Altered platelet functions in non-insulin-dependent diabetes mellitus (NIDDM).

We have studied platelet aggregation and membrane fluidity, along with various biochemical parameters, in 19 non-insulin-dependent diabetes mellitus (NIDDM) patients prior to control of blood sugar, 11 patients after control of blood sugar, and 26 normal subjects. Platelet cholesterol: phospholipid ratio and basal levels of)[Ca+] were comparable between normal and uncontrolled NIDDM. Basal levels of malonaldehyde (MDA) and the levels of [Ca++]i, as well as MDA after the addition of arachidonic acid, were 2.5-fold, 5-fold, and 2.5-fold higher, respectively, in the uncontrolled NIDDM group than normals. Platelet aggregation in response to ADP (0.25 microM), epinephrine (1.25 microM), and arachidonic acid (0.25 mM) was significantly higher in uncontrolled NIDDM than in normals (75%, 40% and 52%, respectively). Platelet fluorescence polarization was also higher in NIDDM patients indicating decreased membrane fluidity in such patients as compared to normals. After control of blood sugar in 11 NIDDM patients, agonist-stimulated platelet aggregation and other biochemical parameters were comparable to normals.