Relationship of muscle capillary basement membrane thickness and diabetic retinopathy.

We examined the relationship between the thickness of the quadriceps muscle capillary basement membrane and diabetic retinopathy. Basement membrane thickness was measured in two groups of patients with long-standing type II diabetes mellitus. One group of patients (N = 13) had no evidence of diabetic retinopathy on fluorescein angiography, whereas the other (N = 12) had proliferative microvascular disease. All the patients were male, and both groups were of similar ages, duration of diabetes, serum creatinines, and glycemic control as reflected by HbA1 levels. Mean muscle capillary basement membrane width (+/- SE) of the patients with proliferative retinopathy (3346 +/- 262) was significantly greater (P less than .05) than that observed in the patients without retinopathy (2660 +/- 177). The results of this study suggest that there is a relationship between capillary basement membrane thickness in skeletal muscle and the severity of microangiopathy in the eye. However, there was a substantial overlap between the two groups, indicating that for any individual patient the measurement of muscle capillary basement width will probably not be useful in identifying the presence or absence of retinopathy.