UKPDS 50: Risk factors for incidence and progression of retinopathy in Type II diabetes over 6 years from diagnosis

Abstract

Diabetic retinopathy is a common complication of Type II (non-insulin-dependent) diabetes mellitus and carries with it the threat of blindness. The St Vincent declaration [1] calls for intervention to lower both the incidence and prevalence of sight-threatening retinopathy. Thus, the identification and quantification of factors associated with onset and progression is essential if this is to be achieved. This paper reports the onset of new retinopathy and the progression of established retinopathy in the United Kingdom Prospective Diabetes Study (UKPDS [2]), a multicentre randomised controlled clinical trial of Diabetologia (2001) Abstract Aims/hypothesis. To determine risk factors related to the incidence and progression of diabetic retinopathy over 6 years from diagnosis of Type II (non-insulindependent) diabetes mellitus. Methods. This report describes 1919 patients from within the United Kingdom Prospective Diabetes Study (UKPDS), with retinal photographs taken at diagnosis and 6 years later and with complete data available. Photographs were centrally graded for lesions of diabetic retinopathy using the modified Early Treatment of Diabetic Retinopathy Study Final scale. Risk factors were assessed after 3 months diet from the time of diagnosis of diabetes. Patients were seen every 3 months in a hospital setting. Biochemical measurements were done by a central laboratory. End points of vitreous haemorrhage and photocagulation were confirmed by independent adjudication of systematically collected clinical data. The main outcome measures were incidence and progression of retinopathy defined as a two-step Early Treatment of Diabetic Retinopathy Study (ETDRS) final scale change.Results. Of the 1919 patients, 1216 (63 %) had no retinopathy at diagnosis. By 6 years, 22 % of these had developed retinopathy, that is microaneurysms in both eyes or worse. In the 703 (37 %) patients with retinopathy at diagnosis, 29 % progressed by two scale steps or more. Development of retinopathy (incidence) was strongly associated with baseline glycaemia, glycaemic exposure over 6 years, higher blood pressure and with not smoking. In those who already had retinopathy, progression was associated with older age, male sex, hyperglycaemia (as evidenced by a higher HbA 1 c ) and with not smoking. Conclusion/interpretation. The findings re-emphasise the need for good glycaemic control and assiduous treatment of hypertension if diabetic retinopathy is to be minimised. [Diabetologia (2001) 44: 156±163]

Capsule Commentary on Clair et al., The Effect of Cigarette Smoking on Diabetic Peripheral Neuropathy: A Systematic Review and Meta-Analysis

“…In fact, one of the largest prospective studies (n=903 patients) concluded that smoking might offer Bprotectionâ gainst development and progression of retinopathy. 5 A similar signal of Bprotection^could be inferred from this study's analyses of type 2 DM patients, although it could also be argued that the analysis was underpowered.…”

Diabetic retinopathy

“…Moderate alcohol consumption [21] and smoking [22] do not appear to influence the course of DR. If anything, smoking was associated with reduced progression in the UKPDS cohort [23]. According to the EURODIAB-PCS follow-up study of the original EURODIAB cohort, onset of diabetes before puberty could be independently associated with later progression to PDR [24].…”

Five-year incidence and progression of diabetic retinopathy in a defined older population: the Blue Mountains Eye Study

“…These findings are consistent with recent data on glycaemic control in older type II diabetes subjects from the United Kingdom Prospective Diabetes Study. 19 Strengths of this study include its population-based sample and stereo retinal photographic documentation of the retinopathy level, graded initially by LC and adjudicated by a retinal specialist (PM). The limitation of our study is a relatively low follow-up rate among participants with diabetes compared to an overall follow-up rate of 75% in the whole study sample.…”