Platelet aggregation related to age in diabetes mellitus

Platelet aggregation induced by ADP and collagen was studied in 174 diabetic patients before entering a controlled clinical trial. The clinical characteristics have been precisely defined. The degree of retinal abnormality was assessed by fundus angiofluorography in every patient. Most patients had background retinopathy; the remainder were normal. All results were computer analysed. The only significant relationship observed was between platelet sensitivity to ADP which increases regularly in relation to age in both insulin- and non-insulin-treated diabetic patients with or without background retinopathy. Spontaneous platelet aggregation was observed in 13 subjects and was not correlated to the existence of a neuropathy or any other clinical characteristics.