Materials for this week:
- Case and discussion
- NHLBI Expert Guidelines on Cardiovascular Health in Children and Adolescents 2011 – see Table 9-1 for Recommended Lipid Levels (page 38) and Table 9-5 for Evidence-based recommendations for lipid assessment (page 42)
- Who should be recommended for lipid testing? It depends on if you follow targeted screening vs universal screening, or if you believe in no benefit of screening in childhood. The 2011 NHLBI guidelines recommend targeted screening for children 2-8 years old and adolescents 12-16 years old and universal screening for children 9-11 years old and adolescents 17-21 years old. The repeat is done at age 17-21 to assess after puberty which can alter levels. These same recommendations are endorsed by the AAP. In the targeted approach, screening is indicated in children or adolescents with a positive family history of dyslipidemia or premature cardiovascular disease (CVD) (including parent or 2nd degree relative <55 male, <65 female), an unknown family history, or children with other risk factors for CVD, like obesity, hypertension and diabetes.
- If you are screening, what tests would you do? In the NHLBI guidelines, the recommendation for universal screening was to use non-fasting lipids and calculate the non-HDL-C as follows: Non-HDL-C = total cholesterol (TC) – HDL-C. If the non-HDL-C was >=145, then do follow-up with fasting lipid panel. For targeted screening, the rec was getting an average of 2 sets of fasting lipid profiles (FLP) separated by 2 weeks to 3 months (as the individual levels can vary by up to 30mg/dl). Triglycerides (TG) are much more likely to be overestimated with non-fasting draw, but total and non-HDL levels are considered more reliable when non-fasting. All of this seems much more complicated, and in practice, most pediatricians may only obtain one measurement.
- What is the first-line treatment for elevated lipids? Initially, we recommend lifestyle intervention, including more fruits, vegetables, fish, wholegrains and low-fat dairy products, with reduced intake of fruit-juice, sugar-sweetened beverages and foods, and decreasing salt. We also recommend physical activity and losing weight, if appropriate. The fact that we essentially recommend this diet for all children is partly why many advocate not testing lipids because it does not change recs unless you have serious disease, which is rare. To treat overall elevated cholesterol or LDL, we focus more on dietary fat intake, but to treat elevated TG, we focus more on sugar and carbohydrate intake.
- If children have higher lipid levels that don’t respond to diet or have familiar hypercholesterolemia (FH), what is the treatment? There is more controversy here as well! The NHLBI guidelines do not recommend medication for children under 10 unless they have severe primary hyperlipidemia or a high-risk condition associated with serious morbidity. For children with FH, statin treatment in childhood is associated with improved carotid thickness. For children ≥10 years, starting a statin is recommended for those who have persistent elevated LDL (range from 130-190 based on family history and risk factors) after 6 months of lifestyle changes, with the goal of lowering LDL to below the 95th percentile (≤130 mg/dl). The safety of statins for long-term use has not been adequately studied for children, so we usually consult a specialist before starting statins. Routine monitoring for muscle and hepatic toxicity with CPK and transaminase levels would be done for patients on statins.
- When do we refer to a specialist and which one? Referral to a specialist has been recommended for those with LDL ≥250 mg/dl and TG ≥500 mg/dl even before a trial of lifestyle management, or when more than one lipid-lowering medication may be needed (such as a bile acid sequestrant or cholesterol absorption inhibitor). Around the country, different specialists manage lipids; in our region, the Endocrine Division runs the lipid clinic so patients would be referred to them when needed.