My training in both internal medicine and pediatrics is generally a complementary thing. My internal medicine helps me care for medically complex kids and understand medications better, while my pediatrics training lets me handle adults with congenital diseases and many infectious diseases better. Yet there are some areas where the two areas of training come in conflict with one another. No area is more clearly an area of conflict than that of cholesterol management.
For adults, there are some clear guidelines, and then some areas in which things become murky. Here are the USPSTF recommendations for cholesterol screening in adults:
Summary of Recommendations
- The U.S. Preventive Services Task Force (USPSTF) strongly recommends that clinicians routinely screen men aged 35 years and older and women aged 45 years and older for lipid disorders and treat abnormal lipids in people who are at increased risk of coronary heart disease.Rating: A recommendation.
- The USPSTF recommends that clinicians routinely screen younger adults (men aged 20 to 35 and women aged 20 to 45) for lipid disorders if they have other risk factors for coronary heart disease. (Go to Clinical Considerations for discussion of risk factors.)Rating: B recommendation.
- The USPSTF makes no recommendation for or against routine screening for lipid disorders in younger adults (men aged 20 to 35 or women aged 20 to 45) in the absence of known risk factors for coronary heart disease.Rating: C recommendation.
- The USPSTF recommends that screening for lipid disorders include measurement of total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C).Rating: B recommendation.
- The USPSTF concludes that the evidence is insufficient to recommend for or against triglyceride measurement as a part of routine screening for lipid disorders.Rating: I recommendation.
If you are not familiar with it, the rating system is as follows:
A The USPSTF strongly recommends that clinicians routinely provide [the service] to eligible patients. (The USPSTF found good evidence that [the service] improves important health outcomes and concludes that benefits substantially outweigh harms.)
B The USPSTF recommends that clinicians routinely provide [the service] to eligible patients. (The USPSTF found at least fair evidence that [the service] improves important health outcomes and concludes that benefits outweigh harms.)
C The USPSTF makes no recommendation for or against routine provision of [the service]. (The USPSTF found at least fair evidence that [the service] can improve health outcomes but concludes that the balance of the benefits and harms is too close to justify a general recommendation.)
D The USPSTF recommends against routinely providing [the service] to asymptomatic patients. (The USPSTF found at least fair evidence that [the service] is ineffective or that harms outweigh benefits.)
I The USPSTF concludes that the evidence is insufficient to recommend for or against routinely providing [the service]. (Evidence that [the service] is effective is lacking, of poor quality, or conflicting and the balance of benefits and harms cannot be determined.)
So these guidelines state clearly that high-risk adults (either by age or by risk factors) should be screened for hyperlipidemia. Why? Because the treatment of high cholesterol in high-risk populations (people with diabetes or atherosclerotic disease, for instance) prolongs the life of these individuals (see reference for the first guideline).
The whole thing gets murkier the as the individual risk for atherosclerosis goes down. Even people with other risk factors (diabetes, smoking, high blood pressure, or strong family history get only a "B" recommendation - which is still good enough to follow). Even within the subgroup of males age 20-35, there is significant question of whether a 20-year old smoker who has an LDL of 200 should be treated with anything other than dietary counseling. This is counseling we should be giving to all of our patients, and (as Sandy at Junkfood Science would attest) is largely ineffective at really changing behavior.
So as an internist, I have serious hesitation in even testing the cholesterol in any adults under 35 who do not have risk factors, and I don't quite know how to handle those with increased cholesterol in the younger segment who do have risk factors. This plays greatly into how I respond to the parent who asks me, "when do you check my child's cholesterol?"
Parents have gotten used to hearing about the need for children to get their cholesterol checked. An old policy statement of the American Academy of Pediatrics stated:
This updated statement reviews the scientific justification for the recommendations of dietary changes in all healthy children (a population approach) and a strategy to identify and treat children who are at highest risk for the development of accelerated atherosclerosis in early adult life (an individualized approach). Although the precise fraction of risk for future coronary heart disease conveyed by elevated cholesterol levels in childhood is unknown, clear epidemiologic and experimental evidence indicates that the risk is significant. Diet changes that lower fat, saturated fat, and cholesterol intake in children and adolescents can be applied safely and acceptably, resulting in improved plasma lipid profiles that, if carried into adult life, have the potential to reduce atherosclerotic vascular disease.
The inference is that there is value to know a child has high cholesterol so you can counsel them more aggressively on diet. This statement was retired (meaning retracted) in May of 2006, as the practical implications of testing in children was not clear. In fact, the American Heart Association states clearly that they do not recommend screening cholesterol testing in all children.
Yet the overall perception among the public, and even many pediatricians, is that it is necessary to test all children's cholesterol. Some examples of this include Keepkidshealty.com:
Children who are at high risk of having an elevated cholesterol should have their cholesterol tested. Risk factors include having a parent with an elevated blood cholesterol level of 240mg/dl or higher, being overweight, and/or smoking.
Children with an acceptable total cholesterol of less than 170 mg/dl should have a repeat test within 5 years.
While this does limit it to high risk children, the guidelines are simply not this clear cut.
The same thing is reiterated on eMedicinehealth.com:
Most parents never know their children?s cholesterol levels. Some should. This is not part of routine blood testing done for children during well baby checks or regular exams by children?s health care providers. In fact, the government?s expert panel says that routine screening is not needed for all children and might lead to unnecessary drug treatment because nearly half of children who have high blood cholesterol are likely to have almost normal levels as adults. However, children meeting the following criteria are at risk and should be screened:
- If a parent or grandparent had coronary heart disease when aged 55 years or younger
- If a parent has a blood cholesterol level 240 mg/dL or above (About 90% of children with high cholesterol have a parent who also has high cholesterol.)
- If lipid abnormalities are in the family history
- If a child has a medical condition that predisposes to coronary heart disease, such as severe obesity, physical inactivity, smoking, diabetes, elevated blood pressure, renal disease, and low thyroid activity
- If family history is unknown
The real question I have in this circumstance is: what are you going to do with the results? Imagine the following scenario:
A child has a grandfather who has had a heart attack at age 40 (he was a heavy smoker). The child is significantly overweight, and so a cholesterol test is done (following the above guidelines). The results show a total cholesterol of 250, and an LDL of 180. What do you do? Do you put the child on Lipitor? No way!
It seems to me that the only benefit of testing in this case is that you can scare them into changing their lifestyle (or the parent into changing the child's lifestyle). We can point at the parent and say, "See how you are harming your child by what you are feeding them!" All you do is get information that you cannot practically use from a clinical standpoint.
I do not test anyone under age 25 for elevated cholesterol unless they have significant risk factors for very premature atherosclerosis. These risk factors include diabetes (although type 1 and type 2 convey very different cardiovascular risks), certain childhood diseases (such as Kawasaki's disease) and very premature heart disease in the family (first-degree relatives with CAD in 20's and 30's - not grandparents).
The problem with this is that there is a bit of a PR problem trying to explain to parents who think I am not doing what I should by testing their children. Many of my straight-pediatric colleagues still routinely test children's cholesterol, so parents are surprised when I don't do it. Yet I stand by my choice based on what I think is best for the child, and do my best to explain this to the parents. I don't think that using high cholesterol as a tool to fear-monger is appropriate.
I think I am right in this, but sometimes it is harder to be right.