Pediatric Nutrition in Practice

236 Koletzko^

[triglycerides (mg/dl) × 0.2]. (Cholesterol in mg/
dl is converted into mmol/l by multiplication
with 0.0259.) Increased plasma levels (>30 mg/dl)
of lipoprotein(a), an LDL particle with added
apoprotein(a), are an independent risk factor for
coronary artery disease and juvenile thrombosis.
The liver and gut secrete apoprotein A containing
HDL low in cholesterol (‘nascent HDL’), which
takes up cholesterol from tissues and from VLDL
and LDL and transports it back to the liver. In
contrast to LDL, high plasma levels of HDL are
protective against the development of atheroscle-
rotic diseases. Reference values for plasma lipids,
lipoproteins and apoproteins in children and ado-
lescents are shown in table 2.

Hypercholesterolemia

The heterozygous form of familial hypercholester-
olemia is one of the most frequent inherited meta-
bolic disorders, affecting about 1 in 500 newborns
in Europe and North America. The underlying de-
fect in LDL receptor function is dominantly inher-
ited (i.e. affects ∼ 50% of children of an affected
parent). From the onset of enteral feeding, levels
are markedly increased for LDL cholesterol (usu-
ally >180 mg/dl), total cholesterol (>250 mg/dl)
and apoprotein B (>150 mg/dl; Frederickson hy-
perlipidemia type IIa). In untreated patients, coro-
nary heart disease may manifest itself already in the
third decade of life. Diagnosis is performed based
on repeated measurement of plasma lipoproteins
in the fasted state, family history (dominant inher-
itance) and, if desired, by molecular genetic analy-
sis of the underlying mutation. The rare homo-
zygous form of familial hypercholesterolemia is
found in about 1 of 1,000,000 individuals and leads
to excessive levels of cholesterol (>600 mg/dl) from
infancy due to an almost complete deficiency of
LDL receptor function. Affected children develop
xanthomas already in the first decade of life ( fig. 1 )
and usually die before the age of 20 years unless ef-
fectively treated with extracorporeal LDL apheresis

or liver transplantation. A phenotype similar to the

heterozygous form of familial hypercholesterol-

emia is found in children with familial defective

apoprotein B, which also leads to defective receptor

binding of LDL. Its prevalence is almost as high as

that of the LDL receptor defect. Secondary hyper-

Fig. 1. Xanthomas over the patellae and elbow in a

12-year-old child with homozygous familial hypercholes-

terolemia.

Ta b l e 3. Selected secondary hyperlipidemias in children

and adolescents

Hypercholesterolemias

Acute intermittent porphyria

Anorexia nervosa

Cholestatic liver diseases

Cushing syndrome

Hypothyreosis

Nephrotic syndrome, renal failure, dialysis

Hypertriglyceridemias

Obesity

Diabetes mellitus

Glycogen storage disease type 1

Pancreatitis

Combined hyperlipidemias

Obesity

Diabetes mellitus

Glycogen storage disease type 1

Hepatitis

Nephrotic syndrome, renal failure, dialysis

Drugs: β-blockers, corticoids, estrogens,

progesterone, thiazide diuretics

Pregnancy

Systemic lupus erythematosus

Koletzko B, et al. (eds): Pediatric Nutrition in Practice. World Rev Nutr Diet. Basel, Karger, 2015, vol 113, pp 234–238

DOI: 10.1159/000375191