Adolescent growth and BMI and their associations with early childhood growth in an urban South African cohort

Abstract

Objectives The timing and magnitude of adolescent growth may be influenced by ethnicity and early life factors. We aimed to (a) characterize ethnic differences in the magnitude, timing, and intensity of adolescent growth in height, weight, and BMI; (b) assess the effect of early childhood growth on adolescent growth in black children. Methods Data were from the Birth to Twenty Plus cohort (Bt20+) in Johannesburg, South Africa (n = 3273). Height, weight, and BMI were modeled with ethnic comparisons using the SuperImposition by Translation and Rotation for 2089 participants who had data from 7 to 23 years. Relative weight gain and relative linear growth between 0 and 24 months and 24 and 60 months were generated. Multiple regression analyses were used to assess associations between childhood and adolescent growth. Results White children were 5 cm (SE: 0.7) taller than black children through adolescence. Black boys had a later timing of adolescent height (0.65 years ±0.12) than white boys, which in black girls was 0.24 years (0.11) earlier than in white girls. Black girls had faster BMI velocity than white girls. Among black children, birth weight and both relative weight gain 0 to 24 and relative linear growth between 3 and 24 months and 24 and 60 months were positively associated with the magnitude of adolescent growth and negatively associated with timing. Conclusion Sex dimorphism in ethnic differences in timing of adolescent height growth may reflect some yet unexplained drivers for rapid weight gain and obesity in black females but not black males. Rapid weight gain in early life may contribute to faster adiposity accrual in adolescence.

Growth Profiles of Children and Adolescents Living with and without Perinatal HIV Infection in Southern Africa: A Secondary Analysis of Cohort Data

“…In spite of improvements in height-for-age Z-score over follow-up, children in these profiles remained stunted and thin. Overall, we observed little change in Z-scores over one-year of follow-up (in profiles 1-5), indicating that early growth trajectories may continue to have persistent effects through adolescence, a finding consistent with the South African Birth-to-20 s cohort, where greater linear growth up to five years of age was associated with greater subsequent adolescent growth [20]. CWH with co-morbid CLD from BREATHE were more likely to have the most malnourished (growth profiles 6 and 7).…”

“…We explored associations between risk factors and growth profiles using multinomial logistic regression to generate relative risk ratios (RRR) and 95% confidence intervals (CI). Available risk factors were sex [20], age [3], HIV and comorbidity status [9,21,22], and country of residence [23], and for CWH [8], age at initiation of ART, HIV viral load and CD4 cell count.…”

Context Matters—Child Growth within a Constrained Socio-Economic Environment

“…The concept of male susceptibility to stress may explain the sex difference in resilience score [28]. Data from South Africa show that black males experience greater disadvantage in physical growth and maturity status than black females despite being exposed to the same growth-limiting environment [29,30]. With regards to the caregiver's mental health status, a decreased capacity to provide nurturing care may explain the lower resilience score in children of caregivers with depression.…”

A growth area

“…Additionally, as both contemporary and past populations faced nutritional and other socioeconomic challenges, greater investigation of bone dimensions among groups facing socioeconomic challenges would clarify the amount of skeletal variation that may arise under these circumstances. For example, the Birth to Twenty Plus (Bt20+) cohort study in Johannesburg, South Africa, conducted longitudinal investigations of height, weight, and BMI and determined the range of variation in growth distance, growth velocity, and absolute dimensions across sex and ethnicity among Black and White boys and girls [ 149 ]. White children were 5 cm taller than Black children during adolescence [ 149 ].…”

“…For example, the Birth to Twenty Plus (Bt20+) cohort study in Johannesburg, South Africa, conducted longitudinal investigations of height, weight, and BMI and determined the range of variation in growth distance, growth velocity, and absolute dimensions across sex and ethnicity among Black and White boys and girls [ 149 ]. White children were 5 cm taller than Black children during adolescence [ 149 ]. This study also calculated how much of the variance in growth timing and magnitude was explained by early childhood and maternal conditions, including socioeconomic status.…”