Children who were overweight or obese at ages 2-3 years and at 6-7 years were significantly more likely than were healthy-weight children to show cardiometabolic risk factors at 11-12 years in a population-based study of more than 5,000 children.
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Previous studies of the impact of childhood body mass index on cardiovascular disease have used a single BMI measurement, wrote Kate Lycett, PhD, of Deakin University, Victoria, Australia, and colleagues. “This overlooks the considerable physiologic changes in BMI throughout childhood as part of typical growth.”
In a study published in Pediatrics, the researchers examined overweight and obesity at five time points in a cohort of 5,107 infants by measuring BMI every 2 years between the ages of 2-3 years and 10-11 years.
Overall, children with consistently high BMI trajectories from age 3 years had the highest risk of metabolic syndrome. At age 6-7 years, overweight and obese children had, respectively, higher metabolic syndrome risk scores by 0.23 and 0.76 mean standard deviation (SD) units, compared with healthy-weight children; these associations approximately doubled by age 11-12 years.
In addition, obese children had higher pulse wave velocity (PWV) from age 6-7 years (0.64-0.73 standard deviation units) and slightly higher carotid artery intima-media thickness (cIMT) at all measured ages, compared with healthy-weight children (0.20-0.30 SD units).
The findings were limited by several factors, including the inability to evaluate the effects of BMI on actual cardiovascular disease because of the young age of the study population, the researchers noted.
However, the “results are in keeping with previous studies but provide additional important insights that suggest BMI from as early as 2 to 3 years of age is predictive of preclinical cardiometabolic phenotypes by ages 11 to 12 years,” Dr. Lycett and associates said. The results have implications for public health by highlighting the subclinical effects of obesity in childhood and the importance of early intervention, they concluded.
“This important and comprehensive study has two important implications: first, high BMI by age 2 to 3 tends to stay high, and second, normal BMI occasionally increases to high BMI, but the reverse is rarely true,” Sarah Armstrong, MD, Jennifer S. Li, MD, and Asheley C. Skinner, PhD, wrote in an accompanying editorial (Pediatrics. 2020 Jul 6. doi: 10.1542/peds.2020-1353).
noted the editorialists, who are affiliated with Duke University, Durham, N.C.
“An important caveat is that although the relationships were significant, the amount of variance attributable directly to child BMI was small,” which highlights the complex relationship between obesity and health, they noted.
“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,” and parents and primary care providers have an opportunity to “flatten the curve” by addressing BMI increases early in life to delay or prevent obesity, the editorialists concluded.
The study was supported by Australia’s National Health and Medical Research Council, The Royal Children’s Hospital Foundation, Murdoch Children’s Research Institute, The University of Melbourne, National Heart Foundation of Australia, Financial Markets Foundation for Children, and Victorian Deaf Education Institute. A number of the researchers were supported by grants from these and other universities and organizations. The researchers had no relevant financial disclosures. The editorialists had no financial conflicts to disclose.
SOURCE: Lycett K et al. Pediatrics. 2020 Jul 6. doi: 10.1542/peds.2019-3666.