Changing prevalence of retinopathy in newly diagnosed non-insulin dependent diabetes mellitus patients in Hong Kong

Abstract

In this retrospective study, the prevalence of chronic microangiopathic complications was determined in 474 Chinese patients with non-insulin dependent diabetes mellitus (NIDDM) who presented within l year of diagnosis to the diabetes clinic from January 1990 to December 1996. Mean age (± S.E.) was 53.6 (± 0.6) years. The overall prevalence of retinopathy was 21.9%. A significant increase was observed from 1990 to 1994 (P < 0.005), with the prevalence being 14.8, 13.0, 24.5, 32.3 and 35.4%, respectively, in consecutive years. A decreasing prevalence was seen from 1994 to 1996 (P < 0.001), being 8.2 and 7.4% in 1995 and 1996, respectively. A total of 95% of patients had nonproliferative retinopathy - proliferative retinopathy was found in 5% only. The overall prevalence of clinical nephropathy (proteinuria > 0.5 g/day) was 3.7%. Clinical neuropathy (increased vibration perception threshold) was found in 12.8% of patients. Patients with retinopathy and neuropathy were older (P < 0.0001 and P < 0.005, respectively) than those without the complications and systolic hypertension was more prevalent in patients with retinopathy (P < 0.05). In conclusion, a high prevalence of diabetic microangiopathic complications, especially of retinopathy, is present in newly diagnosed NIDDM patients in our population. It remains to be determined whether the changing prevalence of retinopathy at diagnosis bears any relationship to the increasing public awareness of diabetes and its complications in Hong Kong in recent years. Examination for chronic microangiopathic complications should be carried out in all newly diagnosed NIDDM patients.