Cardiovascular risk in children: apoB/apoA1 and non-HDL-cholesterol

Objective: Atherosclerosis starts in childhood although clinical manifestations of cardiovascular disease (CVD) do not usually emerge before middle age. Clinical studies have established that elevated cholesterol (TC) and triglyceride (Tg) levels, low high density lipoprotein-cholesterol (HDL-C) and raised Lipoprotein(a) (Lp(a)) levels are associated with increased CVD risk. Measurements of TC, LDL cholesterol (LDL-C) and HDL-C are widely recommended for CVD risk assessment. However many studies in adults have demonstrated that apolipoprotein B (apoB) and apolipoprotein A-I (apoA-I) and their ratio have a greater prognostic value than LDL-C. Furthermore, it is increasingly being recognized that the non-HDL-C level is a simple and accurate index of CVD risk. Aim of the study was the evaluation of TC, LDL-C, apoB and apoA-I levels, apoB/apoA-I ratio and non-HDL-C in a cohort of children affected by primary dyslipidemia, divided in two groups according to the family history of CVD. Methods: we studied 285 children aged 10.04 ± 3.34 years (89 FH, 88 FCHL, 54 dominant Hypercholesterolemia, 40 Hyperlipoprotein(a), 11 Familial hypertriglyceridemia, 2 Hyperchilomicronemia, 1 Phytosterolemia) with a family history of dyslipidemia and/or premature cardiovascular disease and 74 controls (age 9.35 ± 4.71 years). TC, HDL-C, Tg, apoB and apoA-I were evaluated after an overnight fasting. LDL-C was estimated usig the Friedewald formula while non-HDL-C was calculated as TC minus HDL-C. Patients were divided in two groups according to a positive (group 1) or negative (group 2) family history of CVD. Results: dyslipidemic children showed TC, LDL-C, apoB, apoB/apoA-I ratio and non-HDL-C levels significantly higher (p<0.001) than controls. We found differences of non-HDL-C and apoB/apoA-I ratio levels comparing the two groups of patients, however they only approached the statistical significance resulting p=0.085 and p=0.06 respectively. Any difference of TC, LDL-C and apoB was detected. Conclusion: The present findings indicate the prognostic value of childhood apoB/apoA-I ratio and non-HDL-C levels in evaluating CVD risk. Measurement of apolipoproteins (apoB and possibly apoA-I) should be routinely added to the standard lipid profile (TC, Tg, HDL-C) to assess the atherogenic potential of lipid disorders. This is particularly relevant to dyslipidemias characterized by an elevation in plasma triglycerides. The apoB/ApoA-I ratio and non-HDL-C represent an advantage over traditional lipid variables for risk prediction and especially apoB could also replace the standard ‘lipid profile’ as a target for therapy in at-risk patients.