Biorheological and metabolic dysfunctions of density-fractionated erythrocytes in diabetics with peripheral vascular disease.

Preliminary communications are presented about a serial study of biorheological and metabolic dysfunctions of density-fractionated erythrocytes (RBC) in diabetics with vaso-occlusive disorders. The study aimed at evaluating the influence of metabolic disorder due to diabetes mellitus on RBC substrates, deformability and glycohaemoglobin (HbA1) levels. The peak HbA1 level served to confirm the duration of serum metabolic disorder due to diabetic crisis. The rheological and metabolic changes of RBC were compared with serial estimations repeated on the same patients when asymptomatic concerning diabetes after insulin therapy. RBC deformability was measured optoelectronically by microcomputer-assisted polymicroviscometry (filtrometry) following separation of RBC into old (dense) and young (buoyant) fractions by means of density-layer centrifugation. 15 adult patients with diabetes mellitus typ II associated with macroangiopathy Fontaine II underwent RBC investigations before and after diabetic therapy. Those RBC fractions containing older cells disclosed an impaired metabolism, increased HbA1 levels and markedly altered deformability which significantly differed from values obtained from young RBC. But after insulin-therapy old RBC fractions only revealed persistently an increase of HbA1 levels and metabolic disorder associated with a still altered deformability, in contrast to young RBC which in again showed normal values. The preliminary results suggest an adaptable alteration of RBC metabolism and function in diabetes, predominantly existing in old RBC, but after insulin-therapy still persisting only in old (dense) fractions. Thus, a prolonged pathologic effect of older RBC occurred in diabetes probably resulting in a further persistent maintenance of diabetic vascular disease.(ABSTRACT TRUNCATED AT 250 WORDS)