Puberty, but not precocious puberty is influenced by weight gain in the first years of life

Introduction: Factors favouring the secular trend of decreasing average age of puberty include eating habits, environmental endocrine disruptors, genetics, stress and lifestyle. The association between higher BMI and timing and tempo of puberty has long been documented in the general population but data for children with precocious puberty are poor. Aims: To evaluate the relationship between the role of weight gain in the first years of life on the onset of central precocious puberty. Patients and Methods: We analyzed the data of 120 Caucasian girls diagnosed with CPP between May 2020 and March 2021 (group 1) and a control group of 540 girls. Patients with CPP associated with hypothalamic–pituitary congenital malformations, neurological, neurosurgical and/or genetic diseases, psychomotor delay, oncological diseases, other endocrine impairments requiring hormonal treatments, or taking drugs that may interfere with pubertal development were excluded. Results: In CPP girls (group 1), mean age of B2 was 7.67 ± 0.88 years; BMI was 0.14 ± 0.88 SDS, and average BW was −0.08 ± 1.04 SDS. In this group an evaluation of delta SDS BMIB2-BW did not reveal a statistically significant relationship between thelarche and increased BMI. In comparison, the mean age of B2 in the control group (group 2) was 10.06 ± 1.03 years, BMI was −0.02 ± 1.01 SDS, and mean BW was −0.03 ± 0.93 SDS and we found a clear correlation between delta SDS BMIB2-BW and thelarche age (R: 0.27; p < 0.0001). Conclusions: Our data confirm that weight gain plays a crucial role in the trend of earlier pubertal development in the general population, but precocious puberty does not appear to be influenced by weight variation in the first years of life. It is therefore important to consider other factors which may contribute to triggering or aggravating this condition.