Diabetes Care, Vol 16, Issue 2 445-449, Copyright © 1993 by American Diabetes Association
Plasma C3d levels and ischemic heart disease in type II diabetes
A Figueredo, JL Ibarra, J Bagazgoitia, A Rodriguez, AM Molino, A Fernandez-Cruz and R Patino
Department of Internal Medicine III, Hospital Universitario de San Carlos, Madrid, Spain.
OBJECTIVE--To test the hypothesis that the complement system may be
activated in patients with type II diabetes and CAD. RESEARCH DESIGN AND
METHODS--The plasma C3d concentration was measured in 106 type II diabetic
patients and 25 nondiabetic control subjects. The patient group was
subdivided according to AER, and the groups were adjusted for age, sex, and
known duration of diabetes. For the assignment to a given subgroup,
normoalbuminuria was defined as AER < 15 microns/min, microalbuminuria
as AER 16-250 micrograms/min, and macroalbuminuria as AER > 250
micrograms/min. The presence or absence of coronary disease was assessed
through clinical examination, ECG, and coronary angiography. An RIA system
was used for measurement of urinary albumin levels, and the plasma C3d
concentrations were measured by ELISA. RESULTS--Within each of the
AER-defined subgroups, the plasma C3d levels were significantly higher in
patients with IHD than in those without. Thus, in the normoalbuminuric
group, plasma C3d levels were 16.3 AU/ml (95% CI 13.9-19) in patients with
IHD vs. 11.6 AU/ml (95% CI 10.5-12.7) in those without (P < 0.001). The
corresponding data for the microalbuminuric and macroalbuminuric groups
were 21.8 (95% CI 18.1-26.3) vs. 13.6 (95% CI 12.3-15.1) and 31.6 (95% CI
24.9-40) vs. 17.5 (13.6-22.6) AU/ml (P < 0.01), respectively. Patients
with IHD also had significantly higher plasma C3d levels than normal
control subjects, regardless of AER subgroup. A multiple logistic
regression analysis demonstrated an association between the plasma C3d
concentration and IHD and AER. CONCLUSIONS--Activation of the complement
system may play a role in the development of macrovascular disease in type
II diabetes.