Serum or urinary concentration of type IV collagen in diabetics

Concentrations of serum or urinary type IV collagen, determined by sandwich enzyme immunoassay, were significantly elevated in diabetics compared to controls (P less than .01). Serum or urinary levels of type IV collagen were significantly increased in patients with microangiopathy compared to those without microvascular disease (P less than .05). Serum type IV collagen levels were also augmented in diabetics who showed an increased albumin index for 1 year. Serum levels of type IV collagen were not affected by any conditions of metabolic control. The measurement of serum or urinary type IV collagen may be a useful indicator for monitoring the development of diabetic microangiopathy, especially in early diabetic nephropathy.