Lipoprotein(a) levels in black and white children and adolescents with IDDM

To examine the relationship between levels of lipoprotein(a) [Lp(a)], diabetes, and glycemic control in white and black nondiabetic control and insulin-dependent diabetic (IDDM) children and adolescents, fasting blood analyses were conducted on a subject sample drawn from referral-based diabetes and endocrine clinics and a primary-care general pediatric clinic.

Thirty-six white and 16 black children with IDDM who volunteered to participate in this study were compared with 30 white and 42 black nondiabetic control children.

Lp(a) protein levels were significantly higher (P less than 0.05) in both groups of black children compared with whites (black vs. white nondiabetic children 6.8 +/- 0.95 vs. 3.1 +/- 0.68 mg/dl and black vs. white diabetic children 7.5 +/- 1.52 vs. 3.0 +/- 0.64 mg/dl). Lp(a) protein levels directly correlated with the level of glycosylated hemoglobin (r = 0.46, P less than 0.01) in white diabetic children but not in black diabetic children. Well-controlled white diabetic children (n = 12, glycosylated hemoglobin less than 10%) had a mean Lp(a) protein level of 1.4 +/- 0.3 mg/dl compared with poorly controlled white diabetic children (n = 10, glycosylated hemoglobin greater than 13%) whose mean Lp(a) protein level was 5.7 +/- 1.7 mg/dl (P less than 0.01).

We conclude that circulating levels of Lp(a) protein are increased in hyperglycemia. A genetically determined elevated level of Lp(a) is a risk factor for atherosclerotic disease in white and Asian adults. Elevated Lp(a) should be investigated as an independent risk factor for atherosclerotic disease in IDDM. It could prove to be an additional mechanism for the development of diabetic complications in selected populations.