Thailand Diabetes Registry Project: Prevalence of Diabetic Retinopathy and Associated Factors in Type 1 Diabetes Mellitus
Thanya Chetthakul MD*, Supawadee Likitmaskul MD**, Nattachet Plengvidhya MD***, Sompongse Suwanwalaikorn MD****, Natapong Kosachunhanun MD*****, Chaicharn Deerochanawong MD*,*****, Sirinate Krittiyawong MD*******, Rattana Leelawatana MD********, Yupin Benjasuratwong MD*********, Pongamorn Bunnag, MD**********, Thongchai Prathipanawatr MD***********, Chardpraorn Ngarmukos MD**********, Sirima Mongkolsomlit BS************, Petch Rawdaree MD*************
Affiliation : * Department of Medicine, Maharat Nakhon Ratchasima Hospital ** Department of Pediatrics, Siriraj Hospital, Mahidol University *** Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University **** Department of Medicine, Faculty of Medicine, Chulalongkorn University ***** Department of Medicine, Faculty of Medicine, Chiang Mai University ****** Rajavithi Hospital, ******* Theptarin General Hospital ******** Department of Medicine, Faculty of Medicine, Prince of Songkla University ********* Department of Internal Medicine, Phramongkutklao Hospital ********** Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University *********** Deptpartment of Medicine, Faculty of Medicine, Khon Kaen University ************ TDR research coordinator, ************* BMA Medical College and Vajira Hospital
Objective : To determine the prevalence and factors associated with Diabetic Retinopathy (DR) of type 1 diabetes mellitus in
Thailand.
Materials and Methods : A cross-sectional, multicenter, hospital-based study was carried out from April to December 2003.
Diabetic patients in diabetic clinics of 11 tertiary centers were registered. Retinopathy was evaluated by the ophthalmologists.
Results : Seven thousand one hundred and nineteen diabetic patients received retinal examination. The number of patients with
type 1 diabetes was 347. The prevalence of DR in type 1 diabetes was 21.6% (75). This consisted of Non-Proliferative DR
(NPDR) 10.9% (38) and Proliferative DR (PDR) 10.7%. Patients with DR were significantly older, predominantly female,
longer duration of diabetes, had higher BMI, systolic Blood Pressure (BP), diastolic BP, serum creatinine, and TriGlycerides
(TG) levels than those without DR. Both groups of patients were not different in term of plasma glucose and glycosylated
hemoglobin levels. Although the patients with DR had a higher percentage of overt proteinuria than those without DR, there
was no difference in percentage of patients with positive microalbuminuria in both groups. This may be explained by limitation
of data (only 16% had results of microalbuminuria and 19% had results of proteinuria). After adjusted for duration of
diabetes, serum creatinine and smoking status, factors (adjusted odds ratio [95% confidence interval]) associated with DR
were duration of diabetes 5-9.9 years (4.0 [1.49-10.91]), 10-14.9 years (6.86 [2.45-19.20]), 15-19.9 years (21.13 [7.22-
61.78]), ≥ 20 years (22.15 [7.32-66.99]) when compared with duration of diabetes less than 5 years, serum creatinine > 2
mg/dl (6.0 [2.09-17.22]) when compared with creatinine less than 2 mg/dl. From the presented model, age, gender, systolic
BP > 140 mmHg, diastolic BP > 90 mmHg, serum TG and smoking status were not factors associated with DR.
Conclusion : Diabetic retinopathy affects about one fifth of type 1 diabetic patients in our study. The authors found the factors
associated with DR in type 1 DM were duration of diabetes and serum creatinine. Regular screening for DR and more
aggressive management of metabolic factors should be done to reduce the prevalence of DR.
Keywords : Type 1 diabetes, Diabetic retinopathy
