Complements in non-insulin-dependent diabetes mellitus with complications.

A relation of the complement system to the development of complications in non-insulin-dependent diabetes mellitus (NIDDM) was evaluated by measuring some components of the complement system. CH50, C3, C4 and C3bINA were significantly elevated in subjects with NIDDM as compared with healthy non-diabetic controls. However, CH50 and C3 did not differ between diabetics with and without complications. C4 was higher in diabetics with retinopathy as well as with retinopathy and neuropathy than in diabetics without these complications. ACH50, beta 1Hg1 and C3d were similar in subjects with NIDDM and non-diabetics, and not associated with complications of NIDDM. C3d/C3 in NIDDM without complications was lower than in healthy subjects, but did not significantly differ between the types of complications. These results suggest that the high level of complements in NIDDM might be due to enhanced production of complements and the development of diabetic complications would be related to the elevated level of complements.