Incidence of and risk factors for diabetic retinopathy in diabetic clinic attenders

Association of obesity and risk of diabetic retinopathy in diabetes patients: A meta-analysis of prospective cohort studies

BACKGROUND

Diabetic retinopathy (DR) was considered to be a common complication of diabetes. The purpose of the current study was to investigate the potential association between obesity and DR risk by conducting a meta-analysis of prospective studies.

METHODS

A consummate literature search of PubMed, EMBASE, and web of science was conducted until July 2016. A total of 13 prospective cohort studies were included in this meta-analysis.

RESULTS

On meta-analysis of all the studies assessing DR risk, obesity was associated with a significant increase in DR incidence (relative risk [RR], 1.20; 95% confidence interval [CI], 1.01-1.43; I = 59.6%). When only proliferative DR (PDR) was considered, no significant association between obesity and risk of PDR was detected. Significant harmful effect was detected in type 2 diabetes mellitus (T2DM) group (RR, 1.40; 95% CI, 1.05-1.87; I = 67.6%) but not mixed group (RR, 1.04; 95% CI, 0.97-1.18; I = 0.00%). No significant publication bias was detected in the selected 13 studies.

CONCLUSION

Obesity was a risk factor for non-proliferative DR. However additional well-designed and well-conducted epidemiologic studies were required to deepen our understanding of the relation between obesity and DR.

Diabetic retinopathy is associated with oxidative stress and mitigation of gene expression of antioxidant enzymes

Type 2 diabetes is a metabolic disease associated with serious complications, including diabetic retinopathy (DR). The authors' main aim was to investigate biochemical parameters and the oxidative stress associated with the type 2 DR patients and to study gene expression of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) among patients with DR [DR(+)] compared with a control nondiabetic group. In all, 67 patients with DR included in this study were diabetic for more than 10 years. Among them, 22 patients were DR(+), and 45 patients did not have DR [DR(-)]. The subjects' age range was 14 years to 80 years old with diabetes duration range between 2 and 45 years. Body mass index (BMI) was 31.43 ± 5.94 and 32.33 ± 6.54, systolic blood pressure was 117.15 ± 18.16 mmHg and 126.15 ± 20.26 mmHg, diastolic blood pressure was 81.11 ± 10.55 mmHg and 82.77 ± 10.85 mmHg, HbA1c was 7.2 ± 1.1 and 8.19 ± 1.95, serum total cholesterol was 6.61 ± 1.11 and 4.11 ± 0.31, serum triglycerides were 3.52 ± 0.89 and 3.42 ± 0.79, serum low-density lipoprotein (LDL) was 2.12 ± 0.10 and 2.42 ± 0.15, high-density lipoprotein (HDL) was 2.66 ± 0.30 and 2.55 ± 0.21, SOD was 3.12 ± 0.87 and 1.53 ± 0.14, GPx was 11.14 ± 2.21 and 8.2 ± 1.84, CAT was 26.43 ± 3.34 and 9.60 ± 2.14, for DR(-) and DR(+) patients, respectively. SOD, GPx and CAT polymerase chain reaction (PCR) products of the DR(+) patients revealed the diminished expression of CAT gene followed by GPx and SOD genes. All were significant compared with the normal controls, P < 0.05. Linear regression analysis revealed a strong significant positive correlation between the retinopathy grade and the diastolic blood pressure, diabetes duration, hemoglobin A1c (HA1c)%, and fasting blood glucose (P < 0.001). A marginally significant positive correlation between the retinopathy grade and LDL-cholesterol was observed (P < 0.05), and a significant negative correlation between the retinopathy grade and total cholesterol was observed (P < 0.05). Poor glycemic control and alteration in mRNA gene expression of antioxidant enzymes are strongly associated with development of DR and the regular screening is mandatory for early detection and treatment.

Prevalence of diabetic retinopathy in Tehran province: a population-based study

Background

To determine the prevalence and characteristics of diabetic retinopathy (DR) among Iranian patients with diabetes.

Methods

Design: population-based cross-sectional study.

Participants: patients with diabetes aged 25 to 64 years in Tehran province, Iran. This survey was conducted from April to October 2007. The study sample was derived from the first national survey of risk factors for non-communicable disease. Diabetes mellitus was defined as a fasting plasma glucose of ≥ 7.0 mmol/l (126 mg/dl) or more, use of diabetic medications, or a physician's diagnosis of diabetes. All patients known to have diabetes underwent an eye examination by bio-microscope and indirect ophthalmoscope to check for any signs of DR through dilated pupils by + 78 lens. Participants were also interviewed and examined to determine their demographic characteristics, medical conditions and the regularity of their eye visits.

