Pacific Islands Families Study: Signs of Puberty Are Associated with Physical Growth at Ages 9 and 11 Years

Aim: To prospectively observe, at ages 9 and 11, the relationship of parental report of pubertal signs with height, weight, body mass index and birth weight in children of the Pacific Islands Families cohort born in the year 2000.

Method: At ages 9 and 11 years a parental questionnaire assessed five gender-specific pubertal signs for 619 children and height and weight were objectively measured. At 9 years, body fatness was derived from frequency bioimpedance analysis. Birth weight was obtained from hospital records. Anthropometric measures of children with and without pubertal signs at each age were compared.

Results: At both 9 and 11 years, more than 80% of both boys' and girls' parents reported the presence of a growth spurt. The growth trajectory between 9 and 11 years was steep compared to the Centers for Disease Control reference child. At age 11, girls showing pubertal signs had substantially greater height, weight and body mass indexes than girls who did not. Girls with a growth spurt at age 9 years (91%) had a heavier birth weight than those without; a difference of 250 g (95% CI 50, 450 g).

Conclusion: The relationships between birth weight, rapid growth in childhood and early pubertal signs are complex. In addition to biological factors, food security and socioeconomic factors need to be addressed to ensure that the children of these children are exposed to an environment that is supportive of healthy rates of growth and development.