Blood rheology and cardiovascular risk factors in type 1 diabetes: relationship with microalbuminuria.

Whole blood and plasma viscosity, erythrocyte aggregation and deformability, plasma fibrinogen, lipids, lipoproteins, apolipoproteins, and measures of blood glucose control were compared between 21 Type 1 diabetic patients with microalbuminuria (overnight albumin excretion rate 30-200 micrograms min-1) and 21 patients with albumin excretion below this range matched for age, sex, and duration of diabetes. Patients with microalbuminuria had significantly higher glycosylated haemoglobin (9.4 +/- 1.6 (+/- SD) vs 7.9 +/- 1.8% (normal range 5.0 to 7.6%)), total-cholesterol (5.6 +/- 1.1 vs 4.6 +/- 1.3 mmol l-1), apolipoprotein B (0.82 +/- 0.21 vs 0.66 +/- 0.14 g l-1), and apolipoprotein B:A1 ratio (0.58 +/- 0.18 vs 0.50 +/- 0.15) than those without microalbuminuria (all p less than 0.05). HDL-cholesterol was also raised (1.71 +/- 0.46 vs 1.43 +/- 0.37 mmol l-1, p less than 0.05). Lipoprotein(a) concentration was possibly higher in the microalbuminuric group (median (95% Cl) 105 (82-140) vs 72 (52-114) mg l-1, p = 0.06). No differences were seen in any of the rheological measurements. These results confirm the presence of potentially atherogenic lipoprotein changes in Type 1 diabetic patients with microalbuminuria, but suggest that altered blood rheology does not predate the development of nephropathy.