Early life growth is related to pubertal growth and adult height - a QEPS-model analysis.

Background: The early life growth period, from conception to ~2 years of age, has proven crucial for later health. We hypothesized that early life growth could explain variations in pubertal growth and timing, and adult height.

Methods: This retrospective, population-based study was conducted in Sweden. A subgroup, including individuals of all gestational ages and birth sizes (n = 4700, 50% males), from the longitudinal GrowUp_1974&1990Gothenburg cohorts was used. QEPS variables were analyzed in univariate and multivariate linear regression models, separately per sex; Q-function throughout all growth periods, and specific E- and P-functions, for early life growth and pubertal growth, respectively.

Results: In multivariate models, early life growth explained 37-38% of the variability in specific pubertal growth, but less so the variability in pubertal timing. Variability in adult height was explained by birth size (57-62%), early growth (66-67%), childhood growth (65-69%), and to a lesser degree by mid-parental height (35-39%). The change in height during puberty explained 8-9% of the variation in adult height.

Conclusion: This study indicates that early life growth is strongly associated with the variability in pubertal growth, and adult height, but not with the timing of pubertal growth.

Impact: Early life growth is important as it can serve as a marker for future growth, development, and health. The association between length growth during fetal life and infancy and pubertal growth and timing, and adult height, is only partly understood. Using the QEPS growth model, specific early life growth (E-function) and specific pubertal growth (P-function), including individual variations in tempo and amplitude, can be studied separately from ongoing basic growth (Q-function). This study showed that early life growth is strongly associated with and explains specific pubertal height gain and adult height but less so the timing of pubertal growth.