Hemorheological studies in the diabetes control & complications trial

Abstract

The Diabetes Control and Complications Trial (DCCT), an NIH-sponsored study being conducted at 29 institutions in the US and Canada, was designed to examine the effects of close control of type I diabetes. It was started in 1979 and randomized its 1441st (last) patient in July, 1989. Half had diabetes of 1–5 years duration and no microvascular complications and half had diabetes for 5 or more years and background retinopathy. The study will be completed by June, 1994. HbA1c levels and complications information have been recorded, including hypoglycemic events, neurobehavioral changes, retinopathy evaluated both ophthalmologically and using retinal photographs, and kidney function impairment measured as proteinuria and glomerular filtration rate.

I measured plasma levels of fibrinogen, haptoglobin, albumin and total protein from 1347 DCCT patients from April to August of 1991. Treatment classification and HbAlc levels will not be available until the study is completed, but other information was made available for analysis. Fibrinogen (quantitized both by coagulation amount and by clotting time after dilution) and haptoglobin were elevated in diabetes, both being higher in females than males (fibrinogen 9% and haptoglobin 16%). Albumin was more depressed and globulin more elevated in females. Correlations between the four measured parameters were significant but low enough to conclude that they were independently affected. Smoking (n=211) raised fibrinogen 6% and haptoglobin 18% in diabetes. Pregnancy (n=24) raised fibrinogen level 18% while lowering haptoglobin 40% and albumin 16%. The lowering of haptoglobin was unexplained but similar to that described in nondiabetic pregnancy. The increase in acute phase protein level found in type I diabetes was similar to that seen in trauma, inflammation, or neoplasm in nondiabetics; the effect of smoking to further raise protein levels was small, suggesting that the stimulation of acute phase protein changes by smoking and diabetes may operate through a common mechanism.