as a continuous variable.

Progression of diabetic retinopathy severity after treatment with dexamethasone implant: a 24-month cohort study the 'DR-Pro-DEX Study'

PURPOSE

Intravitreal anti-vascular endothelial growth factor agents have been shown to reduce diabetic retinopathy (DR) progression; data on the effects of intravitreal corticosteroids on modifying disease severity are limited. This study evaluates the long-term effect of intravitreal dexamethasone implant (DEX) on the severity and progression of non-proliferative DR (NPDR).

METHODS

This was a retrospective cohort study. Sixty eyes from 60 consecutive patients with NPDR and diabetic macular edema (DME) treated with dexamethasone implant (DEX group) and 49 eyes from consecutive 49 patients without DME requiring observation only. Fundus angiography images from baseline and after 24 months were graded by two masked assessors into mild, moderate and severe NPDR and PDR, according to the ETDRS classification. Patients were followed up 1-3 and 4-6 months after each DEX implant. Re-treatment with DEX implant was on a pro re nata basis. Records were reviewed for performance of panretinal photocoagulation. Main outcome was as follows: change of DR ≥ 1 grade and progression to proliferative diabetic retinopathy (PDR).

RESULTS

Three eyes (5%) in the DEX group and 43 (87.8%) eyes in the control group progressed to PDR (P < 0.0001). Twenty-five eyes (41.7%) in the DEX group but none in the control group demonstrated an improvement in DR severity (P < 0.0001).

CONCLUSION

This study provides the first long-term evidence that DEX implant has the potential to not only delay progression of DR and PDR development, but may also improve DR severity over 24 months. Better understanding of the effects of corticosteroids will help guide its use in the treatment pathway of DR.

Differential effect of body mass index on the incidence of diabetes and diabetic retinopathy in two Asian populations

AIMS

To examine the association of body mass index (BMI) with the incidence of diabetes mellitus (DM) and diabetic retinopathy (DR) in Asians.

METHODS

We analysed data from 4101 adults (Malay, n = 1901 and Indian, n = 2200) who participated in the baseline (2004-2009) and 6-year follow-up (2011-2015) of two independent population-based studies with similar methodology in Singapore. BMI was categorised into normal (<25 kg/m²), overweight (25-29.9 kg/m²) and obese (≥30 kg/m²). DM was diagnosed as random plasma glucose ≥200 mg/dL, HbA_1c ≥6.5% or self-reported physician diagnosed DM. DR was assessed from retinal photographs graded using a standard protocol. The associations of baseline BMI with incident DM and DR was examined using multivariable poisson regression models adjusting for potential confounders including duration of DM, family history of DM and HbA_1c.

RESULTS

The incidence of DM was 12.8% and among 1586 participants with DM, the incidence of DR was 17.6% over a median follow-up period of 6.2 years. Compared to those with BMI < 25, the relative risk (95% confidence interval) of incident DM was 1.77 (1.36-2.29) for overweight and 2.01 (1.50-2.71) for obese (p trend < 0.001). Relative risk of DR was 0.80 (0.59-1.09) for overweight and 0.60 (0.39-0.92) for obese (p trend = 0.02). In analyses stratified by ethnicity, similar pattern of associations with DM and DR were observed in both ethnicities.

CONCLUSION

Our results suggest that, overweight and obesity increased the 6-year risk of DM but decreased the 6-year risk of DR in these Asian populations.

Diabetic Retinopathy in the Asia-Pacific

Diabetic retinopathy (DR), the most common complication of diabetes mellitus, is the leading cause of new cases of blindness in middle-aged and elderly in the Asia-Pacific. It has been estimated that 51% of all those with blindness due to DR globally (n = 424,400) and 56% of those with visual impairment due to DR (2.1 million) come from the Asia-Pacific. Prevalence of DR among those with diabetes ranged from 10% in India to 43% in Indonesia within the Asia-Pacific. Awareness of DR among persons with diabetes ranged from 28% to 84%. Most common modifiable risk factors for DR in the Asia-Pacific were hyperglycemia, blood pressure, dyslipidemia, and obesity. Implementation of systematic screening programs for DR and advancement in telemedicine screening methods have increased patient coverage and cost-effectiveness, though there are still numerous factors impeding screening uptake in the low-middle income regions of the Asia-Pacific. Management and treatment of DR in the Asia-Pacific is mainly limited to traditional laser retinopexy, but it is suboptimal despite new clinical approaches such as use of intravitreal anti.vascular endothelial growth factor and steroids due to limited resources. Further research and data are required to structure a more cost-effective public healthcare program and more awareness-building initiatives to increase the effectiveness of DR screening programs.

