Adiposity rebound and cardiometabolic health in childhood: results from the Generation XXI birth cohort

Abstract

Background We aimed to evaluate the association of adiposity rebound (AR) timing on cardiometabolic health in childhood. Methods Participants were part of the Generation XXI birth cohort, enrolled in 2005/2006 in Porto. All measurements of the child’s weight and height performed by health professionals as part of routine healthcare were collected. Individual body mass index (BMI) curves were fitted for 3372 children, using mixed-effects models with smooth spline functions for age and random effects. The AR was categorized into very early (<42 months), early (42–59 months), normal (60–83 months) and late (≥84 months). At age 10 years, cardiometabolic traits were assessed and age- and sex-specific z-scores were generated. Adjusted regression coefficients and 95% confidence intervals [β (95% CI)] were computed. Results The mean age at AR was 61.9 months (standard deviations 15.7). Compared with children with normal AR, children with very early or early AR had higher z-scores for BMI [β = 0.40 (95% CI: 0.28; 0.53); β = 0.21 (95% CI: 0.12; 0.30)], waist circumference [β = 0.33 (95% CI: 0.23; 0.43); β = 0.18 (95% CI: 0.10; 0.25)], waist–height ratio [β = 0.34 (95% CI: 0.24; 0.44); β = 0.14 (95% CI: 0.07; 0.22)], fat mass index [β = 0.24 (95% CI: 0.15; 0.33); β = 0.14 (95% CI: 0.08; 0.21)], fat-free mass index [β = 0.25 (95% CI: 0.14; 0.35); β = 0.11 (95% CI: 0.03; 0.19)], systolic blood pressure [β = 0.10 (95% CI: 0.01; 0.20); β = 0.08 (95% CI: 0.01; 0.15)], insulin [β = 0.16 (95% CI: 0.04; 0.29); β = 0.10 (95% CI: 0.01; 0.19)], HOMA-IR [β = 0.17 (95% CI: 0.04; 0.29); β = 0.10 (95% CI: 0.03; 0.19)] and C-reactive protein [β = 0.14 (95% CI: 0.02; 0.26); β = 0.10 (95% CI: 0.01; 0.19)]. Children with very early AR also had worse levels of diastolic blood pressure [β = 0.09 (95% CI: 0.02; 0.16)], triglycerides [β = 0.21 (95% CI: 0.08; 0.34)] and high-density lipoprotein cholesterol [β=−0.18 (95% CI: −0.31; −0.04)]. When analysed continuously, each additional month of age at the AR was associated with healthier cardiometabolic traits. Conclusion The earlier the AR, the worse the cardiometabolic health in late childhood, which was consistently shown across a wide range of outcomes and in the categorical and continuous approach.

Pre-Birth and Early-Life Factors Associated With the Timing of Adiposity Peak and Rebound: A Large Population-Based Longitudinal Study

“…We excluded 8,512 records that met one of the following exclusion criteria: null value for all the measures ( n = 6,845), duplicate records ( n = 982), and records with fewer than three measurement times ( n = 685). We selected only children who had at least three measurement times (weight and length/height at the same measurement, and only one measurement per month) during their 1st and 80th months of age for growth trajectory modeling ( 24 ). To avoid influential points, high leverage points, and outliers, we also removed records of children with abnormal growth patterns ( n = 153).…”

“…All data of multiple observations obtained in early life regarding children's age, weight, and length/height were used to estimate BMI and its trajectories. To guarantee the quality of BMI trajectory fitting, children with no measurement between the 1st and 12th months of age were excluded for AP estimation ( n = 3,711), and children with no measurement after 18 months of age or between 42 and 84 months of age were excluded for AR estimation ( n = 457) ( Figure 1 ) ( 24 ). The individual-specific BMI trajectory from the 1st to 80th months of age was fitted using non-linear mixed-effect models with natural cubic spline functions for age to capture the non-linear trend ( 14 , 24 ).…”

“…To guarantee the quality of BMI trajectory fitting, children with no measurement between the 1st and 12th months of age were excluded for AP estimation ( n = 3,711), and children with no measurement after 18 months of age or between 42 and 84 months of age were excluded for AR estimation ( n = 457) ( Figure 1 ) ( 24 ). The individual-specific BMI trajectory from the 1st to 80th months of age was fitted using non-linear mixed-effect models with natural cubic spline functions for age to capture the non-linear trend ( 14 , 24 ). Estimates of age at AP and AR were drawn from the BMI-for-age curve for each child.…”

Longitudinal association between the timing of adiposity peak and rebound and overweight at seven years of age

“…Every anthropometric measurement taken for the children was recorded by the health care professionals. We only selected children who had at least three anthropometric measurements (weight and length/height at the same assessment and only one measurement per month) during their 1st and 80th months of age for growth trajectory fitting to identify their AP and AR timing [ 62 ]. Additionally, information concerning the parental ages at delivery, parental education levels, gestational weeks, delivery modes, birth weight and birth length was retrieved from their birth records.…”

“…The growth data were available in 13 612 children who had at least three anthropometric measurements during their first and 80th months of age. Their growth trajectories were fitted [ 62 ], and the AP and AR could not be estimated for 3708 and 2343 children, respectively. In our study, 9904 children with estimable AP and 11 269 children with estimable AR were found.…”