Results

Among 7989 screened patients, 759 (9.5%) had diabetes. Of them, 639 patients (84.2%) underwent eye examination. Five patients (0.7%) with media opacity were excluded. Of 634 examined patients with diabetes, 240 had some degree of diabetic retinopathy, and the overall standardized prevalence of any retinopathy was 37.0% (95% CI: 33.2-40.8), including 27.3% (95% CI: 23.7-30.8) (n = 175) with non-proliferative and 9.6% (95% CI: 7.3-11.9) (n = 65) with proliferative diabetic retinopathy. Clinically significant macular edema and vision-threatening retinopathy were detected in 5.8% (95% CI: 4.0-7.7) (n = 38) and 14.0% (95% CI: 11.3-16.7) (n = 95) of patients, respectively. Only 143 patients (22.6%) with diabetes had a history of regular eye examination.

Conclusion

This study demonstrated a high prevalence and poor control of DR in Tehran province. This suggests the need for adequate prevention and treatment in patients with diabetes.

Incidence and progression of diabetic retinopathy in Hong Kong Chinese with type 2 diabetes mellitus

OBJECTIVE

We conducted a cohort study to determine the incidence and progression of diabetic retinopathy (DR) in a Chinese population with type 2 diabetes mellitus in a district hospital in Hong Kong, and to identify the risk factors associated with the development and progression of DR over 4 years.

RESEARCH DESIGN AND METHODS

A total of 413 type 2 diabetic patients who followed up in our diabetic clinic and had a diabetic complication screening performed in 2001 were studied. The final analysis included 354 subjects (85.7%) after a mean follow-up period of 4.2 years. The severity of DR was graded according to the modified Early Treatment Diabetic Retinopathy Study (ETDRS). The relationship between clinical variables and DR development and progression was determined.

RESULTS

The baseline prevalence of DR was 39.2%. On 4-year follow-up, the incidence of DR was 20.3% (43 of 212). In those with baseline DR, 34.7% (42 of 121) progressed by >or=2 steps in ETDRS. On multivariate analysis, a high baseline glycosylated hemoglobin (HbA(1c)) was the only predictor of DR development, while macroalbuminuria and high mean HbA(1c) predicted progression. Regression of DR, defined by a >or=2-step decrement in ETDRS, occurred in 13.2% (12 of 91) of subjects and was associated with lower baseline HbA(1c) and absence of albuminuria.

CONCLUSION

The incidence of DR in our study was similar to--but progression of DR was higher than--those reported in Caucasians. More frequent retinal screening should be offered to those with baseline DR, high HbA(1c), or albuminuria. Good glycemic control is important in order to prevent the development and progression of DR, and can lead to regression of DR.

Incidence and risk factors of hypertension among Saudi type 2 diabetes adult patients: an 11-year prospective randomized study

AIMS

Insofar as hypertension is a risk factor for cardiovascular morbidity and mortality in Type 2 diabetes mellitus (T2DM), this study investigated the incidence of hypertension and associated risk factors in Saudi T2DM patients.

METHODS

A hospital-based, 11-year (1993-2004) prospective study of 916 adult originally normotensive T2DM Saudi patients (488 male and 428 female). T2DM was diagnosed as per World Health Organization (WHO) criteria, while hypertension was assessed according to the Seventh Joint National Criteria for Hypertension Classification (JNVII). Risk factors were analyzed on those who developed hypertension.

RESULTS

The hypertension incidence was 17.2/100 person-years, based on 2833.63 person-years of cohort group follow-up. Age-adjusted Cox regression coefficient showed that the significant risk factors for developing hypertension were older age, higher HbA(1c), BMI, elevated triglycerides (>1.8 mmol/l) and creatinine (>115 mmol/l), smoking, proteinuria, microalbuminuria, lack of physical exercise, and retinopathy, while anti-platelet and lipid-lowering drugs had lower hypertension hazard ratios. Cox proportional hazard showed that older age, male gender, higher BMI, diabetes duration (<5 years), and retinopathy were independent predictors of hypertension, while exercise, lipid-lowering, and anti-platelet medications were associated with reduced hypertension incidence rate.

CONCLUSIONS

Incidence of hypertension in Saudi T2DM patients is comparable to other communities, with older age, male gender, higher BMI, diabetes duration of <5 years and retinopathy being strong predictors for hypertension development.

Hypertension in type 2 diabetes mellitus in Isfahan, Iran: incidence and risk factors

BACKGROUND

Evidence on the long-term incidence of and risk factors of hypertension in diabetic patients is scarce and mainly derived from studies in developed countries. Evidence from developing countries is required for planning a well-co-ordinated approach to this public health problem in these countries.

OBJECTIVE

The objectives of present study were to estimate the incidence of and risk factors for the development of hypertension in people with type 2 diabetes mellitus using routinely collected data from a clinical information system at Isfahan Endocrinology and Metabolism Research Centre, Iran.

