Plasma levels of cellular fibronectin in diabetes

OBJECTIVE- Cellular fibronectin is an endothelium-derived protein involved in subendothelial matrix assembly. Elevated plasma levels of cellular fibro nectin therefore reflect loss of endothelial cell polarization or injury to blood vessels. Consequently, elevated plasma levels of circulating cellula r fibronectin have been described in clinical syndromes with vascular damag e, although not in diabetes or atherosclerosis. RESEARCH DESIGN AND METHODS- We determined fibronectin levels in 52 patient s with type 1 diabetes, 50 patients with type 2 diabetes, 54 patients with a history of ischemic stroke, 23 patients with renal artery stenosis, and 6 4 healthy subjects. RESULTS- Circulating cellular fibronectin was significantly elevated in pat ients with diabetes (4.3 +/- 2.8 mug/ml) compared with patients with ischem ic stroke (2.0 +/- 0.9 mug/ml), patients with renovascular hypertension (1. 7 +/- 1.1 mug/ml), and healthy subjects (1.4 +/- 0.6 mug/ml). Patients with diabetes and at least one cardiovascular risk factor had an almost 2.5-fol d increase in cellular fibronectin compared with diabetic subjects without such a risk factor. In multivariate regression analysis, higher triglycerid es, current or past cigarette smoking, and higher urinary albumin excretion were independently associated with an increase in circulating cellular fib ronectin in diabetes. CONCLUSIONS- These results suggest that circulating cellular fibronectin ma y be a marker protein for endothelial cell activation, especially in diabet es. Prospective studies are needed to explore this possibility.