Lipoprotein (a) and other risk factors in children with insulin-dependent diabetes mellitus and children without diabetes.

Aims: To study serum Lp (a) levels and other metabolic cardiovascular risk factors in children with type 1 diabetes mellitus (DM) as compared to sex and age matched nondiabetic children. The correlation of Lp (a) serum levels and other lipid parameters with HbA1c concentration in diabetic children was investigated.

Design: Transversal observational study.

Target population: 36 C-peptide negative Type 1 diabetic children without microalbuminuria and no macromicrovascular nor neurological complications, aged 8 to 15 years; 17 boys, 19 girls. Mean duration of Type 1 diabetes was 4.99 +/- 3.04 years, daily insulin needs 32.79 +/- 12.64 Units. 41 healthy children with no family history of diabetes mellitus, aged 8 to 15 years, 26 boys, 15 girls, were studied in parallel as the control group.

Methods: Serum total cholesterol and triglycerides were assayed by enzymatic methods, High-density lipoprotein (HDL) cholesterol by enzymatic method after precipitation of very-low-density (VLDL) and low-density lipoprotein (LDL) fractions. The LDL fraction was estimated after serum precipitation as the difference between total cholesterol and supernatant cholesterol concentrations. Apo-AI, apoA-II and apo-B were measured by radial immunodiffusion assays. Serum Lp(a) was measured by a monoclonal anti-Lp(a) antibody (ELISA) method and whole blood glycosylated hemoglobin A1c (HbA1c) by high resolution liquid chromatography.

Results: HbA1c concentration in diabetic children was 7.51 +/- 1.54% vs 4.16 +/- 0.35% in nondiabetic children. Lp(a) serum levels did not significantly differ among both groups (25 +/- 22 mg/dl in diabetics; 22 +/- 22 mg/dl in controls). Significant correlation was found between HbA1c levels and each of TC, LDL and TG serum concentrations in the diabetic group. Lp (a) levels were only correlated with glycated hemoglobin in the two patients showing the highest levels of HbA1c; in the diabetic group: HbA1c 10.9 and 11.5%.

Conclusions: In 36 children aged 8-15 years with uncomplicated Type 1 diabetes for less than 15 years duration, Lp (a) serum levels were positively correlated with HbA1c only in two of them showing the poorest metabolic control.