OBJECTIVE: To examine the potential associations of lipoprotein(a) and the complications of IDDM and their risk factors. RESEARCH DESIGN AND METHODS: This report focuses on 186 individuals with IDDM (mean age = 34 yr) participating in a 10-yr prospective study examining various complications. Lp(a) concentrations were evaluated for those with and without complications. RESULTS: A weak correlation was seen between Lp(a) and HbA1 (r = 0.16, P < 0.05). Lp(a) concentrations were not significantly different for those with or without proliferative retinopathy, overt nephropathy, peripheral vascular disease, or definite myocardial infarction or angina. However, an inverse association (P < 0.05) was seen with distal symmetric polyneuropathy. These results were also confirmed by categorical analyses (i.e., Lp(a) levels < or = 30 vs. > 30 mg/dl). CONCLUSIONS: These results suggest that any association of Lp(a) concentration with IDDM complications is likely to be weak or nonexistent. However, prospective studies are needed before its full role can be determined.