A study by the Instituto de Saúde Pública da Universidade do Porto (ISPUP) concluded that children whose adiposity rebound happens earlier have higher levels of adiposity and worse cardiometabolic indicators at the age of 10, which may place them on a worse health trajectory.
During the first year of life, a child’s body mass index (BMI) reaches its maximum, then decreases until it reaches a minimum value, normally at around 5-7 years of age, when it increases again all the way up to adulthood. The minimum point before the second increase in BMI is called the adiposity rebound.
The age at which the adiposity rebound occurs has been described as a predictor of the development of obesity in adolescence and adulthood. Usually, this rebound occurs between 5 and 7 years of age.
Several studies have shown that children whose adiposity rebound happens earlier tend to develop, throughout life, higher levels of adiposity and obesity, as well as worse cardiometabolic indicators.
ISPUP researchers assessed the correlation between the age at which adiposity rebound occurs and cardiometabolic health throughout childhood, using data from 3372 children participating in the Generation XXI cohort – a longitudinal study that has, since 2005, followed around 8600 children born in public maternity hospitals in the Metropolitan Area of Porto, in Portugal.
“We took advantage of the large amount of longitudinal information on growth measures that the Generation XXI cohort provides and assessed the effect of the timing of adiposity rebound on the development of adiposity and on the change in cardiometabolic indicators, already at 10 years of age”, says Ana Cristina Santos, research coordinator of the study published in the International Journal of Epidemiology.
Over 40% of Generation XXI children have an early adiposity rebound
The research concluded that almost half (47.2%) of the children experienced this phenomenon within a period that is considered normal: between 5 and 6 years of age.
However, in 12.7% of children, the adiposity rebound happened very early (around three and a half years of age) and in 29.9% of the children it happened early: between three and a half and five years of age. This means that over 40% of the Generation XXI children had an earlier than expected rebound.
Children whose rebound occurred earlier had higher adiposity levels and a worse cardiometabolic profile at 10 years of age, including higher blood pressure, higher levels of insulin, triglycerides and C-reactive protein, and lower levels of HDL cholesterol, which is considered a protective factor in the prevention of cardiovascular disease.
“We found that these children, despite not being ill already exhibit worse cardiometabolic indicators at 10 years of age and are therefore at a greater risk of developing more adverse health conditions throughout their lives,” stresses the ISPUP researcher.
The next steps
The next step will consist in understanding which are the determinants that lead to an earlier than normal adiposity rebound in children.
“We want to identify which are the modifiable factors that determine this occurrence and act on these determinants, so as to minimise the number of children who experience adiposity rebound earlier.”
The research developed under the Epidemiology Research Unit (EPIUnit) of ISPUP is called Adiposity rebound and cardiometabolic health in childhood: results from the Generation XXI birth cohort. Researchers Maria João Fonseca and Carla Moreira also sign the study.
Image: Unsplash/Jamie Taylor
