An analysis of low-density lipoprotein levels in children found similar levels at ages 9 and 18, indicating the importance of early screening.
Elevated levels of low-density lipoprotein cholesterol (LDL-C) leads to the development of atherosclerosis and is a risk factor for cardiovascular disease. Some evidence suggests an association between childhood obesity and the subsequent risk of biochemical abnormalities in adults. Nevertheless, there is a lack of longitudinal data linking the presence of childhood cardiovascular risk factors with adult disease. Furthermore, little is known about the extent to which risk factors such as LDL-C levels vary during childhood and how this might contribute towards atherosclerosis and adverse cardiovascular outcomes in adult life. A better understanding the childhood trajectories of LDL-C cholesterol could lead to improved preventative strategies. In trying to shed more light on this topic, a team from the Division of General Medicine, Columbia University, Irving Medical Centre, New York, turned to data available in the International Childhood Cardiovascular Cohort (i3C) Consortium. While children virtually never experience adverse cardiovascular events, the i3C is the first longitudinal cohort study designed to locate adults with detailed and repeated childhood biological, and physical measurements and includes over 10,000 individuals from several countries. The Irving Medical Centre team used data from i3C individuals who had at least one LDL-C measurement between the ages of 3 and 17 years of age and extracted demographic and body mass index information from these participants. The team considered LDL-C levels greater than 160mg/dl (4.14mmol/l) as consistent with probable familial hypercholesterolaemia (FH) and used the more stringent criteria of an LDL-C of greater than 160mg/dl on at least two occasions and a level of LDL-C of 190mg/dl or greater as a threshold for FH. In order to examine LDL-C trajectories during childhood, the team fitted a linear model of LDL-C against age, adjusting for sex, ethnicity and body mass index.
Findings
A total of 15,045 children with a mean age of 9.9 years (48.7% male) were included in the analysis. Overall, 2.8% of children had an LDL-C greater than 160mg/dl and 0.6% had values exceeding 190mg/dL. Using the more stringent criteria, 1% of children had elevated LDL-C levels (> 160mg/dL) on two occasions and 0.3%, levels above 190mg/dl, consistent with FH. Using the linear model it could be seen that mean LDL-C cholesterol levels increased from age 3 to 10 years, decreased from age 10 to 15 but then increased again to reach adult levels. LDL-C levels were consistently and significantly higher in female children and those of Black ethnicity or with a higher body mass index.
In a discussion of their findings, the authors noted how LDL-C levels peaked between ages 9 and 11 and that these levels were comparable to those aged 18 years. This, the authors suggested, highlighted the importance of childhood lipid screening from as early as 9 years of age.
Citation
Zhang Y et al. Low-Density Lipoprotein Cholesterol Trajectories and Prevalence of High Low-Density Lipoprotein Cholesterol Consistent with Heterozygous Familial Hypercholesterolemia in US Children. JAMA Pediatr 2021
