Hormonal 'minipuberty' influences the somatic development of boys but not of girls up to the age of 6 years.

Abstract

Hormonal 'minipuberty' refers to a transient sex-specific surge of LH, FSH, testosterone (T) and estradiol (E2) in the first few months of life. We hypothesized a potential long-term effect of this hormonal surge on somatic parameters in the following years and therefore designed this longitudinal study. A hierarchical multiple regression analysis was used to analyse the potential influence of hormone concentrations during minipuberty on anthropometric measurements conducted in the first 6 years of life. Thirty-five healthy babies (17 male, 18 female) were the participants. Testosterone, E2, SHBG, LH and FSH were measured at the ages of four, eight and 20 weeks. Anthropometric measurements were taken eight times in the first 12 months, then every 6 months up to the age of 6 years. A significant negative effect was found in boys between testosterone and LH levels at 8 weeks and body weight up to the age of 6 years and BMI up to 6 years (LH) and 3 years (T), respectively. A further negative effect was found between E2 levels at the age of 20 weeks and body weight as well as body length in the years that followed. A positive effect was observed between E2 at the age of 4 weeks and skinfold thickness up to the age of 6 years in boys. No significant effects were found in girls. The findings seem to reflect an up to now unknown long-term influence of the physiological early hormonal surge on the subsequent male but not female somatic development.