A prospective, observational clinical trial on the impact of COVID-19-related national lockdown on thyroid hormone in young males

Trying to manage the dramatic coronavirus disease 2019 (COVID-19) infection spread, many countries imposed national lockdown, radically changing the routinely life of humans worldwide. We hypothesized that both the pandemic per se and the consequent socio-psychological sequelae could constitute stressors for Italian population, potentially affecting the endocrine system. This study was designed to describe the effect of lockdown-related stress on the hypothalamic-pituitary-thyroid (HPT) axis in a cohort of young men. A prospective, observational clinical trial was carried out, including patients attending the male infertility outpatient clinic before and after the national lockdown for COVID-19 pandemic. The study provided a baseline visit performed before and a follow-up visit after the lockdown in 2020. During the follow-up visit, hormonal measurements, lifestyle habits and work management were recorded. Thirty-one male subjects were enrolled (mean age: 31.6±6.0years). TSH significantly decreased after lockdown (p=0.015), whereas no significant changes were observed in the testosterone, luteinising hormone, follicle-stimulating hormone, estradiol and prolactin serum levels. No patient showed TSH serum levels above or below reference ranges, neither before nor after lockdown. Interestingly, TSH variation after lockdown was dependent on the working habit change during lockdown (p=0.042). We described for the first time a TSH reduction after a stressful event in a prospective way, evaluating the HPT axis in the same population, before and after the national lockdown. This result reinforces the possible interconnection between psychological consequences of a stressful event and the endocrine regulation.