Ultrastructural aspects of the liver perisinusoidal space in diabetic patients with and without microangiopathy.

To determine whether abnormalities of the perisinusoidal space of Disse are present in the liver of diabetic patients with microangiopathy, an ultrastructural stereologic study of the space of Disse was performed in six insulin-treated diabetics with severe performed in six insulin-treated diabetics with severe proliferative retinopathy and six insulin-treated diabetics with normal fluorescein angiography, six patients with familial unconjugated hyperbilirubinemia were studied as controls. No patient had clinical and/or biochemical hepatic abnormalities and none suffered from any of the pathologic conditions known to be associated with collagenization of the perisinusoidal space. In control patients, the space of Disse of liver sinusoids contained occasional small deposits of collagen fibers. The relative volume of these fibers per unit of sinusoid represented 2.63 +/- 0.82%. In all diabetic patients with retinopathy, marked deposition of collagen fibers within the perisinusoidal space was constantly observed, a finding confirmed by ultrastructural stereologic analysis which showed that the relative volume of collagen fibers per unit of sinusoid represented 7.33 +/- 1.44% and differed significantly from control patient values (P less than 0.001). On the contrary, the relative volume of collagen fibers within the space of Disse in diabetic patients without retinopathy (3.95 +/- 2.96%) did not differ significantly from control patient values. These findings demonstrate that collagenization of the space of Disse is positively correlated with the presence of diabetic microangiopathy. Ultrastructural examination of the liver sinusoids might constitute a sensitive and useful approach for detecting the early changes of the microcirculation in diabetic patients.