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) compared to sex and age matched nondiabetic children. The correlation of Lp(a) serum levels and other lipid parameters with HbA1c concentrations in diabetic children was investigated.

DESIGN

Transversal observational study.

TARGET POPULATION

36 C-peptide negative Type 1 DM children without microalbuminuria and no macromicrovascular or neurological complications, aged 8 to 15 years; 17 boys, 19 girls. Mean duration of Type 1 DM was 4.99 +/- 3.04 years, daily insulin need were 32.79 +/- 12.64 Units. 41 healthy children with no family history of DM, aged from 8 to 15 years, 26 boys, 15 girls, were studied in parallel as the control group.

METHODS

Serum total cholesterol (TC) and triglycerides (TG) 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 fractions was estimated after serum precipitation as the difference between total cholesterol and supernatant cholesterol concentrations. Apo-AI, apo-AII and apo-B were measured by radial immunodiffusion assays. Serum Lp(a) was measured by 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 +/- 54% vs 4.16 +/- 0.35% in non diabetic children. Lp(a) serum levels did not significantly differ among both groups (25 +/- 22 mg/dl in diabetics subjects, 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 correlated with glycated hemoglobin in the whole diabetic group. But, in the 2 patients with the poorest metabolic control (HbA1c 10.5%) were excluded, the correlation disappeared.

CONCLUSIONS

In 36 children aged 5-15 years with uncomplicated Type 1 DM lasting less than 15 years, Lp(a) serum levels did not differ from age-matched controls but highest Lp(a) values were associated with poorest metabolic control.