medwireNews: Being overweight or obese in early childhood is associated with having increased cardiometabolic risk in preteens, researchers report.
The study participants, drawn from the Longitudinal Study of Australian Children birth cohort, comprised 1811 children who had participated in a physical health check at age 11–12 years and had at least one cardiometabolic health measure plus early-life BMI available.
Kate Lycett (The Royal Children’s Hospital, Parkville, Victoria, Australia) and co-researchers calculated a metabolic syndrome risk score based on four of the five standard components (systolic blood pressure, high-density lipoprotein cholesterol, triglycerides and blood glucose), omitting BMI because this was the exposure of interest.
Overall, they found that cardiometabolic risk at age 11–12 years was associated with overweight/obesity status in early childhood, with overweight from age 4–5 years and obesity from age 2–3 years predicting poorer cardiometabolic health in later childhood.
For example, the metabolic syndrome risk score at age 11–12 years was on average 0.23 standard deviation (SD) units greater in children who had been overweight at age 6–7 years and 0.76 SD units greater in those who had been obese than in those who had a healthy BMI at this age.
Carotid–femoral pulse wave velocity – a measure of arterial stiffness – was significantly higher in children who were obese at the age of 4–5 years or older than in those who had a healthy weight. And carotid artery intima media thickness, which is a measure of early atherosclerosis, was slightly but significantly greater in children who were obese at the age of 2–3 years or older.
The researchers adjusted these associations for factors including age, puberty status, socioeconomic status, passive smoke exposure and whether the children were born small for gestational age. They note that the amount of variance in cardiometabolic risk directly explained by childhood BMI was “relatively small”, but stress that this would increase with age and would regardless be important at a population level.
The team also identified five BMI trajectories in the cohort. Four of these were stable trajectories of low, healthy, high and very high BMI, with BMI SD scores remaining at approximately –1, 0, +1 and +2, respectively. The fifth trajectory, of low to high BMI, started at a BMI SD score of approximately –1, at age 2–3 years, and rose to around +1 by age 10–11 years.
Children with stable very high BMI had the poorest cardiometabolic health at age 11–12 years, by all measures.
In a linked commentary accompanying the article in Pediatrics, Sarah Armstrong, from Duke Clinical Research Institute in Durham, North Carolina, USA, and co-authors highlight the implications of these trajectories, stating: “Simply put, infants and toddlers with obesity are unlikely to ‘grow out of it’.”
They add: “In this study, it is definitively established that obesity by age 3 is predictive of future obesity up to early adolescence, and evidence is added that risk for cardiovascular disease accumulates the earlier children develop their obesity.
“The point cannot be understated: early-onset obesity is unlikely to change and, if it persists, will lead to detectable precursors of atherosclerosis by the time a child enters middle school.”
By Eleanor McDermid
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Pediatrics 2020; 146: e20193666
Pediatrics 2020; 146: e20201353