IS HYPERTENSION A MAJOR INDEPENDENT RISK FACTOR FOR RETINOPATHY IN TYPE-1 DIABETES

Hypertension is an established risk factor for retinopathy. Whether it is an independent risk factor or acts only by association with nephropathy is not known. Therefore, we studied 273 Type 1 diabetic patients. They were divided into four groups. Group 1 (n = 55) were normotensive and normoalbuminuric, group 2 (n = 51) had hypertension but were normoalbuminuris, group 3 (n = 33) had nepropathy but were normotensive, and group 4 (n = 134) had nephropathy and hypertension. Hypertensive patients with normoalbuminuria (blood pressure 146 +/- 19 (+/- SD)/87 +/- 12 mmHg) had the same prevalence of retinopathy as normoalbuminuric normotensive patients (123 +/- 12/75 +/- 5 mmHg). Hypertensive nephropathic patients (blood pressure 147 +/- 18/87 +/- 8 mmHg) had more retinopathy than hypertensive normoalbuminuric patients despite similar blood pressure (normal retina/advanced retinopathy: 3 %/73 % vs 46 %/17 %, p < 0.001). Nephropathic normotensive patients had worse retinal changes than hypertensive normoalbuminuric patients (19 %/49 %, p < 0.001) but fewer than the nephropathic hypertensive patients p < 0.001). Thus hypertension per se is not associated with increased retinal changes but may aggravate these in patients with clinical nephropathy.