Reduced forearm reactive hyperaemia in normoalbuminuric subjects with Type 1 diabetes and retinopathy

Aim  To determine whether the forearm vasodilatory response to reactive hyperaemia (RH) is reduced in normoalbuminuric subjects with Type 1 diabetes mellitus and retinopathy compared with subjects with no retinopathy. Methods  Forearm RH, an indicator of endothelial function, was measured, using strain-gauge plethysmography, in 39 normoalbuminuric subjects (22 with retinopathy) with long-standing Type 1 diabetes mellitus. Results were evaluated in relation to conventional risk factors for atherosclerosis, and C-reactive protein (CRP), which we have recently determined to be an independent correlate of forearm RH. Results  Forearm RH was decreased in subjects with retinopathy compared with those with no retinopathy (219 ± 182 vs. 473 ± 355, P < 0.01). Both retinopathy and CRP proved to be independent and negative predictors, and explain 27% of the variance, in forearm RH. Conclusion  Retinopathy in subjects with Type 1 diabetes mellitus may reflect a generalized process of endothelial dysfunction, even in the absence of microalbuminuria.