METHOD

During the mean (standard deviation (S.D.)) follow-up period of 2.9 (2.5) (range 1-11) years, 3202 diabetic patients (1315 male and 1887 female) from Isfahan Endocrinology and Metabolism Research Centre out patient clinics, Iran have been examined. The mean (S.D.) age of participants was 48.3 (10.6) years with a mean (S.D.) duration of diabetes of 6.5 (6.7) years at initial registration. Blood pressure was measured by standardised protocols, and hypertension was defined as at least in two consecutive measurements within 2 months a systolic and/or diastolic blood pressure of >or=130 and/or >or=80 mmHg and/or taking anti-hypertensive medication.

RESULTS

Among the 3202 patients free of hypertension at initial registration who attended the clinic at least twice in the period 1992-2004, the incidence of hypertension was 20.8 (20.6 male and 20.9 female) per 100 person-years based on 9403 person-years of follow-up. The age-adjusted incidence rate of hypertension was 22% lower among insulin-treated than non-insulin-treated type 2 diabetes mellitus clinic attenders and it was greater with older age. Using a Cox's Proportional Hazards Model, male gender, and treatment regimen were significant independent predictors of hypertension. Smoking, duration of diabetes, age at diagnosis of diabetes, fasting blood glucose, glycosylated haemoglobin, BMI, proteinuria and creatinine, had no significant independent association with hypertension when other covariates were considered.

CONCLUSION

These findings will help the identification of those patients at particular risk of hypertension and strongly support the case for vigorous control of blood pressure on type 2 diabetic patients.

Gender differences in the utilisation of optometric services in Victoria

Medicare and population data demonstrate clear gender differences in utilisation of health services. There are three broad hypotheses that may explain different utilisation rates of health services by gender: differences in access, differences in incidence and differences in attitudes in seeking health care between the genders. Men are 28 per cent less likely than women to see an optometrist in Victoria. Both women's and men's utilisation of optometric services in Victoria increase with age but there are clear gender differences apparent at every stage of life after childhood. These utilisation rates between genders are tested against incidence rates between genders for eye conditions. There are few noted gender differences apparent in the incidence or prevalence of ocular conditions. The data on the incidence of health conditions often has limitations, either in measurement tools or in differences in incidence between genders. These limitations are not as evident in eye care incidence data. Access and incidence differences do not adequately explain the differences in optometric service utilisation rates. This promotes the hypothesis that attitudinal differences in seeking health care between men and women are significant.

Incidence of and risk factors for diabetic retinopathy in Isfahan, Iran

BACKGROUND

Evidence on the incidence of and risk factors for diabetic retinopathy is mainly derived from studies in developed countries. Locally derived evidence is required for planning a well-coordinated approach to this public health problem in developing countries.

OBJECTIVE

The objectives of the present study were to estimate the incidence of and risk factors for the development of diabetic retinopathy using routinely collected data from a clinical information system at the Isfahan Endocrinology and Metabolism Research Center, Iran, for non-insulin-dependent (insulin-treated and non-insulin-treated) diabetes.

METHOD

During the mean (standard deviation (SD)) follow-up period of 5.1 (2.1) (range 1-9) years, 549 diabetic patients (161 male and 388 female) from the Isfahan Endocrinology and Metabolism Research Center outpatient clinics at Amin University Hospital, Iran, were examined. The mean (SD) age of the participants was 45.7 (9.3) years with a mean (SD) duration of diabetes of 6.9 (5.7) years at initial registration.

RESULTS

Among the 549 patients free of retinopathy at initial registration with at least one follow-up visit between 1992 and 2001, the incidence of any retinopathy was 89.4 (95% confidence interval (CI): 79.0, 101.0) [96.1 (95% CI: 76.7, 118.0) in males and 86.6 (95% CI: 74.5, 99.9) in females] per 1000 person-years based on 2786 person-years of follow-up. The incidence rate of retinopathy was 60% greater among insulin-treated than non-insulin-treated non-insulin-dependent diabetes mellitus (NIDDM) clinic attenders. The incidence of any retinopathy was greater with older age, longer duration of diabetes, higher diastolic blood pressure and poor metabolic control. Using a Cox's Proportional Hazards Model for insulin-treated and non-insulin-treated NIDDM diabetes separately, poor metabolic control was a significant independent predictor of retinopathy for insulin-treated and non-insulin-treated NIDDM patients. When all variables were entered in the model, age, poor metabolic control and fasting blood glucose were significant predictors of retinopathy. In the insulin-treated group, fasting blood glucose was also a significant predictor of retinopathy. Systolic and diastolic blood pressure, gender, smoking, proteinuria, body mass index and creatinine had no significant independent association with retinopathy when other covariates were considered.

CONCLUSION

These data suggest that diabetic retinopathy in this population of Iranian non-insulin-dependent diabetic patients is common, being found in almost half of the patients after a mean 5-year follow-up. Poor metabolic control is the major risk factor.