Prevalence and associated factors of diabetic retinopathy in Beijing, China: a cross-sectional study

OBJECTIVES

The study aimed to determine the exact risk factors for diabetic retinopathy (DR) in the Chinese population using a cohort of 17  985 individuals from Beijing, China.

DESIGN

Cross-sectional study.

SETTING

A hospital.

PARTICIPANTS

17  985 individuals from Beijing, China.

PRIMARY AND SECONDARY OUTCOME MEASURES

This was a cross-sectional study of permanent residents from the Changping area (Beijing, China) recruited from July 2010 to March 2011 and from March 2014 to February 2015 during a routine health examination at the Tongren Hospital of Beijing. Eye examinations were conducted by experienced ophthalmologists. Medical history, height, weight, body mass index (BMI) and blood pressure were recorded. Routine laboratory examinations were performed.

RESULTS

The prevalence of DR was 1.5% in the general study population and 8.1% among individuals with diabetes. Compared with the non-DR group, individuals in the DR group in the diabetes population had longer disease duration, higher systolic blood pressure (SBP), fasting plasma glucose (FPG) and uric acid (UA) (in men) and lower UA (in women) (all p<0.05). The multivariate analysis showed that disease duration (p<0.001), BMI (p=0.046), SBP (p=0.012), creatinine clearance rate (CCR) (p=0.014), UA (p=0.018) and FPG (p<0.001) were independently associated with DR in patients with diabetes.

CONCLUSION

The prevalence of DR was 8.1% among patients with diabetes. Disease duration, BMI, SBP, CCR, UA and FPG were independently associated with DR.

Lifestyle-tailored interventions for South Asians with type 2 diabetes living in high-income countries: a systematic review

AIM

To summarize evidence on the effectiveness of educational interventions for type 2 diabetes control in South Asians living in high-income countries.

METHODS

We systematically searched PubMed, EMBASE, Cinahl and the Cochrane Library, using Medical Subject Heading and free-text terms. The considered outcomes were: mortality, morbidity, glycaemic control, blood pressure, practice (diet, physical activity and self-care), attitudes/awareness and knowledge. Papers published up to July 2015 were considered. Two reviewers independently screened the title and abstract and then read the full text of selected papers.

RESULTS

Nine studies were included, four non-randomized studies of interventions and five randomized controlled trials. All studies except one were conducted in the UK. Target population ranged from 39 to 1486 individuals; the follow-up ranged from 1 to 24 months. The interventions were mostly based on a tailored educational package, individually or group administered, conducted by lay link workers, health professionals or both. No study measured mortality or morbidity. An effect on glycaemic control was observed only in before/after studies, while a randomized study showed a non-significant improvement (percentage of glycated haemoglobin -0.15, P = 0.11). Two randomized studies found a reduction in blood pressure. Changes in practice and attitudes showed heterogeneous results, mostly favouring intervention.

CONCLUSIONS

There was weak evidence that interventions using link workers and tailored education can modify attitudes, self-care skills and blood pressure in South Asian migrants to industrialized countries. Only one larger trial, with adequate follow-up, showed a small non-significant improvement of glycaemic control.

Optical coherence tomography angiography analysis of retinal vascular plexuses and choriocapillaris in patients with type 1 diabetes without diabetic retinopathy

AIMS

To analyze retinal vascular plexuses and choriocapillaris by optical coherence tomography angiography (OCT-A) and retinal nerve fiber layer and ganglion cell layer (GCL) by structural optical coherence tomography (OCT) in patients with type 1 diabetes mellitus (T1DM) without diabetic retinopathy (DR).

METHODS

A total of 25 eyes of 25 consecutive T1DM patients without signs of DR were prospectively recruited and compared to 25 healthy subjects (control eyes). All patients underwent OCT-A (CIRRUS HD-OCT model 5000, Carl Zeiss Meditec, Dublin, CA) and structural OCT. Qualitative and quantitative analyses with vessel density were performed on OCT-A images in the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris for all patients.

RESULTS

By means of OCT-A, a rarefaction of the perifoveal capillary network in SCP was detected in 7 out of 25 eyes. No significant difference was found in FAZ area of both SCP and DCP comparing diabetic and control groups. By analyzing the DCP, diabetic eyes revealed a significant decreased vessel density compared to control eyes [0.464 ± 0.016 and 0.477 ± 0.014, respectively (p = 0.005)]. Instead, no significant difference was found in the vessel density of all-retina plexus, SCP and choriocapillaris. By RFNL and GCL thickness analysis, no significant differences were disclosed between diabetics and healthy subjects.

