COVID-19 stressful conditions in the increase of central precocious puberty: long-term follow-up and timelines of this phenomenon demonstrate the declines to pre-pandemic levels after the end of online classes period in Italy

Introduction: COVID-19 pandemic resulted in serious social challenges and physical and mental repercussions. In many countries, central precocious Puberty (CPP) increased dramatically but long-term data are really reduced. Aim: A retrospective evaluation of incidence and characteristics of CPP before and during COVID-19 pandemic in four Italian Paediatric Hospitals (Florence, Modena, Reggio-Emilia and Parma). Patients and methods: 449 patients diagnosed by 01 January 2018 to 31 December 2022 were collected. We divided this period in pre-COVID-19 (pre-Cov19: from 01/01/2018 to 08/03/2020) and COVID-19 period (Cov19: from 08/03/2020 to 31/12/ 2022); Cov19 period was further divided into lockdown (lock-Cov19), restrictions (restr-Cov19), post-restriction (postrestr-Cov19) periods. Results: During pre-Cov19, 111 CPP (7.8 ± 0.6 years) were diagnosed (4.3 cases for month); of these, 7.2% showed a rapidly progressive course (RPPP) and 14.4% were untreated CPP disclosing a RPPP during the lockdown. During Cov19, 338 CPP (7.8 ± 0.9 years) were diagnosed (10.0 cases for month; P < 0.05); among Cov19, we diagnosed 9.8 cases for month (P < 0.05) during lock-Cov19 (7.4 ± 1.2; P < 0.005), 14.4 cases for month (P < 0.0001) during restr-Cov19 (7.7 ± 1.0; P = NS), and 5.4 cases for month (P = NS) during postrestr-Cov19 (7.8 ± 1.0: P = NS). In the Cov19 period 36.7% of CPP were RPPP: 55.5% in lock-Cov19 (P < 0.0001), 36.7% in restr-Cov19 (P < 0.0001) and 8.8% in postrestr-Cov19 (P = NS). Basal LH (BLH), peak LH (PLH), DPLH/BLH, ovary volume and uterine length were significantly different in lock-Cov19 and restr-Cov19, but not postrestr-Cov19, in respect to pre-Cov19. BMI, bone age and height SDS were not different among these groups. Conclusion: CPP diagnosis significantly increase during the first year of the Covid-19 pandemic in respect to pre-pandemic years and post-restriction year; CPP incidence decrease particularly after the end of online classes at home, stressing the use of electronic devices as one of the main causes of CPP during the COVID-19 pandemic.