This year you may notice several changes in the testing (screening) your child's physician does. If your child is between 9 and 11 years old, he or she will be screened for cholesterol via a blood test.
This change is based on a recommendation from the American Academy of Pediatrics(AAP). The AAP creates "Standards of Care" outlining the type and frequency of testing recommended for children.
Studies have shown the single greatest predictor of adult cardiovascular disease is the blood cholesterol level in childhood.
Identifying people with cardiovascular disease/risk (hypertension, obesity, elevated cholesterol, coronary artery narrowing, etc.), and instituting intervention (dietary, exercise, and medication); has decreased the incidence of disease (heart attack, hypertension, stroke) and improved outcome. It is no longer the number one killer of people in the U.S.A.
Treatment certainly works if the patient cooperates; but it can be costly, the drugs used have potential side effects, and while intervention prevents progression of disease it is less effective in reversing the damage already done.
What does a cholesterol screening identify?
Dyslipidemia [elevated total cholesterol, high triglycerides, elevated LDL ("bad cholesterol") and low HDL ("good cholesterol")] is responsible for the pathology in cardiovascular disease.
How does elevated cholesterol hurt the body?
Elevated cholesterol can lead to fat accumulation and fibrous plaque build-up in the blood vessel walls (including the coronary arteries). This plaque build-up is responsible for:
- Plaque narrows the blood vessel, compromising blood flow (elevating blood pressure).
- Over time plaque buildup can totally block a blood vessel (predisposing to heart attack and stroke).
Why screen children?
Fatty streaks and fibrous plaques have been found in the blood vessel walls (including the coronary arteries) of very young children.
The two best studies on cardiovascular disease (the Muscatine and Bogalusa Heart studies) have shown the greatest single predictor of adult hypercholesterolemia (and thus cardiovascular disease) is the blood cholesterol level in childhood.
Correcting dyslipidemia in children not only interrupts disease progression, but can reverse pathology (for example, decrease blood vessel narrowing). It therefore makes sense to screen for cardiovascular disease and dyslipidemia in children.
How should screening be done?
Coronary artery disease is strongly associated instances of dyslipidemia (elevated cholesterol) in the family. Other factors, however, have led to the recommendation.
A family history of coronary artery diseases is strongly associated with dyslipidemia in both children and adults. 1/500 children are heterozygous (meaning both parents have a family history) for familial dyslipidemia and/or cardiovascular disease.
If one screens a population of children with a family history of dyslipidemia and/or coronary artery disease:
- Many of these children will have elevations in their total and low density cholesterol (LDL, "Bad" cholesterol) from birth, and:
- 5% will have a serious coronary artery event before 30 years of age.
- 8-10% of children with a family history of elevated cholesterol will have dyslipidemia
- 1.2-1.5% of those found to have dyslipidemia will have levels high enough to warranty possible drug treatment.
Why screen all children?
If family history alone is used to determine which children should be screened for cardiovascular disease, effected children will be missed.
Studies have indicated up to 30-60% of kids with hypercholesterolemia will be missed because:
- Some people are unaware of their family histories and/or have incorrect information.
- When a group of children with NO FAMILY HISTORY of cardiovascular disease is screened the results are about the SAME AS those with a FAMILY HISTORY; 9-10% will have dyslipidemia (1.5-2% with levels high enough to treat with medication).
For the above reasons the American Academy of Pediatrics has recommended universal non-fasting cholesterol screening for all children (with and without a family history) between 9 and 11 years of age.
Total cholesterol remains stable throughout the day and barely, if at all, fluctuates with what you eat. However the components of cholesterol (the LDL or "Bad cholesterol" and HDL or "Good cholesterol"), are influenced by what you eat and fluctuate throughout the day. Therefore it is recommended cholesterol screening be done on a random non-fasting total cholesterol.
Why screen the 9 - 11 year old age group?
The 9 - 11 year old age group ((prior to the onset of adolescence) was chosen as the age to screen because:
- Children are required by law to be seen about this age, for a "middle school" physical (in Nebraska this happens at 7th grade when children are usually 12 years of age). Most pediatricians in Nebraska would screen a child on his/her 7th grade physical (when 12 years of age) if the child had not been seen and screened between 9-11 years of age.
- LDL ("Bad") cholesterol levels can temporarily fall during puberty (returning to pre-puberty levels once puberty ends). A person with dyslipidemia prior to puberty could appear normal during adolescence, only to return to elevated levels after adolescence.
What if my child has a high result on the non-fasting screening?
If a screening non-fasting cholesterol level is elevated then the child should have a fasting coronary risk panel (blood test); which includes: Cholesterol, Triglycerides, HDL cholesterol, and LDL cholesterol; done to delineate what is going on.
Diagnosis and treatment would be made based on the results of the fasting coronary risk profile shows.
There is more information about the 6 major changes in screening guidelines in this Ask an Expert answer.