CONCLUSIONS

We demonstrated the ability of OCT-A to disclose early vascular alterations in patients with T1DM diagnosed as without any signs of DR on the basis of fundus biomicroscopy. Our results also suggest that microvascular changes could precede detectable damage of diabetic neuroretinopathy.

Body mass index and risk of diabetic retinopathy: A meta-analysis and systematic review

Diabetic retinopathy (DR) is a frequent cause of acquired blindness worldwide. Various studies have reported the effects of body mass index (BMI) on the risk of DR, but the results remain controversial. Therefore, a meta-analysis was performed to evaluate the relationship between BMI and the risk of DR.A systematic search was performed using the Cochrane Library, PubMed, and Embase databases to obtain articles published through December 2016. Articles regarding the association between BMI and the risk of DR were retrieved. The adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were included and then pooled with a random effects model.A total of 27 articles were included in this meta-analysis. When BMI was analyzed as a categorical variable, neither being overweight (OR = 0.89, 95% CI 0.75-1.07; P = .21; I = 65%) nor obesity (OR = 0.97, 95% CI 0.73-1.30; P = .86) were associated with an increased risk of DR when compared with normal weight. When BMI was analyzed as a continuous variable, a higher BMI was not associated with an increased risk of DR (OR = 0.99, 95% CI 0.97-1.01; P = .25; I2 = 79%). The pooled results did not significantly change after the sensitivity analysis.Based on the current publications, neither being overweight nor obesity is associated with an increased risk of DR. Further studies should confirm these findings.

Retinal neurodegeneration in patients with type 1 diabetes mellitus: the role of glycemic variability

AIMS

Recent studies have identified neuroretinal abnormalities in persons affected by diabetes mellitus, before the onset of microvascular alterations. However, the role of glycemic variability (GV) on early retinal neurodegeneration is still not clarified.

METHODS

To explore the relationship between glycemic control and neuroretinal characteristics, 37 persons with Type 1 diabetes mellitus (Type 1 DM) divided into two groups with no signs (noRD) and with mild non-proliferative diabetic retinopathy (NPDR) compared to 13 healthy control participants (C) were recruited. All persons underwent an optical coherence tomography with automatic segmentation of all neuroretinal layers. Measurements of mean of nasal (N)/temporal (T)/superior (S)/inferior (I) macular quadrants for individual layer were also calculated. Metabolic control was evaluated by glycated hemoglobin (HbA1c), and indexes of GV were calculated from continuous glucose monitoring.

RESULTS

The difference among the three groups in terms of RNFL thickness was significantly dependent on quadrant (F(6;132) = 2.315; p = 0.037). This interaction was due to a specific difference in RNFL-N thickness, where both Type 1 DM groups showed a similar reduction versus C (-3.9 for noDR and -4.9 for NPDR), without any relevant difference between them (-1.0). Inner nuclear layer (INL) was increased in all quadrants in the two Type 1 DM groups compared to C (mean difference = 7.73; 95% CI: 0.32-15.14, p = 0.043; mean difference = 7.74; 95% CI: 0.33-15.15, p = 0.043, respectively). A negative correlation between RNFL-N and low blood glucose index (r = -0.382, p = 0.034) and positive correlation between INL and continuous overall net glycemic action -1, -2, -4 h (r = 0.40, p = 0.025; r = 0.39, p = 0.031; r = 0.41, p = 0.021, respectively) were observed in Type 1 DM patients. The triglycerides were positively and significantly correlated to INL (r = 0.48, p = 0.011), in Type 1 DM subjects. GV and triglycerides resulted both independent predictors of increased INL thickness. No correlation was found with HbA1c.

CONCLUSIONS

Early structural damage of neuroretina in persons with Type 1 DM patients is related to glucose fluctuations. GV should be addressed, even in the presence of a good metabolic control.

Diabetic macular oedema

Diabetic macular oedema, characterised by exudative fluid accumulation in the macula, is the most common form of sight-threatening retinopathy in people with diabetes. It affects one in 15 people with diabetes resulting in more than 20 million cases worldwide. Few epidemiological studies have been done to specifically investigate risk factors for diabetic macular oedema, although poor glycaemic and blood pressure control are associated with the presence and development of the disorder. The pathophysiological processes begin with chronic hyperglycaemia, and interplay between vascular endothelial growth factor (VEGF) and inflammatory mediators. Non-invasive imaging using optical coherence tomography has allowed clinicians to detect mild levels of diabetic macular oedema in order to monitor progress and guide treatment. Although focal or grid laser photocoagulation was the traditional mode of treatment, intraocular pharmacotherapy with anti-VEGF agents is now the standard of care. However, these therapies are expensive and resource intensive. Emerging therapeutic strategies include improving efficacy and duration of VEGF suppression, targeting alternative pathways such as inflammation, the kallikrein-kinin system, the angiopoietin-Tie2 system, and neurodegeneration, and using subthreshold and targeted laser therapy. Ongoing research should lead to improvements in screening, diagnosis, and management of diabetic macular oedema.

Type 2 diabetes: A 21st century epidemic

Around 415 million people around the world have diabetes (9% of adults), and the vast majority live in low- and middle-income countries. Over the next decade, this number is predicted to increase to 642 million people. Given that diabetes is a major cause of mortality, morbidity, and health care expenditures, addressing this chronic disease represents one of the greatest global health challenges of our time. The objectives of this article are three-fold: (1) to present data on the global burden of type 2 diabetes (which makes up 87-91% of the total diabetes burden), both in terms of prevalence and incidence; (2) to give an overview of the risk factors for type 2 diabetes, and to describe obesity and the developmental origins of disease risk in detail; and (3) to discuss the implications of the global burden and point out important research gaps.

The association of peroxisome proliferator-activated receptor α with diabetic retinopathy, and additional gene-obesity interaction in Chinese type 2 diabetes mellitus patients

AIMS

To investigate the impact of peroxisome proliferator-activated receptor α (PPAR α) SNPs and gene-obesity interaction on diabetic retinopathy (DR) susceptibility in a Chinese Han population.

METHODS

A total of 812 patients (373men, 439 women) with type 2 diabetes mellitus (T2DM), with a mean age of 53.3±14.0 years old, were selected, including 402 diabetic retinopathy patients and 410 controls. Three single nucleotide polymorphisms (SNPs) were selected for genotyping in the case-control study: rs4253778, rs135539 and rs1800206. Generalised multifactor dimensionality reduction (GMDR) and logistic regression model was used to examine the association and interaction between SNP and obesity on DR, odds ratio (OR) and 95% confident interval (95%CI) were calculated.

RESULTS

The carriers of homozygous mutant of rs1800206 SNP revealed decreased DR risk than those with wild-type homozygotes, OR (95%CI) was 0.78 (0.66-0.94). GMDR analysis indicated a significant two-locus model (p=0.0107) involving rs1800206 and abdominal obesity, indicating a potential interaction among rs1800206 and abdominal obesity. Overall, the two-locus models had a cross-validation consistency of 10 of 10, and had the testing accuracy of 60.72%. We also found that subjects with abdominal obesity and LV or VV genotype have lowest DR risk, compared to subjects with normal WC and LL genotype, OR (95%CI) was 0.39 (0.30-0.74), after covariates adjustment.

CONCLUSIONS

Our results support an important association between rs1800206 minor allele of PPAR α and DR, and the interaction analysis also shown a combined effect of Leu162 allele-abdominal obesity interaction on DR.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.

Serum Cystatin C, Markers of Chronic Kidney Disease, and Retinopathy in Persons with Diabetes

PURPOSE

We examined the association of CKD defined by serum creatinine, serum cystatin C, and albuminuria with moderate diabetic retinopathy (DR).

METHODS

We examined 1,119 Indian adults with diabetes, aged 40-80 years, who participated in the Singapore Indian Eye Study (2007-2009), a population-based cross-sectional study. The associations of CKD defined by each of the three markers alone and in combination with moderate DR were examined using logistic regression models adjusted for potential confounding factors including duration of diabetes, smoking, body mass index, systolic blood pressure, and HbA1c.

RESULTS

The prevalence of moderate DR was significantly higher among those with CKD defined by triple markers (41.1%) compared to CKD defined separately by creatinine (26.6%), cystatin C (20.9%), and albuminuria (23.4%). People with CKD defined by triple markers had a fourteenfold higher odds of moderate DR (OR (95% CI) = 13.63 (6.08-30.54)) compared to those without CKD by any marker. Nearly half (48.7%) of participants with cystatin C ≥ 1.12 mg/L have moderate DR.

CONCLUSIONS

CKD defined by a triple marker panel was strongly associated with moderate DR in this Asian population with diabetes.

Current concepts in diabetic retinopathy

For the past several decades, tremendous efforts have been made to decrease the complications of diabetes, including diabetic retinopathy. New diagnostic modalities like ultrawide field fundus fluorescein angiography and spectral domain optical coherence tomography has allowed more accurate diagnosis of early diabetic retinopathy and diabetic macular edema. Antivascular endothelial growth factors are now extensively used to treat diabetic retinopathy and macular edema with promising results. There remains uncertainty over the long term effects and the socioeconomic costs of these agents.